Brown adipose tissue (BAT) is the site of heat production (thermogenesis). This unique function is performed by uncoupling protein 1 (UCP1) specifically expressed in mitochondria of BAT. UCP1 dissipates the driving force of ATP synthesis, and thus causes heat production followed by energy expenditure. The thermogenic function of BAT has the role of maintaining body temperature under cold conditions. When animals are exposed to cold, the expression of UCP1 gene is increased to activate thermogenesis. To date, functional analysis of BAT has been focused on UCP1, because it plays an indispensable role in thermogenesis. However, the gene expression of not only UCP1 but also that of other genes in BAT is expected to be regulated to achieve effective thermogenesis. Our previous investigations showed increased expression of genes that encode several energy metabolic enzymes in the BAT of rats kept in the cold. These changes in gene expression imply that the enhancement of energy metabolism is needed to activate thermogenesis. Furthermore, various reports from studies focused on genes whose expression is changed in response to cold stimulation have provided new insights into the function of BAT. In this review, to understand the thermogenic function of BAT systematically, we have provided an overview of previous findings on changes in the expression of genes thought to be related to the activation of thermogenesis in BAT.
N-Benzoyl-L-tyrosyl-1-13C-L-alanine sodium is a dipeptide used for evaluating pancreatic exocrine function. The method of evaluation, however, is not yet satisfactory, especially in experimental animals. The relation between diabetes and pancreatic exocrine function also is not clear. Therefore, this study sought to establish a method for evaluating pancreatic exocrine function and to validate the method by determining non-invasively the effect of alloxan-induced diabetes in conscious rats. After fasting, rats were orally administered Racol containing N-benzoyl-L-tyrosyl-1-13C-L-alanine sodium or 1-13C-L-alanine and housed in desiccators. The expired air in the desiccator was collected in a breath-sampling bag using a tube and aspiration pump, and the level of 13CO2 in this air was measured using an infrared spectrometer at appropriate intervals over a 120 min period. The rate of 13CO2 excretion increased, peaked and then decreased in a dose-dependent manner. The maximum concentration and area under the curve of 13CO2 excretion significantly and positively correlated with the doses of N-benzoyl-L-tyrosyl-1-13C-L-alanine sodium. In the rats made diabetes by the administration of alloxan, the level of expired 13CO2 air changed at significantly lower levels as compared with that of the control rats on day 3, although the level of expired 13CO2 air from 1-13C-L-alanine was also markedly lower than that of the control rats. These results showed that pancreatic exocrine function can be evaluated using this breath test system and that alloxan-induced diabetes affects this function.
Berberine, a main component of Coptidis Rhizoma, has been extensively studied and is known to exhibit multiple pharmacologic activities. In this study, we investigated whether the combination of berberine and cisplatin exhibited significant cytotoxicity in HeLa cells. Apoptosis was evaluated based on DNA fragmentation and cytofluorometrically with the annexin-V/propidium iodide labeling method. Combined treatment with berberine and cisplatin acted in concert to induce loss of mitochondrial membrane potential (ΔΨm), release of cytochrome-c from mitochondria, and decreased expression of antiapoptotic Bcl-2, Bcl-x/L, resulting in activation of caspases and apoptosis. Further study showed that cell death induced by the combined treatment was associated with increased reactive oxygen species generation and lipid peroxidation. Moreover, we discovered that the combined treatment-induced apoptosis was mediated by the activation of the caspase cascade. These results indicated that the potential of cytotoxicity mediated through the mitochondria-caspase pathway is primarily involved in the combined treatment-induced apoptosis.
Latanoprost, a prostaglandin F2alpha analogue, has been shown to be an effective ocular hypotensive agent when used alone on ocular hypertensive or open angle glaucoma patients. Carbonic anhydrase (CA) inhibitors are also used to reduce ocular hypertension by decreasing aqueous humor secretion, and are given in combination with prostaglandin F2alpha analogue. It has been shown that prostaglandin F2alpha, Minprostin F2α, has been shown to increase the carbonic anhydrase (CA) activity and blood pressure. However, the effects of latanoprost on CA have not been clarified. Therefore, we studied the effects of latanoprost free acid on human carbonic anhydrase (HCA) I and II using the stopped flow method. Latanoprost free acid inhibited the hydration activity of HCA I or II by a noncompetitive mechanism. The inhibition constants (Ki) of latanoprost free acid for HCA I and II were 0.22 and 2.3 mM, respectively. Therefore, latanoprost free acid is a weak inhibitor of HCA I or II. AutoDock simulation of the latanoprost free acid-HCA I or II complex showed that the carboxylic moiety of latanoprost free acid, which is located at the end of the molecule, binds to the zinc ion of the active site by stretching of the chain of latanoprost free acid through the narrow and deep active site cavity of HCA I or II. In the active site cavity of HCA I or II, one side is hydrophilic and the other is hydrophobic. AutoDock simulation results clearly showed that latanoprost free acids lie down on the hydrophobic sides of the active site cavities in HCA I and II. The noncompetitive inhibition mechanism and the binding mode of latanoprost free acid indicate that the behavior of latanoprost free acid is very similar to that of simple anions.
Low molecular weight acid phosphatase (LM-ACP) peak 2 (the isoenzyme corresponding to isoform 2, IF-2) from the liver of fish Rahu (Labeo rohita) was purified to homogeneity. 900 times purification resulted with specific activity of 35 U/mg of protein and recovery of 0.2%. The enzyme was found homogeneous on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Molecular weight of 18 killo Daltons (kDa) was obtained. The peak 1 isoenzyme corresponding to isoform1 (IF-1) was partially purified about 160 times with specific activity of 7 U/mg of protein. Major protein band corresponding to 18 kDa was seen along with other protein faint bands. High molecular weight acid phosphatase (HM-ACP) was also partially purified. The molecular weight was estimated to be a 100 kDa by gel filtration on Sephadex G-100. LM-ACP isoenzymes and HM-ACP enzyme were studied for their substrate specificity, sensitivity to inhibitors or activators and other kinetic parameters. LM-ACP isoenzymes were not inhibited by tartrate and fluoride but were inhibited by sulfhydryl reagent whereas high molecular weight enzyme was strongly inhibited by fluoride and tartrate. Phosphate vanadate and molybdate inhibited both types of enzymes competitively, but their action was more pronounced in HM-ACP enzyme. LM-ACP was effectively activated by purine compounds whereas HM-ACP was not. LM-ACP showed strict substrate specificity while HM-ACP showed broad substrate specificity. The two types of acid phosphatases also differed in their rate of hydrolysis of α-naphthyl phosphate and β-glyerophosphate.
Doxorubicin (Dox) is a highly effective anticancer drug but exhibits cumulative dose-dependent cardiomyopathy. In this study, we investigated effects of Magnolia seed extract (MagS) on the Dox-induced cardiotoxicity. The results showed that MagS significantly reduces doxorubicin (Dox)-induced increase in intracellular Ca2+ concentration ([Ca2+]i), generation of reactive oxygen species (ROS), and apoptosis in rat cardiomyocytes. Analyses of the bioactive compounds in MagS by thin layer chromatography and gas chromatography/mass spectroscopy revealed that bioactive compounds in MagS are linoleic acid, oleic acid, and palmitic acid. All three fatty acids were able to inhibit the Dox-induced increase in [Ca2+]i, ROS generation, and apoptosis with a similar potency. Efficacy of MagS was examined in in vivo using a murine Dox-induced cardiomyopathy model. Dox (12 mg/kg, intravenously) was administered to mice and treated with the MagS (2 mg/kg/d, intraperitoneally) or saline for three weeks. Dox-treated mice showed structural disarray in heart tissue, including lymphocyte infiltration and loss of body weight. In contrast, treatment of the MagS substantially attenuated the Dox-induced cardiac damages including the loss of body weight. These results indicate that fatty acids in MagS and other seeds may ameliorate cardiotoxicity of the anticancer drug.
Green tea is an acknowledged cancer preventive in Japan, and the main constituent of green tea catechins is (−)-epigallocatechin gallate (EGCG). To investigate the bioavailability of EGCG in humans, we generated a monoclonal antibody against EGCG in BALB/c mice by immunizing thyroglobulin-conjugated EGCG. Out of 32 hybridoma cell lines, three hybridomas were selected by enzyme-linked immunosorbent assay (ELISA), and then determined by surface plasmon resonance assay: One hybridoma TG38 produced a specific monoclonal antibody against EGCG. The primary structure of TG38 light chain was then deduced from DNA sequence of the light chain gene. The NCBI-BLAST search showed the uniqueness of TG38 monoclonal antibody, and three amino acid residues specific for TG38 were aligned on two loops and one β-sheet of the tertiary structure of the antibody. The TG38 antibody is the first monoclonal antibody against EGCG and catechins, since it bound to four green tea catechins with a galloyl group.
Silurus asotus lectin (SAL) is a member of the rhamnose-binding lectin (RBL) family, and recognizes globotriaosylceramide (Gb3) on the cell surface of Burkitt's lymphoma cell lines, such as Raji and Daudi cells. The variation of gene expression in the treatment of both cells with SAL was analyzed using the differential display (DD) method with combination of 16 kinds of arbitary primers and 3 kinds of anchor primers. Treatment of Raji cells with SAL down-regulated mitochondria-associated granulocyte-macropharge colony-stimulating factor (GM-CSF) signaling molecule (Magmas) gene, and up-regulated N-myc downstream regulated gene (NDRG) 3. On the other hand, treatment of Daudi cells with SAL down-regulated Rad50 gene. Since Magmas gene expression was repressed in SAL-treated Raji cells, but did not change in SAL-treated D-threo-1-phenyl-2-decanoylamino-3-morphorino-1-propanol (PDMP)-pretreated Raji cells, it was clear that the expression of Magmas, NDRG3 or Rad50 was regulated by SAL binding to Gb3.
Imbalance between oxidative stress and antioxidative defence system is generally known as one of mechanisms causing an oxidative stress-medieated neuropathogenesis. Peroxiredoxins (Prxs), a family of antioxidative enzymes neutralizing cellular hydroperoxides, was characterized recently, but their distributions and roles have not been resolved clearly or controversial in the central nervous system, Therefore, the present study was carried out to determine the specific cell types that express Prx I in the mouse brain and primary neural cells, and to examine its antioxidative role in the preferential cell types. Immunohistochemical reactivity for Prx I was detected dominantly in oligodendrocytes and rarely in microglia, whereas strong and specific immunoreactivity for Prx I was observed exclusively in microglia of primary neural cell culture. Further evidences for Prx I specificity were its relatively high expression in BV-2 microglial cells and its upregulated expression in microglia after lipopolysaccharide (LPS) stimulation. These results imply that Prx I can be used as an indicator of microglial activation. Inhibition of p38 MAPK ablated LPS-mediated Prx I upregulation and sensitized the microglia to H2O2-mediated cell death. These findings indicate that Prx I function as a scavenger for H2O2 generated during microglial activation. The results of this study will help in unraveling the neuropathologic roles of the six Prx isoforms in neural function.
The ginsenoside Rk1 is one of major components of heat-processed Panax ginseng C. A. MEYER, Sun Ginseng (SG). Here, we investigated the mechanisms underlying the anti-tumor activity of Rk1 in human hepatocellular carcinoma HepG2 cells in vitro. Rk1 markedly inhibited telomerase activity and cell growth along with significant morphological change. The expression levels of telomerase reverse transcriptase (hTERT) and c-Myc mRNA were obviously decreased with Rk1 treatment, while that of telomerase RNA (hTR) was not. Furthermore, Rk1 induced apoptosis through activation of caspases-8 and -3. However, Fas-associated death domain (FADD) expression decreased with Rk1 treatment, though it was known that the signaling cascade of FADD was associated with caspase-8 activity. Interestingly, activation of extracellular-regulated kinase (ERK) increased with Rk1 treatment. In conclusion, these results represent the first identification of the biological activity of Rk1 against HepG2 cell growth and show that the mechanism underlying the anti-tumor activity of Rk1 involves coordination between inhibition of telomerase activity and induction of apoptosis.
Thelephora vialis is a mushroom that grows in symbiosis with pine trees in Yunnan, China, a place known to have some of the richest and most diverse bioresources in the world. This is one of the most favored edible mushrooms, due to its flavor. Our screening for bioactive compounds from these mushrooms isolated a novel potent antioxidant, vialinin A, together with known compounds, from the dry fruiting bodies of T. vialis. Vialinin A is a terphenyl derivative and was elucidated by spectroscopic and chemical methods. Vialinin A showed anti-allergic activities, inhibition of β-hexosaminidase, tumor necrosis factor (TNF)-α, interleukin 4 and monocyte chemotactic protein 1 release from RBL-2H3 cells, whereas atromentin and an inseparable mixture of ganbajunins D and E showed no such effects. Vialinin A displayed potent inhibition of TNF-α production from RBL-2H3 cells (IC50, 0.09±0.01 nM), indicating stronger inhibition than tacrolimus for organ transplantation (IC50, 0.25±0.03 nM). The potent inhibitory activities of these compounds against TNF-α production indicate promising new candidates for anti-allergic agents.
Small ubiquitin-related modifier (SUMO) is a type I ubiquitin-like protein family member and is covalently attached to various target proteins. Through this post-translational modification, SUMO plays important roles in various cellular events. Here, we show that SUMO is secreted from cultured cells in an endoplasmic reticulum (ER)/Golgi-independent manner and that this secretion occurs without covalent binding to target proteins or chain formation. Overexpression experiments using C-terminally truncated mutants of SUMO revealed that the secretion requires the C-terminal sequence. Recombinant SUMO-3 protein was capable of binding to and promoting the proliferation of cultured cells. Thus, we propose that SUMO functions as a cytokine-like molecule extracellularly.
Environmental pollutants including dioxins activate the aryl hydrocarbon receptor (AhR) and cause a wide range of pathologies. Development of AhR antagonists will be useful for prevention and treatment of the diseases related to AhR activation. Towards this goal, we aimed at seeking for potential AhR antagonists in herbal medicines using the dioxin responsive element-based sensing via secreted alkaline phosphatase (DRESSA). Through initial rough screening, 4 formulae were selected from 20 herbal medicines and subjected to the second, detailed screening. We found that only Formula bupleuri minor (TJ-9) significantly inhibited activation of AhR by 2,3,7,8-tetrachlorodibenzo-p-dioxin. Among 7 raw herb extracts in TJ-9, Glycyrrhizae Radix and Scutellariae Radix were responsible for the antagonistic effect of TJ-9 against dioxin. Some constituents including Bupleuri Radix and Zingiberis Rhizoma rather activated AhR. Among 12 major constituents of Glycyrrhizae Radix and Scutellariae Radix, we identified that licopyranocoumarin, glycyrrhizic acid and genistein in Glycyrrhizae Radix and baicalein, wogonin and daidzein in Scutellariae Radix had substantial antagonistic effects on AhR. Among these, baicalein most effectively blocked activation of AhR triggered by cigarette smoke, a strong activator of AhR. The antagonistic substances identified here may be useful for prevention from diseases associated with aberrant activation of AhR.
Tumor metastasis is affected by the host immune surveillance system. Since aging may attenuate the host immune potential, the experimental tumor metastasis may be enhanced with age. In the present study, we investigated this alteration of experimental tumor metastasis with age. We used senescence-accelerated mice prone 10 (SAMP10) as a model of aged animals. Natural killer cell (NK) activity, as an indicator of immune surveillance potential, in 8-month-old (aged) SAMP10 mice was observed to be much lower than that in 2-month-old (young) mice. When we examined the in vivo trafficking of lung-metastatic K1735M2 melanoma cells in SAMP10 with positron emission tomography (PET), K1735M2 cells labeled with [2-18F]2-deoxy-2-fluoro-D-glucose ([18F]FDG) were observed in both young and aged SAMP10 just after injection of the cells, whereas the clearance of 18F from the lungs was retarded in aged animals. The accumulation of 5-[125I]iodo-2′-deoxyuridine ([125I]IUdR)-labeled K1735M2 cells in the lungs of SAMP10 at 24 h after injection was significantly higher in aged mice. Corresponding to these results, the number of metastatic colonies in the lung was larger in the aged SAMP10 of the experimental tumor metastasis model. The present study demonstrated that the aging process produced a susceptible environment allowing the tumor cells to metastasize due to decrease in the host immune surveillance potential with age.
Genes encoding 1-deoxy-D-xylulose 5-phosphate synthase (DXS; EC 18.104.22.168) and 2C-methyl-D-erythritol 4-phosphate synthase (MEPS; EC 22.214.171.1247), the first two enzymes in the deoxyxylulose phosphate (DXP) pathway, were cloned from young leaves of Croton stellatopilosus, and designated as 1-deoxy-D-xylulose 5-phosphate synthase (CSDXS) and 2C-methyl-D-erythritol 4-phosphate synthase (CSMEPS), respectively. Analysis of deduced amino acid sequences of the CSDXS and the CSMEPS confirmed their nucleotide sequences as they shared high identities to other known DXSs and MEPSs in higher plants. Physiological roles of the CSDXS and the CSMEPS were determined for the mRNA expressions in leaves, twigs and roots. Transcription profiles analyses of the CSDXS and the CSMEPS genes were investigated using semi-quantitative RT-PCR technique. Relative intensities of the CSDXS and the CSMEPS expressions to house-keeping gene (18S rRNA) were calculated. The results indicated that the levels of mRNAs expressions of the CSDXS and the CSMEPS were high in leaves and twigs. This evidence was in line with the high content of plaunotol, accumulated in leaves and twigs. Neither the CSDXS nor the CSMEPS were expressed in roots, where plaunotol was not detected. From this study, it can be concluded that plaunotol is biosynthesized in the chloroplastic tissue and regulated by the CSDXS and the CSMEPS.
Previously, we revealed that theanine, a green tea component, induced phospholipase C (PLC)-β1 and -γ1, stress-responsible molecules, in primary cultured rat cerebral cortical neurons, suggesting its protective effect on oxidative stress in neurons. In this study, we investigated whether the same favorable effect occurs in vivo. On the oral administration of theanine (10 mmol (1.74 g)/kg, once a day) to rats via gastric intubation for 2 weeks, there was no change in the weight of the body or the cerebral cortex (Cx), cerebellum (Cb), or hippocampus (Hip) in the brain. On assessment of oxidation levels in the brain with thiobarbiturate reactive substances as a marker, the levels were found to be 20% lower in the Cx of theanine-treated rats than in that of control ones. The protein expression levels of PLC-β1 and -γ1 were significantly increased in the Cx on theanine administration and the same tendency was observed in the Cb, but not the Hip. In addition, the protein expression level of PLC-δ1, which plays an opposite role to the other two isozymes, was not affected in any brain regions on theanine administration. Overall, it was demonstrated that theanine is a safe compound and its repeated oral administration reduces oxidation levels in the brain, especially the Cx, by increasing PLC-β1 and -γ1 protein expression, suggesting its favorable effect on the brain in vivo.
In addition to humoral angiogenic factors, including vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), integrin-mediated adhesion of vascular endothelial cells to the extracellular matrix plays an important role in neovascularization. We recently found that TNIIIA2, a peptide derived from tenascin-C, induces functional activation of β1 integrins. Here we investigated the effect of TNIIIA2 on vascular endothelial cell migration and proliferation, key processes for angiogenesis. TNIIIA2 was shown to activate β1-integrins on human dermal microvascular endothelial cells (HDMEC). HDMEC adhered to fibronectin mainly via integrin α5β1 and their haptotactic migration on that substrate was inhibited by TNIIIA2, in concomitant with a marked inhibition of Rac activation. TNIIIA2-treatment unaffected autophosphorylation of focal adhesion kinase (FAK), but induced its physical association with phospho-paxillin (Tyr118), suggesting the FAK/paxillin-dependent negative regulation of Rac activation. HDMEC proliferation on the fibronectin substrate was also inhibited by TNIIIA2-treatment, and this was accompanied either by an increase in the population of G0/G1 cells and, conversely, a decrease in the population of S and G2/M cells or by dephosphorylation/inactivation of MAP-kinase (ERK1/2). Inhibited HDMEC migration and proliferation were both restored by pretreating the cells with a fibronectin peptide, FNIII14, which is capable of inactivating β1-integrins. The chorioallantoic membrane assay demonstrated an antiangiogenic effect of TNIIIA2 in vivo. Thus, TNIIIA2 appears to negatively regulate angiogenesis by inhibiting migration and proliferation of endothelial cells. The ability to activate β1-integrins may be responsible for the antiangiogenic effect of TNIIIA2, although it cannot be excluded the possibility that an additional mechanism(s) may play a role.
Serum-free mouse embryo (SFME) cells, the astrocyte progenitor cells in the central nervous system (CNS), were exposed to 10 ng/ml leukemia inhibitory factor (LIF) and 10 ng/ml bone morphogenic protein 2 (BMP2) to induce differentiation, and expression of cell-type specific markers. Nestin, a marker of early neural lineage, βIII-tubulin, a marker of neuronal lineage, oligodendrocyte marker O4 (O4), a marker of oligodendrocytic lineage and glial fibrillary acidic protein (GFAP), a marker of astrocytic lineage, were analyzed. Characteristics of SFME cells, as a CNS progenitor, were identified and a possible mechanism, underlying SFME cell specification into an astrocytic lineage upon differentiation, was investigated. These markers were present, both at the initial proliferative phase and after induction of differentiation. GFAP expression increased strongly upon differentiation, while expression of the other markers changed very little. These results indicate that astrocytic differentiation is associated with the asymmetric production of these markers, rather than through induction of astrocytic markers.
Legionella pneumophila, the causative agent of Legionnaires' disease, is a human pathogen that multiplies within alveolar macrophages. L. pneumophila establishes specialized phagosomes in which it evades the host defense through largely unknown mechanisms. Here we analyzed the role of an actin-binding protein, p57/coronin-1, a member of the coronin protein family, during Legionella infection. On fluorescence microscopy, p57/coronin-1 and F-actin were found to be co-localized at the sites on the plasma membrane where L. pneumophila adhered to U937 human macrophage-like cells. The localization of p57/coronin-1 at the sites of bacterial adherence was inhibited by treatment with cytochalasin D (an inhibitor of actin polymerization), suggesting that p57/coronin-1 is involved in the actin-dependent uptake of L. pneumophila into U937 cells. In addition, we showed that p57/coronin-1 was excluded from phagosomes containing live L. pneumophila throughout the infection, whereas transient accumulation of p57/coronin-1 was observed on phagosomes containing Texas-Red-labeled opsonized zymosan (TROpZ) or heat-killed L. pneumophila at an early stage of phagocytosis. The exclusion of p57/coronin-1 from phagosomes containing live another Legionella species Legionella gratiana at an early stage of infection was also observed. Taken together, these results suggest that the endocytic pathways of live Legionella species are distinct from general phagocytic pathways, which lead to lysosomal degradation.
Previous study on racemic SPFF [2-(4-amino-3-chloro-5-trifluomethyl-phenyl)-2-tert-butylamino-ethanol hydrochloride], a novel β2-adrenoceptor agonist, has validated that it is a potent, long-acting bronchodilator with relative higher β2-adrenoceptor selectivity. On the basis of this study, we compared the pharmacological properties of SPFF and its enantiomers ((−)-SPFF and (+)-SPFF) in guinea pigs taking isoprenaline or salbutamol (SAB) as referenced drugs. For the relaxation of both normal and precontracted trachea strips in vitro, (−)-SPFF was found more potent than (±)-SPFF or (+)-SPFF. Moreover, we confirmed that the bronchodilator effect of (−)- and (+)-enantiomers were due to activation of the β2-adrenoceptor because this effect was antagonized by a specific β2-adrenoceptor antagonist, ICI-118551, with similar pA2 values to those of (±)-SPFF. Radioligand binding assay revealed that affinity of (−)-enantiomer to β2-adrenoceptor was 6 and 164 fold greater than that of (±)- and (+)-SPFF, respectively. In addition, isomeric difference of overall selectivity between (−)-SPFF and (+)-SPFF was 10.7 fold for lung versus atria. (−)-SPFF displayed almost the same protective effect against bronchospasm induced by histamine-acetylcholine aerosol in conscious guinea pigs as (±)-SPFF did. However, the latent time of (+)-SPFF (1 mg·kg−1) was significantly shorter than that of (±)- and (−)-SPFF at the same doses. Finally, in the inhibition of histamine-induced increase of pulmonary resistance (RL) in anesthetized guinea pigs, (−)-SPFF was 1.3 and 3.5 times more potent than (±)- and (+)-SPFF. Correspondingly, in inhibiting the decrease of pulmonary compliance (CL) , the potencies of (−)- and (+)-enantiomers were approximately equivalent to that of (±)-SPFF. Furthermore, a study on the long-lasting action of the test drugs had shown that the effects of (−)-SPFF (30 μg·kg−1), (±)-SPFF (30 μg·kg−1) and (+)-SPFF (100 μg·kg−1) in inhibiting the increase of RL all lasted for 4 h. Nevertheless, the effects of (−)- and (+)-enantiomers were slightly lower 4 h after intraduodenal administration in inhibiting the decrease of CL. In conclusion, (−)-SPFF may be beneficial for the treatment of asthma because of its more potent efficacy and higher adrenoceptor affinity than (±)- or (+)-SPFF.
Over-expression of P-glycoprotein (P-gp) in lymphocytes is implicated in the failure of immunosuppressant therapy. We investigated P-gp function in peripheral-blood CD3+, CD4+, and CD8+ cells of 14 healthy subjects and 12 patients with systemic lupus erythematosus (SLE). P-gp function was estimated by the transporter activity of the cells based on the efflux of Rhodamine-123 (Rh123) from the cells in the presence or absence of a P-gp inhibitor, cyclosporine A. P-gp function in the CD8+ cells of the healthy subjects was significantly higher than that of the SLE patients (p=0.0318), whereas the function in CD3+ cells and CD4+ cells were not significantly different between the healthy subjects and the SLE patients. The patients were divided into two subgroups according to their clinical response to glucocorticoid (GC) therapy, i.e., a high-response group (HR) (n=6) and a low-response group (LR) (n=6). In contrast, P-gp function in CD4+ cells of the LR group was significantly higher than that of the HR group (p=0.0432). Further, no significant differences in the P-gp function in CD3+ and CD8+ cells were observed between the two groups. The data showed a relationship between clinical sensitivity to GC therapy and P-gp function of CD4+ cells in SLE patients. Thus, the estimation of P-gp function in peripheral-blood CD4+ cells might be useful for the estimation of clinical response to GC therapy.
Radioiodinated 1-[2-(3,4-dimethoxyphenyl)ethyl]-4-(2-iodophenylpropyl)piperazine (o-BON) and 1-[2-(3,4-dimethoxyphenyl)ethyl]-4-(3-iodophenylpropyl)piperazine (m-BON) were evaluated as single photon emission computed tomography (SPECT) radiopharmaceuticals for tumor imaging by visualization of sigma receptors. In vivo biodistribution studies of [125I]o-BON and [125I]m-BON in tumor-bearing mice showed a high tumor uptake and prolonged retention of radiolabeled compounds in the tumor. In contrast with these factors, the blood and muscle accumulations were low, which resulted in a good tumor-to-blood ratio and tumor-to-muscle ratio. In peripheral organs, [125I]o-BON showed rapid clearance in comparison with [125I]m-BON. Selective interactions of [125I]o-BON and [125I]m-BON with sigma receptors on tumor cell membranes were confirmed by pretreatment experiments with various sigma and other receptor ligands. [125I]o-BON possesses higher specific binding toward sigma receptors than does [125I]m-BON; thus, [125I]o-BON was chosen for further evaluations. High uptake of [125I]o-BON was observed in various tumors, and a good linear correlation (R2=0.70) was found between accumulation of [125I]o-BON and the sigma receptor expression level. Furthermore, the accumulation of [125I]o-BON in tumors reflected their proliferation rate. These results suggest that it is feasible to use radioiodinated o-BON as a marker for measuring the proliferative status associated with sigma receptor expression.
We have previously shown that the oral administration of heat-killed Lactobacillus brevis (L. brevis) SBC8803 strain inhibits IgE production in ovalbumin (OVA)-sensitized BALB/c mice through improvement of the type-1 helper T (Th1)/Th2 balance toward Th1 dominance. Atopic dermatitis is one of the most common skin diseases and is frequently associated with elevated immunoglobulin E (IgE) antibodies against many kinds of allergens. In this study, we investigated the inhibitory effect of oral administration of L. brevis SBC8803 on the development of dermatitis and IgE elevation using the NC/Nga atopic dermatitis model mice. Male 8-week-old NC/Nga mice were sensitized by the topical application of picryl chloride to foot pads and shaved abdomen. These mice were boosted with picryl chloride by topical application onto the ears once a week for 9 weeks. The mice (n=10 per group) were fed a diet containing 0%, 0.05% or 0.5% of heat-killed L. brevis SBC8803 from 2 weeks before the first sensitization to the end of the study. Total IgE concentration in serum, clinical score, and ear thickness were periodically examined throughout the study. Finally, cytokine (interleukin (IL)-4, IL-5, IL-6, IL-10, IL-12, IFN-γ and transforming growth factor (TGF)-β) productions from splenocytes and Peyer's patch (PP) cells of mice were measured. Oral administration of L. brevis SBC8803 significantly inhibited IgE production and ear swelling, and suppressed the development of dermatitis in a dose-dependent manner. Immunosuppressive cytokines such as IL-10 and TGF-β production from PP cells significantly increased in the 0.5% group compared to the control group although Th1-type and Th2-type cytokines production was not affected.
Pringle described a new technique to reduce blood loss during liver surgery. Adult Wistar rats were subjected to 1 h of partial liver ischemia and followed by 3 h reperfusion. Eighteen Wistar rats were divided into sham-operated control group (I) (n=6), ischemia and reperfusion (I/R) group (II) (n=6), L-arginine treated group (100 mg/kg body weight/daily by oral route for 7 d before induced ischemia reperfusion maneuver) (III) (n=6). Ischemic and reperfusion hepatocellular injury occurred as indicated by increased-alanine transaminase (ALT), aspartate transaminase (AST). Pre-treatment with L-arginine significantly decreased serum-ALT, AST after 1 h ischemia followed by 3 h of reperfusion. Nitric oxide production, in hepatocytes was increased 2 fold and MDA levels significantly decreased by L-arginine treatment as compared to I/R rat. Histopathology and TEM studies showed markedly diminished hepatocellular injury in L-arginine pretreated rats during the hepatic I/R, which reached a level comparable to saline-treated rat of sham operated group. Thus, findings it may be concluded that L-arginine afforded significant protection from hepatobiliary function from I/R injury by nitric oxide production.
The Kampo medicines are more and more often used in recent years, usually together with the Western drugs. The need for the investigation of drug interactions between Kampo medicines and Western drugs are, therefore, widely recognized. In the present study, the effects of 3 Kampo medicines (Rikkunshito, Yokukansan and Boiogito) on the activity of cytochrome P450 (CYP), a superfamily of drug-metabolizing enzymes, were investigated in an in vitro study using human CYP recombinants. Their effects on the P-glycoprotein (P-gp), one of the major drug transporters, were also evaluated by the ATPase assay using human P-gp membranes and verapamil as a substrate. The inhibition rate of Rikkunshito, Yokukansan and Boiogito on human CYP3A4, 2C9, 2C19, 2D6 and 2E1 was less than 50% at the concentrations below 0.1 mg/ml except for the inhibition of CYP2D6 by Boiogito. Furthermore, none of the Kampo medicines affected the ATPase activity at the concentrations lower than 0.1 mg/ml, either in the absence or presence of verapamil, indicating their low inhibitory potency against P-gp. These findings indicate that Rikkunshito, Yokukansan and Boiogito are unlikely to cause clinically relevant drug interactions involving the inhibition of major CYP isozymes and P-gp.
Deficiency in the vasorelaxant capacity is a result of an oxidative stress in diabetic animals and seems to be an etiological factor of vascular complications of diabetes. The present study was designed to examine whether resveratrol (RSV), a polyphenolic compound which is naturally present in grape and red wine, has a protective effect on diabetic aorta. Resveratrol (5 mg/kg/d, i.p.) was administered for 42 d to streptozotocin (STZ) (60 mg/kg) induced diabetic rats. Loss of weight, hyperglycemia, and elevated levels of plasma malondialdehyde (MDA) were observed in diabetic rats. Resveratrol treatment was significantly effective for these metabolic and biochemical abnormalities. The contractile responses of the aorta were recorded. Compared with control subjects, the aorta showed significantly enhanced contractile responses to noradrenaline (NA), but not to potassium chloride (KCl), in diabetic rats. Treatment of diabetic rats with resveratrol significantly reversed the increases in responsiveness and sensitivity of aorta to noradrenaline. In diabetic aorta, the relaxation response to acetylcholine (Ach) was found to be significantly decreased compared with control subjects, and resveratrol treatment reversed this; no such change was observed in the relaxation response to sodium nitroprusside (SNP). These results indicated that resveratrol significantly improved not only glucose metabolism and oxidative injury but also impaired vascular responses in streptozotocin induced diabetic rats.
Xanthine oxidase (XO)/xanthine dehydrogenase (XD) oxidizes oxypurines to uric acid, with only the XO form producing reactive oxygen species. In the present study, the effects of cystamine S-monoxide and cystine S-monoxide (disulfide S-monoxides) on the conversion of XD to XO in rat liver were examined. A partially purified enzyme fraction from the rat liver was incubated with xanthine in the presence or absence of NAD+, and the uric acid formed was measured by HPLC. Under basal conditions, XO activity represented about 15% of the total XO plus XD activity. Cystamine S-monoxide and cystine S-monoxide converted XD into XO in a dose-dependent manner, and the concentrations required to increase XO activity by 50% were approximately 1 and 2 μM, respectively. Their respective thiols (cysteamine and cysteine) and disulfides (cystamine and cystine) up to 10 μM showed weak or no effects on the activities of XO and XD and their conversion. Experiments utilizing a sulfhydryl reducing reagent (dithiothreitol) and sulfhydryl modifiers (4,4′-dithiodipyridine and 1-fluoro-2,4-dinitrobenzene) indicated that disulfide S-monoxides-induced conversion of XD to XO occurs via disulfide bridge formation in XD, but not the modification of sulfhydryl groups. These results suggest that disulfide S-monoxides have the potential to increase the generation of reactive oxygen species through the conversion of XD to XO in liver.
(−)-Carvone is a monoterpene ketone that is the main active component of Mentha plant species like Mentha spicata. This study aimed to investigate the antinociceptive activity of (−)-carvone using different experimental models of pain and to investigate whether such effects might be involved in the nervous excitability elicited by others monoterpenes. In the acetic acid-induced writhing test, we observed that (−)-carvone-treated mice exhibited a significant decrease in the number of writhes when 100 and 200 mg/kg was administered. It was also demonstrated that (−)-carvone inhibited the licking response of the injected paw when 100 and 200 mg/kg was administered (i.p.) to mice in the first and second phases of the formalin test. Since naloxone (5 mg/kg, s.c.), an opioid antagonist, showed no influence on the antinociceptive action of (−)-carvone (100 mg/kg), this suggested nonparticipation of the opioid system in the modulation of pain induced by (−)-carvone. Such results were unlikely to be provoked by motor abnormality, since (−)-carvone-treated mice did not exhibit any performance alteration on the Rota-rod apparatus. Because the antinociceptive effects could be associated with neuronal excitability inhibition, we performed the single sucrose gap technique and observed that (−)-carvone (10 mM) was able to reduce the excitability of the isolated sciatic nerve through a diminution of the compound action potential amplitude by about 50% from control recordings. We conclude that (−)-carvone has antinociceptive activity associated with decreased peripheral nerve excitability.
Recently, we found that unsaturated long-chain fatty acids (such as α-linolenic acid) promote the secretion of glucagon-like peptide-1 (GLP-1) via G protein-coupled receptor GPR120, which is expressed predominantly in the colon. In order to ensure that the triglycerides or free fatty acids, such as α-linolenic acid, reach the distal intestinal tract effectively, we developed a Calshell technique. Following single treatment of Calshell perilla oil powder, the GLP-1 secretion level was significantly higher than following vehicle treatment, 120 min after treatment. Next, we examined the effects of long-term Calshell perilla oil powder treatment on GLP-1 secretion. Plasma GLP-1 level of Calshell perilla oil powder treatment was significantly higher than of vehicle treatment for 1, 14, 28 and 56 d. We thereby demonstrated for the first time the utility of Calshell oil powder treatment for effective and sustainable GLP-1 secretion. The Calshell technique is apparently useful as a drug delivery system, since Calshell unsaturated oil powder is protected from gastric acid, reaches enteroendocrine cells in the gastrointestinal tract, and then induces effective incretin secretion.
Costunolide, isolated from the stem bark of Magnolia sieboldii, is a sesquiterpene lactone that exhibits various biological and immunological actions. We investigated the induction mechanism of apoptosis by costunolide in a human B cell leukemia NALM-6 cell culture system. Costunolide (10 μM)-induced apoptosis time-dependently increased, estimated by nuclear damage observation and flow cytometric analysis. Costunolide did not change Fas-associated factor 1 (FAF1), but the phosphorylation of Fas-associated death domain (FADD) at serine 194 increased from early treatment. The activation of caspase-8 and -9 and degradation of poly-(ADP-ribose) polymerase (PARP) was time-dependently detected by incubation with costunolide. Pretreatment of cells with caspase-3, -8 and broad spectrum caspase inhibitors significantly blocked costunolide-induced apoptosis, but caspase-9 inhibitor failed to block apoptosis. Telomerase activity was significantly suppressed after treatment with costunolide, and human telomerase reverse transcriptase (hTERT), a critical determinant of the enzyme activity of telomerase, decreased the expression of both mRNA and protein levels by costunolide. Costunolide-induced repression of telomerase was prevented by pretreatment of cells with caspase-3, -8 and broad spectrum caspase inhibitors, but caspase-9 inhibitor was no effect. These data suggest that one of the costunolide-induced apoptotic mechanisms is that the receptor-mediated pathway precedes the mitochondria-dependent pathway, caused by the inhibition of telomerase activity via suppression of hTERT in NALM-6 cells.
We investigated the role of endothelial nitric oxide synthase (eNOS) in the remnant kidney model of chronic renal failure, by using eNOS-deficient (eNOS−/−) and wild-type mice. There were significant increments of blood urea nitrogen level, plasma creatinine concentration and proteinuria in both wild-type and eNOS−/− mice at 8 weeks after 5/6 nephrectomy, but observed changes were more prominent in eNOS−/− mice. Only 7 out of 30 eNOS−/− mice were alive during 8-week experimental period, whereas survival rate in the wild-type mice was 69%. The glomerular size distribution indicated that the glomeruli of 5/6 nephrectomized eNOS−/− mice tended to be larger compared with cases of wild-type mice. It seems likely that eNOS-derived NO is protective against renal injuries in this disease model.
Breast cancer resistance protein (BCRP), the product of the ABCG2 gene, is a recently identified ATP binding cassette half-transporter. BCRP is expressed in a variety of tumor cells and many normal human tissues. In the small intestine, BCRP can limit the influx and facilitate the efflux to prevent intracellular accumulation of BCRP substrates. Ischemia-reperfusion (I/R) induces the release of reactive oxygen species, and organs are severely damaged by I/R. It has been shown that the expression of transporters was altered in the organ after I/R. The present study was undertaken to clarify the expression of BCRP after intestinal I/R. We showed that the expression level of Bcrp was significantly decreased at 1 h after I/R. Bcrp mRNA level was not altered at 1 h after I/R. These results suggest that Bcrp expression was regulated by a post-transcriptional regulation mechanism after intestinal I/R. Bcrp mRNA level was increased at 24 h after I/R, and the expression level of Bcrp protein was of the same level or slightly increased compared with sham operated-rats. Bcrp was slightly located at the intestinal membrane at 24 h after intestinal I/R. These results suggested that Bcrp was not translocated to the intestinal membrane after intestinal I/R. There is little information on post-transcriptional regulation compared with information on transcriptional regulation. In this study, it was shown that Bcrp expression is regulated by post-transcriptional regulation after intestinal I/R. These results of this study may provide important information for further studies aimed at revealing the biological function of Bcrp.
Intracranial self-stimulation (ICSS) behavior is an experimental methodology to study reward and motivational effects. We have established a new paradigm to evaluate enhancing motivation by drugs in the runway method using the priming stimulation of ICSS. In the present study, we investigated the effects of nomifensine on the experimental extinction process of non-reinforcing reward and pre-trial electric priming stimulations in lateral hypothalamic self-stimulation. In this study, the experimental extinction process of the non-reinforcing reward means the experimental method of excluding reward effect in ICSS behavior. The extinction process in the runway method consisted of these 15 trials. Nomifensine, an antidepressant drug, delayed the running speed of the extinction process at doses of 5 and 10 mg/kg (i.p.) compared with the vehicle alone. This result suggests that the delay in the running speed of the extinction process promotes a motivational effect in rats. Previously, priming stimulation in the runway method was found to affect motivational function of ICSS. Therefore, our findings suggest the possible application of nomifensine for improving motivation.
The synthetic n-alkyl esters of gallic acid, also known as gallates, are widely employed as antioxidants by food and pharmaceutical industries. Besides the antioxidant activity, other biological activities have been described for this group of molecules, mainly anticancer, antibacterial and antifungal properties. In the present study, the anti-herpes simplex virus (HSV)-2 activity of gallic acid and pentyl gallate was evaluated followed by the determination of the site of antiviral activity of these compounds. Our results demonstrated that both compounds reduced HSV-2 replication in a concentration-dependent manner when either incubated with the virus prior to the addition of the mixture to cells, or added to and incubated with cells after their infection. In summary, the anti-HSV-2 activity of gallic acid and pentyl gallate was ascribed to their virucidal effect on virus particles, a change that was likely accompanied by partial inhibition of the virus attachment to cells and its subsequent cell-to-cell spread activity. This suggests that these compounds can be regarded as promising candidates for development as topical anti-HSV-2 agents.
The objective of this research was to re-evaluate the antioxidant effects of the prenylated flavonoids from Sophora flavescens viain vitro 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), peroxynitrite (ONOO−), and total reactive oxygen species (ROS) assays. In addition, a further examination of kuraridinol, kurarinol, and kurarinone, also isolated from S. flavescens, was carried out by the inhibition of tert-butylhydroperoxide (t-BHP)-induced intracellular ROS generation and t-BHP-induced activation of nuclear factor-kappaB (NF-κB). Upon re-examination of the ethyl acetate (EtOAc) soluble fraction of S. flavescens, two major prenylated chalcones, including kuraridin and kuraridinol, along with a minor prenylated flavonol, kushenol C, were isolated as good DPPH scavengers. This was in contrast to the prenylated flavanones, sophoraflavanone G and kurarinone, which were isolated from the methylene chloride (CH2Cl2) fraction of the same source. Five flavanones consisting of kushenol E, leachianone G, kurarinol, sophoraflavanone G, and kurarinone exhibited significant antioxidant potentials in the ABTS, ONOO−, and total ROS assays; however, the prenylated chalcones and prenylated flavonol showed more potent scavenging/inhibitory activities than the prenylated flavanones. Therefore, the prenylated chalcones and prenylated flavonol, rather than the prenylated flavanones, may make important contributions toward the marked antioxidant capacities of S. flavescens. Furthermore, kuraridinol, kurarinol, and kurarinone showed significant inhibitory activities against intracellular ROS levels as well as NF-κB activation by t-BHP. Overall, the results indicate that S. flavescens and its prenylated flavonoids may possess good anti-inflammatory activity, which is implicated in their significant antioxidant activity.
Our laboratory has been investigating the use of compounds which disrupt β-catenin/T cell factor (TCF) binding to treat human colon cancer. There are several cysteine residues on the surface of β-catenin where it binds to TCF. Some bis[2-(acylamino)phenyl] disulfides might have the ability to form a disulfide bond with the cysteine residues of β-catenin, leading to inhibition of the growth of human colon cells. Bis[2-(acylamino)phenyl] disulfides were screened to inhibit the growth of cancer cells. Among them, bis[2-(2,2-dimethylpropanoylamino)phenyl] disulfide (1) had promising inhibitory effects (HCT116, IC50: 9.7 μM; DLD-1, IC50: 6.9 μM) on cell proliferation, and did not show any cytotoxicity among normal human fibroblast CCD-1059SK cells even at 200 μM. This derivative reduced the β-catenin/TCF4 association in the HCT116 cells to ca. 50% at 150 μM. Furthermore, it activated markedly the phosphorylation of c-Jun N-terminal kinase (JNK) connected to stress-activated apoptosis at a lower concentration (30 μM). In view of cell cycle analyses, Hoechst staining, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin Nick end-labeling (TUNEL) assays along with the above results, it is likely that 1 inhibited the growth of HCT116 cells through pathways including the JNK-mediated apoptosis.
We prepared two series of polysaccharide compounds derived from algae extracts and investigated their stimulatory activity on insulin secretion in vitro using the rat pancreatic cell line, RIN-5F. Several of the compounds exhibited significant stimulatory activity in a dose-dependent manner without apparent cytotoxicity at concentrations above 10 μM. Glybenclamide, a commonly prescribed sulfonylurea (SU) against diabetes mellitus type II, was used as a positive control and showed moderate cytotoxicity in the cell culture assay system. Amylin (IAPP; islet amyloid polypeptide), an inhibitor for glybenclamide, did not inhibit the activity of the isolated compounds, suggesting that they act through a mechanism(s) different from glybenclamide. Algae-derived extracts could be candidates for a new class of anti-diabetic drugs.
In a previous study we found that 50% ethanol extracts of immature fruits of Citrus unshiu (satsuma mandarin) have anti-allergic effects against the Type I, II and IV allergic reactions. However, many adverse interactions between citrus fruit, especially grapefruit juice, and drugs have been reported due to the inhibition of cytochrome P450 (CYP) activities. The purpose of this study was to examine the competitive inhibitory effects of extracts from immature citrus fruit on CYP activity. Extracts were prepared from 12 citrus species or cultivars, and were tested against three kinds of major CYPs, CYP2C9, CYP2D6 and CYP3A4, in human liver microsomes. We also estimated the amounts of flavonoids (narirutin, hesperidin, naringin and neohesperidin) and furanocoumarins (bergapten, 6′,7′-dihydroxybergamottin and bergamottin) in each extract using HPLC. Citrus paradisi (grapefruit) showed the greatest inhibition of CYP activities, while Citrus unshiu which has an antiallergic effect, showed relatively weak inhibitory effects. Extracts having relatively strong inhibitory effects for CYP3A4 tended to contain higher amounts of naringin, bergamottin and 6′,7′-dihydroxybergamottin. These results, providing comparative information on the inhibitory effects of citrus extracts on CYP isoforms, suggest that citrus extracts containing high levels of narirutin and hesperidin and lower levels of furanocoumarins such as C. unshiu are favorable as antiallergic functional ingredients.
Bupleuran 2IIc, a pectic polysaccharide isolated from the roots of Bupleurum falcatum L., was previously characterized as a T cell-independent B cell mitogen. The endo-(1→4)-α-D-polygalacturonase-resistant moiety of bupleuran 2IIc (bupleuran 2IIc/PG-1) was the active site for expression of the activity, and expression of the cyclin D2 gene by bupleuran 2IIc/PG-1 may be mediated via activation of Src family tyrosine kinase, phosphatidylinositol 3-kinase (PI 3-K) and phospholipase C (PLC)-γ followed by activation of protein kinase C (PKC) and calcium mobilization (Matsumoto et al., Int. Immunopharmacol., 5, 1373—1386 (2005)). Plasma membrane microdomains (lipid rafts) are enriched in signaling molecules and suggested to be involved in numerous cell functions, including membrane traffic and signaling. When B cells were stimulated with bupleuran 2IIc/PG-1, clustering of membrane lipid rafts was observed. To consider whether lipid rafts are implicated in bupleuran 2IIc/PG-1-mediated B cell proliferation, we analyzed the phosphorylation of tyrosine residues of proteins in lipid rafts. When murine B cells were stimulated with bupleuran 2IIc/PG-1, tyrosine phosphorylation of proteins in lipid rafts fraction was observed within 5 min. Tyrosine phosphorylation in lipid rafts fraction by bupleuran 2IIc/PG-1 was inhibited by the Src-family tyrosine kinase inhibitor, PP2. Together with previously published data, the results presented in this study suggest that activation of signaling molecules in lipid rafts by stimulation of bupleuran 2IIc/PG-1 contributes to B cell proliferation as the membrane-proximal signaling event.
The hypoglycemic effects of the chemical constituents of Morinda citrifolia roots was evaluated in streptozotocin (STZ)-induced diabetic mice. The CHCl3, EtOAc, n-BuOH and H2O soluble phases of the MeOH extract of M. citrifolia roots were administrated orally to STZ-induced diabetic mice. Only the n-BuOH soluble phase showed a significant reduction of the blood glucose levels. From the biologically active n-BuOH soluble phase, two iridoids and three anthraquinones were isolated as main constituents. These compounds were identified by spectroscopic analysis to be deacetylasperulosidic acid (1), asperulosidic acid (2), damnacanthol-3-O-β-D-primeveroside (3), lucidin 3-O-β-D-primeveroside (4) and morindone-6-O-β-D-primeveroside (5). 3 and 4 exhibited the hypoglycemic effects, which were anthraquinones with no substituents in one aromatic ring.
A novel sesquiterpene furan compound CJ-01 was isolated from the methanol extract of the whole plant of Chloranthus japonicus SIEB. by monitoring the inhibitory activity of chitin synthase 2 from Saccharomyces cerevisiae. Based on spectroscopic analysis, the structure of compound CJ-01 was determined as 3,4,8a-trimethyl-4a,7,8,8a-tetrahydro-4a-naphto[2,3-b]furan-9-one. The compound inhibited chitin synthase 2 of Saccharomyces cerevisiae in a dose-dependent manner with an IC50 of 39.6 μg/ml, whereas it exhibited no inhibitory activities against chitin synthase 1 and 3 of S. cerevisiae up to 280 μg/ml. CJ-01 has 1.7-fold stronger inhibitory activity than polyoxin D (IC50=70 μg/ml), a well-known chitin synthase inhibitor. These results indicate that the compound is a specific inhibitor of chitin synthase 2 from S. cerevisiae. In addition, CJ-01 showed antifungal activities against various human and phytopathogenic fungi. Therefore, the compound might be an interesting lead to develop effective antifungal agents.
To improve its dissolution, ibuprofen solid dispersions (SDs) were prepared in a relatively easy and simple manner, characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR), and evaluated for solubility, in-vitro drug release and oral bioavailability of ibuprofen in rats. Loss of individual surface properties during melting and resolidification as revealed by SEM micrographs indicated the formation of effective SDs. Absence or shifting towards the lower melting temperature of the drug peak in SDs and physical mixtures in DSC study indicated the possibilities of drug–polymer interactions. FT-IR spectra showed the presence of drug crystalline in SDs. Quicker release of ibuprofen from SDs in rat intestine resulted in a significant increase in AUC and Cmax, and a significant decrease in Tmax over pure ibuprofen. Preliminary results from this study suggested that the preparation of fast dissolving ibuprofen SDs by low temperature melting method using polyethylene glycol 4000 (PEG 4000) as a meltable hydrophilic polymer carrier could be a promising approach to improve solubility, dissolution and absorption rate of ibuprofen.
Cinnamic acid is a wildly distributed phenylpropanoid component naturally occurring in plants, and is mainly found in Cinnamomum cassia BLUME and Panax ginseng. Cinnamic acid was recently reported to exert a tyrosinase inhibitory effect. However, research on melanocytes and animal bodies was not reported until now. In this study, we examined the effects of cinnamic acid on melanin biosynthesis within the melanocytes and brown guinea pigs. Melan-a cells were used to examine the effects of cinnamic acid in the melanocytes. Treatment with 100 ppm of cinnamic acid resulted in a significant reduction of melanin production in the melan-a cells at 29.0%. This compound also exhibited a potent inhibitory effect on tyrosinase activity and reduced tyrosinase expression in the melan-a cells. Moreover, cinnamic acid exhibited depigmenting activity on the UV-B-induced hyperpigmentation of brown guinea pig skin. Our results suggest that cinnamic acid might act as a skin whitening agent via inhibition of tyrosinase activity and expression within melanocytes.
Ergosterol peroxide (EPO, 1) is a major antitumor sterol produced by edible or medicinal mushrooms. Following oral administration of 1 to rats or anaerobic in vitro incubation of 1 with rat fecal bacteria, three metabolites were detected and their structures were identified to be 5α,6α-epoxyergosta-8(14),22-diene-3β,7α-diol (M1, 2), 5α,6α-epoxyergosta-8,22-diene-3β,7α-diol (M2, 3), and 5α,6α-epoxy-3β-hydroxyergosta-22-ene-7-one (M3, 4) by spectroscopic analysis. Of these, M2 and M3 showed more potent inhibitory activity than the original compound 1 against proliferation of CACO-2, WiDr, DLD-1 and Colo320 human colorectal adenocarcinoma cells. These findings suggest that bacterial metabolites of EPO play a significant role in its cytotoxic activity against human colorectal cancer cells.
Resveratrol, the main active polyphenol in red wine, has been demonstrated to show benefits against skin disorders. The bioavailability of orally administered resveratrol is insufficient to permit high enough drug concentrations for systemic therapy. In this study, we examined the feasibility of the topical/transdermal delivery of resveratrol. The effects of vehicles on the in vitro permeation and skin deposition from saturated solutions such as aqueous buffers and soybean oil were investigated. The general trend for the delivery from solutions was: pH 6 buffer=pH 8 buffer>10% glycerol formal in pH 6 buffer>pH 9.9 buffer>pH 10.8 buffer>soybean oil. A linear relationship was established between the permeability coefficient (Kp) and drug accumulation in the skin reservoir. Viable epidermis/dermis served as the predominant barrier for non-ionic resveratrol permeation. On the other hand, both the stratum corneum (SC) and viable skin acted as barriers to anionic resveratrol. Several prototype hydrogel systems were also studied as resveratrol vehicles. The viscosity but not the polarity of the hydrogels controlled resveratrol permeation/deposition. Piceatannol, a derivative of resveratrol with high pharmacological activity, showed 11.6-fold lower skin permeation compared to resveratrol. The safety profiles of resveratrol suggested that the hydrogel caused no SC disruption or skin erythema. It was concluded that delivery via a skin route may be a potent way to achieve the therapeutic effects of resveratrol. This is the first report to establish the permeation profiles for topically applied resveratrol.
Paclitaxel (PTX) is an antitumor agent for the treatment of various human cancers. Cremophor EL® and ethanol are used to formulate PTX in commercial injection solutions, because of its poor solubility in water. However, these agents cause severe allergic reaction upon intravenous administration. The aim of this study is to synthesize water-soluble macromolecular prodrugs of PTX for enhancing the therapeutic efficacy. Poly(vinyl alcohol) (PVA, 80 kDa), water-soluble synthetic polymer, was used as a drug carrier which is safe and stable in the body. The 2′-hydroxyl group of PTX was reacted with succinic anhydride and then carboxylic group of the succinyl spacer was coupled to PVA via ethylene diamine spacer, resulting the water-soluble prodrug of poly(vinyl alcohol)–paclitaxel conjugate (PVA–SPTX). The solubility of PTX was greatly enhanced by the conjugation to PVA. The release of PTX from the conjugate was accelerated at the neutral to basic conditions in in vitro release experiment. [125I]-labeled PVA–SPTX was retained in the blood circulation for several days and was gradually distributed into the tumorous tissue after intravenous injection to the tumor-bearing mice. PVA–SPTX inhibited the growth of sarcoma 180 cells subcutaneously inoculated in mice. It was suggested that the water-solubility of PTX was markedly enhanced by the conjugation to PVA, and PVA–SPTX effectively delivered PTX to the tumorous tissue due to the enhanced permeability and retention (EPR) effect.
We have established an ocular pharmacokinetic/pharmacodynamic (PK/PD) model for a β-adrenergic antagonist, timolol, after instillation into rabbits. Timolol concentrations were determined by HPLC in the tear fluid, aqueous humor, cornea, and iris-ciliary body after instillation or ocular injection into the anterior chamber of the eye in rabbits. In addition, intraocular pressure (IOP) measurement was performed after instillation of timolol by a telemetry system, which was able to obtain detailed IOP data automatically. The PK/PD parameters were estimated by fitting the concentration–time profiles and the ocular hypotensive effect–time profiles using MULTI (RUNGE) program. The PK model consisted of six compartments and the PD model included aqueous humor dynamics based on an action mechanism of timolol, which causes lowering of IOP by suppressing aqueous humor production. The PK/PD model described well the concentration–time profiles and the ocular hypotensive effect–time profiles after instillation of timolol. This study is the first trial to develop an ocular PK/PD model for timolol after instillation. This model can predict both the drug concentrations in various ocular tissues and the ocular hypotensive effect after instillation of timolol.
The purpose of this study was to evaluate the pharmacokinetics of R- and S-carvedilol in routinely treated Japanese patients with heart failure. We measured peak and trough blood concentrations at steady state following repeated oral administration to 24 patients. The blood concentration of S-carvedilol with potent β-blocking activity was lower than that of R-carvedilol. The mean oral clearance (CL/F) of R- and S-carvedilol was not altered by CYP2D6*10, UGT2B7*3, and the etiology of heart failure. In addition, the CL/F values of enantiomers were not correlated with age, creatinine clearance, and plasma concentrations of α1-acid glycoprotein and brain natriuretic peptide. On the other hand, the mean CL/F values of R- and S-carvedilol in patients with heart failure were 0.89 and 1.52 l/h/kg, respectively, considerably lower than those estimated previously in healthy subjects. These results suggested that the pharmacokinetics of R- and S-carvedilol was altered significantly by heart failure.
The ICR/f rat is a recessive-type hereditary cataractous strain, and opacity in the lens usually becomes evident at around 75 d of age. We previously found that the instillation of eye drops containing a disulfiram and hydroxypropyl-β-cyclodextrin inclusion complex (DSF eye drops) delays lens opacification in ICR/f rats. In this study, we attempted to clarify the mechanisms of the delaying effect of DSF eye drops on cataract development in ICR/f rats. The calcium ion (Ca2+) content in the lenses of ICR/f rats increases at 77 d of age, and this elevation is preceded by a decrease in Ca2+-ATPase activity. On the other hand, the levels of nitric oxide (NO) and lipid peroxide (LPO) also increase in the lenses of ICR/f rats at 63 d of age, while the lenses are still transparent. The instillation of DSF eye drops reduces the changes in Ca2+ content, Ca2+-ATPase activity, NO and LPO levels in the lenses of ICR/f rats. The present study demonstrates that excessive NO production induces the increase in LPO, which causes the decrease in Ca2+-ATPase activity, and the increase in Ca2+ content in the lenses of ICR/f rat during cataract development. DSF eye drops have the ability to attenuate the increase in the NO and LPO levels, resulting in a delay in cataract development.
To explore a new method for the transdermal delivery of praziquantel (PZQ), the effects of solvents on permeation across rabbit skin were investigated. The solubility of PZQ in five different solvents, ethylene glycol monophenyl ether (EGPE), 1,4-dioxane, tetrahydrofuran, dimethyl sulfoxide, and oleic acid, were measured with a UV–Vis spectrophotometer. The determination of the n-octanol/water partition coefficient of PZQ in the five different solutions and assay of serum concentration following PZQ transdermal administration in rabbits were performed using HPLC. The results indicated that the transdermal absorption of the drug was related to the partition coefficient and lipophilic characteristics of the solvent. The optimal solvent for PZQ transdermal delivery was EGPE in our protocol. The solubility of PZQ in EGPE is >400 mg/ml, and the apparent partition coefficient of PZQ in the solution is 0.895 (log P value). After transdermal administration of PZQ in EGPE solution, the bioavailability is 2.85-fold that after oral administration. The serum drug concentration was maintained at 4.0 μg/ml over 4 h, which is sufficient for the treatment of schistosomiasis. At the same time, no apparent side effects were found on the skin. EGPE may thus be a promising vehicle for the transdermal delivery of PZQ in the future.