The rate and force of contraction of the heart are precisely controlled by compartmentalized regulation of cardiac ion channels which determine electrical activities. It is known that modulation of cardiac ion channels, which is caused by drug administration, sympathetic nervous system stimulation and gender difference, can increase risks of lethal arrhythmias in carriers of inherited disease mutations. These modulations are thought to also be involved in common cardiac arrhythmias. Because many signaling molecules are localized within single cells, an understanding of the molecular basis of compartmentalized regulation of cardiac channels is a key for understanding and treating the lethal arrhythmias. In this review, I will discuss molecular mechanisms of compartmentalized regulation of cardiac ion channels via drugs, cAMP and sex hormones.
A total of 56 healthy Japanese males were enrolled in single- or multiple- dose pharmacokinetic trials of intravenous lansoprazole administration. The population pharmacokinetics of the drug was evaluated using nonlinear mixed effects model (NONMEM) software. In addition, the effect of CYP2C19 polymorphism on proton pump inhibition by lansoprazole was investigated using 24-h intragastric pH monitoring in the 32 subjects. Time course of serum lansoprazole concentration following intravenous short infusion was well described by a 2-compartment model. The mean volume of the central and peripheral compartments was 0.110 and 0.201 l/kg, respectively. The mean inter-compartment clearance was estimated to be 0.0882 l/h/kg. The population mean value of systemic clearance in the homoEM (CYP2C19*1/*1), heteroEM (CYP2C19*1/*2 and *1/*3), and PM (CYP2C19*2/*2, *2/*3, and *3/*3) groups was 0.179, 0.109, and 0.038 l/h/kg, respectively. The mean intragastric pH following twice-daily doses of 30 mg lansoprazole was approximately 6, 5, and 4 in the PM, heteroEM, and homoEM groups, respectively. These findings indicate that large interindividual variability exists in the pharmacokinetics of intravenously administered lansoprazole, but that twice-daily infusion of a 30 mg dose leads to significant and sustained proton pump inhibition, even in the homoEM group, despite the short elimination half-life of the drug.
Depletion of glutathione levels and perturbations in redox status are considered to play a crucial role in aging and chronic inflammatory processes through the activation of redox sensitive transcription factors, including nuclear factor-κB (NF-κB). In the current study, we assessed the regulatory action of dietary betaine in the suppression of NF-κB by comparing kidney tissue from old, betaine-supplemented rats or non-betaine-supplemented rats (age 21 months) and 7 month-old rats. In addition, cultured HEK 293T cells were utilized for the molecular assessment of betaine's restorative ability of redox status when treating cells with potent glutathione (GSH)-depleting agents. Results showed that in old rats a short-term feeding (10 d) with betaine attenuated the age-related decrease in thiol levels, increase in reactive species and TNFα expression via NF-κB activation, compared to the young controls. These findings were verified in the cell-cultured system. Further investigations found that redox imbalance due to thiol depletion caused increased NF-κB activation, and cyclooxygenase (COX)-2 and TNFα levels, both of which were suppressed by betaine treatment. Based on both in vivo and in vitro data, we concluded that betaine exerts its efficacy by maintaining thiol status in the regulation of COX-2 and TNFα via NF-κB activation during aging.
Macrophage colony stimulating factor (M-CSF) is a cytokine which has been recently reported to have a neuroprotective effect on ischemic rat brain. In this study, we investigated the effect of chotosan, an oriental medicine, which has been clinically demonstrated to be effective for the treatment of vascular dementia, on M-CSF gene expression in rats with permanent occlusion of bilateral common carotid arteries (P2VO) in vivo and in a C6Bu-1 glioma cell line in vitro. The expression level of M-CSF mRNA in the cerebral cortices of P2VO rats was significantly higher than that in the cerebral cortices of sham-operated animals. Repeated treatment of P2VO rats with chotosan (75 mg/kg per day) for 4 d after P2VO significantly increased the expression level of M-CSF mRNA in the cortex but it had no effect on the expression of β-actin, granulocyte colony stimulating factor (G-CSF), granulocyte/macrophage colony stimulating factor (GM-CSF) mRNAs. Moreover, the present in vitro studies revealed that chotosan treatment (10—100 μg/ml) of C6Bu-1 glioma cells dose-dependently enhanced M-CSF mRNA expression without affecting the expression of G-CSF, GM-CSF, and inducible nitric oxide synthase mRNAs. The effect of chotosan was reversed by Ro 31-8220 (1 μM), a selective protein kinase C (PKC) inhibitor, but not by H-89 (10 μM), a selective protein kinase A (PKA) inhibitor. These findings suggest that the upregulatory effect of chotosan on M-CSF mRNA expression involves PKC and may play an important role in the anti-vascular dementia action of this formula.
Morphine is implicated in diverse functions, from development to immune modulation in the central and peripheral nervous systems. At the present time, morphine is one of the most effective antinociceptive agents used to manage pain. It has been used extensively in the clinical management of pain due to its potent analgesic effect. In this study, the in vitro and in vivo inhibitory effects of morphine on erythrocyte carbonic anhydrase (CA) were investigated. Human erythrocyte isoenzymes, HCA-I and HCA-II, were purified by Sepharose-4B affinity chromatography column with a yield of 66.95 and 62.82%, a specific activity of 3892.3 and 11663.2 EU/mg proteins with 745.1 and 2232.6-fold purification of each isoenzyme, respectively. To determine enzyme purity, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed. In vitro inhibition of erythrocyte HCA-I and HCA-II by morphine using the CO2-hydratase enzyme gave IC50 values 4.50×10−5 M (r2: 0.954) and 9.23×10−5 M (r2: 0.996), respectively. CA activity was significantly attenuated in vivo in Spraque-Dawley rats for up to 3 h (p<0.001) following intraperitoneal administration of morphine. In conclusion, morphine inhibited CA activity both in vitro and in vivo.
A novel aldo-keto reductase (AKR) was cloned and sequenced from roots of Aloe arborescens by a combination of RT-PCR using degenerate primers based on the conserved sequences of plant polyketide reductases (PKRs) and cDNA library screening by oligonucleotide hybridization. A. arborescens AKR share similarities with known plant AKRs (40—66% amino acid sequence identity), maintaining most of the active-site residues conserved in the AKR superfamily enzymes. Interestingly, despite the sequence similarity with PKRs, recombinant enzyme expressed in Escherichia coli did not exhibit any detectable PKR activities. Instead, A. arborescens AKR catalyzed NADPH-dependent reduction of various carbonyl compounds including benzaldehyde and DL-glyceraldehyde. Finally, a homology model on the basis of the crystal structure of Hordeum vulgare AKR predicted the active-site architecture of the enzyme.
Chemoprevention has emerged as a very effective preventive measure against carcinogenesis. Several bioactive compounds present in fruits and vegetables have revealed their cancer curative potential on benzo(a)pyrene (B(a)P) induced carcinogenesis. In the present study, the efficacy of quercetin on the level of lipid peroxides, activities of antioxidant enzymes and tumor marker enzymes in B(a)P induced experimental lung carcinogenesis in Swiss albino mice was assessed. In lung cancer bearing animals there was an increase in lung weight, lipid peroxidation and marker enzymes such as aryl hydrocarbon hydroxylase, gamma glutamyl transpeptidase, 5′-nucleotidase, lactate dehydrogenase and adenosine deaminase with subsequent decrease in body weight and antioxidant enzymes—superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase, reduced glutathione, vitamin E and vitamin C. Quercetin supplementation (25 mg/kg body weight) attenuated all these alterations, which indicates the anticancer effect that was further confirmed by histopathological analysis. Overall, the above data shows that the anticancer effect of quercetin is more pronounced when used as an chemopreventive agent rather than as a chemotherapeutic agent against B(a)P induced lung carcinogenesis.
Prodrugs that can readily release polyamine into cells without the problem of generating cytotoxic compound by serum amine oxidase would be extremely useful for elucidation of polyamine function. As linear polyamines with acetamide groups on both sides are thought to be stable in the presence of serum amine oxidase and produce polyamines by the catalytic reaction of acetylpolyamine oxidase (PAO), a series of diacetyltetraamines, diacetylpentaamines and diacetylhexaamines was prepared as prodrugs and tested for substrate activity against PAO, partially purified from rat liver. Of the compounds, N1,N15-diacetyl-1,15-diamino-4,8,12-triazapentadecane (DA3333) and N1,N16-diacetyl-1,16-diamino-4,8,13-triazahexadecane (DA3343) were found to be stable in culture medium containing newborn bovine serum, and to produce reasonable amounts of norspermidine and spermidine, respectively. DA3333 and DA3343 were then applied to 1-aminooxy-3-aminopropane (AOAP)-treated HTC cells with depleted putrescine and spermidine, and arrested growth. Cell growth recovered with DA3333 and DA3343, but growth rate was reduced in cells with added DA3333 compared with growth rates in cells with added DA3343 and control cells untreated with AOAP. Significant amounts of norspermidine and spermidine were found in cells with added DA3333 and DA3343, respectively. These results show the potential use of diacetylpolyamines in introducing polyamines into cells.
The aims of this study were to investigate whether chemically modified non-anticoagulation heparin derivate (Periodate-Oxidized/Borohydride-Reduced modified heparin (OR-heparin)) can inhibit high glucose-induced human mesangial cell proliferation and its influence on the cell cycle. OR-heparin with low anticoagulation activity inhibited high glucose-induced early proliferation in a dose-dependent manner. OR-heparin released high glucose-arrested mesangial cells at G1 phase, and dose-dependently increased S phase. OR-heparin also inhibited high glucose-activated ERK1/2 phosphorylation, induced p27Kip1 expression, and suppressed reactive oxygen species (ROS) accumulation in a dose-dependent manner. Our results suggest that OR-heparin releases high glucose-arrested cells on G1 phase and inhibits high glucose-induced mesangial cell proliferation through blocking ERK1/2 phosphorylation and delaying S phase progression, which may be in correlation with OR-heparin suppressing ROS accumulation.
Although anticancer chemotherapeutic drugs have been designed to inhibit the growth of tumor cells, chemotherapy frequently fails due to the development of multidrug resistance (MDR). In this paper, the effect of survivin on multidrug resistance mediated by P-glycoprotein (Pgp) was investigated in breast cancer cells. Overexpression of survivin in MCF-7 cells transfected with survivin expression vector pEGFP/survivin results in decreasing sensitivity to anticancer drugs and activation of Pgp to export drug out of cells. Down regulation of survivin in MCF-7/adriamycin (ADR) transfected with RNAi directed against survivin vector psh1/survivin could increase the drug accumulation in cells by inhibiting Pgp. Downregulation of the expression of the Pgp with the specific inhibitor verapamil could markedly suppress the survivin mRNA expression, whereas the reverse impact was not observed. Survivin might modulate the turnover of Pgp or transport by Pgp in cells, which result in anti-apoptosis and drug resistance. Our results suggest that survivin might play a key role in MDR in the presence of Pgp, and this might represent a novel strategy for modulating MDR in cancer cells.
High glucose accelerates O-N-acetylglucosaminylation (O-GlcNAcylation) of proteins and causes diabetic complications. In the present study, we found that treatment of HuH-7 human hepatoma cells with high glucose or the protein O-N-acetylglucosaminidase (O-GlcNAcase) inhibitor O-(2-acetoamide-2-deoxy-D-glucopyranosylidene)amino-N-phenylcarbamate (PUGNAc) increased the cell surface expression of E-selectin. A dual luciferase reporter assay indicated that high glucose and PUGNAc suppressed promoter activities of the cyclic AMP response element (CRE) and enhanced those of activator protein 1 (AP-1). Enhanced CRE promoter activities in HuH-7 cells treated with dibutyryl cAMP or co-transfected with a protein kinase A expression vector pFC-PKA that enhances the phosphorylation of CRE binding protein (CREB) were suppressed by PUGNAc. In contrast, PUGNAc further increased the enhanced AP-1 promoter activity in cells transfected with a mitogen-activated protein kinase kinase kinase expression vector pFC-MEKK that enhances c-Jun phosphorylation. Immuno-blotting using an anti-O-GlcNAc antibody revealed that high glucose and PUGNAc accelerated protein O-GlcNAcylation and that there were substantial differences in the O-GlcNAcylated proteins in the cytoplasmic and nuclear fractions. In addition, PUGNAc increased the nuclear import of O-GlcNAcylated CREB. These results suggest that protein O-GlcNAcylation modulates the promoter activities of E-selectin gene, suppression of CRE and enhancement of AP-1, and enhances E-selectin protein expression on hepatocytes.
Licochalcones have a variety of biological properties including anti-tumor, anti-parasitic and anti-bacterial activities. Recently, a new retrochalcone (licochalcone E, Lico-E) was isolated from the roots of Glycyrrhiza inflata (Chem. Pharm. Bull., 53, 2005, Yoon et al.) by cytotoxicity-guided fractionation. This study examined whether or not Lico-E-induced endothelial cell death occurs through apoptosis, and investigated molecular mechanisms involved in this process. Lico-E was found to suppress ECV304 cell growth and induce apoptosis. The induction of apoptosis by Lico-E was confirmed by the ladder-patterned DNA fragmentation, the presence of cleaved and condensed nuclear chromatin and the increased number of annexin V-positive cells. Lico-E could effectively inhibit the constitutive NF-κB activation, as revealed by the electrophoretic mobility shift assay and NF-κB-dependent luciferase reporter study. In addition, the Lico-E treatment caused a change in the Bax/Bcl-2 ratio that favored apoptosis. These results suggest that Lico-E induces endothelial cell apoptosis by modulating NF-κB and the Bcl-2 family.
Neuroblastoma (NB) is the most common malignant solid tumor in childhood. There are well-recognized prognostic factors in NB such as age at diagnosis, organ of origin, stages, MYCN gene amplification, and expression of H-ras, trkA and survivin. Moreover, we investigated the expression of vascular endothelial growth factor (VEGF), tyrosine hydroxylase (TH), p53, stem cell factor (SCF) and c-kit of its receptor with quantitative real-time polymerase chain reaction (PCR) in 22 NBs and 4 other tumors (one malignant lymphoma, one malignant teratoma, and 2 rhabdomyosarcomas) samples. The correlation between patients' prognoses and the expression of TH or c-kit was newly recognized, particularly the good prognosis in patients in whom c-kit highly expressed and the poor prognosis contrarily associated with low or no expression, although the SCF of its ligand had no relationship with patient prognosis. It is possible that tumors without c-kit expression can not react with SCF (via the autocrine or paracrine system) and remain immature. It may be that this is a new critical clinical event in NB patients.
To characterize the protein expression profiles and identify the molecules associated with tumor angiogenesis, the cellular proteins of human umbilical vein endothelial cells (HUVECs) in response to cancer cell-conditioned medium (CM) prepared from HT1080 human fibrosarcoma cells were analyzed using fluorescence-labeled 2D gel-based proteomics. Most differentially expressed proteins in HT1080-CM-stimulated cells were found to be downregulated (88%) rather than upregulated (12%) based on statistical analysis of protein spot signals. Additionally, we examined the effects of vascular endothelial cell growth factor (VEGF), a proangiogenic factor, on cellular protein expression. In contrast, most differentially expressed proteins were found to be upregulated (59%) rather than downregulated (41%) in VEGF-stimulated HUVECs. Comparative analyses of 29 and 35 protein species identified in CM-stimulated and VEGF-stimulated HUVECs, respectively, revealed the remarkable differences between these two stimulations. Only four proteins were differentially expressed by both treatments: annexin A2, enolase 1, and T-plastin (downregulated by CM but upregulated by VEGF), and RAN (downregulated by both CM and VEGF). These findings provide new information regarding the regulation of protein expression associated with tumor angiogenesis.
It is well known that it would be important to cultivate human hepatocytes of about 1010 cells at a high cell density, about 1×107 cells/cm3, in the bioreactor for the development of bioartificial liver. However, since primary human hepatocytes lack an ability to proliferate in vitro, it is essential to establish a culture method for the proliferation of normal human hepatic stem cells as a cell source. In this study, it was found that human hepatoblasts, a kind of hepatic stem cells, were induced from human fetal hepatocytes while keeping the ability of proliferation by the treatment of 1mM sodium butyrate (SB) for 12 d of culture. The transformation of hepatoblasts was evaluated by abnormal prothrombin (PIVKA-II) assay, which is a clinical marker for hepatocellular carcinoma. The PIVKA-II production rate of the cells was suppressed to the normal level under 1 mM SB. The cells including hepatoblasts under 1 mM SB attached to the porous hydroxyapatite carriers and proliferated to a high cell density of about 1×107 cells/cm3 in the carriers. The liver-specific function, cytochrome P450 3A4 activity (4.2 pmol/mg protein/min) of the cells in the carriers under 1 mM SB was comparable to that of primary human hepatocytes. Ammonia metabolizing activity (0.21 μmol/106 cells/h) of the cells was also comparable to that of porcine hepatocytes used in the bioartificial liver. The PIVKA-II production rate of the cells in the carrier was suppressed to the normal level. These results suggested that induction of human hepatoblasts from fetal hepatocytes by the treatment of 1mM SB and proliferation of the cells at a high cell density using hydroxyapatite carriers should be one of the more promising culture methods for bioartificial liver developments.
Although flavonoids, which are both qualitatively and quantitatively one of the largest groups of natural products, exhibit a variety of beneficial health effects, the exact molecular mechanism of the cellular activities is still not fully explained and there currently exists a lack of evidence for any relationship between the structure–activity relationship and apoptosis-inducing activity. In order to determine the importance of the OH group or substitution of the 5 or carbon-7 in the diphenylpropane skeleton of flavonoids, we originally synthesized several modified naringenin derivatives, including 7-O-benzyl naringenin (KUF-1) and 7-O-(MeO-L-Leu-D-Pro-carbonylmethyl) naringenin (KUF-7). Treatment with KUF-1 or KUF-7 resulted in significant apoptosis-inducing effects concomitant with chromatin condensation, caspase activation, and intracellular ROS production. Our data indicate that originally synthesized naringenin derivatives, KUF-1 and KUF-7 differentially regulate the apoptosis of A549 cells via intracellular ROS production coupled with the concomitant activation of the caspase cascade signaling pathway, thereby implying that hydroxylation or substitution at Carbon-7 is critical for the apoptosis-inducing activity of flavonoids.
We have developed a septic shock model in mice by sequential administration of β-glucan, a biological response modifier, and indomethacin (IND), a nonsteroidal anti-inflammatory drug. Lethality was significantly related to the translocation of gut flora to various organs and mal-adjustment of the cytokine network. In the present study, we have examined the effect of antibiotics on this model to further clarify meanings of microbial flora. Schizophyllan (SPG), antitumor β-glucan for clinical use, obtained from the culture filtrate of Schizophyllum commune, was used to induce sepsis. Lincomycin (LCM), imipenem (IPM), cilastatine (CS), and ampicillin (ABPC) were used for antibiotics treatment. The survival rate of SPG/IND-treated mice was significantly increased by administering LCM or ABPC/IPM/CS, and the effect was more significant by LCM. In in vitro spleen cell culture, LCM decreased proinflammatory cytokine production. Moreover, prednisolone, immune suppresser treatment improved survival of SPG/IND-treated mice. These findings suggest that LCM is an effective antibiotic in this endogenous septic model by modulating gut microbial flora and, at least a part, by regulating cytokine production of leukocytes.
In vitro metabolism of nobiletin, a polymethoxy-flavonoid abundantly present in citrus peels, was studied using liver microsomes of rats, hamsters and guinea pigs and ten cDNA-expressed rat cytochrome P450 (P450). The effects of P450 inducers on nobiletin metabolism were also investigated. Aerobical incubation with NADPH and animal liver microsomes transformed nobiletin to five metabolites, M-1, M-2, M-3, M-4 and M-5. From LC-MS and 1H-NMR data and a time-course study, these were assumed to be 4′-hydroxy (OH)-, 7-OH-, 6-OH-, 3′,4′-diOH- and 6,7-diOH-metabolites, respectively. Pretreatment of animals with phenobarbital increased M-2 and M-3 to about 2-fold that in untreated animals. Pretreatment with 3-methylcholanthrene (MC) resulted in remarkable increases of both M-1 and M-4 (3 to 9-fold that of untreated). Males had 2—3 times higher M-2 and M-3 formation activities in rats, and for M-2 in hamsters than did females. Immunoinhibition study using antiserum against P450 revealed the involvement of hamster CYP1A2 in the formation of M-1 and M-4 in hamster liver. Of ten rat P450s, CYP2C11, CYP3A1, CYP3A2 and CYP2D1 had high activities for the formation of M-1, M-2 and M-3. Another P450s (CYP1A1, CYP2C12 and CYP1A2) also showed activity for the formation of M-1. Only CYP1A1 produced 3′,4′-diOH-metabolites (M-4). However, CYP2A1, CYP2B1 and CYP2E1 had no activity for nobiletin. These results suggested that constitutive P450s such as CYP2C11, CYP2D1, CYP3A1, CYP3A2 and CYP2C12 are responsible for the demethylation at the 6-, 7-, 3′- and 4′-positions; whereas, MC-inducible P450s, CYP1A1 and CYP1A2, preferentially catalyzed demethylation at the 3′-and 4′-positions.
Solifenacin succinate is a novel muscarinic receptor antagonist used for the treatment of overactive bladder (OAB). We investigated the effects of solifenacin by oral and intravenous administration on carbachol (CCh)-induced intravesical pressure (IVP) elevation and compared its efficacy with that on CCh-induced salivary secretion in anesthetized mice. Additionally, we also investigated the change in effects between single and repeated oral administration of solifenacin on CCh-induced IVP elevation. Results showed that intravenous administration of solifenacin dose-dependently inhibited the IVP elevation and salivary secretion. The ratio of bladder response to salivary response (ratio of ID50 values) was 2.1. Oral administration of solifenacin (0.3—30 mg/kg) also inhibited CCh-induced IVP elevation and salivary secretion. Although inhibition of these responses by solifenacin (10, 30 mg/kg) was comparable at early time points (0.5 and 1 h after administration at 10 mg/kg and 0.5 to 2 h after administration at 30 mg/kg), inhibition of CCh-induced IVP elevation was stronger at later time points (2 to 8 h after administration at 10 mg/kg and 4 to 24 h after administration at 30 mg/kg). No significant difference in ID50 values for IVP elevation was observed between single and repeated (11 d) oral administration of solifenacin (1—30 mg/kg), suggesting no change in efficacy on chronic administration. In conclusion, intravenous and oral solifenacin inhibits CCh-induced IVP elevation more potently than salivary secretion. These results provide further evidence for the clinical use of solifenacin as a promising therapeutic drug for OAB with a low incidence of dry mouth.
We constructed a reproducible, simple, and small-scale determination method of the psychoactive drugs that acted directly on the monoamine receptor by measuring the activation of [35S]guanosine-5′-O-(3-thio)-triphosphate binding to guanine nucleotide-binding proteins (G proteins). This method can simultaneously measure the effects of three monoamines, namely dopamine (DA), serotonin (5-HT), and norepinephrine (NE), in rat brain membranes using a 96-well microplate. Activation of D1 and D2 receptors in striatal membranes by DA as well as 5-HT and NEα2 receptors in cortical membranes could be measured. Of 12 tested phenethylamines, 2,5-dimethoxy-4-chlorophenethylamine (2C-C), 2,5-dimethoxy-4-ethylphenethylamine (2C-E), and 2,5-dimethoxy-4-iodophenethylamine (2C-I) stimulated G protein binding. The other phenethylamines did not affect G protein binding. All 7 tryptamines tested stimulated G protein binding with the following rank order of potency; 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT)>5-methoxy-N,N-diallyltryptamine (5-MeO-DALT)>5-methoxy-α-methyltryptamine (5-MeO-AMT)≥5-methoxy-N,N-methylisopropyltryptamine (5-MeO-MIPT)>5-methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT)>N,N-dipropyltryptamine (DPT)≥α-methyltryptamine (AMT). This assay system was able to designate psychoactive drugs as prohibited substances in accordance with criteria set forth by the Tokyo Metropolitan government.
The effects of milnacipran, a serotonin and noradrenaline reuptake inhibitor (SNRI) on the obsessive compulsive disorder (OCD) model, marble burying behavior, were investigated in mice. Milnacipran above the dosage of 10 mg/kg inhibited marble burying behavior significantly in mice as similar to fluvoxamine. Milnacipran inhibiting marble burying behavior did not affect locomotor activity. These results suggest that milnacipran can inhibit marble burying behavior and that milacipran may be useful for OCD therapy.
Cancer is one of the major causes of death. For cancer, the general conventional treatment and standard of care for clinical oncology remains surgery followed by radiation and/or systemic chemotherapy as deemed appropriate based on the clinical findings. Chemoimmunotherapy is an approach to treat cancer where chemotherapy is given along with immunotherapy. Chemoimmunotherapy may be useful to enhance survival time in cancer by improve immunity of the patients. This approach may enhance the therapeutic efficacy. A comparative study was done to assess the therapeutic efficacy of the whole cell vaccine and the tumor extract with or without combination chemotherapy with the synthesized glutamine and glutamic acid derivatives and analogs as well as the standard drug etoposide against Ehrlich Ascites Carcinoma (EAC) cells in Swiss Albino mice. The study showed promising results with the compound 5-N-n-hexyl-2-(4-iso-butylbenzenesulphonyl)glutamine. The compound when combined with the whole cell vaccine as well as the tumor extract increases the survival time and the therapeutic efficacy which is comparable with that of standard drug etoposide.
In this report, we investigated the effect of ginkgolide C (GC) from Ginkgo biloba leaves in collagen (10 μg/ml)-stimulated platelet aggregation. It has been known that matrix metalloproteinase-9 (MMP-9) is released from human platelets, and that it significantly inhibited platelet aggregation stimulated by collagen. Zymographic analysis confirmed that pro-MMP-9 (92-kDa) was activated by GC to form an activated MMP-9 (86-kDa) on gelatinolytic activities. And then, GC dose-dependently inhibited platelet aggregation, intracellular Ca2+ mobilization, and thromboxane A2 (TXA2) formation in collagen-stimulated platelets. In addition, GC significantly increased the formation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which have an anti-platelet function in both resting and collagen-stimulated platelets. Therefore, we demonstrate that the inhibitory effect of GC on platelet aggregation might be involved into the following pathways. GC may increase intracellular cAMP and cGMP production and MMP-9 activity, inhibit intracellular Ca2+ mobilization and TXA2 production, thereby leading to inhibition of platelet aggregation. These results strongly indicate that GC is a potent inhibitor of collagen-stimulated platelet aggregation. It may be a suitable tool for a negative regulator during platelet activation.
We previously reported that poncirin, a flavanone glycoside isolated from the EtOAc extract of the dried immature fruits of Poncirus trifoliata, is an anti-inflammatory compound that inhibits PGE2 and IL-6 production. The present work was undertaken to investigate the molecular actions of poncirin in RAW 264.7 macrophage cell line. Poncirin reduced lipopolysaccharide (LPS)-induced protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and the mRNA expressions of iNOS, COX-2, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in a concentration-dependent manner, as determined by Western blotting and RT-PCR, respectively. Furthermore, poncirin inhibited the LPS-induced DNA binding activity of nuclear factor-κB (NF-κB). Moreover, this effect was accompanied by a parallel reduction in IκB-α degradation and phosphorylation that in by nuclear translocations of p50 and p65 NF-κB subunits. Taken together, our data indicate that anti-inflammatory properties of poncirin might be the result from the inhibition iNOS, COX-2, TNF-α and IL-6 expression via the down-regulation of NF-κB binding activity.
The ethanol extract of the aerial part of the Mongolian medicinal plant Saussurea salicifolia induced a dose-dependent cell growth inhibition in both human gastric adenocarcinoma AGS cells and mouse hepatoma Hepa 1c1c7 cells (IC50=30.22 and 116.96 μg/ml), respectively. The extract induced an apoptosis in AGS cells inference from the externalization of the phosphatidylserine, the increase of the sub G0/G1 content (%) and the apoptotic morphological changes including membrane blebbing, the formation of apoptotic bodies and chromatin condensation. In order to identify active substances causing the apoptosis, we further isolated major compounds present in Saussurea salicifolia and 7 compounds were isolated including a sesquiterpene lactone, cynaropicrin, 3 lignans (trachelogenin, matairesinol and arctigenin) and 3 lignan glycosides (tracheloside, matairesinoside and arctiin). In general the lignan aglycones were more cytotoxic than their lignan glycosides in both AGS cells and Hepa 1c1c7 cells. Cynaropicrin not only showed the most potent cytotoxicity among the 7 major compounds but also it induced an apoptosis and a weak G2/M arrest in AGS cells. Arctigenin had the second-best cytotoxicity among 7 major compounds, and induced an apoptosis. In order to evaluate the induction of the phase II detoxification enzyme, we measured the induction of quinone reductase activity of the extract, fractions and compounds in Hepa 1c1c7 cells. The ethyl acetate fraction and arctigenin showed the strongest cancer chemopreventive activity (chemoprevention index=9.88 and 7.57, respectively). These data suggest that the extract as well as the lignan compounds (especially arctigenin) originated from Saussurea salicifolia may be served as potential cancer chemopreventive agents for prevention or treatment of human cancers.
Previously we reported that Piper nigrum leaf extract showed a potent stimulation effect on melanogenesis and that (−)-cubebin (1) and (−)-3,4-dimethoxy-3,4-desmethylenedioxycubebin (2) were isolated as active constituents. As a part of our continuous studies on Piper species for the development of cosmetic hair-care agents, testosterone 5α-reductase inhibitory activity of aqueous ethanolic extracts obtained from several different parts of six Piper species, namely Piper nigrum, P. methysticum, P. betle, P. kadsura, P. longum, and P. cubeba, were examined. Among them, the extracts of P. nigrum leaf, P. nigrum fruit and P. cubeba fruit showed potent inhibitory activity. Activity-guided fractionation of P. nigrum leaf extract led to the isolation of 1 and 2. Fruits of P. cubeba contain 1 as a major lignan, thus inhibitory activity of the fruit may be attributable to 1. As a result of further assay on other known constituents of the cited Piper species, it was found that piperine, a major alkaloid amide of P. nigrum fruit, showed potent inhibitory activity, thus a part of the inhibitory activity of P. nigrum fruit may depend on piperine. The 5α-reductase inhibitory activities of 1 and piperine were found for the first time. In addition, the P. nigrum leaf extract showed in vivo anti-androgenic activity using the hair regrowth assay in testosterone sensitive male C57Black/6CrSlc strain mice.
The purpose of this study was to investigate the continuous and real-time influence of ophthalmic ingredients on rabbit cornea by monitoring electrophysiological characteristics. The tight junctional permeabilities of FITC-dextran 4400 (FD-4) was also determined through the cornea in the presence of ophthalmic ingredients. Intact cornea showed approximately one k-ohm×cm2 of transepithelial electrical resistance (TEER) and extremely low permeability of FD-4. The ophthalmic ingredients used in the present study were benzalkonium chloride (BK; 0.002%, 0.01%, 0.05%), ethylenediaminetetraacetic acid (EDTA; 0.5%), capric acid (C10; 0.25%), saponin (SP; 0.1%), taurocholic acid (TA; 1.0%) and sodium dodecyl sulfate (SDS; 0.01%). They were previously reported to be effective on corneal penetrations of various drugs at those concentrations without severe toxicity. These ingredients decreased TEER and increased corneal permeability of FD-4. BK reduced TEER in a concentration-dependent manner. There was a significant correlation (γ=0.860) between the permeability coefficient (Papp) of FD-4 and conductance (Gm), which is the reciprocal value of TEER. It was also indicated that Papp and Gm have a relationship with the corneal cytotoxicity of the ingredients. In conclusion, an electrophysiological method using isolated cornea was very useful to determine the continuous and real-time influence of ophthalmic ingredients on the cornea. In this method, electrophysiological conductance must be able to predict corneal tight junction permeability and the corneal cytotoxicity of ingredients.
DE-310 is composed of the topoisomerase-I inhibitor DX-8951 (exatecan) and carboxymethyldextran polyalcohol (CM-Dex-PA) carrier, which are covalently linked via peptidyl spacer (Gly-Gly-Phe-Gly). In this study, we investigated relationship between the cathepsin activity and the drug release of DE-310 by use of human liver origin cathepsin (B, L and H) and tumor cells (murine tumor cells (Meth A and M5076), and human tumor cells (HCT116, A549, PC-12, T98G, and HL-60)). Preliminary studies indicated that human liver cathepsin B produced Glycyl DX-8951 (G-DX-8951) from DE-310 more preferentially than DX-8951, whereas human liver cathepsin L produced DX-8951 preferentially. Release of drugs from DE-310 and cathepsin activities were measured in tumor cell types. The release of both DX-8951 and G-DX-8951 from DE-310 correlated well with cathepsin B activity of tumor cells. The release of DX-8951 was weakly, but not significantly, correlated with cathepsin L activity. In M5076 (high cathepsin activity) or Meth A (low cathepsin activity) xenograft models, the levels of DX-8951 and G-DX-8951 in M5076 were higher than in Meth A after single intravenous administration of DE-310. Our findings suggest that cathepsin B is primarily responsible for drug release from DE-310 in tumor.
Cyclosporine (CsA)-induced nephrotoxicity can become a major obstacle to continuous use. The aim of this study was to optimize CsA dose to avoid its irreversible nephrotoxicity. Twenty-three Japanese patients with pediatric-onset systemic lupus erythematosus or idiopathic nephrotic syndrome, who were maintained in a stable condition by oral dosing of CsA microemulsion, were enrolled in this study. The patients were stratified into 3 groups; those with no, reversible, and irreversible nephrotoxicity, according to periodically performed renal pathohistological examinations. A higher concentration of CsA in blood (p=0.002—0.011) and a longer duration of CsA treatment (p=0.002) were risk factors for irreversible nephrotoxicity, and the cumulative CsA dose, the product of the maintenance dose and duration of CsA treatment, was predictive of nephrotoxicity (p=0.036). The maximum target blood concentration at 2 h post-dose, C2, to avoid CsA-induced irreversible nephrotoxicity was 700 ng/ml, although the cumulative CsA dose of 4850 mg/kg would result in a 50% probability of nephrotoxicity.
Kumazasa extract (KE) and its whole solid component (EXT)-containing chitosan films produced by drying in air and lyophilization, abbreviated to ND and FD films, respectively, were examined for efficacy and healing features using a deep skin ulcer model in rats. Their effects were compared with those of clinically available dosage forms, Beschitin® W, Geben® cream and U-PASTA. KE alone exhibited a better effect as compared with other preparations, and FD films also more effective than control in the early stage. Histological analysis showed that KE alone reduced necrosis rapidly and accelerated granulation. ND films delayed healing rate as compared with control. FD films showed histological features between control and KE alone, but tended to delay healing rate in the later period. Thus, reduction rate of wound area and histological features suggested that KE alone should be excellent for the promotion of wound healing. Although FD films were less effective than KE alone, they were superior as to usability such as changing the preparation.
In previous studies, we found that 3-methyl-4-nitrophenol (4-nitro-m-cresol; PNMC) isolated from diesel exhaust particles, and also a degradation product of the insecticide fenitrothion, exhibited testicular toxicity in the male of both immature rat and adult Japanese quail. It is well established that a functional relationship exists between the gonads and adrenals. The present study investigates the effect of PNMC on the adrenocortical functions of immature male rats. We subcutaneously injected 28-d-old rats with PNMC (1, 10 or 100 mg/kg) daily for 5 d. The adrenal glands weights significantly decreased in rats treated with 10 or 100 mg/kg PNMC. Plasma concentrations of adrenocorticotropic hormone (ACTH) were significantly increased in animals treated with 100 mg/kg PNMC. In contrast, plasma concentrations of corticosterone were significantly decreased in all PNMC-treated groups, and plasma concentrations of progesterone were significantly decreased in rats treated with 10 or 100 mg/kg PNMC. To investigate the direct effects of PNMC on the secretion of ACTH from the anterior pituitary gland, and on the secretion of corticosterone from the adrenal, we exposed cultured primary anterior pituitary and adrenal cells to PNMC (10−8, 10−7, 10−6, or 10−5 m) for 24 h. PNMC did not change basal levels of ACTH released from cultured anterior pituitary cells. However, PNMC significantly inhibited ACTH-stimulated production of corticosterone and progesterone from cultured adrenal cells. These results clearly show that PNMC has a direct effect on the adrenal gland to reduce corticosterone secretion, and the associated increase in plasma ACTH is probably due decreased negative feedback regulation by corticosterone.
Effects of supplemented docosahexaenoic acid (DHA), given as diacylglycerol (DG) rich in DHA (DHA-DG), triacylglycerol (TG) rich in DHA (DHA-TG) or fish oil concentrate (DHA-70), on the serum concentration of TG and its bioavailability in the rats with diet-induced hyperlipidemia were studied. Hypertriglyceridemia was induced by feeding male Wistar rats a semi-purified diet that contained 5% corn oil and 50% sucrose by weight. In addition to the feeding of dietary corn oil, the rats received DHA intragastrically at a dose of 500 mg/kg body weight once a day for 28 d and the control rats were given olive oil. The serum concentration of TG in the rats that received DHA-DG was significantly lower than in the control rats. However, there were no significant differences in diet intake, energy intake, body weight gain, visceral fat mass or fecal excretion of total fatty acids among the four groups. The amounts of DHA excreted into the feces of the three groups of rats that received DHA were approximately 0.4% of the DHA administered. The extent of the decreases induced by DHA-DG in the serum level of TG was almost the same as those induced by DHA-TG and DHA-70. The administration of DHA, regardless of the differences in molecular structure, did not affect the hepatic contents of TG or phospholipid. The administration of DHA-DG considerably increased the proportions of DHA and eicosapentaenoic acid (EPA) while decreasing the proportion of arachidonic acid in hepatic lipids, and as a result in the lipids in serum and erythrocytes, to the same extents as did DHA-TG and DHA-70. These results suggest that the hypotriglyceridemic effects and bioavailability of DHA when supplemented in the form of DG are essentially equivalent to those of DHA-TG and DHA-70.