We found that the acetone extract of the peel of Japanese persimmon (Diospyros kaki ‘Fuyu’) inhibits melanin biosynthesis in mouse B16 melanoma cells. The activity-guided purification of the extract resulted in isolation of two active compounds, which have been identified as flavonoid glycosides, isoquercitrin (quercetin-3-O-glucoside) and hyperin (quercetin-3-O-galactoside) by spectral analysis. Isoquercitrin and hyperin strongly inhibited the production of melanin (IC50: 21.7 and 18.2 μM, respectively). The inhibitory effects were found to be mediated by suppression of tyrosinase expression.
Intercellular adhesion molecule-1 (ICAM-1) is associated with processes of inflammation. We investigated the effects of deoxypodophyllotoxin (DPT) on tumor necrosis factor-α (TNF-α) induced ICAM-1 expression in the mouse lung epithelial cell line, LA4. DPT (5 to 20 nM) inhibited TNF-α-induced ICAM-1 expression through nuclear factor-kappa B (NF-κB) in a dose-dependent manner and repressed ICAM-1 promoter activity. NF-κB reporter gene activity and DNA binding activity were also strongly inhibited. In addition, DPT inhibited degradation by the TNF-α induced inhibitory κB-α (IκB-α) in a concentration-dependent manner. Taken together with our previous results suggest DPT might provide a basis for novel anti-inflammatory drug development.
4,4′-Butylidenebis(6-t-butyl-m-cresol) (BBBC) can be eluted from disposable gloves made of nitrile-butadiene rubber and possibly also detected in food. It has been reported that BBBC is an androgen and estrogen antagonist in vitro. Previously, BBBC (1.0 mg/kg body weight (bw)/d) was subcutaneously administered to pregnant rats from gestation days 11 through 18, and the effects on male offspring (postnatal day 102) were examined. Altered levels and turnover of the monoamines dopamine, serotonin, and noradrenalin as well as their metabolites were detected. This report measured the level of serum testosterone following prenatal exposure to BBBC (0.1, 1.0, 10 mg/kg bw/d) in male rats, and measured aromatase activity of the hypothalamus-preoptic area with a close connection to the sexual differentiation and sexual behavior of BBBC-treated rat brains. The serum testosterone level rose depending on exposure, and aromatase activity of the basomedial nucleus of amygdale region was increased in the BBBC-treated group compared with the control. These results suggested that prenatal exposure to BBBC affects the central nervous system of male rat offspring, and BBBC may be an endocrine disrupting-chemical during the fetal period, and might influence the functional development of the brain.
The complex molecular cascades of ischemic tolerance in brain cells remain unclear. Recently, sphingolipid-related metabolite ceramide has been implicated as a second messenger in many biological functions, including neuronal survival and death. The present study, therefore, examined the roles of ceramide (Cer) in ischemic tolerance induced by preconditioning with sublethal oxygen-glucose deprivation (OGD) using primary cultured cortical neurons of rats. Preconditioning of the neurons with sublethal 1-h OGD produced robust neuroprotection against cell death induced by lethal 3-h OGD imposed 12 h after preconditioning when measured by the MTT assay. Analysis of sphingolipids using LC-MS/MS showed that the ischemic preconditioning resulted in significant increases in the levels of C16 : 0 Cer, C18 : 0 Cer, C20 : 0 Cer, C24 : 0 Cer, C24 : 1 Cer and the total ceramide contents compared with the sham-washed control group. However, sphingomyelin contents were not significantly changed by the ischemic preconditioning, suggesting that ceramides were increased through the de novo synthetic pathway. In the case of severe OGD paradigm, levels of ceramide and sphingomyelin in the lethal OGD group were not significantly different from those of the control group or the lethal OGD group with preconditioning at any time points studied. Treatment with an inhibitor of de novo ceramide synthesis, fumonisin B1, during the ischemic preconditioning period completely blocked preconditioning-induced ischemic tolerance. Moreover, application of a non-cytotoxic concentration of exogenous cell-permeable ceramide produced neuroprotection against lethal OGD. The results suggest that ceramides increased by sublethal OGD preconditioning play an important role in induction of ischemic tolerance.
Neural stem cells (NSCs) arise through neurogenesis, and comprise all newly-formed neurons in the central and peripheral nervous systems. DJ-1 is associated with autosomal recessive familial Parkinson's disease (PD). The relationship between DJ-1 and NSC proliferation may shed light on the underlying pathogenesis of, and potential treatments for, PD. To investigate the relationship between DJ-1 and NSCs, embryonic cortical NSCs were isolated and cultured from E14 fetal rats. Immunocytochemistry, flow cytometry, and immunohistochemistry were applied to evaluate DJ-1 expression in proliferating NSCs. We found that DJ-1 was co-expressed with nestin, a marker of progenitors, during NSC proliferation from days 1—7. The present results suggest that DJ-1 is co-expressed with nestin in NSCs during proliferation.
We reported previously that N-linked glycoproteins were accumulated in the cytosol of the normal aging rat brain, and that one protein had been identified as cathepsin D (Mech. Ageing Dev., 127, 771—778 (2006)). In this study, to elucidate the mechanism of cathepsin D accumulation in the cytosol, we examined the effects of oxidative stress and proteasome inhibition on the apoptosis and subcellular localization of cathepsin D in primary cultured neurons and astrocytes. Using 4′-6-diamidino-2-phenylindole (DAPI)- or Hoechst 33342-staining and annexin V detection, we found that oxidative stress caused by tert-butyl hydroperoxide and proteasome inhibition by lactacystin induced apoptosis in neurons and astrocytes. Furthermore, after cell fractionation, it was demonstrated that cathepsin D was translocated from lysosomes to cytosol under apoptosis-inducing conditions in both cells. These results suggested that oxidative stress and the suppression of proteasome activity triggered the translocation of cathepsin D from lysosomes to cytosol. The possible mechanism of age-related accumulation of cathepsin D in the cytosol of the normal rat brain will be discussed.
Ferulic acid (FA) has been demonstrated to have a remarkable antioxidant activity, the mechanism of FA of protecting human umbilical vein endothelial cells (HUVECs) from radiation induced oxidative stress was investigated in the present study. The oxidative protection of FA was assessed by cellular glutathione (GSH) content, nicotinamide adenine dinucleotide phosphate (NADPH) levels, and reactive oxygen species (ROS) analysis. Nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation was detected using Western blotting. The upstream signaling pathway involved in FA mediated Nrf2 activation was determined by signaling inhibitors. FA significantly increased the transcription of antioxidant related genes such as GCLC (glutamate-cysteine ligase catalytic subunit), GCLM (glutamate-cysteine ligase regulatory subunit), NQO1 (NADPH quinone oxidoreductase-1) and heme oxygenase-1 (HO-1) mRNA in radiated cells, and these changes involved in a significant increase of the intracellular GSH content and the expression of NAPDH. FA evidently promoted Nrf2 translocation into nuclei and increased the intracellular GSH and NADPH levels in radiated cells. Phosphatidylinositol 3-kinase (PI3K) and extracellular signal regulated kinase (ERK) pathways were associated with FA-induced Nrf2 activation. The results suggested that FA-induced Nrf2 activation play key role in cytoprotective effect of FA against oxidative stress via PI3K and ERK signaling pathways.
We previously demonstrated that FGD1, the Cdc42 guanine nucleotide exchange factor (GEF) responsible for faciogenital dysplasia, and its homologue FGD3 are targeted by the ubiquitin ligase SCFFWD1 upon phosphorylation of two serine residues in their DSGIDS motif and subsequently degraded by the proteasome. FGD1 and FGD3 share highly homologous Dbl homology (DH) and adjacent pleckstrin homology (PH) domains, both of which are responsible for GEF activity. However, their function and regulation are remarkably different. Here we demonstrate extracellular signal-responsive translocation of FGD1, but not FGD3. During the wound-healing process, translocation of FGD1 to the leading edge membrane occurs in cells facing to the wound. Furthermore, epidermal growth factor (EGF) stimulates the membrane translocation of FGD1, but not FGD3. As the most striking difference, FGD3 lacks the N-terminal proline-rich domain that is conserved in FGD1, indicating that proline-rich domain may play a crucial role in signal-responsive translocation of FGD1. Indeed, there is a faciogenital dysplasia patient who has a missense mutation in proline-rich domain of FGD1, by which the serine residue at position 205 is substituted with isoleucine. When expressed in cells, the mutant FGD1 with S205/I substitution fails to translocate to the membrane in response to the mitogenic stimuli. Thus we present a novel mechanism by which the activity of FGD1, a GEF for Cdc42, is temporally and spatially regulated in cells.
The Gram-positive bacterium Propionibacterium acnes is the causative agent of acne vulgaris. Antibiotics such as tetracycline and macrolide derivatives are used to treat this skin disease; however, the isolation frequency of antibiotic-resistant P. acnes has been increasing. The anti-P. acnes activity of imidazole antifungal agents was reported more than 20 years ago, and since then, new azole antifungal agents have been marketed. Thus, this study determined the in vitro activities of azole antifungal agents against P. acnes isolated from patients with acne vulgaris. Of the five agents tested, miconazole, ketoconazole, and itraconazole showed concentration-dependent anti-P. acnes activity, including against antibiotic-resistant isolates. Time-kill assay also showed the time-dependent activity of the drugs. Fluconazole and voriconazole showed no anti-P. acnes activity.
Induction of immunotolerance has become a new strategy for treating autoimmune conditions in recent decades. However, so far there is no ideal therapeutics available for clinical use. Medicinal herbs are a promising potential source of immunotolerance inducers. In the current study, we sought first to optimize conditions for a validated cellular model of human Jurkat cells; and then used this model to screen bioactive compounds derived from medicinal plants for inducing T cell anergy in comparison with the effect of well-known T cell anergy inducer, ionomycin. The results showed that passage of the cells, and concentration and stimulation time of ionomycin on the cells could influence the ability of T cell anergy induction. Matrine, a small molecule derived from the root of Sophora flavescens AIT., was demonstrated to be effective in inducing T cell anergy in human Jurkat cells. The cells exposed to matrine showed markedly decreased mRNA expression of interleukin-2, an indicator of T cell anergy, when the cells were stimulated by antigens, anti-OKT3 plus anti-CD28. Mechanistic study showed that ionomycin and matrine could up-regulate the anergy-associated gene expressions of CD98 and Jumonji and activate nuclear factor of activated T-cells (NFAT) nuclear translocation in absence of cooperation of AP-1 in Jurkat cells. Pre-incubation with matrine or ionomycin could also shorten extracellular signal-regulated kinase (ERK) and suppress c-Jun NH2-terminal kinase (JNK) expression on the anergic Jurkat cells when the cells were stimulated with anti-OKT-3 plus anti-CD28 antibodies. Thus, matrine is a strong candidate for further investigation as a T cell immunotolerance inducer.
We investigated the effect of the phenylalkylamine Ca2+ channel inhibitor verapamil on voltage-dependent K+ (Kv) channels in rabbit coronary arterial smooth muscle cells using a whole-cell patch clamp technique. Verapamil reduced the Kv current amplitude in a concentration-depenent manner. The apparent Kd value for Kv channel inhibition was 0.82 μM. Although verapamil had no effect on the activation kinetics, it accelerated the decay rate of Kv channel inactivation. The rate constants of association and dissociation by verapamil were 2.20±0.02 μM−1 s−1, and 1.79±0.26 s−1, respectively. The steady-state activation and inactivation curves were unaffected by verapamil. The application of train pulses increased the verapamil-induced Kv channel inhibition. Furthermore, verapamil increased the recovery time constant, suggesting that the inhibitory effect of this agent was use-dependent. The inhibitory effect of verapamil was not affected by intracellular and extracellular Ca2+-free conditions. Another Ca2+ channel inhibitor, nifedipine (10 μM) did not affect the Kv current, and did not alter the inhibitory effect of verapamil. Based on these results, we concluded that verapamil inhibited Kv current in a state-, time-, and use-dependent manner, independent of Ca2+ channel inhibition.
We previously reported that long-term treatment with some antidepressants at low concentrations upregulates BCL2/adenovirus E1B 19-kDa-interacting protein 3 (BNIP3) mRNA expression in NG108-15 cells without causing cell damage, suggesting that BNIP3 is a candidate of intrinsic depressive disorder-related factor(s). In this study, to clarify the physiologic functions of BNIP3, we investigated whether BNIP3 is actually related to the depressive condition in the brain using learned helplessness (LH) mice, an animal model of depression. Based on the score of escape failure, an index of depression degree, stressed animals were divided into groups with LH and without depressive-like symptoms (i.e., non-depressed phenotype, non-LH). The score of escape failure of the LH group was decreased after 14 d of treatment with imipramine in a dose-dependent manner. BNIP3 mRNA expression was enhanced in both the LH and non-LH groups. Imipramine treatment at 5 and 20 mg/kg/d enhanced BNIP3 mRNA expression only in the LH group but not in non-LH group or non-stressed group. These results raise the possibility that BNIP3 acts as an antistress factor in the brain.
A novel histamine receptor subtype, histamine H3 receptor, mediates inhibition of peripheral autonomic neurotransmission. The present study was designed to examine vascular effects of histamine H3 receptor by using a selective histamine H3 receptor agonist, R-(−)-α methylhistamine (α-methylhistamine), in rat mesenteric resistance arteries. The isolated mesenteric vascular beds were perfused with Krebs solution and perfusion pressure was measured. Active tone was produced by perfusion of Krebs solution containing 7 μM methoxamine. In preparations with intact endothelium, perfusion of α-methylhistamine (1—100 μM) for 1 min produced a concentration-dependent vasodilation. The maximum vasodilation at the highest concentration was approximately 45%. This vasodilation was abolished by endothelium removal and attenuated by histamine H3 receptor antagonists, thioperamide and clobenpropit, but not by chlorpheniramine (histamine H1 receptor antagonist) and cimetidine (histamine H2 receptor antagonist). Nω-nitro-L-arginine methyl ester (L-NAME, nitric oxide (NO) synthase inhibitor), indomethacin (cyclooxygenase inhibitor) and tetraethylammonium (nonselective K+-channel blocker) and high KCl (30 mM) significantly inhibited α-methylhistamine-induced endothelium-dependent vasodilation. These findings suggest that α-methylhistamine induces endothelium-dependent vasodilation mainly via endothelium histamine H3 receptors. It is also suggested that activation of histamine H3 receptors in the endothelium releases mainly NO and partially prostaglandin I2 and endothelium-derived hyperpolarizing factors to induce endothelium-dependent vasodilation.
The aim of the present study was to clarify the involvement of prostaglandin E2 (PGE2) in nasal congestion in Brown Norway (BN) rats. For this purpose, we studied the effects of PGE2 receptor (EP1, EP2, EP3 and EP4) agonists on nasal congestion and sneezing induced by toluene 2,4-diisocyanate (TDI). Enhanced pause (Penh) was increased 1 h (early phase) and 4 h (late phase) after TDI challenge. Sulprostone (an EP3 receptor agonist) inhibited the increase of Penh, an index of nasal congestion, in both early and late phase responses. On the other hand, PGE1 alcohol (an EP4 agonist) increased Penh in the early phase response. Moreover, sulprostone inhibited sneezing, an immediate response by TDI challenge. These results indicate that EP3 receptor is responsible for the relief of nasal congestion in both early and late phase responses, and EP4 receptor is correlated with the development of nasal congestion in the early phase response. In addition, EP3 receptor also participates in sneezing in allergic rhinitis induced by TDI challenge in BN rats.
Dorsal root ganglia (DRG) are recognized as one of the organs which are damaged in peripheral sensory diabetic neuropathy. In an experimental animal model, the alteration of the mRNA expression level of neurotrophins, their receptors and neuronal cytoskeletal protein have been reported. In this study, we examined whether these changes are improved by treatment with the aldose reductase inhibitor, zenarestat, in early-stage diabetic neuropathy of streptozotocin (STZ)-induced diabetic rats. Two weeks after the induction of diabetes mellitus by STZ treatment, zenarestat or a vehicle were given orally for two weeks. After the zenarestat treatment, the mRNA expression levels of neurotrophin receptors and neuronal cytoskeletal proteins in dorsal root ganglia were determined with a real-time polymerase chain reaction (PCR) method. Compared with the expression level of normal rats, a significant increase in Trk-C and Tα1 α-tubulin and a decrease in neurofilament H mRNA expression level were observed in the DRG of STZ rats, while there were no significant changes in Trk-A, Trk-B, p75, neurofilament L, neurofilament M and βIII tubulin mRNA expression. Zenarestat treatment significantly ameliorated the abnormal increase in Trk-C mRNA expression level. These data suggest that hyperactivation of the polyol pathway induces a deficit in neurotropism on peripheral sensory diabetic neuropathy.
Coffee is a popular beverage worldwide with various nutritional benefits. Diterpene cafestol, one of the major components of coffee, contributes to its beneficial effects through various biological activities such as chemopreventive, antitumorigenic, hepatoprotective, antioxidative and antiinflammatory effects. In this study, we examined the precise molecular mechanism of the antiinflammatory activity of cafestol in terms of prostaglandin E2 (PGE2) production, a critical factor involved in inflammatory responses. Cafestol inhibited both PGE2 production and the mRNA expression of cyclooxygenase (COX)-2 from lipopolysaccharide (LPS)-treated RAW264.7 cells. Interestingly, this compound strongly decreased the translocation of c-Jun into the nucleus and AP-1 mediated luciferase activity. In kinase assays using purified extracellular signal-regulated kinase 2 (ERK2) or immunoprecipitated ERK prepared from LPS-treated cells in the presence or absence of cafestol, it was found that this compound can act as an inhibitor of ERK2 but not of ERK1 and mitogen-activated protein kinase kinase 1 (MEK 1). Therefore our data suggest that cafestol may be a novel ERK inhibitor with AP-1-targeted inhibitory activity against PGE2 production in LPS-activated RAW264.7 cells.
Whether tumor progression locus 2 (Tpl2)/cancer Osaka thyroid (Cot) protein kinase participates in osteoclastogenesis from receptor activator of nuclear factor-κB ligand (RANKL)-stimulated monocytes/macrophages remains elusive. To clarify this, a selective and potent inhibitor of Tpl2, 1,7-naphtyridine-3-carbonitrile, was used. When RAW264.7 cells were stimulated with RANKL, Tpl2 was found to be activated. Under this condition, the Tpl2 inhibitor suppressed osteoclastogenesis in a dose-dependent manner. This was due to the blockade of the phosphorylation of mitogen activated protein kinase/ERK kinase (MEK) and extracellular signal-regulated kinase (ERK), but not c-Jun N-terminal kinase (JNK) or p38, concomitant with the down-regulation of the c-Fos and nuclear factor of activated T cells (NFAT)c1 genes. A long period of RANKL-stimulated cell exposure to the inhibitor suppressed osteoclastogenesis as assessed by tartrate-resistant acid phosphatase (TRAP) staining and pit formation on dentin slices. Almost identical results were obtained with macrophage colony-stimulating factor (M-CSF) and RANKL-stimulated bone marrow cells. These findings suggest the possibility that Tpl2 plays a pivotal role in osteoclastogenesis and thus that its inhibitor is useful for investigating the differentiation of monocytes/macrophages to osteoclasts after treatment with RANKL or other stimuli.
Effects of NIP-142, a benzopyran compound which terminates experimental atrial arrhythmia, on potassium channel α-subunits and mouse atrial repolarization were examined. NIP-142 concentration-dependently blocked the outward current through potassium channel α subunits Kv1.5, Kv4.2 and Kv4.3 expressed in Xenopus oocytes. In isolated mouse atrial myocardia, NIP-142 prolonged the action potential duration and effective refractory period, and increased the contractile force. These results suggest that NIP-142 blocks the potassium channels underlying the transient and sustained outward currents, which may contribute to its antiarrhythmic activity.
Mucosal inflammation in ulcerative colitis (UC) is presumed to be regulated primarily by type 2 T helper cell immune responses and mucosal mast cells in the colon are thought to play an important role in the pathogenesis of the mucosal inflammation. Saireito, a Japanese herbal medicine of standardized quality, originating from traditional Chinese medicine (Kampo medicine), is composed of two different Kampo medicines (shosaikoto and goreisan) and is often used for UC in Japan. In this study, we examined the direct effects of these Kampo medicines and their constituents on the antigen-induced degranulation of mucosal-type mast cells. Mucosal-type murine bone marrow-derived mast cells (mBMMCs) were pretreated by these drugs for 24 h, and immunoglobulin E (IgE) receptor-triggered degranulation of mBMMCs was assessed by β-hexosaminidase release. Goreisan showed inhibitory effects on degranulation of mBMMCs in a dose-dependent manner. Among the five constituent medicinal herbs of goreisan, Poria and Polyporus had the inhibitory effects on mBMMCs. Ergosterol, a principal and common component of Poria and Polyporus, also suppressed the degranulation of mBMMCs. Our results provide a molecular basis to explain a portion of the beneficial therapeutic properties of saireito on UC.
The signal transducer and activator of transcription (STAT) family of molecules play a critical role in the signaling of many cytokines. In addition to STAT6, implication of STAT1 and STAT3 in the development of airway hyperresponsiveness (AHR) has also been suggested in allergic bronchial asthma. However, there is little information whether or not antigen challenge really causes the in vivo activation of these STAT molecules in bronchial smooth muscles (BSMs). In the present study, the activations of these STATs were examined in BSMs of mice with allergic bronchial asthma. Male BALB/c mice were sensitized and repeatedly challenged with ovalbumin (OA) antigen. Total protein samples of the left main bronchi were prepared at 3 after the last OA challenge, and Western blot analyses for total and tyrosine-phosphorylated STATs molecules were conducted. In addition to the phosphorylation of STAT6, a significant increase in the level of phosphorylated STAT1 was also observed after the antigen exposure. In contrast, no significant increase in the level of phosphorylated STAT3 was observed in this mouse model of allergic bronchial asthma. The antigen exposure did not change the protein expressions of these STATs themselves. These findings suggest that STAT6 and STAT1, but not STAT3, might be crucial signal transducers in the development of BSM hyperresponsiveness, one of the causes of AHR in asthmatics.
We examined the effects of chondroitinases on the release of dermatan sulfate (DS)-induced arginine amidase (AA) from rabbit ear artery. DS-induced AA release was significantly decreased by treatment with chondroitinase ABC (ABCase) in the rabbit ear artery. On the other hand, Chondroitinase ACII (ACIIase) enhanced spontaneous and DS-induced AA release. Heat-inactivated ABCase and ACIIase did not affect spontaneous and DS-induced AA release. Furthermore, ABCase, but not ACIIase and heat-inactivated chondroitinases, degraded DS. These results indicate that the facilitatory effect of DS-induced AA release from the rabbit ear artery is affected by the molecular size of DS.
Zeolite 4A, synthetic silicate, has been shown to exhibit diverse biological activities such as anti-cancer and anti-oxidant activity. In the present study, we report that the zeolite 4A may improve skin-whitening. We found that zeolite 4A inhibited melanin production in a dose-dependent manner, which has not cytotoxicity. Zeolite 4A also inhibited alpha-melanocyte-stimulating hormone (α-MSH)-induced melanin synthesis in B16F10 cells. Interestingly, zeolite 4A decreased α-MSH-induced tyrosinase activity in B16F10 cells, which did not inhibit tyrosinase activity under cell-free conditions. The results of this study indicate that zeolite 4A may reduce pigmentation by way of an indirect nonenzymatic mechanism. We also found that zeolite 4A decreased α-MSH-induced microphthalmia-associated transcription factor (MITF) and tyrosinase expression and that zeolite 4A induced the activation of extracellular signal-regulated kinase (ERK). These results suggest that the depigmenting effect of zeolite 4A may result from the down-regulation of MITF and tyrosinase expression by increasing ERK activity. The results thus provide evidence that zeolite 4A can be used as a potential skin-whitening agent.
Nitric oxide (NO) and the partial pressure of oxygen (pO2) in the liver were simultaneously quantified in rats with partial hepatic ischemia/reperfusion injury (PHIRI). Real-time NO/pO2 monitoring and immunohistochemical analysis for superoxide dismutase and inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) were performed to evaluate the protective effects of a dihydropyridine-type calcium-channel blocker—CV159—on PHIRI. Serum high-mobility-group box-1 (HMGB-1) was measured to assess cellular necrosis. Moreover, we used in vitro/ex vivo electron paramagnetic resonance spin trapping to assess the hydroxyl radical (·OH)-scavenging activity (OHSA) of CV159 and the liver tissue. The NO levels were significantly higher in CV159-treated rats than in control rats throughout the ischemic phase. Immediately after reperfusion, the levels temporarily increased in waves and then gradually decreased in the treated rats but remained constant in the control rats. pO2 was continually higher in the treated rats. In these rats, hepatic eNOS expression increased, whereas iNOS expression decreased. The treated rats exhibited significantly higher cytosolic and mitochondrial concentrations NOx (NO2+NO3). The serum HMGB-1 levels significantly decreased in the treated rats. Moreover, CV159 directly scavenged ·OH and both mitochondrial and cytosolic OHSA were preserved in the treated rats. Thus, CV159-mediated inhibition of intracellular Ca2+ overloading may effectively minimize organ damage and also have ·OH-scavenging activity and the cytoprotective effects of eNOS-derived NO.
We investigated the association of interleukin-12 (IL-12) with development of dextran sulfate sodium (DSS)-induced colitis in mice, and examined the effects of TJN-419, a synthetic compound derived from acteoside, on this process. Enhanced IL-12 production in lipopolysaccharide (LPS)-stimulated macrophages was dose-dependently inhibited by addition of TJN-419 to culture medium, and this effect was abolished by pretreatment with PD98059, an inhibitor of extracellular-regulated kinase. We then assessed the effect of TJN-419 or a neutralizing antibody against murine IL-12 in a DSS-induced colitis model in C57 BL/6 mice. Colitis was induced by 5% DSS solution given as drinking water. Treatment with the anti-IL-12 antibody was performed intravenously and TJN-419 was administered orally. We also investigated the effect of TJN-419 on erosion in the rectum in a DSS-induced colitis model in rat. The IL-12 level in the rectum was significantly enhanced and the IL-10 level was significantly decreased in animals with DSS-induced colitis compared with untreated controls. Intravenous injection of the anti-IL-12 antibody and oral administration of TJN-419 inhibited clinical symptoms in DSS-induced colitis. TJN-419 also inhibited the increase in IL-12 and suppressed the area of erosion in the rectum in DSS-induced colitis in rats. These results indicate that IL-12 has a possible role in development of DSS-induced colitis and that TJN-419 is effective for treatment of this disease model via inhibition of IL-12 production.
In Ayurveda and Thai traditional medicines, material from Coscinium fenestratum is commonly prescribed as active ingredients with diverse therapeutic purposes. However, C. fenestratum is also a seriously endangered medicinal liana. Thus, its crude material is very rare and is being substituted with substances from Arcangelisia flava or Fibraurea tinctoria (Menispermaceae), which have high morphological similarity. In this current study, nuclear 18S ribosomal RNA (rRNA) gene and nuclear ribosomal DNA internal transcribed spacer (ITS) gene sequences with the polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) technique were exploited to identify these three species. The nuclear 18S rRNA gene sequences of C. fenestratum, A. flava, and F. tinctoria consisted of 1809, 1805, and 1809 base pairs (bps), respectively, while their ITS gene regions were 694, 622, and 631 bps in length, respectively. The 18S rRNA gene of C. fenestratum digested with SmaI restriction enzyme displayed the electrophoresis profile of 729 and 790 bps; for A. flava and F. tinctoria, the digested products showed fragments of 1519 bps. Although the ITS gene regions of A. flava and F. tinctoria had unrecognized sequences with SalI, the SalI-digested ITS of C. fenestratum exhibited fragments of approximately 599 bp. Thus, the 18S rRNA gene and ITS gene sequences with PCR-RFLPs were proven to be powerful molecular markers for identifying C. fenestratum and distinguishing it from the other two Menispermaceae plants.
We examined the binding of various basic drugs to the F1S and A genetic variants of α1-acid glycoprotein (AGP), which were isolated from native human commercial AGP (total AGP) by chromatography on an immobilized copper(II) affinity adsorbent. The values of the dissociation constant (Kd) of some basic drugs with the F1S variant in equilibrium dialysis differed characteristically from those with the A variant. The selective binding to these variants was evaluated by measuring the displacement ratio of dicumarol bound to the F1S variant or that of acridine orange bound to the A variant, using circular dichroism spectroscopy. There was reasonably good agreement between the Kd values and displacement ratios. There was a characteristic difference between the values of inhibition constant (Ki) of basic drugs towards dipyridamole binding to F1S and towards disopyramide binding to A in total AGP. We found that the Ki values for dipyridamole binding were well correlated with the Kd values for the F1S variant, whereas those for disopyramide binding were well correlated with the Kd values for the A variant. In conclusion, the higher the affinity of basic drugs for AGP, the more they inhibit the binding of other basic drugs, and further, the inhibitory potency depends on the selectivity of binding to the AGP variants.
To develop an external preparation of oregonin (ORG) for the treatment of atopic dermatitis (AD), conventional creams (CC) and elastic liposomes (EL) containing ORG have been formulated and examined for their in vitro skin permeation properties and in vivo therapeutic efficacy assessments. EL, consisting of soybean phosphatidylcholine and Tween 80 (85 : 15 w/w %), were of flexible nanocarriers: they were about 130 nm in size and had a 4-fold greater deformability index than conventional liposomes. In a skin permeation study using a Franz diffusion cell mounted with depilated mouse skin, liposomal systems were superior to cream, revealing greater flux values. Both CC and EL were diversified with the addition of Trans-activating transcriptional activator (Tat) peptide, a sort of cell penetrating peptide, and subjected to in vivo efficacy evaluations in NC/Nga mice with AD-like lesions. On clinical observation for skin severity, rapid and profound improvement was observed in the treatment group with Tat-added liposomes (EL/T), showing a significant difference (p<0.05) versus Tat-added cream. The results indicated that EL/T treatment is effective for normalizing the immune-related responses and alleviating AD, evaluated as changes in the levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin (IL)-4, immunoglobulin E (IgE), and eosinophils in skin or blood.
We developed a new electrophysiological method mimicking tear flow to evaluate the epithelial tight junction of rabbit cornea quantitatively. We investigated the effect of tear flow on the corneal damage induced by ophthalmic preservatives using this method. An Ussing chamber system with Ag/AgCl electrodes was used in the electrophysiological experiment. The excised rabbit cornea was mounted in the Ussing chamber and the precorneal solution in the chamber was perfused with a peristaltic pump at the rate of human tear flow. Corneal transepithelial electrical resistance (TEER) was monitored as corneal barrier ability. In the electrophysiological method mimicking tear flow, we observed stable TEER, which rapidly decreased with benzalkonium chloride (BAC), an eye drop preservative. Using this system, we first found that 0.004% BAC decreased corneal TEER reversibly. A high concentration of BAC showed strong irreversible damage to the tight junction. The influence of BAC on corneal TEER was not only concentration-dependent but also tear flow rate-dependent. The electrophysiological method mimicking tear flow was useful to evaluate the corneal barrier quantitatively. Using this method, we clarified that the tear flow was important to protect the corneal damage induced by preservatives.
To clarify the causes of low oral bioavailability (BA) of drugs in cynomolgus monkeys, the experimental method to evaluate the drug permeability and the metabolism in the intestine of cynomolgus monkeys was established. An in situ intestinal perfusion method was performed with blood sampling from both portal and peripheral veins to calculate the intestinal permeability and the metabolism of drugs simultaneously. In all experiments, antipyrine was co-perfused with test drugs as a non-metabolized reference to calculate the individual portal vein blood flow. The effective permeability coefficient (Peff) of acetaminophen and piroxicam were high, and the fraction of dose absorbed from the gastrointestinal tract (Fa) thought to be 1. The intestinal availability (Fg) of acetaminophen and piroxicam were calculated to be 0.39 and 1.09, respectively. The Fa*Fg values of these drugs calculated from the perfusion study almost coincided with those obtained from the in vivo PK analysis in the previous report. In addition, the Fg values of verapamil and midazolam were calculated as 0.16 and 0.26, respectively, suggesting these drugs were metabolized extensively in the intestine after oral administration to cynomolgus monkey. Furthermore, the Fg values of these drugs were increased to 0.8—0.85 in the presence of 1-aminobenzotriazole, a typical cytochrome P450 (CYP) inhibitor. In conclusion, it was clarified that acetaminophen, verapamil and midazolam were metabolized extensively in the intestine of cynomolgus monkeys. This intestinal perfusion method is considered to be useful to identify the factors of species difference in the oral absorption of drugs.
Successful avoidance of the immune surveillance system is critical for the development of a blood–borne metastasis. Previous findings suggest that experimental tumor metastasis was enhanced in senescence-accelerated mice prone 10 (SAMP10) due to a reduction in immune surveillance potential with age. In the present study, water containing green tea (GT)-catechins was freely given to SAMP10 mice, and the chemopreventive effect of GT-catechin intake on tumor metastasis was examined. Natural killer cell activity, which is an indicator of immune surveillance potential and is reduced in control mice with age, was maintained by GT-catechin intake. The early accumulation of lung-metastatic K1735M2 melanoma cells in lungs after intravenous injection of the cells and subsequent experimental lung metastasis was investigated in mice given GT-catechins. The accumulation at 6 and 24 h after injection of K1735M2 cells was significantly suppressed, and the number of lung-metastatic colonies was significantly reduced, in comparison with those in control mice. The results suggest that GT-catechin intake prevented the experimental tumor metastasis in aged SAMP10 mice via its inhibition of a reduction in immune surveillance potential with age.
The combination of diabetes and hyperlipidemia promotes the development of atherosclerosis. Therefore, it is important for diabetic patients to control blood fat. 3-Hydroxy-3-methylglutaryl enzyme A (HMG-CoA) reductase inhibitors (statins), like pravastatin, are frequently administered to diabetic patients for this purpose. Although the alterations of metabolic enzymes and transporters in the diabetic liver maybe change the disposition of pravastatin, the effect has not been fully investigated. In the present study, we investigated the disposition of pravastatin and the mRNA expression of transporters in the liver. Pravastatin (5 mg·kg−1 body weight) was administered intravenously to diabetic rats, and the pravastatin concentrations in the plasma, urine, and bile were measured by high-performance liquid chromatography. Changes in the mRNA expressions of multidrug resistance-associated protein 2 (MRP2) and organic anion transporting polypeptide 2 (OATP2) in the liver were also estimated using reverse transcriptase-polymerase chain reaction (RT-PCR). We found that the plasma pravastatin concentration was lower in the diabetic rat because the transportation of pravastatin into hepatocytes was promoted along with increased expression of OATP2. The biliary excretion ratio of pravastatin was significantly lower in the diabetic rat because the pravastatin transportation into bile was reduced along with the decreased expression of MRP2. To clarify these phenomena, the analysis of mRNA expression using real-time PCR and the measurement of the amount and the activity of proteins are necessary in future study.