Potentiation of flutamide-induced hepatotoxicity in mice by Xian-Ling-Gu-Bao through induction of CYP1A2.

ETHNOPHARMACOLOGICAL RELEVANCE: Xian-Ling-Gu-Bao (XLGB) Fufang is herbal formula widely used to treat osteoporosis and other bone disorders. Because of its commonality in the clinical use, there is a safety concern over the use of XLGB combined with other androgen deprivation therapy (ADT) drugs such as flutamide (FLU) that is associated with reduced bone density. To date, there have been no evaluations on the side effects of the drug-drug interaction between XLGB and FLU. AIM OF THE STUDY: The present study was designed to investigate the hepatotoxicity in the context of the combined treatment of XLGB and FLU in a mouse model, and to determine whether the metabolic activation of FLU through induction of CYP1A2 plays a role in the increased hepatoxicity caused by the combination of XLGB and FLU. MATERIALS AND METHODS: C57 mice were administered with either XLGB (6,160 mg/kg), FLU (300 mg/kg), or with the combination of the two drugs. Animals were treated with XLGB for 5 days before the combined administration of XLGB and FLU for another 4 days. The serum of mice from single or the combined administration groups was collected for biochemical analysis. The mouse liver was collected to examine liver morphological changes, evaluate liver coefficient, as well as determine the mRNA expression of P450 isozymes (Cyp1a2, Cyp3a11 and Cyp2c37). For metabolism analysis, mice were treated with XLGB, FLU, or the combination of XLGB and FLU for 24 h. The urine samples were collected for the analysis of FLU-NAC conjugate by UPLC-Q-Orbitrap MS. The liver microsomes were prepared from fresh livers to determine the activity of metabolizing enzyme CYP1A2. RESULTS: The combined treatment of XLGB and FLU caused loss of mice body weight and elicited significant liver toxicity as evidenced by an increased liver coefficient and serum lactate dehydrogenase (LDH) activity as well as pathological changes of fatty lesion of liver tissue. FLU increased hepatic expression of Cyp1a2 mRNA that was further elevated in the liver of mice when administered with both FLU and XLGB. Treatment of FLU resulted in an increase in the expression of Cyp3a11 mRNA that was negated when mice were co-treated with FLU and XLGB. No significant difference in Cyp2c37 mRNA expression was observed among the different treatment groups as compared to the control. Analysis of metabolic activity showed that the combined administration caused a synergic effect in elevating the activity of the CYP1A2 enzyme. Mass spectrometry analysis identified the presence of FLU reactive metabolite derived FLU-NAC conjugate in the urine of mice treated with FLU. Strikingly, about a two-fold increase of the FLU-NAC conjugate was detected when treated with both FLU and XLGB, indicating an elevated amount of toxic metabolite produced from FLU in the present of XLGB. CONCLUSION: FLU and XLGB co-treatment potentiated FLU-induced hepatoxicity. This increased hepatoxicity was mediated through the induction of CYP1A2 activity which in turn enhanced bioactivation of FLU leading to over production of FLU-NAC conjugate and oxidative stress. These results offer warnings about serious side effects of the FLU-XLGB interaction in the clinical practice.

Dendrobium nobile Lindl. alkaloids alleviate Mn-induced neurotoxicity via PINK1/Parkin-mediated mitophagy in PC12 cells.

Modern pharmacological studies have demonstrated that Dendrobium nobile Lindl. Alkaloids (DNLA), the main active ingredients of Dendrobium nobile, is valuable as an anti-aging and neuroprotective herbal medicine. The present study was designed to determine whether DNLA confers protective function over neurotoxicant manganese (Mn)-induced cytotoxicity and the mechanism involved. Our results showed that pretreatment of PC12 cells with DNLA alleviated cell toxicity induced by Mn and improved mitochondrial respiratory capacity and oxidative status. Mn treatment increased apoptotic cell death along with a marked increase in the protein expression of Bax and a decrease in the expression of Bcl-2 protein, all of which were noticeably reversed by DNLA. Furthermore, DNLA significantly abolished the decrease in protein levels of both PINK1 and Parkin, and mitigated the increased expression of autophagy marker LC3-II and accumulation of p62 caused by Mn. These results demonstrate that DNLA inhibits Mn induced cytotoxicity, which may be mediated through modulating PINK1/Parkin-mediated autophagic flux and improving mitochondrial function.

Cortex dictamni-induced liver injury in mice: The role of P450-mediated metabolic activation of furanoids.

Many furan containing compounds have been reported to be toxic resulted from the metabolic activation of the furan ring to reactive metabolite (RM). Cortex Dictamni (CD), a widely used herbal medicine, has been reported to cause severe even fatal hepatotoxicity. The injurious components and mechanism of CD-induced liver injury remain unclear. Our preliminary study showed that dictamnine, one major furanoid in CD, caused mouse liver injury via its reactive epoxide metabolite. Besides dictamnine, the major components of CD are series of bioactivation-alerting furanoids. Thus, we hypothesize that series of furanoids in CD may undergo metabolic activation and play a key role in CD-induced liver injury. Here, a single oral dose of 60 g/kg ethanol extract of CD (ECD) caused severe hepatocellular necrosis in mice at 24 h post-dose. ECD-induced liver injury showed a dose- and time-dependent manner. The hepatotoxic effects could be completely abolished by P450 nonselective inhibitor 1-aminobenzotriazole (ABT) and strongly modulated by other P450 modulators. The furanoids-concentrated fraction of ECD was responsible for the hepatotoxicity. At least ten furanoids with high abundance in ECD, such as obakunone, dictamnine, fraxinellone, limonin, were found to be metabolized to reactive epoxide or cis-enedione. The RM levels were consistent with the liver injury degree. Multiple furanoids, rather than single one, cooperatively contributed to the hepatotoxicity. ECD-induced liver injury could be reproduced by a mixture of pure furanoids. In summary, this study provides toxic component profiles of CD and demonstrates that P450-mediated bioactivation of multiple furanoids is responsible for CD-induced liver injury.

New insights and rethinking of cinnabar for chemical and its pharmacological dynamics.

Cinnabar is an attractive mineral with many different uses. It is reported that cinnabar is one of the traditional Chinese's medicines extensively use. The main objective of this critical review is to identify the current overview, concept and chemistry of cinnabar, which includes the process developments, challenges, and diverse options for pharmacology research. It is used as a medicine through probable toxicity, especially when taking overdoes. This review is the first to describe the toxicological effects of cinnabar and its associated compounds. Nuclear magnetic resonance (NMR) dependent metabolomics could be useful for examination of the pharmaceutical consequence. The analysis indicated that the accurate preparation methods, appropriate doses, disease status, ages with drug combinations are significant factors for impacting the cinnabar toxicity. Toxicologically, synthetic mercury sulfide or cinnabar should be notable for mercuric chloride, mercury vapor and methyl mercury for future protection and need several prominent advancements in cinnabar research.

Alkaloids of dendrobium nobile lindl. Altered hepatic lipid homeostasis via regulation of bile acids.

ETHNOPHARMACOLOGICAL RELEVANCE: Accumulation of hepatic lipid promotes systemic metabolic dysfunction and results in fatty liver. Our previous studies have shown that the alkaloids of Dendrobium nobile Lindl. (DNLA) could regulate the lipid metabolism gene expression in livers of mice. However, the protective effects on hepatic lipid homeostasis and the underlying mechanisms are still unclear. MATERIALS AND METHODS: The C57BL/6 male mice were randomly divided into four groups, including control group, model group, DNLA treatment group, and simvastatin positive control group. Mice in the control group and the other three groups were fed with control diet and high fat diet during the full course of this study, respectively. Hepatic lipid accumulation was induced by HFD in mice after 18 weeks of feeding. DNLA (15 mg/kg) and simvastatin (20 mg/kg) were administrated intragastrically in the DNLA treatment group and simvastatin positive control group for another 18 weeks, respectively. HE staining and Oil-Red-O staining of liver tissues were observed. TC and TG levels in liver were assayed. The amount of major bile acids in mice livers were quantified by UPLC-MS. Expression levels of genes were tested by the real-time PCR. RESULTS: The results of HE staining and Oil-Red-O staining showed that DNLA could improve hepatic lipid homeostasis. DNLA significantly decreased liver TC and TG levels in the DNLA group. Moreover, the UPLC-MS analysis showed that DNLA did not only influence the hepatic bile acid quantity but did raise the hydrophilicity. Compared with the model group, DNLA decreased the hepatic levels of several free bile acids, including LCA, DCA, CA, and CDCA, and increased most important taurine-conjugated bile acids levels in liver, including TMCAs, TCDCA, TUDCA, and THDCA. In addition, DNLA also decreased the CA/CDCA ratio. The gene expression levels of Cyp27a1, Cyp3a11, Fxr, and Shp were up-regulated in DNLA treatment group. CONCLUSION: DNLA may improve the hepatic abnormal lipid profile of HFD-fed mice via two pathways: (1) enhancing the taurine-conjugated bile acids which are highly hydrophilic and contribute to the excretion of cholesterol; (2) decreasing the CA/CDCA ratio which is positively related to cholesterol absorption.

Oleanolic acid reprograms the liver to protect against hepatotoxicants, but is hepatotoxic at high doses.

Oleanolic acid (OA) is a triterpenoid that exists widely in fruits, vegetables and medicinal herbs. OA is included in some dietary supplements and is used as a complementary and alternative medicine (CAM) in China, India, Asia, the USA and European countries. OA is effective in protecting against various hepatotoxicants, and one of the protective mechanisms is reprogramming the liver to activate the nuclear factor erythroid 2-related factor 2 (Nrf2). OA derivatives, such as CDDO-Im and CDDO-Me, are even more potent Nrf2 activators. OA has recently been shown to also activate the Takeda G-protein-coupled receptor (TGR5). However, whereas a low dose of OA is hepatoprotective, higher doses and long-term use of OA can produce liver injury, characterized by cholestasis. This paradoxical hepatotoxic effect occurs not only for OA, but also for other OA-type triterpenoids. Dose and length of time of OA exposure differentiate the ability of OA to produce hepatoprotection vs hepatotoxicity. Hepatotoxicity produced by herbs is increasingly recognized and is of global concern. Given the appealing nature of OA in dietary supplements and its use as an alternative medicine around the world, as well as the development of OA derivatives (CDDO-Im and CDDO-Me) as therapeutics, it is important to understand not only that they program the liver to protect against hepatotoxic chemicals, but also how they produce hepatotoxicity.

Dictamnine-induced hepatotoxicity in mice: the role of metabolic activation of furan.

Cortex Dictamni is extensively used as an herbal medicine worldwide, but is believed to induce hepatotoxicity and even causes mortality in many Asian and European countries. As the most abundant furoquinoline alkaloid ingredient of Cortex Dictamni, dictamnine (DIC) can be metabolically activated by CYP3A to an epoxide metabolite, which possesses the potential to induce hepatotoxicity by covalent binding with proteins. As yet, the hepatotoxicity of DIC and the role played by metabolic activation remain unknown. Here, we found that DIC caused acute liver injury in a time- and dose-dependent manner in mice. The hepatic and urinary DIC epoxide intermediates were observed in DIC-treated mice. Ketoconazole, a CYP3A inhibitor, significantly reduced the hepatotoxicity of DIC and inhibited the formation of reactive metabolites of DIC. Moreover, treatment with 2,3-dihydro-DIC, a DIC analog synthesized by selective reduction of the furan moiety, produced no hepatotoxicity in mice, and no reactive metabolite was formed, suggesting a structural necessity of furan moiety in DIC hepatotoxicity. A time course of gradual hepatic glutathione consumption was observed in DIC-treated mice, while depletion of hepatic glutathione by L-buthionine-S,R-sulfoximine enhanced the hepatotoxicity of DIC. Collectively, this study demonstrates that DIC induces acute hepatocellular injury in mice, and that metabolic activation of furan plays a crucial role in DIC-induced hepatotoxicity.

A review of cinnabar (HgS) and/or realgar (As4S4)-containing traditional medicines.

ETHNOPHARMOCOLOGICAL RELEVANCE: Herbo-metallic preparations have a long history in the treatment of diseases, and are still used today for refractory diseases, as adjuncts to standard therapy, or for economic reasons in developing countries. AIM OF THE REVIEW: This review uses cinnabar (HgS) and realgar (As4S4) as mineral examples to discuss their occurrence, therapeutic use, pharmacology, toxicity in traditional medicine mixtures, and research perspectives. MATERIALS AND METHODS: A literature search on cinnabar and realgar from PubMed, Chinese pharmacopeia, Google and other sources was carried out. Traditional medicines containing both cinnabar and realgar (An-Gong-Niu-Huang Wan, Hua-Feng-Dan); mainly cinnabar (Zhu-Sha-An-Shen Wan; Zuotai and Dangzuo), and mainly realgar (Huang-Dai Pian; Liu-Shen Wan; Niu-Huang-Jie-Du) are discussed. RESULTS: Both cinnabar and realgar used in traditional medicines are subjected to special preparation procedures to remove impurities. Metals in these traditional medicines are in the sulfide forms which are different from environmental mercurials (HgCl2, MeHg) or arsenicals (NaAsO2, NaH2AsO4). Cinnabar and/or realgar are seldom used alone, but rather as mixtures with herbs and/or animal products in traditional medicines. Advanced technologies are now used to characterize these preparations. The bioaccessibility, absorption, distribution, metabolism and elimination of these herbo-metallic preparations are different from environmental metals. The rationale of including metals in traditional remedies and their interactions with drugs need to be justified. At higher therapeutic doses, balance of the benefits and risks is critical. Surveillance of patients using these herbo-metallic preparations is desired. CONCLUSION: Chemical forms of mercury and arsenic are a major determinant of their disposition, efficacy and toxicity, and the use of total Hg and As alone for risk assessment of metals in traditional medicines is insufficient.

Activation of intestinal GR-FXR and PPARα-UGT signaling exacerbates ibuprofen-induced enteropathy in mice.

Nonsteroidal anti-inflammatory drugs (NSAIDs)-induced small intestinal injury (enteropathy) occurs in about two-thirds of regular NSAID users. To date, there is no proven-effective treatment for NSAID enteropathy, and its underlying mechanism remains obscure. The present study showed that glucocorticoids are an important determinant of NSAID enteropathy. High dose dexamethasone (DEX, 75 mg/kg) markedly exacerbated the acute toxicity of ibuprofen (IBU, 200 mg/kg) in the small intestine of mice, which was not due to the pregnane-X-receptor pathway. Instead, glucocorticoid receptor (GR) mediated the effect of DEX (5 mg/kg) on both the acute (200 mg/kg) and 7-day repeated-dose (50 mg/kg) toxicity of IBU in the small intestine. Combined treatment of DEX (5 mg/kg) and IBU (50 mg/kg) synergistically repressed the intestinal farnesoid X receptor (FXR)-cystathionine-γ-lyase signaling, which was accompanied with an elevation in the biliary excretion of bile acids, especially the FXR antagonist tauro-ß-muricholic acid. DEX (5 mg/kg) also activated intestinal peroxisome proliferator-activated receptor α (PPARα)-UDP-glucuronosyltransferase (UGT) pathway, which increased the formation and enterohepatic circulation of IBU-acyl glucuronide. Furthermore, DEX (5 mg/kg) and IBU (50 mg/kg) altered the intestinal microbial composition, characterized with a marked decrease in Actinobacteria. To conclude, the present study for the first time suggests that glucocorticoids play vital roles in control of IBU enteropathy via intestinal GR-FXR and PPARα-UGT signaling.

[Effect of Zuotai and HgS on gene expression of drug-metabolizing enzymes in livers of mice].

Zuotai and cinnabar(96%HgS) are contained in many traditional medicines. To examine their potential effects on drug metabolism genes, mice were orally given Zuotai or HgS at doses of 10, 30, 100, 300 mg•kg⁻¹ for 7 days. HgCl2(33.6 mg•kg⁻¹) was gavaged for control. Twenty-four hour later after the last administration, livers were collected, and expressions of genes related to metabolic enzymes and transporters were examined. Zuotai and HgS had no effects on major phase-1, phase-2 and transporter genes; HgCl2 increased the expressions of CYP2B10, CYP4A10, OATP1A4, UGT1A1, UGT2A3, SULT1A1, SULT2A1, MRP1, MRP3 and MRP4; expression of OATP1A1 was decreased by HgCl2, but not by Zuotai and HgS. Therefore, Zuotai and HgS have different adverse effects on drug-metabolizing genes from HgCl2.

Dendrobium nobile Lindl. alkaloids regulate metabolism gene expression in livers of mice.

OBJECTIVES: In our previous studies, Dendrobium nobile Lindl. alkaloids (DNLA) has been shown to have glucose-lowering and antihyperlipidaemia effects in diabetic rats, in rats fed with high-fat diets, and in mice challenged with adrenaline. This study aimed to examine the effects of DNLA on the expression of glucose and lipid metabolism genes in livers of mice. METHODS: Mice were given DNLA at doses of 10-80 mg/kg, po for 8 days, and livers were removed for total RNA and protein isolation to perform real-time RT-PCR and Western blot analysis. KEY FINDINGS: Dendrobium nobile Lindl. alkaloids increased PGC1α at mRNA and protein levels and increased glucose metabolism gene Glut2 and FoxO1 expression. DNLA also increased the expression of fatty acid ß-oxidation genes Acox1 and Cpt1a. The lipid synthesis regulator Srebp1 (sterol regulatory element-binding protein-1) was decreased, while the lipolysis gene ATGL was increased. Interestingly, DNLA increased the expression of antioxidant gene metallothionein-1 and NADPH quinone oxidoreductase-1 (Nqo1) in livers of mice. Western blot on selected proteins confirmed these changes including the increased expression of GLUT4 and PPARα. CONCLUSIONS: DNLA has beneficial effects on liver glucose and lipid metabolism gene expressions, and enhances the Nrf2-antioxidant pathway gene expressions, which could play integrated roles in regulating metabolic disorders.

The Tibetan medicine Zuotai influences clock gene expression in the liver of mice.

Background. The circadian clock is involved in drug metabolism, efficacy and toxicity. Drugs could in turn affect the biological clock as a mechanism of their actions. Zuotai is an essential component of many popular Tibetan medicines for sedation, tranquil and "detoxification," and is mainly composed of metacinnabar (ß-HgS). The pharmacological and/or toxicological basis of its action is unknown. This study aimed to examine the effect of Zuotai on biological clock gene expression in the liver of mice. Materials and methods. Mice were orally given Zuotai (10 mg/kg, 1.5-fold of clinical dose) daily for 7 days, and livers were collected every 4 h during the 24 h period. Total RNA was extracted and subjected to real-time RT-PCR analysis of circadian clock gene expression. Results. Zuotai decreased the oscillation amplitude of the clock core gene Clock, neuronal PAS domain protein 2 (Npas2), Brain and muscle Arnt-like protein-1 (Bmal1) at 10:00. For the clock feedback negative control genes, Zuotai had no effect on the oscillation of the clock gene Cryptochrome (Cry1) and Period genes (Per1-3). For the clock-driven target genes, Zuotai increased the oscillation amplitude of the PAR-bZip family member D-box-binding protein (Dbp), decreased nuclear factor interleukin 3 (Nfil3) at 10:00, but had no effect on thyrotroph embryonic factor (Tef); Zuotai increased the expression of nuclear receptor Rev-Erbα (Nr1d1) at 18:00, but had little influence on the nuclear receptor Rev-Erbß (Nr1d2) and RORα. Conclusion. The Tibetan medicine Zuotai could influence the expression of clock genes, which could contribute to pharmacological and/or toxicological effects of Zuotai.

[Distinct effect of Wansheng Huafeng Dan containing ardisia crenata on renal transporters, mercury accumulation and Kim-1 expression from mercuric chloride].

To study the effect of Wansheng Huafeng Dan (WSHFD) and mercuric chloride on renal mercury (Hg) extraction transporters (Oat1, Oct2), renal mercury excretion transporters (Mrp4, Mate2K), renal mercury accumulation and kidney injury molecule-1 (Kim-1). The ancient prescription of WSHFD containing 10-fold Hg caused much lower renal mercury accumulation and renal toxicity than HgCl2 in rats, with less effect on renal transporters than HgCl2. The above indicators had no significant difference in WSHFDO, WSHFD2 and WSHFD3 groups, indicating no effect of WSHFD with reduced or no cinnabar.

Effect of icariin on UDP-glucuronosyltransferases in mouse liver.

Icariin is a flavonol glycoside isolated from Epimedium genus and has been used in the treatment of sexual dysfunction and osteoporosis. Our laboratory has shown that icariin is beneficial in brain disorders and cardiovascular diseases. Since icariin is widely used with other herbs and drugs, to understand its potential herb-drug interactions is of importance. Recently, icariin was shown to inhibit UDP-glucuronosyltransferases, particularly the Ugt1 family enzymes in vitro, but little is known about such effects in vivo. This study investigated the effects of icariin on the expression of UDP-glucuronosyltransferases and cytochrome P450 enzymes in the livers of mice. Adult mice were treated with icariin at doses of 0, 40, 80, 160, and 320 mg/kg, p. o., for 7 days. Phenobarbital (120 mg/kg, p.o.) and rifampin (360 mg/kg, p. o.) were given twice daily for 3 days as positive controls. The livers were removed to determine UDP-glucuronosyltransferase activity and total RNA isolation. The UDP-glucuronosyltransferase activities towards 2-aminophenol were basically unaltered by the treatments. The expression of Cyp2b10 was increased 35-fold by phenobarbital, and Cyp3a11 was increased 4.5-fold by rifampin. Icariin did not affect Cyp2b10 and Cyp3a11 expression, but unexpectedly increased Cyp4a14 expression. Both phenobarbital and rifampin increased Ugt1a1, Ugt1a6, Ugt1a9, and icariin but did not show any suppressive effects on the Ugt1 family genes. Icariin at the highest dose (320 mg/kg) slightly increased Ugt2b1, Ugt2b5, and Ugt2b36. These findings indicate that icariin did not suppress UDP-glucuronosyltransferase expression, instead, it increased the mRNA of Cyp4a14 and slightly increased Ugt2b isoforms in mouse livers.

Alkaloids enriched extract from Dendrobium nobile Lindl. attenuates tau protein hyperphosphorylation and apoptosis induced by lipopolysaccharide in rat brain.

Neurofibrillary tangles, one of the characteristic pathological features of Alzheimer's disease (AD), are composed of paired helical filaments mainly with hyperphosphorylated tau protein. Inhibition of the hyperphosphorylation of tau protein is an effective therapy for AD. The current study was designed to investigate the protective effects of alkaloids enriched extract from Dendrobium Nobile Lindl. (EDNLA), a Chinese medicinal herb, on hyperphosphorylation of tau protein in AD brain. Rats were administrated intragastrically with different doses of DNLA (20, 40 mg/kg) every 8h for one day, followed by lipopolysaccharide (LPS, 100 µg) injecting into the bilateral ventricle. Two hours later, the hippocampi of each group were collected to examine the hyperphosphorylated tau protein by western blotting. Additional rats were treated by EDNLA thrice daily for one week, to examine the effects on LPS-induced apoptosis in the brain. LPS injection significantly increased the expression of hyperphosphorylated tau protein at Ser396, Ser199-202, Ser404, Thr231, Thr205 sites and GSK-3ß increased, LPS also induced apoptosis in the brain. EDNLA dramatically ameliorated these abnormal changes (P<0.05). The present study demonstrated that EDNLA attenuates LPS-induced hyperphosphorylation of tau protein in rat's hippocampus and protects against LPS-induced apoptosis in rat brain.

Rutaecarpine effects on expression of hepatic phase-1, phase-2 metabolism and transporter genes as a basis of herb-drug interactions.

ETHNOPHARMACOLOGICAL RELEVANCE: Rutaecarpine is an alkaloid of Evodia rutaecarpa which is traditionally used to treat human diseases. Rutaecarpine has been used in combination with other drugs in the treatment of disorders and found to produce herb-drug interactions. The basis of these herb-drug interactions is not completely understood. AIM OF STUDY: To examine the effects of rutaecarpine on the expression of drug processing genes, including Phase-1 (P450 enzyme genes), Phase-2 (glucuronidation and sulfation genes) and Phase-3 (drug transporters) in liver of mice. MATERIALS AND METHODS: Mice were orally administered rutaecarpine at the doses of 10, 20, and 30 mg/kg for consecutive 7 days. Twenty-four hours after the last dose, blood and liver were collected. Total RNA was isolated, purified, and subjected to real-time RT-PCR analysis of genes of interest. RESULTS: Rutaecarpine administration induced Cyp1a2, 2b10 and 2e1 as previously reported. Cyp3a11 and Cyp4a10 were also induced. For phase-2 enzyme genes, rutaecarpine increased glucuronyltransferases (Ugt1a1 and Ugt1a6), but had no effects on sulfotransferase (Sult1a1 and Sult1b1). Most interestingly, rutaecarpine increased hepatic uptake of organic anion transporting peptides (Oatp1a1, Oayp1a4, Oatp1b2, and Oatp2b1) and induced efflux transporter such as multidrug resistance-associated proteins (Mrp1, Mrp2, Mrp3, and Mrp4), especially at the doses of 20mg/kg and above. CONCLUSION: The interactions of rutaecarpine with drugs involve not only the induction of cytochrome P450 enzyme genes, but also the induction of hepatic transporters and phase-2 enzyme genes. The effects of rutaecarpine on these drug processing genes could play integrated roles in producing herb-drug interactions.

Resveratrol protects cortical neurons against microglia-mediated neuroinflammation.

Neuroinflammation is closely associated with the pathogenesis of neurological disorders. The hallmark of neuroinflammation is considered to be microglial activation. Therefore, inhibition of microglial activation might hold a promising therapy for neurological disorders. Resveratrol, a natural non-flavonoid polyphenol found in grapes and red wine, has been recognized as a bioactive agent with potential benefit for health. Several lines of evidence show that resveratrol could exert neuroprotection against ischemia, seizure, and neurodegenerative diseases. However, the mechanisms underlying its beneficial neuroprotective effects are poorly defined. Here, by using rat primary cortical neuron-glia cultures, results showed that resveratrol attenuated lipopolysaccharide (LPS)-induced cortical neurotoxicity. Further studies revealed that microglia were responsible for resveratrol-mediated neuroprotection. Resveratrol significantly inhibited LPS-induced microglial activation and subsequent production of multiple pro-inflammatory and cytotoxic factors such as tumor necrosis factor-α, nitric oxide, and interleukin-1ß. Collectively, resveratrol produced neuroprotection against microglia-induced neurotoxicity. Thus, resveratrol might represent a potential benefit for the treatment of inflammation-related neurological disorders.

Resveratrol Produces Neurotrophic Effects on Cultured Dopaminergic Neurons through Prompting Astroglial BDNF and GDNF Release.

Increasing evidence indicated astroglia-derived neurotrophic factors generation might hold a promising therapy for Parkinson's disease (PD). Resveratrol, naturally present in red wine and grapes with potential benefit for health, is well known to possess a number of pharmacological activities. Besides the antineuroinflammatory properties, we hypothesized the neuroprotective potency of resveratrol is partially due to its additional neurotrophic effects. Here, primary rat midbrain neuron-glia cultures were applied to investigate the neurotrophic effects mediated by resveratrol on dopamine (DA) neurons and further explore the role of neurotrophic factors in its actions. Results showed resveratrol produced neurotrophic effects on cultured DA neurons. Additionally, astroglia-derived neurotrophic factors release was responsible for resveratrol-mediated neurotrophic properties as evidenced by the following observations: (1) resveratrol failed to exert neurotrophic effects on DA neurons in the cultures without astroglia; (2) the astroglia-conditioned medium prepared from astroglia-enriched cultures treated with resveratrol produced neurotrophic effects in neuron-enriched cultures; (3) resveratrol increased neurotrophic factors release in the concentration- and time-dependent manners; (4) resveratrol-mediated neurotrophic effects were suppressed by blocking the action of the neurotrophic factors. Together, resveratrol could produce neurotrophic effects on DA neurons through prompting neurotrophic factors release, and these effects might open new alternative avenues for neurotrophic factor-based therapy targeting PD.

Role of cinnabar and realgar of WSHFD in protecting against LPS-induced neurotoxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: Wan-Sheng-Hua-Feng-Dan (WSHFD) is a traditional Chinese medicine used for the treatment of neurological disorders. Cinnabar (HgS) and realgar (As(4)S(4)) are included in WSHFD. Are they remedies or poisons? AIM OF STUDY: To investigate the role of cinnabar and realgar in the protective effects of WSHFD on lipopolysaccharide (LPS)-induced neurotoxicity. MATERIALS AND METHODS: Rat primary midbrain neuron-glia cultures were used to explore the effects of WSHFD on LPS-induced dopamine (DA) neurodegeneration. The experiment was randomly divided into control, LPS, LPS+removed (cinnabar and realgar in WSHFD were removed), LPS+reduced (cinnabar and realgar in WSHFD were reduced by 65%) and LPS+original (10% cinnabar and 10% realgar in WSHFD) groups. Dopaminergic neurotoxicity was assessed by [(3)H]DA uptake assay and the quantification of tyrosine hydroxylase (TH)-positive neurons. Microglial activation was evaluated using an anti-OX-42 antibody. The release of intracellular reactive oxygen species (ROS) was quantified via the DCFH-DA probe. The transcripts and production of pro-inflammatory factors were examined by real-time RT-PCR analysis and ELISA, respectively. RESULTS: WSHFD (original) significantly attenuated LPS-induced decrease of DA uptake capacity and TH-positive neuron number, inhibited microglial activation, decreased LPS-induced ROS production, ameliorated LPS-induced elevations of the mRNA expressions of TNFα, iNOS, IL-1ß and COX-2 and the subsequent production of TNFα, NO, IL-1ß and PGE(2) in neuron-glia cultures. However, WSHFD (removed) and (reduced) failed to protect against LPS-induced neurotoxicity. CONCLUSION: Cinnabar and realgar were active ingredients of WSHFD in producing protective effects against LPS-induced neurotoxicity.

Evaluation of hepatotoxicity potential of cinnabar-containing An-Gong-Niu-Huang Wan, a patent traditional Chinese medicine.

An-Gong-Niu-Huang Wan (AGNH) is a patent traditional Chinese medicine for brain disorders. It contains 10% cinnabar (HgS). Hg is known to produce toxicity to the kidney, brain and liver. Is AGNH safe? Liver is a major organ for drug metabolism, whether the long-term use of AGNH would affect hepatic P450 enzymes is unknown. To address these concerns, mice were given orally cinnabar (300mg/kg), cinnabar-containing AGNH daily for 44days, and liver toxicity was examined and compared with that of methylmercury (MeHg, 2.6mg/kg) and mercuric chloride (HgCl(2), 32mg/kg). Serum aminotransferases were increased by MeHg and HgCl(2) only. Histopathology showed more severe liver damage in MeHg- and HgCl(2)-treated mice than in the cinnabar and AGNH groups. Accumulation of Hg in MeHg- and HgCl(2)-treated mice was 96- and 71-fold higher than controls, respectively, but was only 2-fold after cinnabar and AGNH administration. Expressions of metallothionein-1 and heme oxygenase-1, biomarkers for Hg toxicity, were increased by MeHg and HgCl(2,) but were not altered in cinnabar- and AGNH-treated mice. Expression of hepatic cytochrome P450 genes, such as Cyp1a1, Cyp1b1 and Cyp4a10 was increased only after MeHg and HgCl(2), and the expressions of Cyp3a11and Cyp3a25 were increased by all treatments, indicating the potential Hg-drug interactions after long-term use of cinnabar-containing traditional medicines. Taken together, the results demonstrate that AGNH is much less hepatotoxic than common mercurials, and that the use of total Hg content to evaluate the toxicity of cinnabar-containing traditional Chinese medicines appears to be inappropriate.