[Determination of concentrations and toxicokinetics of triptolide in plasma and liver of mice by UHPLC-MS/MS].

This study aims to establish an ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS) method for determining the concentrations of triptolide(TP) in plasma and liver, and to explore the toxicokinetics of TP and the relationship between TP exposure and liver injury in C57 BL/6 mice, so as to provide reference for dissecting the toxicity mechanism of TP. The liquid chromatography was conducted with ZORBAX SB-C_(18) column(3.0 mm×100 mm, 3.5 µm) and the mobile phase of methanol-0.05 mmol·L~(-1) ammonium acetate. Electrospray ionization(ESI) and multiple reaction monitoring(MRM) mode were employed for mass spectrometry. After oral administration of TP(toxic dose 600 µg·kg~(-1)), the blood and liver tissues of the C57 BL/6 mice were collected at different time points to measure the TP concentrations in plasma and liver tissues. Furthermore, the blood biochemical indexes, including alkaline phosphatase(ALP), alanine aminotransferase(ALT), aspartate aminotransferase(AST), and total bile acid(TBA), were determined. After being processed by DAS 2.0, the experiment data showed that the TP in mice had the toxicokinetic parameters of T_(max)=5 min, C_(max)=14.38 ng·mL~(-1), t_(1/2)=0.76 h, AUC_(0-t)=5.63 h·ng·mL~(-1), MRT_(0-t)=0.56 h, and CL_(Z/F)=103.19 L·h~(-1)·kg~(-1). The trend of TP concentration in mouse liver tissue was consistent with that in plasma. The concentration of TP peaked at the time point of 5 min and then decreased until TP was completely metabolized. The plasma biochemical indexes(ALT, AST, ALP, and TBA) showed no significant changes within 3 h after TP administration. TP had high clearance rate and short residence time and did not significantly increase the blood biochemical indexes in mice. The results suggested that the exposure amount of free TP in vivo cannot directly cause liver injury, which might be caused by the binding of TP to some substances or the stimulation of inflammation and immune response.

Catalpol counteracts the pathology in a mouse model of Duchenne muscular dystrophy by inhibiting the TGF-ß1/TAK1 signaling pathway.

Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disease caused by a mutation in the gene encoding the dystrophin protein. Catalpol is an iridoid glycoside found in Chinese herbs with anti-inflammatory, anti-oxidant, anti-apoptotic, and hypoglycemic activities that can protect against muscle wasting. In the present study we investigated the effects of catalpol on DMD. Aged Dystrophin-deficient (mdx) mice (12 months old) were treated with catalpol (100, 200 mg·kg-1·d-1, ig) for 6 weeks. At the end of the experiment, the mice were sacrificed, and gastrocnemius (GAS), tibialis anterior (TA), extensor digitorum longus (EDL), soleus (SOL) muscles were collected. We found that catalpol administration dose-dependently increased stride length and decreased stride width in Gait test. Wire grip test showed that the time of wire grip and grip strength were increased. We found that catalpol administration dose-dependently alleviated skeletal muscle damage, evidenced by reduced plasma CK and LDH activity as well as increased the weight of skeletal muscles. Catalpol administration had no effect on dystrophin expression, but exerted anti-inflammatory effects. Furthermore, catalpol administration dose-dependently decreased tibialis anterior (TA) muscle fibrosis, and inhibited the expression of TGF-ß1, TAK1 and α-SMA. In primary myoblasts from mdx mice, knockdown of TAK1 abolished the inhibitory effects of catalpol on the expression levels of TGF-ß1 and α-SMA. In conclusion, catalpol can restore skeletal muscle strength and alleviate skeletal muscle damage in aged mdx mice, thus may provide a novel therapy for DMD. Catalpol attenuates muscle fibrosis by inhibiting the TGF-ß1/TAK1 signaling pathway.

[2,3,5,4'-Tetrahydroxystibane-2-O-ß-D-glucoside induces liver injury by disrupting bile acid homeostasis and phospholipids efflux].

Polygonum multiflorum is a traditional Chinese herbal medicine and has many biological activities such as hair-blacking, anti-atherosclerosis, anti-inflammatory and anti-aging. However, the liver injury induced by P. multiflorum has aroused wide attention in recent years. 2,3,5,4'-tetrahydroxystibane-2-O-ß-D-glucoside(TSG) is a main component of P. multiflorum, but the role of TSG in inducing liver injury is unclear. The aim of present study was to evaluate TSG's potential liver injury and effects on bile acid homeostasis and phospholipids efflux. C57 BL/6 J mice received intraperitoneal administration of 400 mg·kg~(-1) of TSG daily for 15 days, and then biochemical indexes of liver injury and changes of phospholipid content were detected. The changes of bile acid compositions were detected by LC-MS/MS. The results showed TSG 400 mg·kg~(-1) significantly increased the content of serum total bile acid(TBA) and alkaline phosphatase(ALP). Elevated free bile acid levels were observed in TSG-treated groups, including ß-muricholic acid(ß-MCA), ursodeoxycholic acid(UDCA), hyodeoxycholic acid(HDCA), chenodeoxycholic acid(CDCA), deoxcholic acid(DCA) in serum and ß-MCA, CDCA in liver. TSG inhibited the protein expression of farnesoid X receptor(FXR) and down stream bile salt export pump(BSEP), which may result in the accumulation of bile acid. TSG also inhibited the expression of 25-hydroxycholesterol-7 alpha-hydroxylase(CYP7 B1), which may disturb the alternative pathway for bile acid synthesis. In addition, intraperitoneal injection of TSG 400 mg·kg~(-1) significantly decreased the content of phospholipids in bile. The research showed that TSG significantly inhibited the expression of multidrug resistance protein 2(MDR2) and destroyed the regular distribution of MDR2 on the bile duct membrane of liver. In vitro results showed that the IC_(50) of TSG on HepG2 cells was about 1 500 µmol·L~(-1) and TSG at 500 µmol·L~(-1)(for 24 h) could destroy the distribution of MDR2 on the bile duct membrane of liver. In conclusion, TSG induced liver injury by disrupting bile acid homeostasis and phospholipids efflux.

Synthesis and Biological Evaluation of Celastrol Derivatives as Potential Immunosuppressive Agents.

Celastrol, a friedelane-type triterpenoid isolated from the genus Triperygium, possesses antitumor, anti-inflammatory, and immunosuppressive activities. A total of 42 celastrol derivatives (1a-1t, 2a-2l, and 3a-3j) were synthesized and evaluated for their immunosuppressive activities. Compounds 2a-2e showed immunosuppressive effects, with IC50 values ranging from 25 to 83 nM, and weak cytotoxicity (CC50 > 1 µM). Compound 2a, with a selectivity index value 31 times higher than that of celastrol, was selected as a lead compound. Further research showed that 2a exerted its immunosuppressive effects by inducing apoptosis and inhibiting cytokine secretion via Lck- and ZAP-70-mediated signaling pathways.

The hypoglycemic mechanism of catalpol involves increased AMPK-mediated mitochondrial biogenesis.

Mitochondria serve as sensors of energy regulation and glucose levels, which are impaired by diabetes progression. Catalpol is an iridoid glycoside that exerts a hypoglycemic effect by improving mitochondrial function, but the underlying mechanism has not been fully elucidated. In the current study we explored the effects of catalpol on mitochondrial function in db/db mice and C2C12 myotubes in vitro. After oral administration of catalpol (200 mg·kg-1·d-1) for 8 weeks, db/db mice exhibited a decreased fasting blood glucose level and restored mitochondrial function in skeletal muscle. Catalpol increased mitochondrial biogenesis, evidenced by significant elevations in the number of mitochondria, mitochondrial DNA levels, and the expression of three genes associated with mitochondrial biogenesis: peroxisome proliferator-activated receptor gammaco-activator 1 (PGC-1α), mitochondrial transcription factor A (TFAM) and nuclear respiratory factor 1 (NRF1). In C2C12 myotubes, catalpol significantly increased glucose uptake and ATP production. These effects depended on activation of AMP-activated protein kinase (AMPK)-mediated mitochondrial biogenesis. Thus, catalpol improves skeletal muscle mitochondrial function by activating AMPK-mediated mitochondrial biogenesis. These findings may guide the development of a new therapeutic approach for type 2 diabetes.

[Mechanism of psoralen in aggravating hepatotoxicity induced by CCl_4 by delaying liver regeneration].

This study aimed to investigate whether psoralen can aggravate hepatotoxicity induced by carbon tetrachloride(CCl_4) by inducing hepatocyte cycle arrest and delaying liver regeneration. Female C57 BL/6 mice aged 6-8 weeks were randomly divided into control group, model group(CCl_4 group), combined group(CCl_4+PSO group) and psoralen group(PSO group). CCl_4 group and CCl_4+PSO group were given CCl_4 intraperitoneally at a dose of 100 µL·kg~(-1) once; olive oil of the same volume was given to control group and PSO group intraperitoneally; 12 h, 36 h and 60 h after CCl_4 injection, PSO group and CCl_4+PSO group were administrated with PSO intragastrically at a dose of 200 mg·kg~(-1); 0.5% CMC-Na of the same volume was administrated to control group and PSO group intragastrically. The weight of mice was recorded every day. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were measured at 36 h, 60 h and 84 h after CCl_4 injection. Mice were sacrificed after collection of the last serum samples. Liver samples were collected, and liver weight was recorded. Histopathological and morphological changes of liver were observed by haematoxylin and eosin staining. The mRNA levels of HGF, TGF-ß, TNF-α, p53 and p21 in liver were detected by RT-qPCR. Western blot was used to detect the levels of cell cycle-related proteins. According to the results, significant increase of serum ALT and AST and centrilobular necrosis with massive inflammatory cell infiltration were observed in CCl_4+PSO group. After PSO administration in CCl_4 model, the mRNA levels of HGF(hepatocyte growth factor) and TNF-α were reduced, while the mRNA expressions of TGF-ß, p53 and p21 was up-regulated. The expression of PCNA(proliferating cell nuclear antigen) was significantly increased in CCl_4 and CCl_4+PSO group, while the relative protein level in CCl_4+PSO group was slightly lower than that in CCl_4 group. Compared with control and CCl_4 group, the expression of p27(cyclic dependent kinase inhibitor protein p27) was prominently increased in CCl_4+PSO group. These results indicated that hepatotoxicity induced by CCl_4 could be aggravated by intraperitoneal administration with PSO, and the repair process of liver could be delayed. The preliminary mechanism may be related to the inhibition of PCNA and regulation of some cell cycle-associated protein by psoralen, in which the significant up-regulation of p27, p53 and p21 may play important roles.

Toxic effects of triptolide on adrenal steroidogenesis in H295R cells and female rats.

Triptolide (TP), a major active ingredient of Tripterygium wilfordii, exerts potent immunosuppressive effects in the treatment of rheumatoid arthritis but is not widely used in clinical practice due to its multiorgan toxicity, particularly hepatotoxicity, nephrotoxicity, and reproductive toxicity. An LC-MS/MS approach was employed to explore the endocrine-disrupting effects of TP. The endocrine-disrupting effects of various concentrations (0-100 nM) of TP for 48 hour were firstly investigated using an in vitro model (H295R cell line). It was found that TP did not decrease cell viability. The transcriptional levels of steroidogenic enzymes in H295R cells were assessed by quantificational real-time polymerase chain reaction. The possible adrenal and endocrine effects of oral administration of TP (0, 50, and 500 µg/kg) for 28 days on both normal and collagen-induced arthritis (CIA) rats were also explored. The serum and adrenal tissue hormone levels (corticosterone and progesterone) and adrenal histopathology were analyzed, with the results that TP significantly decreased the level of cortisol in H295R cells and the level of plasma corticosterone in both normal and CIA rats. Histological alterations in adrenal cortex were observed at the dose of 500 µg/kg. Exposure to TP for 48 hour had an obvious inhibitory effect on the messenger RNA transcript levels of HSD3B2, CYP21A2, CYP17A1, and CYP11B1, which is essential for the synthesis of corticosteroids. In a word, TP leads to the disorder of corticosteroid synthesis and secretion, and corticosteroid may be a potential biomarker for the treatment of multiorgan toxicity of TP.

Preventive Effects of Total Flavonoid C-Glycosides from Abrus mollis on Nonalcoholic Fatty Liver Disease through Activating the PPARα Signaling Pathway.

Abrus pulchellus subsp. mollis (Hance) Verdc. (Leguminosae) is a well-known edible plant usually added to soups and beverages. In this study, vicenin-2 (1: ), isoschaftoside (2: ), schaftoside (3: ), and their enrichment fraction, total flavonoid C-glycosides, derived from the extracts of A. mollis, were firstly found to prevent nonalcoholic fatty liver disease both in vitro and in vivo. In the in vitro study, total flavonoid C-glycosides decreased the lipid accumulation in oleic acid-treated HepG2 cells. The mechanisms of total flavonoid C-glycosides are involved in the regulation of peroxisome proliferator-activated receptor α and its downstream, and the reduction of proinflammatory cytokines. In high-fat diet-induced fatty liver rats, total flavonoid C-glycosides decreased the levels of glutamic-oxalacetic transaminease and glutamic-pyruvic transaminase, and decreased the lipid accumulation both in the liver and blood without affecting food intake. In addition, total flavonoid C-glycosides also increased the activities of the antioxidant enzyme system in vivo. In conclusion, total flavonoid C-glycosides are active components of A. mollis on nonalcoholic fatty liver disease, and can be used in functional food and supplements for nonalcoholic fatty liver disease prevention and treatment.

[Effect of triptolide on Th17/Treg cells in spleen].

Triptolide( TP) is isolated from the traditional Chinese medicine Tripterygium wilfordii,which exhibits notable immuneregulative effect. Th17 cells involve in inflammatory response and Treg cells contribute to immune tolerance. They both play an important role in immune response. Previous studies have investigated that TP induced hepatic Th17/Treg imbalance. However,the effect of TP on spleen Th17/Treg cells remains unclear. Therefore,the aim of present study was to investigate the effect of TP on Th17/Treg cells in spleen. In this study,the effect of TP on the proliferation of splenic lymphocyte was detected by cytotoxicity test in vitro. After different concentrations of TP( 2. 5,5,20,40 nmol·L~(-1)) were given to splenic lymphocyte,cytokines secreted from the supernatant of splenic lymphocyte were detected by cytometric bead array,and the expression of suppressor of cytokine signaling( SOCS) mRNA was detected by qRT-PCR. Female C57 BL/6 mice were continuously observed for 24 h after treatment of 500 µg·kg-1 TP. The effects of TP on the splenic tissue structure and the percentage of Th17/Treg cells were examined. The results showed that the IC50 of TP was19. 6 nmol·L~(-1) in spleen lymphocytes. TP inhibited the secretion of IL-2 and IL-10 and induced the expression of SOCS-1/3 mRNA in spleen lymphocytes at the dosage of 2. 5 and 5 nmol·L~(-1) after 24 h in vitro. Administration of TP at dosage of 500 µg·kg-1 had no significant spleen toxicity in vivo. TP treatment increased the percentage of Th17 cells after 12 h and inhibited the proportion of Treg cells after 12 and 24 h. In conclusion,TP reduced the secretion of IL-2 and IL-10 through SOCS-1/3 signaling pathway,thereby induced the percentage of Th17 cells and inhibited the percentage of Treg cells.

[Progress of effect and mechanisms of Tripterygium wilfordii on immune system].

Traditional Chinese medicine Tripterygium wilfordii Hook.f( TWHF) is a natural botanical drug in China. It has complex chemical compositions and has been used for a long history. TWHF was used as an insecticide to protect crops at early stage,and it was later found to have significant effects in the treatment of rheumatoid arthritis,attaining great concerns. With further researches,it was found that TWHF can treat various diseases in the medical field due to a variety of pharmacological activities such as anti-cancer,neuroprotection,anti-inflammatory and immune-suppressing,particularly. Multiple extracts of TWHF have unique immunosuppressive function,playing an immune role through multi-target and multi-channel,with significant effect in the treatment of autoimmune diseases. As an immune-suppressing drug,TWHF is worthy of in-depth research due to its broad application prospects. While achieving good clinical efficacy,reports about its toxic effects to multiple systems of the body are also increasing,greatly hindering its clinical application. In order to fully understand the immune-suppressing function of TWHF and reduce or avoid the occurrence of toxic and side effects,we summarized recent progress of TWHF on the immune organs,cells and factors in recent years,as well as the pharmacology and toxic effects,hoping to provide a scientific and reasonable reference for its wider use in clinical treatment.

[Study on difference of liver toxicity and its molecular mechanisms caused by Tripterygium wilfordii multiglycoside and equivalent amount of triptolid in rats].

Tripterygium wilfordii multiglycoside( GTW),an extract derived from T. wilfordii,has been used for rheumatoid arthritis and other immune diseases in China. However its potential hepatotoxicity has not been investigated completely. Firstly,the content of triptolid( TP) in GTW was 0. 008% confirmed by a LC method. Then after oral administration of GTW( 100,150 mg·kg-1) and TP( 12 µg·kg-1) in female Wistar rats for 24 h,it was found that 150 mg·kg-1 GTW showed more serious acute liver injury than 12 µg·kg-1 TP,with the significantly increased lever of serum ALT,AST,TBA,TBi L,TG and bile duct hyperplasia even hepatocyte apoptosis. The expression of mRNA and proteins of liver bile acid transporters such as BSEP,MRP2,NTCP and OATP were down-regulated significantly by GTW to inhibit bile acid excretion and absorption,resulting in cholestatic liver injury. Moreover,GTW was considered to be involved in hepatic oxidative stress injury,although it down-regulated SOD1 and GPX-1 mRNA expression without significant difference in MDA and GSH levels. In vitro,we found that TP was the main toxic component in GTW,which could inhibit cell viability up to 80% in Hep G2 and LO2 cells at the dose of 0. 1 µmol·L-1. Next a LC-MS/MS method was used to detect the concentration of triptolid in plasma from rats,interestingly,we found that the content of TP in GTW was always higher than in the same amount of TP,suggesting the other components in GTW may affect the TP metabolism. Finally,we screened the substrate of p-glycoprotein( p-gp) in Caco-2 cells treated with components except TP extrated from GTW,finding that wilforgine,wilforine and wilfordine was the substrate of p-gp. Thus,we speculated that wilforgine,wilforine and wilfordine may competitively inhibit the excretion of TP to bile through p-gp,leading to the enhanced hepatotoxity caused by GTW than the same amount of TP.

Activation of natural killer T cells contributes to triptolide-induced liver injury in mice.

Triptolide (TP) is the main active ingredient of Tripterygium wilfordii Hook.f, which has attracted great interest due to its promising efficacy for autoimmune diseases and tumors. However, severe adverse reactions, especially hepatotoxicity, have restricted its approval in the market. In the present study we explored the role of hepatic natural killer T (NKT) cells in the pathogenesis of TP-induced liver injury in mice. TP (600 µg/kg/day, i.g.) was administered to female mice for 1, 3, or 5 days. We found that administration of TP dose-dependently induced hepatotoxicity, evidenced by the body weight reduction, elevated serum ALT and AST levels, as well as significant histopathological changes in the livers. However, the mice were resistant to the development of TP-induced liver injury when their NKT cells were depleted by injection of anti-NK1.1 mAb (200 µg, i.p.) on days -2 and -1 before TP administration. We further revealed that TP administration activated NKT cells, dominantly releasing Th1 cytokine IFN-γ, recruiting neutrophils and macrophages, and leading to liver damage. After anti-NK1.1 injection, however, the mice mainly secreted Th2 cytokine IL-4 in the livers and exhibited a significantly lower percentage of hepatic infiltrating neutrophils and macrophages upon TP challenge. The activation of NKT cells was associated with the upregulation of Toll-like receptor (TLR) signaling pathway. Collectively, these results demonstrate a novel role of NKT cells contributing to the mechanisms of TP-induced liver injury. More importantly, the regulation of NKT cells may promote effective measures that control drug-induced liver injury.

Bakuchiol Contributes to the Hepatotoxicity of Psoralea corylifolia in Rats.

Psoralea corylifolia L. (Fructus Psoraleae) is widely used in Asia, but there are concerns about hepatotoxicity caused by constituents such as psoralens and bakukiol. Bakuchiol (BAK) has antiinflammatory, antipyretic, antibacterial antiviral, anticancer, and estrogenic activity but appears to be hepatotoxic in in vitro tests. This study investigated the hepatotoxicity in vivo in rats. Using intragastrically administered bakuchiol at doses of 52.5 and 262.5 mg/kg for 6 weeks. Bodyweight, relative liver weight, biochemical indicators, histopathology, mRNA expression of CYP7A1, HMG-CoA reductase, BSEP, PPARα, SREBP-2, and MRP3 were measured. Many abnormalities were observed in the bakuchiol-treated groups including suppression of weight gain and food intake, change of some parameters in serum biochemistry, and increased weight of liver. The mRNA expression of CYP7A1, HMG-CoA reductase, PPARα, and SREBP-2 decreased in bakuchiol-treated group, the expression of BSEP increased in bakuchiol-treated low dosage, and the expression of BSEP decreased in bakuchiol-treated high dosage. In conclusion, we provide evidence for the first time that bakuchiol can induce cholestatic hepatotoxicity, suggesting potential hepatotoxicity. The mechanism may be related to effects on liver lipid metabolism, but further investigation is necessary. Copyright © 2017 John Wiley & Sons, Ltd.

Antitumor effect of Deoxypodophyllotoxin on human breast cancer xenograft transplanted in BALB/c nude mice model.

Recently, biologically active compounds isolated from plants used in herbal medicine have been the center of interest. Deoxypodophyllotoxin (DPT), structurally closely related to the lignan podophyllotoxin, was found to be a potent antitumor and antiproliferative agent, in several tumor cells, in vitro. However, DPT has not been used clinically yet because of the lack of in vivo studies. This study is the first report demonstrating the antitumor effect of DPT on MDA-MB-231 human breast cancer xenografts in nude mice. DPT, significantly, inhibited the growth of MDA-MB-231 xenograft in BALB/c nude mice. The T/C value (the value of the relative tumor volume of treatment group compared to the control group) of groups treated with 5, 10, and 20 mg/kg of intravenous DPT-HP-ß-CD was 42.87%, 34.04% and 9.63%, respectively, suggesting the positive antitumor activity of DPT. In addition, the antitumor effect of DPT-HP-ß-CD (20 mg/kg) in human breast cancer MDA-MB-231 xenograft was more effective than etoposide (VP-16) (20 mg/kg) and docetaxel (20 mg/kg). These findings suggest that this drug is a promising chemotherapy candidate against human breast carcinoma.

Triptolide inhibits human breast cancer MCF-7 cell growth via downregulation of the ERα-mediated signaling pathway.

AIM: To investigate the anticancer mechanisms of triptolide, a diterpenoid isolated from the plant Tripterygium wilfordii Hook F, against human breast cancer cells and the involvement of the estrogen receptor-α (ERα)-mediated signaling pathway in particular. METHODS: Human breast cancer ERα-positive MCF-7 cells and ERα-negative MDA-MB-231 cells were tested. PrestoBlue assay was used to evaluate the cell viability. The levels of ERα mRNA and protein were detected with real-time PCR and immunoblotting, respectively. Mouse models of MCF-7 or MDA-MB-231 xenograft tumors were treated with triptolide (0.4 mg·kg(-1)·d(-1), po) or a selective estrogen receptor modulator tamoxifen (mg·kg(-1)·d(-1), po) for 3 weeks, and the tumor weight and volume were measured. RESULTS: Triptolide (5-200 nmol/L) dose-dependently inhibited the viability of both MCF-7 and MDA-MB-231 cells, with a more potent inhibition on MCF-7 cells. Knockdown of ERα in MCF-7 cells by siRNA significantly attenuated the cytotoxicity of triptolide, whereas overexpression of ERα in MDA-MB-231 cells markedly enhanced the cytotoxicity. Triptolide dose-dependently decreased the expression of ERα in MCF-7 cells and MCF-7 xenograft tumors. Furthermore, treatment of MCF-7 cells with triptolide inhibited the phosphorylation of ERK1/2 in dose- and time-dependent manners. In the mice xenografted with MCF-7 cells, treatment with triptolide or tamoxifen resulted in significant reduction in the tumor weight and volume. Similar effects were not obtained in the mice xenografted with MDA-MB-231 cells. CONCLUSION: The anticancer activity of triptolide against ERα-positive human breast cancer is partially mediated by downregulation of the ERα-mediated signaling pathway.

Deoxypodophyllotoxin induces G2/M cell cycle arrest and apoptosis in SGC-7901 cells and inhibits tumor growth in vivo.

Deoxypodophyllotoxin (DPT), a natural microtubule destabilizer, was isolated from Anthriscus sylvestris, and a few studies have reported its anti-cancer effect. However, the in vivo antitumor efficacy of DPT is currently indeterminate. In this study, we investigated the anti-gastric cancer effects of DPT both in vitro and in vivo. Our data showed that DPT inhibited cancer cell proliferation and induced G2/M cell cycle arrest accompanied by an increase in apoptotic cell death in SGC-7901 cancer cells. In addition, DPT caused cyclin B1, Cdc2 and Cdc25C to accumulate, decreased the expression of Bcl-2 and activated caspase-3 and PARP, suggesting that caspase-mediated pathways were involved in DPT-induced apoptosis. Animal studies revealed that DPT significantly inhibited tumor growth and decreased microvessel density (MVD) in a xenograft model of gastric cancer. Taken together, our findings provide a framework for further exploration of DPT as a novel chemotherapeutic for human gastric cancer.

[Study on hepatotoxicity of aqueous extracts of Polygonum multiflorum in rats after 28-day oral administration: cholestasis-related mechanism].

OBJECTIVE: To study the effect of aqueous extracts of Polygonum multiflorum (AEPM) on bile acid synthesis, metabolism and transfer-related molecules in rat liver and the hepatotoxicity-related mechanism of P. multiflorum. METHOD: Sprague-Dawley rats were orally administered with 30, 60 g x kg(-1) APEM once everyday for consecutively 28 days. At the end of the experiment, mRNA and protein expressions of hepatic MRP3, MRP2, BSEP, FXR and CYP7A1 were detected by Real-time PCR and Western blot RESULT: Compared with the normal group, the AEPM high dose group showed significant increases in mRNA expressions of hepatic MRP3 and BSEP of male rats (P < 0.05); AEPM high and low dose groups revealed a notable decrease in mRNA expressions of hepatic FXR (P < 0.05) and remarkable rises in mRNA expressions of hepatic MRP3, MRP2, BSEP, CYP7A1 among female rats (P < 0.05). According to the test results of western blot assay, AEPM high and low dose groups showed consistent changes in protein and mRNA expressions hepatic MRP3, MRP2, BSEP, FXR, CYP7A1. CONCLUSION: The 28 oral administration with AEPM in rats showed a certain effect on expressions of bile acid synthesis, metabolism and transfer-related proteins, as well as cholestatic or choleretic effects in the mRNA expression.

Telmisartan protects central neurons against nutrient deprivation-induced apoptosis in vitro through activation of PPARγ and the Akt/GSK-3ß pathway.

AIM: To determine whether angiotensin II receptor blockers (ARBs) could protect central neurons against nutrient deprivation-induced apoptosis in vitro and to elucidate the underlying mechanisms. METHODS: Primary rat cerebellar granule cells (CGCs) underwent B27 (a serum substitute) deprivation for 24 h to induce neurotoxicity, and cell viability was analyzed using LDH assay and WST-1 assay. DNA laddering assay and TUNEL assay were used to detect cell apoptosis. The expression of caspase-3 and Bcl-2, and the phosphorylation of Akt and GSK-3ß were detected using Western blot analysis. AT1a mRNA expression was determined using RT-PCR analysis. RESULTS: B27 deprivation significantly increased the apoptosis of CGCs, as demonstrated by LDH release, DNA laddering, caspase-3 activation and positive TUNEL staining. Pretreatment with 10 µmol/L ARBs (telmisartan, candesartan or losartan) partially blocked B27 deprivation-induced apoptosis of CGCs with telmisartan being the most effective one. B27 deprivation markedly increased the expression of AT1a receptor in CGCs, inhibited Akt and GSK-3ß activation, decreased Bcl-2 level, and activated caspase-3, which were reversed by pretreatment with 1 µmol/L telmisartan. In addition, pretreatment with 10 µmol/L PPARγ agonist pioglitazone was more effective in protecting CGCs against B27 deprivation-induced apoptosis, whereas pretreatment with 20 µmol/L PPARγ antagonist GW9662 abolished all the effects of telmisartan in CGCs deprived of B27. CONCLUSION: ARBs, in particular telmisartan, can protect the nutrient deprivation-induced apoptosis of CGCs in vitro through activation of PPARγ and the Akt/GSK-3ß pathway.

Resveratrol effectively attenuates α-naphthyl-isothiocyanate-induced acute cholestasis and liver injury through choleretic and anti-inflammatory mechanisms.

AIM: α-Naphthylisothiocyanate (ANIT) is a well-characterized cholestatic agent for rats. The aim of this study was to examine whether resveratrol could attenuate ANIT-induced acute cholestasis and liver injury in rats. METHODS: SD rats were treated with resveratrol (15 or 30 mg/kg, ip) or a positive control drug ursodeoxycholic acid (100 mg/kg, po) for 5 consecutive days followed by a single dose of ANIT (60 mg/kg, po). Bile flow, and serum biochemical markers and bile constituents were measured 48 h after ANIT administration. Hepatic levels of oxidative repair enzymes (glutathione peroxidase, catalase and MnSOD), myeloperoxidase activity, TNF-α, IL-6 and ATP content, as well as the expression of liver transporter genes and proteins were assayed. RESULTS: ANIT exposure resulted in serious cholestasis and liver injury, as shown by marked neutrophil infiltration in liver, dramatically increased serum levels of ALT, AST, GGT, ALP, TBA, TBIL, IBIL and DBIL, and significantly decreased bile excretion and biliary output of GSH and HCO3(-). ANIT significantly increased TNF-α and IL-6 release and myeloperoxidase activity, decreased mitochondrial biogenesis in liver, but had little effect on hepatic oxidative repair enzymes and ATP content. Furthermore, ANIT significantly decreased the expression of Mrp2, FXR and Cyp7a1, markedly increased Mrp3 expression in liver. Pretreatment with resveratrol attenuated ANIT-induced acute cholestasis and liver injury, and other pathological changes. Pretreatment with ursodeoxycholic acid was less effective. CONCLUSION: Resveratrol effectively attenuates ANIT-induced acute cholestasis and liver injury in rats, possibly through suppression of neutrophil infiltration, as well as upregulation of expression of hepatic transporters and enzymes, thus decreasing accumulation of bile acids.

Discovery of novel aromatase inhibitors using a homogeneous time-resolved fluorescence assay.

AIM: Aromatase is an important target for drugs to treat hormone-dependent diseases, including breast cancer. The aim of this study was to develop a homogeneous time-resolved fluorescence (HTRF) aromatase assay suitable for high-throughput screening (HTS). METHODS: A 384-well aromatase HTRF assay was established, and used to screen about 7000 compounds from a compound library. Anti-proliferation activity of the hit was evaluated using alamarBlue(R) assay in a hormone-dependent breast cancer cell line T47D. Molecular docking was conducted to elucidate the binding mode of the hit using the Discovery Studio program. RESULTS: The Z' value and signal to background (S/B) ratio were 0.74 and 5.4, respectively. Among the 7000 compounds, 4 hits (XHN22, XHN26, XHN27 and triptoquinone A) were found to inhibit aromatase with IC50 values of 1.60±0.07, 2.76±0.24, 0.81±0.08 and 45.8±11.3 µmol /L, respectively. The hits XHN22, XHN26 and XHN27 shared the same chemical scaffold of 4-imidazolyl quinoline. Moreover, the most potent hit XHN27 at 10 and 50 µmol/L inhibited the proliferation of T47D cells by 45.3% and 35.2%, respectively. The docking study revealed that XHN27 docked within the active site of aromatase and might form a hydrogen bond and had a π-cation interaction with amino acid residues of the protein. CONCLUSION: XHN27, an imidazolyl quinoline derivative of flavonoid, is a potent aromatase inhibitor with anti-proliferation activity against breast cancer in vitro. The established assay can be used in HTS for discovering novel aromatase inhibitor.