Tripterygium wilfordii multiglycoside-induced hepatotoxicity via inflammation and apoptosis in zebrafish / 中国天然药物

Tripterygium wilfordii multiglycoside (GTW) is a commonly used compound for the treatment of rheumatoid arthritis (RA) and immune diseases in clinical practice. However, it can induce liver injury and the mechanism of hepatotoxicity is still not clear. This study was designed to investigate GTW-induced hepatotoxicity in zebrafish larvae and explore the mechanism involved. The 72 hpf (hours post fertilization) zebrafish larvae were administered with different concentrations of GTW for three days and their mortality, malformation rate, morphological changes in the liver, transaminase levels, and histopathological changes in the liver of zebrafish larvae were detected. The reverse transcription-polymerase chain reaction (RT-PCR) was used to examine the levels of microRNA-122 (miR-122) and genes related to inflammation, apoptosis, cell proliferation and liver function. The results showed that GTW increased the mortality of zebrafish larvae, while significant malformations and liver damage occurred. The main manifestations were elevated levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), significant liver atrophy, vacuoles in liver tissue, sparse cytoplasm, and unclear hepatocyte contours. RT-PCR results showed that the expression of miR-122 significantly decreased by GTW; the mRNA levels of inflammation-related genes il1β, il6, tnfα, il10, cox2 and ptges significantly increased; the mRNA level of tgfβ significantly decreased; the mRNA levels of apoptosis-related genes, caspase-8 and caspase-9, significantly increased; the mRNA level of bcl2 significantly decreased; the mRNA levels of cell proliferation-related genes, top2α and uhrf1, significantly reduced; the mRNA levels of liver function-related genes, alr and cyp3c1, significantly increased; and the mRNA level of cyp3a65 significantly decreased. In zebrafish, GTW can cause increased inflammation, enhanced apoptosis, decreased cell proliferation, and abnormal expression of liver function-related genes, leading to abnormal liver structure and function and resulting in hepatotoxicity.

Altered integrity of hepatocyte tight junctions in rats with triptolide-induced cholestasis / 中国天然药物

Triptolide (TP), an active component of Tripterygium wilfordiiHook. f. (TWHF), has been widely used for centuries as a traditional Chinese medicine. However, the clinical application of TP has been restricted due to multitarget toxicity, such as hepatotoxicity. In this study, 28 days of oral TP administration (100, 200, or 400 μg·kg

2,3,5,4'-Tetrahydroxystibane-2-O-β-D-glucoside induces liver injury by disrupting bile acid homeostasis and phospholipids efflux / 中国中药杂志

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-β-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 β-muricholic acid(β-MCA), ursodeoxycholic acid(UDCA), hyodeoxycholic acid(HDCA), chenodeoxycholic acid(CDCA), deoxcholic acid(DCA) in serum and β-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.

Mechanism of psoralen in aggravating hepatotoxicity induced by CCl_4 by delaying liver regeneration / 中国中药杂志

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-β, 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-β, 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.

Effect of triptolide on Th17/Treg cells in spleen / 中国中药杂志

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 / 中国中药杂志

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 / 中国中药杂志

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.

The role of neutrophils in triptolide-induced liver injury / 中国天然药物

Triptolide (TP) induces severe liver injury, but its hepatotoxicity mechanisms are still unclear. Inflammatory responses may be involved in the pathophysiology. Neutrophils are the first-line immune effectors for sterile and non-sterile inflammatory responses. Thus, the aim of the present study was to investigate the neutrophilic inflammatory response in TP-induced liver injury in C57BL/6 mice. Our results showed that neutrophils were recruited and accumulated in the liver, which was parallel to or slightly after the development of liver injury. Neutrophils induced release of myeloperoxidase and up-regulation of CD11b, which caused cytotoxicity and hepatocyte death. Hepatic expressions of CXL1, TNF-α, IL-6, and MCP1 were increased significantly to regulate neutrophils recruitment and activation. Up-regulation of toll like receptors 4 and 9 also facilitated neutrophils infiltration. Moreover, neutrophils depletion using an anti-Gr1 antibody showed mild protection against TP overdose. These results indicated that neutrophils accumulation might be the secondary response, not the cause of TP-induced liver injury. In conclusion, the inflammatory response including neutrophil infiltration may play a role in TP-induced hepatotoxicity, but may not be severe enough to cause additional liver injury.

Advances in models for predicting drug intestinal permeability / 药学学报

Intestinal permeability is one of key factors determing absorption of oral drug products. It is a big challenge to assess permeability of compounds with high accuracy and high efficacy during research and development process. In this review, the principles, strengths, weaknesses and advances of common intestinal permeability models are summarized, with focus on Ussing chamber and parallel artificial membrane permeability assay. In addition, future trends of permeability models are briefly discussed. This review may provide a reference to accessing permeability of lead compounds.

The role of neutrophils in triptolide-induced liver injury / 中国天然药物

Triptolide (TP) induces severe liver injury, but its hepatotoxicity mechanisms are still unclear. Inflammatory responses may be involved in the pathophysiology. Neutrophils are the first-line immune effectors for sterile and non-sterile inflammatory responses. Thus, the aim of the present study was to investigate the neutrophilic inflammatory response in TP-induced liver injury in C57BL/6 mice. Our results showed that neutrophils were recruited and accumulated in the liver, which was parallel to or slightly after the development of liver injury. Neutrophils induced release of myeloperoxidase and up-regulation of CD11b, which caused cytotoxicity and hepatocyte death. Hepatic expressions of CXL1, TNF-α, IL-6, and MCP1 were increased significantly to regulate neutrophils recruitment and activation. Up-regulation of toll like receptors 4 and 9 also facilitated neutrophils infiltration. Moreover, neutrophils depletion using an anti-Gr1 antibody showed mild protection against TP overdose. These results indicated that neutrophils accumulation might be the secondary response, not the cause of TP-induced liver injury. In conclusion, the inflammatory response including neutrophil infiltration may play a role in TP-induced hepatotoxicity, but may not be severe enough to cause additional liver injury.

Triptolide reduces prostate size and androgen level on testosterone-induced benign prostatic hyperplasia in Sprague Dawley rats / 中国天然药物

Benign prostatic hyperplasia (BPH) is an age-related disease of unknown etiology, characterized by prostatic enlargement coincident with distinct alterations in tissue histology. In the present study, we investigated whether triptolide can prevent testosterone-induced prostatic hyperplasia in rats. Castration was performed via the scrotal route after urethane aesthesia. BPH was induced in experimental groups by daily subcutaneous injections of testosterone propionate (TP) for two weeks. Triptolide was administered daily by oral gavage at a dose of 100 and 50 μg·kg for 2 weeks, along with the TP injections. On day 14, the animals were humanely killed by cervical dislocation after aesthesia. Prostates were excised, weighed, and used for histological studies. Testosterone and dihydrotestosterone (DHT) levels in serum and prostate were measured. The results showed that triptolide significantly reduced the prostate weight, and the testosterone and DHT levels in both the serum and prostate. Histopathological examination also showed that triptolide treatment suppressed TP-induced prostatic hyperplasia. In conclusion, triptolide effectively inhibits the development of BPH induced by testosterone in a rat model.

Research advances in drug-induced mitochondrial toxicity / 中国药理学与毒理学杂志

Mitochondria perform important functions in energy production, balancing redox reac-tions, maintaining homeostasis, cell proliferation and apoptosis. Mitochondrial function is essential for human health.This is evidenced by a large number of diseases caused by mutations in the mitochon-drial genome and the key role of mitochondrial dysfunction in many chronic diseases.A number of commonly used drugs can impair mitochondrial function,leading to adverse reactions or toxicity.Drug-induced mito-chondrial dysfunction includes mitochondrial DNA damage, impaired mitochondrial respiration, increased production of reactive oxygen species and altered mitochondrial permeability. Based on data from experimental and clinical research, this review focuses on toxicity and mechanisms of common drugs such as analgesics,anticancer drugs and hypolipidemic drugs on mitochondria in order to provide guid-ance for clinical medication safety and new thoughts for analysis and screening of drug-induced mito-chondrial toxicity.

Inhibitory effects of Tripterygium wilfordii multiglycoside on benign prostatic hyperplasia in rats / 中国天然药物

The present study was designed to evaluate the inhibitory effects of Tripterygium wilfordii multiglycoside (GTW) against testosterone-induced benign prostatic hyperplasia (BPH) in rats. A total of 45 rats were randomly divided into five groups: Group I, vehicle control group (sham-operated and treated with vehicle); Group II, BPH group; Group III, BPH rats treated with finasteride at a dose of 5 mg·kg(-1); and Groups IV and V, BPH rats treated with GTW at dose levels of 10 and 20 mg·kg(-1), respectively. The drugs were administered orally once a day for 14 days. Prostate weight, prostatic index, and the testosterone and dihydrotestosterone (DHT) levels in serum and prostate, and the serum prostate specific antigen (PSA) levels were measured; prostate tissues were taken for histopathological examination; and serum biochemical analysis was also performed. The BPH rats displayed an increase in prostate weight, prostatic index with increased testosterone and DHT levels in both the serum and prostate, and increased serum PSA levels. GTW treatment at both doses resulted in significant reductions in prostate weight, prostatic index, testosterone and DHT levels in both the serum and prostate, and serum PSA levels, compared with BPH group. Histopathological examination also indicated that GTW treatment at both doses inhibited testosterone-induced prostatic hyperplasia. Serum biochemical analysis showed that the liver and renal functions were normal. In conclusion, GTW inhibited testosterone-induced prostatic hyperplasia in rats, without host toxicity, providing a basis for the development of GTW as a novel therapy for BPH.

Study on hepatotoxicity of aqueous extracts of Polygonum multiflorum in rats after 28-day oral administration: cholestasis-related mechanism / 中国中药杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHOD</b>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</p><p><b>RESULT</b>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.</p><p><b>CONCLUSION</b>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.</p>

Protective effect of total flavonoid C-glycosides from Abrus mollis extract on lipopolysaccharide-induced lipotoxicity in mice / 中国天然药物

Abrus mollis is a widely used traditional Chinese medicine for treating acute and chronic hepatitis, steatosis, and fibrosis. It was found that the total flavonoid C-glycosides from Abrus mollis extract (AME) showed potent antioxidant, anti-inflammatory, and hepatoprotective activities. To further investigate the hepatoprotective effect of AME and its possible mechanisms, lipopolysaccharide (LPS)-induced liver injury models were applied in the current study. The results indicated that AME significantly attenuated LPS-induced lipid accumulation in mouse primary hepatocytes as measured by triglyceride (TG) and total cholesterol (TC) assays and Oil Red O staining. Meanwhile, AME exerted a protective effect on LPS-induced liver injury as shown by decreased liver index, serum aminotransferase levels, and hepatic lipid accumulation. Real-time PCR and immunoblot data suggested that AME reversed the LPS-mediated lipid metabolism gene expression, such as sterol regulatory element-binding protein-1 (SREBP-1), fatty acid synthase (FAS), and acetyl-CoA carboxylase 1 (ACC1). In addition, LPS-induced overexpression of activating transcription factor 4 (ATF4), X-box-binding protein-1 (XBP-1), and C/EBP homologous protein (CHOP) were dramatically reversed by AME. Furthermore, AME also decreased the expression of LPS-enhanced interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2). Here, it is demonstrated for the first time that AME ameliorated LPS-induced hepatic lipid accumulation and that this effect of AME can be attributed to its modulation of hepatic de novo fatty acid synthesis. This study also suggested that the hepatoprotective effect of AME may be related to its down-regulation of unfolded protein response (UPR) activation.

Anti-inflammatory and hepatoprotective effects of total flavonoid C-glycosides from Abrus mollis extracts / 中国天然药物

The aim of this study was to evaluate the anti-inflammatory and hepatoprotective effects of the total flavonoid C-glycosides isolated from Abrus mollis extracts (AME). In the anti-inflammatory tests, xylene-induced ear edema model in mice and carrageenan-induced paw edema model in rats were applied. The hepatoprotective effects of AME were evaluated with various in vivo models of acute and chronic liver injury, including carbon tetrachloride (CCl4)-induced hepatitis in mice, D-galactosamine (D-GalN)-induced hepatitis in rats, as well as CCl4-induced hepatic fibrosis in rats. In the acute inflammation experiment, AME significantly suppressed xylene-induced ear edema and carrageenan-induced paw edema, respectively. In the acute hepatitis tests, AME significantly attenuated the excessive release of ALT and AST induced by CCl4 and D-GalN. In CCl4-induced hepatic fibrosis model, AME alleviated liver injury induced by CCl4 shown by histopathological sections of livers and improved liver function as indicated by decreased liver index, serum ALT, AST, TBIL, and ALP levels and hydroxyproline contents in liver tissues, and increased serum ALB and GLU levels. These results indicated that AME possesses potent anti-inflammatory activity in acute inflammation models and hepatoprotective activity in both acute and chronic liver injury models. In conclusion, AME is a potential anti-inflammatory and hepatoprotective agent and a viable candidate for treating inflammation, hepatitis, and hepatic fibrosis.

Impairment of triptolide on liver mitochondria in isolated liver mitochondria and HL7702 cell line / 中国结合医学杂志

<p><b>OBJECTIVE</b>To observe the impairing effects of triptolide on liver mitochondria in isolated rat-liver mitochondria and human normal liver HL7702 cell line.</p><p><b>METHODS</b>Rat-liver mitochondria were isolated from adult female Sprague-Dawley (SD) rats. Liver mitochondria were incubated with 0, 1.25, 2.5, 5 and 10 μmol/L triptolide for detecting mitochondrial swelling and with 0, 2.5, 5 and 10 μmol/L triptolide for mitochondrial permeability transition pore (MPTP) activity. Mitochondrial swelling was estimated by measuring the apparent absorbance change during 600 s in the mitochondrial suspensions at 520 nm with a mitochondrial swelling examining kit. The effect of triptolide on MPTP was determined with a fluorescence detection kit by detecting the fluorescence intensity at an excitation wavelength of 488 nm emitted at 527 nm. Human normal liver HL7702 cells were treated without or with 0.02, 0.1 and 0.5 μmol/L triptolide for 24 h for analyzing mitochondrial transmembrane potential (Δψm) and reactive oxygen species (ROS). Δψm was measured using the fluorescent probe 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1). ROS was measured using fluorescent probe 2',7'-dichlorofluorescin diacetate (DCFH-DA). The cells were harvested and dyed with JC-1 and DCFH-DA, and analyzed by flow cytometry, respectively.</p><p><b>RESULTS</b>Incubation of isolated mitochondria with triptolide results in swollen mitochondria in a concentration-dependent manner. Moreover, triptolide significantly activated mitochondrial permeability transition at 5 and 10 μmol/L (P<0.05 and P<0.01). When HL7702 cells were exposed to a various concentration triptolide for 24 h, mitochondrial membrane depolarization and increase of ROS were caused by triptolide in a concentration-dependent manner. Triptolide significantly induced the mitochondrial membrane depolarization at 0.1 and 0.5 μmol/L (P<0.05 and P<0.01) and the increase of ROS at 0.1 and 0.5 μmol/L (P<0.05 and P<0.01).</p><p><b>CONCLUSION</b>Triptolide could induce mitochondrial impairment, which may be one of the mechanisms by which hepatotoxicity occurs.</p>

Effective of ginkgolides on expression of apoptosis related gene during PC12 cells glucose deprivation / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the protective effects of ginkgolides on glucose deprivation-induced apoptosis in PC12 cells and the mechanism underlying the protective effect.</p><p><b>METHOD</b>PC12 cells were treated under glucose deprivation, and the proliferation was determined by tetrazolium (MTT) assay. Furthermore, the mRNA levels of Bcl-2, Bax, c-myc were measured by Fluorescence Quantitative PCR (FQ-PCR).</p><p><b>RESULT</b>Ginkgolides could markedly inhibit the injury of glucose deprivation on the PC12 cells and increase the cell proliferation compared with the model groups (P <0.01). Ginkgolides could up-regulate Bcl-2 and down-regulate Bax and c-myc at 12 h, respectively. There were no significant differences in the Bcl-2 and Bax levels in both groups at 24 h, and ginkgolides only reduced the elevation of c-myc from 4. 32-fold to 2. 87-fold at this time.</p><p><b>CONCLUSION</b>Ginkgolides are able to protect the injured PC12 cells against cell apoptosis. During the early period of glucose deprivation, Bcl-2, Bax and c-myc were regulated to inhibit cell apoptosis by ginkgolides. After that, ginkgolides seems inhibit the apoptosis through attenuating the elevation of c-myc.</p>