Hepatic oxidative stress,DNA damage and apoptosis in adult zebrafish following sub‐chronic exposure to BDE‐47 and BDE‐153

Polybrominated diphenyl ethers (PBDEs) are ubiquitous and prolific contaminant in both the abiotic and biotic environment because of the wide industrial applications of these chemicals. In the present study, the effects of 2,2′,4,4′‐tetrabrominateddiphenyl ether (BDE‐47) and 2,2′,4,4′,5,5′‐hexabromodiphenyl ether (BDE‐153) exposure on the induction of hepatic oxidative stress, DNA damage, and the expression of apoptosis‐related genes in adult zebrafish were investigated. The activities of antioxidant enzymes, such as catalase and superoxide dimutase, significantly increased when adult zebrafish was exposed to various concentrations of BDE‐47 and BDE‐153 for 7 and 15 days. BDE‐47 and BDE‐153 elicited significant alterations in zebrafish 7‐Ethoxyresorufin‐O‐deethylase activity at 3, 7, or 15 days of exposure. In addition, the significant increase in comet assay parameters of zebrafish hepatocytes in a concentration‐dependent manner indicated BDE‐47 and BDE‐153 induced DNA damage, probably due to observed oxidative stress. Furthermore, a monotonically upregulation of p53 and Caspase3, which are apoptotic‐regulated genes, and decreased expression ratio of the anti‐apoptotic B‐cell lymphoma/leukaemia‐2 and Bcl2‐associated X protein genes for all BDE‐47 and BDE‐153 treatments at 7 and 15 days indicated apoptosis induction in zebrafish liver. Our findings help elucidate the mechanisms of BDE‐47‐ and BDE‐153‐induced toxicity in zebrafish hepatocytes.     

Triptolide‐induced hepatotoxicity via apoptosis and autophagy in zebrafish

Previous research about the development of triptolide (TP) as a natural active compound has often focused on hepatotoxicity. Among its various mechanisms, autophagy and apoptosis are two important signaling pathways. In this study, we used zebrafish to establish a TP‐induced hepatotoxicity model, and investigated the roles of autophagy and apoptosis in the progress of liver injury. Zebrafish exposed to TP showed increased mortality and malformation because of the increased drug dose and duration of exposure. Meanwhile, we found that TP induced liver injury in a time‐ and dose‐dependent manner, which was observed as a reduction in liver area, slow yolk absorption, upregulation of transaminase and local neurosis. With the application of the high‐content imaging system (HCIS) technique in liver 3D imaging in vivo, clear imaging of the zebrafish liver was achieved. The results showed a decrease in volume and location of necrosis in the liver after TP exposure. Increased expression of inflammatory cytokines genes tumor necrosis factor (Tnf)α, Il1β and Il6 were shown, particularly Tnfα. The Fas‐Caspase8 signaling pathway was activated. The apoptosis‐related gene Bcl‐2 was increased, and Bax, Caspase9 and Caspase3 were increased. However, autophagy related genes Beclin1, Atg5, Atg3 and Lc3 were increased more significantly, and the changes of Beclin1 and Atg5 were the most severe. This study successfully established a TP‐induced zebrafish hepatotoxicity model and applied the HCIS technique in a zebrafish hepatotoxicity study. The result indicated Fas might be the main target of TP‐induced hepatotoxicity. Autophagy played a more important role than apoptosis and was characterized by the overexpression of Beclin1 and Atg5.     

AlCl3 induces lymphocyte apoptosis in rats through the mitochondria–caspase dependent pathway

To investigate apoptosis mechanisms in lymphocytes induced by aluminum trichloride (AlCl₃) through the mitochondria–caspase dependent pathway, the spleen lymphocytes of rats were cultured with RPMI‐1640 medium and exposed to AlCl₃·6H₂O in the final concentrations of 0 (control group, CG), 0.3 (low‐dose group, LG), 0.6 (mid‐dose group, MG), and 1.2 (high‐dose group, HG) mmol·L^?1 for 24 h, respectively. Mitochondrial transmembrane potential (ΔΨm), cytochrome C (Cyt C) protein expression in cytoplasm, Caspase‐3 and Caspase‐9 activity, Bcl‐2, Bax, Caspase‐3 and Caspase‐9 mRNA expressions, DNA ladder and lymphocytes apoptosis index were detected. The results showed that Cyt C protein expression in cytoplasm, Caspase‐3 and Caspase‐9 activity, Bcl‐2, Bax, Caspase‐3 and Caspase‐9 mRNA expressions, the ratio of Bcl‐2 and Bax mRNA expression, lymphocytes apoptosis index increased, while ΔΨm decreased in the AlCl₃‐treated groups compared with those in CG. The results indicate that AlCl₃ induces lymphocyte apoptosis in rats through the mitochondria–caspase dependent pathway. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 385–394, 2016.     

Protective effects of melittin on transforming growth factor-β1 injury to hepatocytes via anti-apoptotic mechanism

Melittin is a cationic, hemolytic peptide that is the main toxic component in the venom of the honey bee (Apis mellifera). Melittin has multiple effects, including anti-bacterial, anti-viral and anti-inflammatory, in various cell types. However, the anti-apoptotic mechanisms of melittin have not been fully elucidated in hepatocytes. Apoptosis contributes to liver inflammation and fibrosis. Knowledge of the apoptotic mechanisms is important to develop new and effective therapies for treatment of cirrhosis, portal hypertension, liver cancer, and other liver diseases. In the present study, we investigated the anti-apoptotic effect of melittin on transforming growth factor (TGF)-β1-induced apoptosis in hepatocytes. TGF-β1-treated hepatocytes were exposed to low doses (0.5 and 1 μg/mL) and high dose (2 μg/mL) of melittin. The low doses significantly protected these cells from DNA damage in TGF-β1-induced apoptosis compared to the high dose. Also, melittin suppressed TGF-β1-induced apoptotic activation of the Bcl-2 family and caspase family of proteins, which resulted in the inhibition of poly-ADP-ribose polymerase (PARP) cleavage. These results demonstrate that TGF-β1 induces hepatocyte apoptosis and that an optimal dose of melittin exerts anti-apoptotic effects against TGF-β1-induced injury to hepatocytes via the mitochondrial pathway. These results suggest that an optimal dose of melittin can serve to protect cells against TGF-β1-mediated injury.     

Mono(2‐ethylhexyl) phthalate induces apoptosis in p53‐silenced L02 cells via activation of both mitochondrial and death receptor pathways

Mono(2‐ethylhexyl) phthalate (MEHP) is one of the main metabolites of di(2‐ethylhexyl) phthalate. The evidence shows that DEHP may exert its toxic effects primarily via MEHP, which is 10‐fold more potent than its parent compound in toxicity in vitro. MEHP‐induced apoptosis is mediated by either p53‐dependent or ‐independent pathway. However, the detailed mechanism of its toxicity remains unclear. In this study, immortalized normal human liver cell line L02 was chosen, as an in vitro model of nonmalignant liver, to elucidate the role of p53 in MEHP‐induced apoptosis. The cells were treated with MEHP (6.25, 12.50, 25.00, 50.00, and 100.00 μM) for 24 and 36 h, then small interfering RNA (siRNA) was used to specifically silence p53 gene of L02 cells. The results indicated that MEHP caused oxidative DNA damage and apoptosis in L02 cells were associated with the p53 signaling pathway. Further study found that MEHP (50.00 and 100.00 μM) induced apoptosis in p53‐silenced L02 cells, along with the up‐regulations of Fas and FasL proteins as well as increased the Bax/Bcl‐2 ratio and Caspase 3, 8, and 9 activities. Additionally, both FasL inhibitor (AF‐016) and Caspase inhibitor N‐benzyloxycarbonyl‐Val‐Ala‐Asp‐ fluoromethylketone (Z‐VAD‐FMK) could prevent the cell apoptosis induced by MEHP. The findings suggested that MEHP‐induced apoptosis in L02 cells involving a Caspases‐mediated mitochondrial signaling pathway and/or death receptor pathway. p53 was not absolutely necessary for MEHP‐induced L02 cell apoptosis. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 1178–1191, 2015.     

The role of GSH in microcystin‐induced apoptosis in rat liver: Involvement of oxidative stress and NF‐κB

Microcystins (MCs) are potent and specific hepatotoxins produced by cyanobacteria in eutrophic waters, representing a health hazard to animals and humans. The objectives of this study are to determine the relationship between oxidative stress and NF‐κB activity in MC‐induced apoptosis in rat liver and the role of glutathione (GSH). Sprague‐Dawley rats were intraperitoneally (i.p.) injected with microcystin‐LR (MC‐LR) at 0.25 and 0.5 LD₅₀ with or without pretreatment of buthionine‐(S,R)‐sulfoximine (BSO), a specific GSH synthesis inhibitor. MC‐LR induced time‐dependent alterations of GSH levels in rat liver. Increased malondialdehyde (MDA) and significant changes of antioxidant enzymes including GSH peroxidase (GPX) and GSH reductase (GR) were also observed, particularly at 24 h post‐exposure. The results indicated that acute exposure to MC‐LR induced oxidative stress, and GSH depletion (BSO pretreatment) enhanced the level of oxidative stress. Furthermore, the modulation of pro‐apoptotic gene p53 and Bax and anti‐apoptotic gene Bcl‐2 was observed in 0.5 LD₅₀ group at 24 h, and the alteration was more pronounced by BSO injection before MC‐LR treatment, suggesting that GSH played a protective role against MC‐induced toxicity. Additionally, electrophoretic mobility shift assay (EMSA) showed that NF‐κB was induced at 0.25 LD₅₀ but inhibited at 0.5 LD₅₀. The above results indicated that the possible crosstalk of oxidative stress and NF‐κB activity was associated with MC‐LR‐induced hepatocytes apoptosis in vivo. Our data will provide a new perspective for understanding the mechanisms of MC‐induced liver injury. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 552–560, 2016.     

蜂蛰伤致儿童中毒24例临床分析

目的总结急性蜂毒中毒致儿童多器官功能障碍的治疗经验。方法综合分析我院1997年至2007年间急性蜂毒中毒患儿24例临床资料。结果24例患儿入院后均呈现不同程度的心、肝、肾功能损害等临床表现。结论治疗蜂毒中毒应尽早采用透析等综合性治疗措施,保护心、肝、肾等多器官功能,促使多器官功能恢复是抢救治疗该病的关键。     

Propolis nanoparticles modulate the inflammatory and apoptotic pathways in carbon tetrachloride‐induced liver fibrosis and nephropathy in rats

This study assessed the use of emulsion‐produced propolis nanoparticles for treating carbon tetrachloride (CCl₄)‐induced liver fibrosis and nephropathy on albino rat model. The evaluation of hepatotoxicity, nephrotoxicity, and the treatment outcomes involved biochemical investigations of blood samples as well as molecular analysis, and histopathological assessment for liver and kidney tissue samples. CCl₄ treatment caused elevated biochemical indicators of hepatotoxic and nephrotoxic effects as detected by liver and kidney functions tests, which improved gradually with propolis nanoparticles treatment. The molecular studies showed an increase in transforming growth factor β (TGF‐β), Nephrin, and Caspase‐9, while Bcl‐2 levels dropped in both liver and kidney tissue samples; such changes were normalized after treatment. The histological findings confirm both biochemical and molecular studies. Our results indicated that propolis nanoparticles had an anti‐inflammatory effect as proved by decreased expression of TGF‐β in liver tissue and Nephrin in kidney tissue. The propolis nanoparticles showed an anti‐apoptotic effect on liver and kidney tissue increasing the expression of Bcl‐2 and decreasing the expression of Caspase‐9.     

Chronic moderate alcohol consumption relieves high‐fat high‐cholesterol diet‐induced liver fibrosis in a rat model

Nonalcoholic fatty liver disease is a worldwide health issue and chronic alcohol consumption may have different effects on this disease. This study explored the role of chronic moderate alcohol consumption on high‐fat high‐cholesterol (HFHC) diet‐induced liver fibrosis in a rodent model. Male Sprague–Dawley rats were divided into five groups: standard chow group, standard chow plus Er Guo Tou (EGT, a Chinese spirit made from fermented cereals) group, HFHC group, HFHC plus EGT group, and HFHC plus pure ethanol (EtOH) group. Rats were fed standard chow or HFHC chow for 12 weeks. EGT or pure ethanol was administrated at a daily dose of 4 g/kg body weight via intra‐gastric gavage from week 4. At the end of week 12, hematoxylin and eosin staining, Sirius red and immunohistochemistry of liver sections were examined. The hepatic expression of F4/80, TNF‐α, IL‐1β, IL‐6, CXCL1, CXCL2, α‐SMA, Collagen, TGF‐β, MMP2, MMP9, and TIMP1 was calculated. Both moderate EGT and pure ethanol did not increase plasma endotoxin in the portal vein comparing with the FHFC group. EGT and pure ethanol did not improve hepatic inflammation, but ameliorated liver fibrosis in histology. Moderate EGT and pure ethanol ameliorated HFHC diet‐induced activation of Kupffer cells and hepatic stellate cells. In conclusion, chronic moderate EGT and pure ethanol could ameliorate HFHC diet‐induced liver fibrosis.     

Antineoplastic effect of β‐elemene on prostate cancer cells and other types of solid tumour cells

Objectives β‐Elemene, a natural compound extracted from over 50 different Chinese medicinal herbs and plants, has been effective in the treatment of hyperplastic and proliferative disorders such as prostatic hypertrophy, hysteromyoma and neoplasms. Our previous studies have demonstrated that β‐elemene exhibits strong inhibitory activity in ovarian cancer cells. The aim of the present study was to assess the effect of β‐elemene on prostate cancer cells as well as other types of tumour cells and to determine whether the effect of β‐elemene on prostate cancer cell death was mediated through the induction of apoptosis. Methods The MTT assay was used to evaluate the ability of β‐elemene to inhibit cellular proliferation in cancer cells. Cellular apoptosis was assessed by annexin V binding, TUNEL and ELISA‐based assays. Caspase activity was measured using a caspases assay kit. The protein levels of Bcl‐2, caspases, cytochrome c and poly(ADP‐ribose) polymerase (PARP) were analysed by Western blotting. Key findings Here, we showed that β‐elemene had an antiproliferative effect on androgen‐insensitive prostate carcinoma DU145 and PC‐3 cells. Treatment with β‐elemene also inhibited the growth of brain, breast, cervical, colon and lung carcinoma cells. The effect of β‐elemene on cancer cells was dose dependent, with IC50 values ranging from 47 to 95 µg/ml (230–465 µm ). TUNEL assay and flow cytometric analysis using annxin V/propidium iodide staining revealed that the percentage of apoptotic prostate cancer cells was increased by β‐elemene in a dose‐ and time‐dependent manner. Moreover, β‐elemene exposure resulted in a decreased Bcl‐2 protein level, increased cytochrome c release, and activated PARP and caspase‐3, ‐7, ‐9, and ‐10 in prostate cancer cells. Conclusions Overall, these findings suggest that β‐elemene exerts broad‐spectrum antitumour activity against many types of solid carcinoma and supports a proposal of β‐elemene as a new potentially therapeutic drug for castration‐resistant prostate cancer and other solid tumours.     

Acid sphingomyelinase mediates the noise‐induced liver disorder in mice

Noise‐induced structural and functional disorder of the liver has been realized, but the underlying mechanism remains to be characterized, which has limited the introduction of precautious measures. Over‐activation of acid sphingomyelinase (ASM)/ceramide (Cer) pathway takes centre stage in hepatocyte injury entailed by various stimulus. We aimed to investigate whether it mediated the noise elicited liver disorder on infrastructure, lipid metabolism, apoptosis, and oxidative stress. Mice were exposed to broad band noise (20–20k Hz, 90–110 dB) for 1, 3, 5 or 7 days by 3 hr/d. Doxepin hydrochloride (DOX), an ASM inhibitor was given by 5 mg/kg/d gavage. We showed that 5 or 7 days intense, broad band noise exposure caused significant infrastructure derangement and lipid droplets storage in hepatocytes. The content of cholesterol, free fatty acids or triglyceride was increased significantly in liver tissue upon noise stimulation. Moreover, the noise promoted apoptosis and superoxide generation in hepatocytes significantly, enhancing activity of aspartate aminotransferase (AST) or alanine amino transferase (ALT) in serum. Acid sphingomyelinase activity and Cer generation in liver tissue were elevated by noise exposure, which was normalized with DOX administrated. Accordingly, DOX alleviated steatosis, apoptosis, oxidative stress and enzymatic change in hepatocytes or serum of noise exposed mice substantially. In summary, our results suggest the ASM/Cer pathway contributes to the broad band noise elicited liver damage in mice.     

Effect of parthanatos on ropivacaine‐induced damage in SH‐SY5Y cells

Ropivacaine is one of the most common but toxic local anaesthetics, and the mechanisms underlying its neurotoxicity are still largely unknown. This study was conducted to prepare a ropivacaine‐induced neuronal injury model and research the effects of ropivacaine on PARP‐1 activation and nicotinamide adenine dinucleotide (NAD)⁺ depletion. The cell death and apoptosis of ropivacaine‐induced SH‐SY5Y cells were detected with flow cytometry. The lactate dehydrogenase cycling reaction measured the NAD⁺ level, and western blots were used to analyze the expression levels of PARP‐1 and apoptosis‐inducing factor (AIF) after ropivacaine treatments with different concentrations and durations. A PARP‐1 inhibitor (PJ‐34) was used to confirm the relationship between PARP‐1 activation and NAD⁺ depletion. Hoechst 33258 nuclear staining and a mitochondrial membrane potential (Δψm) assay were used to detect the role of exogenous NAD⁺ in ropivacaine‐induced neuronal injury. Ropivacaine‐induced SH‐SY5Y cell death and apoptosis, PARP‐1 activation, and AIF increase as well as intracellular NAD⁺ depletion occurred in a time‐ and concentration‐dependent manner (P<.05). PARP‐1 activation led to NAD⁺ depletion (P<.05). Exogenous NAD⁺ impaired ropivacaine‐induced nuclear injury (P<.05). Ropivacaine treatment induced PARP‐1 activation and NAD⁺ depletion (P<.05). Parthanatos (PARP‐1‐dependent cell death) was definitely involved in ropivacaine‐induced neuronal injury, and exogenous NAD⁺ may be a novel therapeutic method for parthanatos‐dependent neuronal injury.     

Suppression of reactive oxygen species‐mediated ERK and JNK activation sensitizes dihydromyricetin‐induced mitochondrial apoptosis in human non‐small cell lung cancer

Nonsmall cell lung cancer (NSCLC) is the most common type of lung cancer with a high mortality rate and still remains a therapeutic challenge. A strategy for targeting NSCLC is to identify agents that are effective against NSCLC cells while sparing normal cells. Dihydromyricetin (DHM) is the major flavonoid component derived from Ampelopsis grossedentata, which has a long history of use in medicine. Herein, the molecular mechanisms by which DHM exerts its anticancer effects against NSCLC cells were investigated. Results from MTS, colony formation, Western blot, flow cytometric, and JC‐1 mitochondrial membrane potential assays revealed that DHM showed a selective cytotoxic effect against NSCLC cells (A549 and H1975), but not against normal lung (WI‐38) fibroblasts, by inducing apoptosis. DHM‐induced cell apoptosis occurred through Bcl‐w suppression‐mediated mitochondrial membrane depolarization, caspase‐9/‐7/‐3 activation, and poly(ADP‐ribose) polymerase (PARP) cleavage in A549 and H1975 cells. Moreover, treatment of A549 and H1975 cells with DHM induced increase of intracellular peroxide and sustained activation of extracellular signal‐regulated kinase (ERK)1/2 and c‐Jun N‐terminal kinase (JNK)1/2, and the reactive oxygen species scavenger, N‐acetylcysteine (NAC), reversed DHM‐induced ERK and JNK activation. Furthermore, treatment of cells with specific inhibitors of ERK and JNK or NAC significantly promoted the DHM‐induced activation of caspase‐9/‐7/‐3 and PARP cleavage and also sensitized the antitumorigenic effect of DHM on NSCLC cells. These findings define and support a novel function of DHM of inducing mitochondrion‐derived apoptosis in human NSCLC cells, and a combination of DHM with ERK and JNK inhibitors should be a good strategy for preventing NSCLC proliferation. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1426–1438, 2017.     

Association of p38MAPK‐p53‐Fas aggregation in S‐allyl cysteine mediated regulation of hepatocarcinoma

Bioactive components of dietary phytochemicals have been reported to possess antitumor activities. Evidences suggested key role of stress responsive p38MAPK in the induction of nutraceuticals mediated apoptosis in hepatocellular carcinoma (HCC). Current study demonstrated detailed molecular bagatelle associated with p38 MAPK mediated effective suppression of cell growth both in HepG2 and chemically induced liver carcinoma after S‐allyl cysteine (SAC) treatment. SAC promoted p38MAPK activity responsible for p53 phosphorylation, its stabilization followed by nuclear translocation leading to induction in expression and oligomerization of Fas protein. Distinctive p38MAPK‐p53 axis dependent Fas‐FasL‐FADD mediated caspase activities along with perturbed cell cycling became normalized with continuation of SAC treatment for another month to diethylnitrosamine induced liver carcinoma. Co‐treatment with SB203580, the p38MAPK inhibitor, prevented pro‐apoptotic effect of SAC by altering p53 phosphorylation and death inducing signaling complex conformation in HepG2 and induced HCC. Collectively study suggested significant contribution of p38MAPK‐p53‐DISC‐Caspase pathway in the regulation of anti‐neoplastic activity of SAC against HCC.     

Nimbolide induced apoptosis by activating ERK‐mediated inhibition of c‐IAP1 expression in human hepatocellular carcinoma cells

Nimbolide is one of the major compounds from the leaves and flowers of the neem tree and exhibits antitumor properties on various cancer cells. However, no report has shown that nimbolide induces apoptosis in vitro and in vivo in human hepatocellular carcinoma cells. Our results indicated that it inhibited cell growth in Huh‐7 and PLC/PRF/5 cells. We also found that nimbolide induced cell death through the induction of G2/M phase arrest and mitochondrial dysfunction, accompanied by the increased expression of cleaved caspase‐7, caspase‐9, caspase‐3, caspase‐PARP, and Bax and decreased expression of Mcl‐1 and Bcl‐2. A human apoptosis antibody array analysis demonstrated that inhibition of the apoptosis family proteins (XIAP, c‐IAP1, and c‐IAP2) was one of the major targets of nimbolide. Additionally, nimbolide sustained activation of ERK expression. Moreover, pretreatment with U0126 (MEK inhibitor) markedly abolished nimbolide‐inhibited cell viability, induced cell apoptosis, ERK phosphorylation, cleaved caspase‐9, caspase‐3, cleaved‐PARP activation, and increased c‐IAP1 expression in Huh‐7 cells. An in vivo study showed that nimbolide significantly reduced Huh‐7 tumor growth and weight in a xenograft mouse model. This study indicated the antitumor potential of nimbolide in human hepatocellular carcinoma cells.     

Autophagy potentially protects against 2,3,7,8‐tetrachlorodibenzo‐p‐Dioxin induced apoptosis in SH‐SY5Y cells

The environmental toxicant TCDD may elicit cytotoxic effects by inducing reactive oxygen species (ROS) generation. Autophagy is one of the first lines of defense against oxidative stress damage. Herein, we investigated whether autophagy played a regulatory role in TCDD‐induced neurotoxicity. Here, we showed that TCDD exposure caused marked autophagy in SH‐SY5Y cells, whose dose range was close to that inducing apoptosis. Electron microscopic and Western blot analyses revealed that TCDD induced autophagy at a starting dose of approximate 100 nM. Interestingly, 100–200 nM TCDD exposure resulted in obviously decreased cell viability and evident apoptotic phenotype. Furthermore, the levels of pro‐apoptotic molecules, Bax and cleaved‐PARP, increased significantly, whereas Bcl2 declined after exposed to 100 nM TCDD. In addition, the apoptosis was verified using flow cytometrical analysis. These data strongly suggested that TCDD induced both autophagy and apoptosis at a similar dose range in SH‐SY5Y cells. Interestingly, pretreatment with ROS scavenger, N‐acetyl‐cysteine (NAC), could effectively block both TCDD‐induced apoptosis and autophagy. More surprisingly, inhibition of autophagy with 3‐methyladenine (3MA), remarkably augmented TCDD‐induced apoptosis. The findings implicated that the onset of autophagy might serve as a protective mechanism to ameliorate ROS‐triggered cytotoxic effects in human SH‐SY5Y neuronal cells under TCDD exposure. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1068–1079, 2016.     

Butein,a Plant Polyphenol,Induces Apoptosis Concomitant with Increased Caspase‐3 Activity,Decreased Bcl‐2 Expression and Increased Bax Expression in HL‐60 Cells

Abstract: In the present study we have investigated whether butein could induce apoptosis in human leukaemic HL‐60 cells. The treatment of HL‐60 cells with butein induced apoptotic cell death as determined by morphological and biochemical changes. Apoptotic DNA fragments in the butein‐treated HL‐60 cells were increased gradually as determined by flow cytometric analysis. The caspase‐3 activity was increased during butein‐induced apoptosis. However, caspase‐3 inhibitor abrogated the butein‐induced DNA fragmentation. Furthermore, the treatment of HL‐60 cells with butein decreased the expression of Bcl‐2 protein, but increased the expression of Bax protein. These results suggest that butein‐induced apoptosis is mediated through the activation of caspase‐3 and it is associated with changed expression of Bcl‐2 and Bax proteins.