Rutin‐protected BisGMA‐induced cytotoxicity,genotoxicity, and apoptosis in macrophages through the reduction of the mitochondrial apoptotic pathway and induction of antioxidant enzymes

Bisphenol‐A‐glycidyldimethacrylate (BisGMA) is a resin monomer frequently used in dentin restorative treatments. The leakage of BisGMA monomer from BisGMA‐based polymeric resins can lead to cytotoxicity in macrophages. Rutin has various beneficial bioeffects, including antioxidation and antiinflammation. In this study, we found that pretreatment of RAW264.7 macrophages with rutin‐inhibited cytotoxicity induced by BisGMA in a concentration‐dependent manner. BisGMA‐induced apoptosis, which was detected by levels of phosphatidylserine from the internal to the external membrane and formation of sub‐G1, and genotoxicity, which was detected by cytokinesis‐blocked micronucleus and single‐cell gel electrophoresis assays, were inhibited by rutin in a concentration‐dependent manner. Rutin suppressed the BisGMA‐induced activation of caspase‐3 and ‐9 rather than caspase‐8. Rutin inhibited the activation of the mitochondrial apoptotic pathway, including cytochrome C release and mitochondria disruption, after macrophages were treated with BisGMA. Finally, BisGMA‐induced reactive oxygen species (ROS) generation and antioxidant enzyme (AOE) deactivation could be reversed by rutin. Parallel trends were observed in the elevation of AOE activation and inhibition of ROS generation, caspase‐3 activity, mitochondrial apoptotic pathway activation, and genotoxicity. These results suggested that rutin suppressed BisGMA‐induced cytotoxicity through genotoxicity, the mitochondrial apoptotic pathway, and relatively upstream factors, including reduction of ROS generation and induction of AOE.     

Cytotoxicity and genotoxicity of triethyleneglycol‐dimethacrylate in macrophages involved in DNA damage and caspases activation

Triethyleneglycol‐dimethacrylate (TEGDMA) is a monomer and widely used in dental composite resins. TEGDMA has been found to exhibit cytotoxicity and genotoxicity on many cells. However, little is known about the potential toxicological implications of TEGDMA on murine macrophage cell line RAW264.7. In this study, TEGDMA demonstrated a cytotoxic effect to RAW264.7 cells in a concentration‐ and time‐dependent manner (p < 0.05). TEGDMA was found to induce two modes of cell death in a concentration‐dependent manner (p < 0.05). TEGDMA‐induced cell apoptosis was demonstrated by the increase in the portion of sub‐G0/G1 phase and DNA ladder formation. In addition, TEGDMA exhibited genotoxicity via a dose‐related increase in the numbers of micronucleus and DNA strand breaks (p < 0.05). Furthermore, the activation of caspase‐3, ?8, and ?9 were generated by TEGDMA in a dose‐dependent manner (p < 0.05). These results indicated that cytotoxicity and genotoxicity induced by TEGDMA in macrophages may be via DNA damage and caspase activation. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 581–588, 2015.     

Wogonin attenuates endotoxin‐induced prostaglandin E2 and nitric oxide production via Src‐ERK1/2‐NFκB pathway in BV‐2 microglial cells

Microglia are the major component of intrinsic brain immune system in neuroinflammation. Although wogonin expresses anti‐inflammatory function in microglia, little is known about the molecular mechanisms of the protective effect of wogonin against microglia activation. The aim of this study was to evaluate how wogonin exerts its anti‐inflammatory function in BV2 microglial cells after LPS/INFγ administration. Wogonin not only inhibited LPS/ INFγ‐induced PGE2 and NO production without affecting cell viability but also exhibited parallel inhibition on LPS/INFγ‐induced expression of iNOS and COX‐2 in the same concentration range. While LPS/INFγ‐induced expression of P‐p65 and P‐IκB was inhibited by wogonin — only weak inhibition on P‐p38 and P‐JNK were observed, whereas it significantly attenuated the P‐ERK1/2 and its upstream activators P‐MEK1/2 and P‐Src in a parallel concentration‐dependent manner. These results indicated that the blockade of PGE2 and NO production by wogonin in LPS/INFγ‐stimulated BV2 cells is attributed mainly to interference in the Src‐MEK1/2‐ERK1/2‐NFκB‐signaling pathway. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1162–1170, 2014.     

Induction of Apoptosis by Lovastatin through Activation of Caspase‐3 and DNase II in Leukaemia HL‐60 Cells

Abstract: Lovastatin, an HMG‐CoA reductase inhibitor, was found to suppress growth and induce apoptosis in culture human promyelocytic leukaemic cell, HL‐60. However, the mechanisms of lovastatin‐induced apoptosis are still unclear. In this study, we attempted to elucidate the signal transduction pathway for lovastatin‐induced apoptosis in HL‐60 cells in a dose‐ and time‐dependent manner. The features of this apoptosis were attenuated by the presence of mevalonate, a metabolic intermediate of cholesterol synthesis. Treatment of lovastatin caused a rapid release of mitochondrial cytochrome c into cytosol and subsequent induction of caspase‐3, but not caspase‐1 activity. Lovastatin also stimulated proteolytic cleavage of poly‐(ADP‐ribose) polymerase (PARP), and followed by the appearance of caspase activity and DNA fragmentation. Pretreatment with caspase‐3 inhibitors, Ac‐DEVD‐CHO and Z‐VAD‐FMK, inhibited lovastatin–induced caspase‐3 activity and DNA fragmentation. Furthermore, we demonstrated that DNase II was involved in the DNA fragmentation induced by lovastatin. These results suggested that the mechanism of lovastatin induced HL‐60 cells apoptosis through activation of caspase‐3 and DNase II activities.     

Protective effect of wogonin on endotoxin‐induced acute lung injury via reduction of p38 MAPK and JNK phosphorylation

Acute lung injury (ALI) is a serious inflammatory disorder which remains the primary cause of incidence and mortality in patients with acute pulmonary inflammation. However, there is still no effective medical strategy available clinically for the improvement of ALI. Wogonin, isolated from roots of Scutellaria baicalensis Georgi, is a common medicinal herb which presents biological and pharmacological effects, including antioxidation, anti‐inflammation, and anticancer. Preadministration of wogonin inhibited not only lung edema but also protein leakage into the alveolar space in murine model of lipopolysaccharide (LPS)‐induced ALI. Moreover, wogonin not only reduced the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)?2 but also inhibited the phosphorylation of mitogen‐activated protein kinase (MAPK) induced by LPS. We further found wogonin inhibited the phosphorylation of p38 MAPK and JNK at a concentration lower than ERK. In addition, inhibition of lung edema, protein leakage, expression of iNOS and COX‐2, and phosphorylation of p38 MAPK and JNK were all observed in a parallel concentration‐dependent manner. These results suggest that wogonin possesses potential protective effect against LPS‐induced ALI via downregulation of iNOS and COX‐2 expression by blocking phosphorylation of p38 MAPK and JNK. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 397–403, 2017.     

Zinc Protects Human Kidney Cells from Depleted Uranium‐induced Apoptosis

Depleted uranium (DU) is a weak radioactive heavy metal, and zinc (Zn) is an effective antidote to heavy metal poisoning. However, the effect of Zn on DU‐induced cytotoxicity and apoptosis is not completely understood. The purpose of this study was to evaluate the effect of Zn on DU‐induced cell apoptosis in human kidney cells (HK‐2) and explore its molecular mechanism. Pre‐treatment with Zn significantly inhibited DU‐induced apoptosis. It reduced the formation of reactive oxygen species in the cells, increased the catalase (CAT) and glutathione (GSH) concentrations, suppressed the DU‐induced soluble Fas receptor (sFasR) and soluble Fas ligand (sFasL) overexpression, suppressed the release of cytochrome c and apoptosis inhibitor factor (AIF) from mitochondria to cytoplasm, inhibited the activation of caspase‐9, caspase‐8 and caspase‐3, and induced metallothionein (MT) expression. Furthermore, exogenous MT effectively inhibited DU‐induced cell apoptosis. In conclusion, mitochondrial and FasR‐mediated apoptosis pathways contribute to DU‐induced apoptosis in HK‐2 cells. Through independent mechanisms, such as indirect antioxidant effects, inhibition of the activation of caspase‐9, caspase‐8 and caspase‐3, and induction of MT expression, Zn inhibits DU‐induced apoptosis.     

Cytotoxicity and genotoxicity of chlorhexidine on macrophages in vitro

Chlorhexidine (CHX) is the most widely used antiseptic for wound, skin disinfection, and dental hygiene. The aim of this study is to investigate the possible correlation between CHX‐induced cytogenotoxicity and alterations in normal cell cycle on RAW264.7 macrophages. The cytotoxicity, mechanism of cell death, mitotic activity, and reactive oxygen species (ROS) generation were determined by tetrazolium bromide reduction assay, flow cytometry, cytokinesis‐block proliferation index, and superoxide dismutase‐inhibitable reduction of ferricytochrome c, respectively. The genotoxicity was measured using comet assay and cytokinesis‐block micronucleus assay. The cytotoxicity of CHX in RAW264.7 cells presented a dose‐ and time‐dependent manner (p < 0.05). The mode of cell death shifted from apoptosis to necrosis when the dosage of CHX increased. The genotoxicity of CHX in RAW264.7 cells had shown DNA damage in a dose‐dependent manner (p < 0.05). Prolongation of cell cycle and the increase of ROS generation also expressed in a dose‐dependent manner (p < 0.05). Taken together, the data suggested that CHX‐induced cytotoxicity and genotoxicity on macrophages may be via ROS generation. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 452–458, 2014.     

Madecassoside induces apoptosis of keloid fibroblasts via a mitochondrial‐dependent pathway

Centella asiatica herb is a frequently prescribed drug in southeastern Asia and China that can simultaneously facilitate wound healing and prevent scar formation. The active constituents and underlying mechanisms responsible for these biphasic actions remain unknown. Previous studies in our laboratory demonstrated that madecassoside, the main active triterpene saponin in C. asiatica herbs, was able to treat trauma‐caused scars in rabbit ear and facilitate burn wound healing in mice. As the formation and progression of keloid scars is closely related to the excessive proliferation and insufficient apoptosis of dermal fibroblasts, the effects of madecassoside on the proliferation and apoptosis of keloid fibroblasts (KFs) were examined in the present study. Primary KFs, originating from human earlobe keloids, were purified and cultured, and then treated with increasing concentrations of madecassoside (10, 30, and 100 µM) for 48 h. Madecassoside inhibited the proliferation of KFs in a time‐and concentration‐dependent manner, and induced KF apoptosis as revealed by Hoechst 33258 staining and flow cytometry analysis. Furthermore, madecassoside activated caspase‐9 and caspase‐3 rather than caspase‐8, depolarized the mitochondrial membrane potential, and regulated expression of Bcl‐2 family members in KFs. These findings suggest that madecassoside induced the apoptosis of KFs through a mitochondrial‐dependent pathway. Drug Dev Res 72: 315–322, 2011. © 2010 Wiley‐Liss, Inc.     

Sulforaphane‐induced apoptosis in human leukemia HL‐60 cells through extrinsic and intrinsic signal pathways and altering associated genes expression assayed by cDNA microarray

Sulforaphane (SFN), one of the isothiocyanates, is a biologically active compound extracted from cruciferous vegetables, and has been shown to induce cytotoxic effects on many human cancer cells including human leukemia cells. However, the exact molecular mechanism and altered gene expression associated with apoptosis is unclear. In this study, we investigated SFN‐induced cytotoxic effects and whether or not they went through cell‐cycle arrest and induction of apoptosis and further examined molecular mechanism and altered gene expression in human leukemia HL‐60 cells. Cell viability, cell‐cycle distribution, sub‐G1 (apoptosis), reactive oxygen species (ROS) and Ca²⁺ production, levels of mitochondrial membrane potential (ΔΨ_m), and caspase‐3, ?8, and ?9 activities were assayed by flow cytometry. Apoptosis‐associated proteins levels and gene expressions were examined by Western blotting and cDNA microarray assays, respectively. Results indicated that SFN decreased viable cells, induced G2/M phase arrest and apoptosis based on sub‐G1 phase development. Furthermore, SFN increased ROS and Ca²⁺ production and decreased the levels of ΔΨ_m and activated caspase‐3, ?8, and ?9 activities in HL‐60 cells. SFN significantly upregulated the expression of BAX, Bid, Fas, Fas‐L, caspase‐8, Endo G, AIF, and cytochrome c, and inhibited the antiapoptotic proteins such as Bcl‐x and XIAP, that is associated with apoptosis. We also used cDNA microarray to confirm several gene expressions such as caspase ?8, ?3, ?4, ?6, and ?7 that are affected by SFN. Those results indicated that SFN induced apoptosis in HL‐60 cells via Fas‐ and mitochondria‐dependent pathways. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 311–328, 2017.     

Epigallocatechin gallate sensitizes cisplatin‐resistant oral cancer CAR cell apoptosis and autophagy through stimulating AKT/STAT3 pathway and suppressing multidrug resistance 1 signaling

Epigallocatechin gallate (EGCG) is a green tea polyphenol that presents anticancer activities in multiple cancer cells, but no available report was addressed for the underling molecular mechanism of cytotoxic impacts on drug‐resistant oral squamous cell carcinoma cells. In the present study, the inhibitory effects of EGCG were experienced on cisplatin‐resistant oral cancer CAR cells. EGCG inhibited cell viability in a time‐ and concentration‐dependent manner by a sulforhodamine B (SRB) assay. EGCG induced CAR cell apoptosis and autophagy by 4′,6‐diamidino‐2‐phenylindole (DAPI) dye, acridine orange (AO) staining and green fluorescent protein (GFP)‐tagged LC3B assay, respectively. EGCG also significantly enhanced caspase‐9 and caspase‐3 activities by caspase activity assay. EGCG markedly increased the protein levels of Bax, cleaved caspase‐9, cleaved caspase‐3, Atg5, Atg7, Atg12, Beclin‐1, and LC3B‐II, as well as significantly decreased the expression of Bcl‐2, phosphorylated AKT (Ser473) and phosphorylation of STAT3 on Tyr705 by western blotting in CAR cells. Importantly, the protein and gene expression of multidrug resistance 1 (MDR1) were dose‐dependently inhibited by EGCG. Overall, downregulation of MDR1 levels and alterations of AKT/STAT3 signaling contributed to EGCG‐induced apoptosis and autophagy in CAR cells. Based on these results, EGCG has the potential for therapeutic effect on oral cancer and may be useful for long‐term oral cancer prevention in the future. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 845–855, 2017.     

Direct‐oxidative DNA damage and apoptosis induction in different human respiratory cells exposed to low concentrations of sodium chromate

The mechanism of Cr(VI) genotoxicity has still not been elucidated. We used Fpg‐modified comet assay to assess direct‐oxidative DNA damage on human lung (A549) and bronchial (BEAS‐2B) cells exposed to 0.1, 0.5, 1.0 and 10 μm sodium chromate for 0.5, 1 and 4 h. Moreover we evaluated apoptosis by morphological analysis and caspase‐3 activity, also after 24 h. On A549 cells a time‐dependent DNA damage, expressed as tail DNA%, beginning from 0.5 μm was found. For oxidative DNA damage an induction after 30 min to 0.5 μm decreasing with time, and a time‐dependent increase at 10 μm was found, indicating for low Cr(VI) concentration the oxidative stress as the first event followed by direct DNA damage and for the highest concentration a time‐dependent increase in oxidative DNA damage. On BEAS‐2B cells DNA damage was induced within 1 h at 0.5–10 μm , without changes with time, showing that BEAS‐2B cells are able to resist to Cr(VI) genotoxicity. Early oxidative DNA damage at 0.1 μm decreasing with time was also found. Significant apoptosis was observed by morphological analysis in A549 cells and to a lower extent in BEAS‐2B at 10 μm . The exposure to 10 μm induced caspase‐3 activity after 4 h in BEAS‐2B and after 24 h in A549 cells. The findings show a higher responsiveness of A549 cells to genotoxic effect of Cr(VI) and early transient oxidative DNA damage in BEAS‐2B. The results emphasize the suitability of this experimental model to evaluate the early genotoxic response of different cells to non‐cytotoxic concentrations of Cr(VI) on target organ. Copyright © 2009 John Wiley & Sons, Ltd.     

Wogonin and fisetin induction of apoptosis through activation of caspase 3 cascade and alternative expression of p21 protein in hepatocellular carcinoma cells SK-HEP-1

Wogonin and fisetin are flavonoids, which are widely distributed in plants. Our recent study demonstrated that, among seven structurally related flavonoids, wogonin and fisetin showed the most potent apoptosis-inducing activities in human promyeloleukemic cells HL-60. In the present investigation, we performed molecular studies to assess the apoptotic effects of wogonin and fisetin on hepatocellular carcinoma cells SK-HEP-1. Both wogonin and fisetin showed dose-dependent cytotoxic effects on SK-HEP-1 cells, accompanied by DNA fragmentation. Microscopic observation under Giemsa staining showed that wogonin and fisetin, at the dose of 80 microM, induced cellular swelling and the appearance of apoptotic bodies, characteristics of apoptosis, in SK-HEP-1 cells. Furthermore, flow cytometry analysis showed an increase of hypodiploid cells in wogonin- and fisetin-treated SK-HEP-1 cells. These data demonstrated that wogonin and fisetin were effective inducers of apoptosis in SK-HEP-1 cells. Treatment with an apoptosis-inducing concentration of wogonin or fisetin caused induction of caspase 3/CPP32 activity, but not of caspase 1 activity. In addition, a caspase 3 inhibitor, Ac-DEVD-CHO, but not the caspase 1 inhibitor Ac-YVAD-CHO, reversed the cytotoxic effects of wogonin and fisetin on SK-HEP-1 cells. Further, cleavage of caspase 3 substrates including poly(ADP-ribose) polymerase (PARP) and D4-GDI protein, and decrease of pro-caspase 3 protein were detected in wogonin- and fisetin-treated SK-HEP-1 cells. Increase of p53 protein was associated with wogonin- and fisetin-induced apoptosis; however, a p53-controlled gene, p21(Waf/Cip-1), was only induced in wogonin- (not fisetin-) treated SK-HEP-1 cells. Serum starvation elevated p21(Waf/Cip-1) protein expression, and enhanced the apoptotic induction activity of wogonin (not fiseitn) in SK-HEP-1 cells. Our study has provided molecular evidence to demonstrate that wogonin and fisetin had effective cytotoxic effects through apoptosis induction in hepatocellular carcinoma cells SK-HEP-1; activation of caspase 3 cascade, induction of p53 protein and alternative expression of p21(Waf/Cip-1) protein were involved.     

Cantharidic acid induces apoptosis of human leukemic HL‐60 cells via c‐Jun N‐terminal kinase‐regulated caspase‐8/‐9/‐3 activation pathway

Cantharidin, a natural toxin from blister beetles, has shown potent anticancer activities on many solid tumor cells. Recently, cantharidin and its analogue, norcantharidin, were also shown to suppress nonsolid tumors such as chronic myeloid leukemia, acute myeloid leukemia (AML), and leukemic stem cells. However, there is no available information to address the effects of cantharidic acid (CAC), a hydrolysis product of cantharidin, on human AML cells. The present study showed that CAC, at a range of concentrations (0‐20 μM), concentration‐dependently inhibited cell proliferation in the HL‐60 AML cell line. Western blot and flow cytometric assays demonstrated that CAC induced several features of apoptosis such as sub G1‐phase cell increase, phosphatidylserine (PS) externalization, and significantly activated proapoptotic signaling including caspase‐8, −9, and −3 activation and poly(ADP‐ribose) polymerase (PARP) cleavage in HL‐60 AML cells. Moreover, treatment of HL‐60 cells with CAC induced concentration‐ and time‐ dependent activation of p38 mitogen‐activated protein kinase (p38 MAPK) and c‐Jun N‐terminal kinase (JNK). Only JNK‐, but not p38 MAPK‐specific inhibitor can reverse the CAC‐induced activation of the caspase‐8, −9, and −3. We concluded that CAC can induce apoptosis in human leukemic HL‐60 cells via a caspases‐dependent pathway, and that the apoptosis‐inducing effect of CAC can be regulated by JNK activation signaling.     

顺铂诱导膀胱癌细胞凋亡及其与凋亡相关蛋白的关系

目的　探讨CDDP诱导Scaber凋亡特点和与凋亡相关蛋白表达的关系。方法　选用CDDP诱导膀胱癌细胞株Scaber凋亡 ,运用HE、TUNEL、透射电镜等方法分别检测细胞凋亡、观察凋亡的形态变化特点及应用S P免疫组化方法检测凋亡相关蛋白bcl 2、Bax、caspase 3表达的动态变化。结果　①顺铂可诱导Scaber细胞凋亡 ,其诱导凋亡作用在一定范围内具有时间及剂量依赖性 ;②CDDP诱导Scaber细胞凋亡时 ,bcl 2降低、Bax增加 ,同时出现了bcl 2的核周及核内移位 ;③不同浓度的CDDP可使Scaber细胞中caspase 3的表达增强 ,并具有时间及剂量的依赖性。结论　顺铂可诱导Scaber细胞凋亡 ,CDDP诱导Scaber细胞凋亡与bcl 2降低、Bax增加及bcl 2移位有关 ;CDDP诱导Scaber细胞凋亡是Caspase 3依赖性的。     

3,3'-Diindolylmethane alters Ca2+ homeostasis and viability in MG63 human osteosarcoma cells

Abstract: The effect of the natural product 3,3′‐diindolylmethane (DIM) on cytosolic Ca²⁺ concentrations ([Ca²⁺]_i) and viability in MG63 human osteosarcoma cells was explored. The Ca²⁺‐sensitive fluorescent dye fura‐2 was applied to measure [Ca²⁺]_i. DIM at concentrations of 40–80 μM induced a [Ca²⁺]_i rise in a concentration‐dependent manner. The response was reduced partly by removing Ca²⁺. DIM‐evoked Ca²⁺ entry was suppressed by nifedipine, econazole, SK&F96365 and protein kinase C modulators. In the absence of extracellular Ca²⁺, incubation with the endoplasmic reticulum Ca²⁺ pump inhibitors thapsigargin or 2,5‐di‐tert‐butylhydroquinone (BHQ) inhibited or abolished DIM‐induced [Ca²⁺]_i rise. Incubation with DIM also inhibited thapsigargin or BHQ‐induced [Ca²⁺]_i rise. Inhibition of phospholipase C with U73122 abolished DIM‐induced [Ca²⁺]_i rise. At concentrations of 10–50 μM, DIM killed cells in a concentration‐dependent manner. This cytotoxic effect was not altered by chelating cytosolic Ca²⁺ with 1,2‐bis(2‐aminophenoxy)ethane‐N,N,N′,N′‐tetraacetic acid (BAPTA). Annexin V/propidium iodide staining data implicate that DIM (20 and 40 μM) induced apoptosis in a concentration‐dependent manner. In sum, in MG63 cells, DIM induced a [Ca²⁺]_i rise by evoking phospholipase C‐dependent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ entry via protein kinase C‐sensitive store‐operated Ca²⁺ channels. DIM caused cell death that may involve apoptosis.     

Chlorpyrifos and Cypermethrin Induce Apoptosis in Human Neuroblastoma Cell Line SH‐SY5Y

Our previous in vivo studies showed that chlorpyrifos (CPF) and cypermethrin (CM) in a mixture dermally administered, strongly inhibited cholinesterase activity in plasma and the brain and were very toxic to the rat central nervous system. In this work, the mechanisms of neurotoxicity have not been elucidated. We used human undifferentiated SH‐SY5Y cells to study mechanisms of pesticide‐induced neuronal cell death. It was found that chlorpyrifos (CPF) and its mixture with cypermethrin (CPF+CM) induced cell death of SH‐SY5Y cells in a dose‐ and time‐dependent manner, as shown by MTT assays. Pesticide‐induced SH‐SY5Y cell death was characterized by concentration‐dependent down‐regulation of Bcl‐2 and Bcl‐xL as well as an increase in the caspase 3 activation. Pan‐caspase inhibitor Q‐VD‐OPh produced a slight but significant reversal effect of pesticide‐induced toxicity indicating that the major caspase pathways are not integral to CPF‐ and CPF+CM‐induced cell death. Furthermore, signal transduction inhibitors PD98059, SL‐327, SB202190, SP600125 and mecamylamine failed to attenuate pesticides effect. Atropine exhibited minimal ability to reverse toxicity. Finally, it was shown that inhibition of TNF‐α by pomalidomide attenuated CPF‐/CPF+CM‐induced apoptosis. Overall, our data suggest that FAS/TNF signalling pathways may participate in CPF and CPF+CM toxicity.     

Deltamethrin induced an apoptogenic signalling pathway in murine thymocytes : exploring the molecular mechanism

Deltamethrin (DLM) is a well‐known pyrethroid insecticide; however, the immunotoxic effects of DLM on the mammalian system and its mechanism is still unclear. This study has been designed to first observe the binding affinity of DLM to immune cell receptors and its effects on the immune system. The docking score revealed that DLM has a strong binding affinity towards the CD4 and CD8 receptors. DLM induces apoptosis in murine thymocytes in a concentration‐dependent manner. The ear\ly markers of apoptosis such as enhanced reactive oxygen species (ROS) and caspase‐3 activation are evident as early as 1 h by 25 and 50 μM DLM. Glutathione (GSH) depletion has also been observed at 1 h by 50 μM DLM concentration. In cell‐cycle studies using flow cytometry, the fraction of hypodiploid cells has gradually increased with all the concentrations of DLM at 18 h. The Annexin V binding assay measures the effect of DLM on apoptotic and necrotic cells. The apoptotic cells raised from 18.6% to 35.21% (10–50 μM DLM) at 18 h. N‐acetyl cysteine (NAC) effectively reduced the percentage of apoptotic cells which is increased by DLM. In contrast, buthionine sulfoximine (BSO) caused an elevation in the percentage of apoptotic cells. These results demonstrate that caspase activation, ROS activation and GSH act as critical mediators in a DLM‐induced apoptogenic signalling pathway in murine thymocytes. In the presence of caspase inhibitor, the percentage of apoptotic cells is partially decreased. Thus, there may be the possibility of some other caspase‐independent pathways in DLM‐induced apoptosis. Copyright © 2013 John Wiley & Sons, Ltd.     

Glabridin induces apoptosis and cell cycle arrest in oral cancer cells through the JNK1/2 signaling pathway

Glabridin, a flavonoid extracted from licorice (Glycyrrhiza glabra), possesses various biological properties, including anticancer activities. However, the effect of glabridin on oral cancer cell apoptosis and the underlying molecular mechanisms has not been elucidated. In this study, we demonstrated that glabridin treatment significantly inhibits cell proliferation in human oral cancer SCC‐9 and SAS cell lines. Flow cytometric assays demonstrated that glabridin induced several features of apoptosis, such as sub‐G1 phase cell increase and phosphatidylserine externalization. Furthermore, glabridin induced apoptosis dose‐dependently in SCC‐9 cells through caspase‐3, −8, and −9 activation and poly (ADP‐ribose) polymerase cleavage. Moreover, glabridin increased the phosphorylation of the extracellular signal–regulated kinase, p38, and c‐Jun N‐terminal kinase (JNK) pathways in a dose‐dependent manner. Moreover, the inhibition of the JNK1/2 inhibitor significantly reversed the glabridin‐induced activation of the caspase pathway. In conclusion, our findings suggest that glabridin induces oral cancer cell apoptosis through the JNK1/2 pathway and is a potential therapeutic agent for oral cancer.     

Exploration of intrinsic and extrinsic apoptotic pathways in zearalenone‐treated rat sertoli cells

Zearalenone (ZEA) is a nonsteroidal estrogenic mycotoxin produced mainly by Fusarium. ZEA causes reproductive disorders and is both cytotoxic and genotoxic in animals; however, little is known regarding the molecular mechanism(s) leading to ZEA toxicity. Sertoli cells are somatic cells that support the development of spermatogenic cells. The objective of this study was to explore the effects of ZEA on the proliferation, apoptosis, and necrosis of rat Sertoli cells to uncover signaling pathways underlying ZEA cytotoxicity. ZEA reduced the proliferation of rat Sertoli cells in a dose‐dependent manner, as indicated by a CCK8 assay, while flow cytometry revealed that ZEA caused both apoptosis and necrosis. Immunoblotting revealed that ZEA treatment increased the ratio of Bax/Bcl‐2, as well as the expression of FasL and caspases‐3, ?8, and ?9, in a dose‐dependent manner. Collectively, these data suggest that ZEA induced apoptosis and necrosis in rat Sertoli cells via extrinsic and intrinsic apoptotic pathways. This study provides new insights into the molecular mechanisms by which ZEA exhibits cytotoxicity. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1731–1739, 2016.