Bacopa monnieri‐Induced Protective Autophagy Inhibits Benzo[a]pyrene‐Mediated Apoptosis

Benzo[a]pyrene (B[a]P) is capable of inducing oxidative stress and cellular injuries leading to cell death and associates with a significant risk of cancer development. Prevention of B[a]P‐induced cellular toxicity with herbal compound through regulation of mitochondrial oxidative stress might protect cell death and have therapeutic benefit to human health. In this study, we demonstrated the cytoprotective role of Bacopa monnieri (BM) against B[a]P‐induced apoptosis through autophagy induction. Pretreatment with BM rescued the reduction in cell viability in B[a]P‐treated human keratinocytes (HaCaT) cells indicating the cytoprotective potential of BM against B[a]P. Moreover, BM was found to inhibit B[a]P‐mediated reactive oxygen species (ROS)‐induced apoptosis activation in HaCaT cells. Furthermore, BM was found to preserve mitochondrial membrane potential and inhibited release of cytochrome c in B[a]P‐treated HaCaT cells. Bacopa monnieri induced protective autophagy; we knocked down Beclin‐1, and data showed that BM was unable to protect from B[a]P‐induced mitochondrial ROS‐mediated apoptosis in Beclin‐1‐deficient HaCaT cells. Moreover, we established that B[a]P‐induced damaged mitochondria were found to colocalize and degraded within autolysosomes in order to protect HaCaT cells from mitochondrial injury. In conclusion, B[a]P‐induced apoptosis was rescued by BM treatment and provided cytoprotection through Beclin‐1‐dependent autophagy activation. Copyright © 2016 John Wiley & Sons, Ltd.     

3‐O‐Acetyloleanolic Acid Induces Apoptosis in Human Colon Carcinoma Hct‐116 Cells

The cytotoxic effect of 3‐O‐acetyloleanolic acid, an oleanolic acid derivative isolated from the seeds of Vigna sinensis K., was investigated in human colon carcinoma HCT‐116 cells. 3‐O‐acetyloleanolic acid dose‐dependently inhibited the viability of HCT‐116 cells. Apoptosis was characterized by detection of cell surface annexin V and sub‐G1 apoptotic cell populations. The number of immunostained cells with annexin V‐FITC was increased after treatment with 3‐O‐acetyloleanolic acid. The sub‐G1 cell population was also increased. Expression of TRAIL‐mediated apoptosis signaling‐related death receptor DR5 was increased in 3‐O‐acetyloleanolic acid‐treated HCT‐116 cells. Activation of caspase‐8 and caspase‐3, critical mediators of extrinsic apoptosis signaling, was also increased by 3‐O‐acetyloleanolic acid. The results indicate that 3‐O‐acetyloleanolic acid induces apoptosis in HCT‐116 cells mediated by an extrinsic apoptosis signaling cascade via up‐regulation of DR5. Copyright © 2012 John Wiley & Sons, Ltd.     

Luteoloside attenuates anoxia/reoxygenation‐induced cardiomyocytes injury via mitochondrial pathway mediated by 14‐3‐3η protein

Ischemia/reperfusion (I/R) injury is the major cause of acute cardiovascular disease worldwide. 14‐3‐3η protein has been demonstrated to protect myocardium against I/R injury. Luteoloside (Lut), a flavonoid found in many Chinese herbs, exerts myocardial protection effects. However, the mechanism remains unclear. We hypothesize that the cardioprotective role of Lut is exerted by regulating the 14‐3‐3η signal pathway. To investigate our hypothesis, an in vitro I/R model was generated in H9C2 cardiomyocytes by anoxia/reoxygenation (A/R) treatment. The effects of Lut on cardiomyocytes with A/R injury were assessed by determining the cell viability, lactate dehydrogenase levels, intracellular reactive oxygen species levels, mitochondrial permeability transition pores (mPTP) openness, caspase‐3 activity, and apoptosis rate. The effects on protein expression were tested using western blot analysis. Lut attenuated A/R‐induced injury to cardiomyocytes by increasing the expression of 14‐3‐3η protein and cell viability; decreasing levels of lactate dehydrogenase, reactive oxygen species, mPTP openness, caspase‐3 activity, and low apoptosis rate were observed. However, the cardioprotective effects of Lut were blocked by AD14‐3‐3ηRNAi, an adenovirus knocking down the intracellular 14‐3‐3η expression. In conclusion, to our knowledge, this is the first study to demonstrate that Lut protected cardiomyocytes from A/R‐induced injury via the regulation of 14‐3‐3η signaling pathway.     

1,7‐Bis(4‐hydroxyphenyl)‐4‐hepten‐3‐one from Betula platyphylla induces apoptosis by suppressing autophagy flux and activating the p38 pathway in lung cancer cells

Betula platyphylla (BP) is frequently administered in the treatment of various human diseases, including cancers. This study was undertaken to investigate the pharmacological function of the active components in BP and the underlying mechanism of its chemotherapeutic effects in human lung cancer cells. We observed that BP extracts and 1,7‐bis(4‐hydroxyphenyl)‐4‐hepten‐3‐one (BE1), one of the components of BP, effectively decreased the cell viability of several lung cancer cell lines. BE1‐treated cells exhibited apoptosis induction and cell cycle arrest at the G2/M phase. Further examination demonstrated that BE1 treatment resulted in suppression of autophagy, as evidenced by increased protein expression levels of both LC3 II and p62/SQSTM1. Interestingly, the pharmacological induction of autophagy with rapamycin remarkably reduced the BE1‐induced apoptosis, indicating that apoptosis induced by BE1 was associated with autophagy inhibition. Our data also demonstrated that BE1 exposure activated the p38 pathway resulting in regulation of the pro‐apoptotic activity. Taken together, we believe that BE1 is a potential anticancer agent for human lung cancer, which exerts its effect by enhancing apoptosis via regulating autophagy and the p38 pathway.     

The Androgenic Alopecia Protective Effects of Forsythiaside‐A and the Molecular Regulation in a Mouse Model

This study examined the inhibitory effect of forsythiaside‐A, a natural substance derived from Forsythia suspensa (F. suspensa), on entry into catagen induced by dihydrotestosterone (DHT) in an androgenic alopecia mouse model. In vitro experiment comparing finasteride with forsythiaside‐A showed that forsythiaside‐A treatment resulted in a 30% greater inhibition of DHT‐induced apoptosis in human hair dermal papilla cell (HHDPCs) and human keratinocytes (HaCaTs). In vivo experiment showed that mouse hair density and thickness were increased by 50% and 30%, respectively, in the forsythiaside‐A‐treated group when compared to a DHT group. Tissue histological results revealed that the forsythiaside‐A‐treated group had an increase in size and shape of the hair follicles and a 1.5 times increase in the follicle anagen/telogen ratio when compared to the finasteride group. Western blot examination of TGF‐β2 expression related to apoptosis signaling in mouse skin verified that forsythiaside‐A reduced the expression of TGF‐β2 by 75% and suppressed apoptosis by reducing the expression of caspase‐9 by 40%, and caspase‐3 by 53%, which play an roles up‐regulator in the apoptosis signal. The forsythiaside‐A group also showed a 60% increase in the Bcl‐2/Bax ratio, which is a factor related to mitochondrial apoptosis. Our results indicated that forsythiaside‐A prevents apoptosis by similar mechanism with finasteride, but forsythiaside‐A is more effective than finasteride. In summary, forsythiaside‐A controlled the apoptosis of hair cells and retarded the entry into the catagen phase and therefore represents a natural product with much potential for use as a treatment for androgenic alopecia. Copyright © 2015 John Wiley & Sons, Ltd.     

Schisandrin B stereoisomers protect against hypoxia/reoxygenation‐induced apoptosis and associated changes in the Ca2+‐induced mitochondrial permeability transition and mitochondrial membrane potential in AML12 hepatocytes

The effects of the schisandrin B stereoisomers, (±)γ‐schisandrin [(±)γ‐Sch] and (?)schisandrin B [(?)Sch B], on hypoxia/reoxygenation‐induced apoptosis were investigated in AML12 hepatocytes. Changes in cellular reduced glutathione (GSH) levels, Ca²⁺‐induced mitochondrial permeability transitions (MPTs) and mitochondrial membrane potentials (Δψ_m values) were also examined in (±)γ‐Sch‐ and (?)Sch B‐treated cells, without or with hypoxia/reoxygenation challenge. The (±)γ‐Sch/(?)Sch B pretreatments (2.5–5.0 µm ) protected against hypoxia/reoxygenation‐induced apoptosis in AML12 cells in a concentration‐dependent manner, with the (?)Sch B effect being more potent. Drug antiapoptotic effects were further evidenced by suppression of hypoxia/reoxygenation‐induced mitochondrial cytochrome c release and subsequent cleavage of caspase 3 and poly‐ADP‐ribose polymerase by (?)Sch B pretreatment. Whereas hypoxia/reoxygenation challenge increased the extent of Ca²⁺‐induced MPT pore opening, and Δψ_m, in AML12 hepatocytes, cytoprotection afforded by (±)γ‐Sch/(?)Sch B pretreatment against hypoxia/reoxygenation‐induced apoptosis was associated with a decreased sensitivity to Ca²⁺‐induced MPT and an increased Δψ_m in both unchallenged and challenged cells, compared with the drug‐free control. The results indicate that (±)γ‐Sch/(?)Sch B pretreatment protected against hypoxia/reoxygenation‐induced apoptosis in AML12 hepatocytes and that the cytoprotection afforded by (±)γ‐Sch/(?)Sch B may at least in part be mediated by a decrease in sensitivity to Ca²⁺‐induced MPT, which may in turn result from enhancement of cellular GSH levels by drug pretreatments. Copyright © 2009 John Wiley & Sons, Ltd.     

Neuroprotective Effects of Puerarin on 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine induced Parkinson's Disease Model in Mice

Puerarin, an active component of Pueraria montana var. lobata (Willd.) Sanjappa & Pradeep is well‐known for its anti‐oxidative and neuroprotective activities. Although anti‐Parkinson's disease activity of puerarin was reported in both of in vivo and in vitro model, detailed mechanisms are not clarified. In this study, we addressed that puerarin attenuated 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐induced behavioral deficits, dopaminergic neuronal degeneration and dopamine depletion. Puerarin administration enhanced glutathione (GSH) activity, glial cell line‐derived neurotrophic factor (GDNF) expression and PI3K/Akt pathway activation, which might ameliorate MPTP injection‐induced progressive elevation of reactive oxygen species (ROS) formation in mice. In addition to the effect on ROS, puerarin ameliorated MPTP‐reduced lysosome‐associated membrane protein type 2A (Lamp 2A) expression. Taken together, our data demonstrate that puerarin attenuates MPTP‐induced dopaminergic neuronal degeneration via modulating GDNF expression, PI3K/Akt pathway and GSH activation, which subsequently ameliorate MPTP‐induced ROS formation and decrease of Lamp 2A expression. Copyright © 2013 John Wiley & Sons, Ltd.     

β‐Eudesmol Induces JNK‐Dependent Apoptosis through the Mitochondrial Pathway in HL60 Cells

β‐eudesmol, a natural sesquiterpenol present in a variety of Chinese herbs, is known to inhibit the proliferation of human tumor cells. However, the molecular mechanisms of the effect of β‐eudesmol on human tumor cells are unknown. In the present study, we report the cytotoxic effect of β‐eudesmol on the human leukemia HL60 cells and its molecular mechanisms. The cytotoxic effect of β‐eudesmol on HL60 cells was associated with apoptosis, which was characterized by the presence of DNA fragmentation. β‐eudesmol‐induced apoptosis was accompanied by cleavage of caspase‐3, caspase‐9, and poly (ADP‐ribose) polymerase; downregulation of Bcl‐2 expression; release of cytochrome c from mitochondria; and decrease in mitochondrial membrane potential (MMP). Activation of c‐Jun N‐terminal kinases (JNK) mitogen‐activated protein kinases was observed in β‐eudesmol‐treated HL60 cells, and the inhibitor of JNK blocked the β‐eudesmol‐induced apoptosis, downregulation of Bcl‐2, and the loss of MMP. These data suggest that β‐eudesmol induces apoptosis in HL60 cells via the mitochondrial apoptotic pathway, which is controlled through JNK signaling. Copyright © 2012 John Wiley & Sons, Ltd.     

Harmine Hydrochloride Triggers G2 Phase Arrest and Apoptosis in MGC‐803 Cells and SMMC‐7721 Cells by Upregulating p21, Activating Caspase‐8/Bid,and Downregulating ERK/Bad Pathway

This study aimed to investigate the effects of harmine hydrochloride (HMH) on digestive tumor cells in vitro and its molecular mechanism. MTT assays showed that HMH inhibited the proliferation of some human cancer cell lines and had no obvious inhibitory effects on human LO2 cells. Flow cytometry assays showed that HMH trigged G2 phase arrest in MGC‐803 cells and SMMC‐7721 cells, while the expression of cyclin A, cyclin B, p21, Myt1, and p‐cdc2 (Tyr15) was upregulated. Flow cytometry assays also showed that the percentages of apoptotic cells were increased, the mitochondrial transmembrane potential (ΔΨm) decreased, and the cleavage of caspase‐9, caspase‐3, and poly (Adenosine diphosphate ribose) polymerase (PARP) were observed, the expression of Bad increased, phospho‐Bad (S112) decreased, pro‐caspase‐8 was cleaved, and Bid (22 kDa) was cleaved. The expression of p‐ERK decreased in both cells. In conclusion, these results demonstrated that HMH upregulates the expression of p21, activates Myt1 and inhibits cdc2 by phospho‐cdc2 (Y15), and triggers G2 phase arrest in both MGC‐803 cells and SMMC‐7721 cells. It can also activate the mitochondria‐related cell apoptosis pathway through the caspase‐8/Bid pathway, inhibiting the ERK/Bad pathway and promoting apoptosis in both of these two cell types. Copyright © 2015 John Wiley & Sons, Ltd.     

Prophylaxis with Centella asiatica confers protection to prepubertal mice against 3‐nitropropionic‐acid‐induced oxidative stress in brain

While the usage of Centella asiatica (CA) is on the increase worldwide, evidence demonstrating its protective efficacy against neurotoxicants is scarce. Hence the present study aimed to understand the neuroprotective efficacy of a standardized aqueous extract of CA against 3‐nitropropionic‐acid(3‐NPA)‐induced oxidative stress in the brain of prepubertal mice. We assessed the degree of oxidative stress in cytoplasm of brain regions of male mice (4 wk‐ old) given CA prophylaxis (5 mg/kg bw) for 10 days followed by 3‐NPA administration (i.p.75 mg/kg bw) on the last 2 days. The neurotoxicant elicited marked oxidative stress in the brain of untreated mice as evident by enhanced malondialdehyde levels, reactive oxygen species (ROS) generation, hydroperoxides and protein carbonyls (a measure of protein oxidation) in striatum and other regions (cortex, cerebellum and hippocampus), while CA prophylaxis completely ameliorated the 3‐NPA‐ induced oxidative stress. Depletion of glutathione (GSH) levels, total thiols, perturbations in antioxidant enzymes and cholinergic enzymes in brain discernible among 3‐NPA‐treated mice were predominantly restored to normalcy with CA prophylaxis. It is hypothesized that the prophylactic protection offered by CA extract against neurotoxicant exposure may be largely due to its ability to enhance GSH, thiols and antioxidant defenses in the brain of prepubertal mice. Copyright © 2009 John Wiley & Sons, Ltd.     

Bacopa monniera extract Induces apoptosis in murine sarcoma cells (S‐180)

The Ayurvedic system of medicine recommends Bacopa monniera (BM) in the treatment of tumors. The present study aims to determine the mode of cell death induced by the ethanolic extract of BM in mouse S‐180 cells. BM‐treated S‐180 cells were assessed for cell viability in a dose‐ and time‐dependent manner using dye exclusion studies. Morphological changes in the BM‐treated and untreated cells were studied by transmission electron microscopy (TEM). Glutathione (GSH) levels were quantified and the percentage of apoptotic cells was determined using Annexin V‐FITC assay. The results indicate that BM induces a dose‐ and time‐dependent loss of cell viability with maximum cytotoxicity at 48 h at a concentration of 550 µg/ml. TEM studies indicate apoptosis in the BM‐treated cells. GSH levels were decreased in the BM‐treated cells and Annexin V‐FITC assay revealed 90.2% of the cells as apoptotic. Conclusively, BM induces cell death by apoptosis in S‐180 cells. Copyright © 2008 John Wiley & Sons, Ltd.     

Ramalin‐Mediated Apoptosis Is Enhanced by Autophagy Inhibition in Human Breast Cancer Cells

Breast cancer, the most commonly diagnosed cancer in women worldwide, is treated in various ways. Ramalin is a chemical compound derived from the Antarctic lichen Ramalina terebrata and is known to exhibit antioxidant and antiinflammatory activities. However, its effect on breast cancer cells remains unknown. We examined the ability of ramalin to induce apoptosis and its mechanisms in MCF‐7 and MDA‐MB‐231 human breast cancer cell lines. Ramalin inhibited cell growth and induced apoptosis in both cell lines in a concentration‐dependent manner. By upregulating Bax and downregulating Bcl‐2, ramalin caused cytochrome c and apoptosis‐inducing factor to be released from the mitochondria into the cytosol, thus activating the mitochondrial apoptotic pathway. In addition, activated caspase‐8 and caspase‐9 were detected in both types of cells exposed to ramalin, whereas ramalin activated caspase‐3 only in the MDA‐MB‐231 cells. Ramalin treatment also increased the levels of LC3‐II and p62. Moreover, the inhibition of autophagy by 3‐methyladenine or Atg5 siRNA significantly enhanced ramalin‐induced apoptosis, which was accompanied by a decrease in Bcl‐2 levels and an increase in Bax levels. Therefore, autophagy appears to be activated as a protective mechanism against apoptosis in cancer cells exposed to ramalin. These findings suggest that ramalin is a potential anticancer agent for the treatment of patients with non‐invasive or invasive breast cancer. Copyright © 2015 John Wiley & Sons, Ltd.     

Cryptolepine,isolated from Sida acuta,sensitizes human gastric adenocarcinoma cells to TRAIL‐induced apoptosis

Bioassay guided separation of Sida acuta whole plants led to the isolation of an alkaloid, cryptolepine (1), along with two kaempferol glycosides (2–3). Compound 1 showed strong activity in overcoming TRAIL‐resistance in human gastric adenocarcinoma (AGS) cells at 1.25, 2.5 and 5 μm . Combined treatment of 1 and TRAIL sensitized AGS cells to TRAIL‐induced apoptosis at the aforementioned concentrations. Copyright © 2010 John Wiley & Sons, Ltd.     

Aloe‐emodin Induces Apoptosis in Human Liver HL‐7702 Cells through Fas Death Pathway and the Mitochondrial Pathway by Generating Reactive Oxygen Species

Aloe‐emodin (1,8‐dihydroxy‐3‐hydroxymethyl‐anthraquinone) is one of the primary active compounds in total rhubarb anthraquinones isolated from some traditional medicinal plants such as Rheum palmatum L. and Cassia occidentalis, which induce hepatotoxicity in rats. Thus, the aim of this study was to determine the potential cytotoxic effects and the underlying mechanism of aloe‐emodin on human normal liver HL‐7702 cells. The CCK‐8 assays demonstrated that aloe‐emodin decreased the viability of HL‐7702 cells in a dose‐dependent and time‐dependent manner. Aloe‐emodin induced S and G2/M phase cell cycle arrest in HL‐7702 cells. This apoptosis was further investigated by flow cytometry and nuclear morphological changes by DAPI staining, respectively. Moreover, aloe‐emodin provoked the production of intracellular reactive oxygen species and the depolarization of mitochondrial membrane potential (MMP). Further studies by western blot indicated that aloe‐emodin dose‐dependently up‐regulated the levels of Fas, p53, p21, Bax/Bcl‐2 ratio, and cleaved caspase‐3, ‐8, ‐9, and subsequent cleavage of poly(ADP‐ribose)polymerase (PARP). Taken together, these results suggest that aloe‐emodin inhibits cell proliferation of HL‐7702 cells and induces cell cycle arrest and caspase‐dependent apoptosis via both Fas death pathway and the mitochondrial pathway by generating reactive oxygen species, indicating that aloe‐emodin should be taken into account in the risk assessment for human exposure. Copyright © 2017 John Wiley & Sons, Ltd.     

THC (Δ9‐Tetrahydrocannabinol) Exerts Neuroprotective Effect in Glutamate‐affected Murine Primary Mesencephalic Cultures Through Restoring Mitochondrial Membrane Potential and Anti‐apoptosis Involving CB1 Receptor‐dependent Mechanism

Aging‐related neurodegenerative diseases, such as Parkinson's disease (PD) or related disorders, are an increasing societal and economic burden worldwide. Δ9‐Tetrahydrocannabinol (THC) is discussed as a neuroprotective agent in several in vitro and in vivo models of brain injury. However, the mechanisms by which THC exhibits neuroprotective properties are not completely understood. In the present study, we investigated neuroprotective mechanisms of THC in glutamate‐induced neurotoxicity in primary murine mesencephalic cultures, as a culture model for PD. Glutamate was administered for 48 h with or without concomitant THC treatment. Immunocytochemistry staining and resazurin assay were used to evaluate cell viability. Furthermore, superoxide levels, caspase‐3 activity, and mitochondrial membrane potential were determined to explore the mode of action of this compound. THC protected dopaminergic neurons and other cell types of primary dissociated cultures from glutamate‐induced neurotoxicity. Moreover, THC significantly counteracted the glutamate‐induced mitochondrial membrane depolarization and apoptosis. SR141716A, a CB₁ receptor antagonist, concentration‐dependently blocked the protective effect of THC in primary mesencephalic cultures. In conclusion, THC exerts anti‐apoptotic and restores mitochondrial membrane potential via a mechanism dependent on CB₁ receptor. It strengthens the fact that THC has a benefit on degenerative cellular processes occurring, among others, in PD and other neurodegenerative diseases by slowing down the progression of neuronal cell death. Copyright © 2016 John Wiley & Sons, Ltd.     

Kaempferol protects HIT‐T15 pancreatic beta cells from 2‐deoxy‐D‐ribose‐induced oxidative damage

During the progression of Type 2 diabetes, glucose toxicity is likely to contribute importantly to progressive beta cell failure. Oxidative stress is an important aspect of glucose toxicity in pancreatic beta cells, and reducing sugars, such as 2‐deoxy‐D‐ribose (dRib), produce reactive oxygen species. Furthermore, many of the biological properties of flavonoids are likely to be related to their antioxidant and free‐radical scavenging abilities. Accordingly, in the present study, we investigated whether kaempferol (a flavonol) protects beta cells from dRib‐induced oxidative damage. HIT‐T15 cells were cultured with various concentrations of dRib for 24h. Cell survivals, amounts of reactive oxygen species (ROS) generated, apoptosis, and lipid peroxidation were measured. dRib was found to dose‐dependently reduce cell survival and to markedly increase intracellular ROS levels, apoptosis, and lipid peroxidation. However, kaempferol (10 µM) suppressed dRib (20 mM) induced intracellular ROS, apoptosis, and lipid peroxidation. So, we demonstrate that kaempferol reduces dRib‐mediated beta cell damage interfering with ROS metabolism and protective effects against lipid peroxidation. Our findings indicate that kaempferol protects HIT‐T15 cells from dRib‐induced associated oxidative damage. Copyright © 2009 John Wiley & Sons, Ltd.     

Pachymic Acid Induces Apoptosis of EJ Bladder Cancer Cells by DR5 Up‐Regulation,ROS Generation,Modulation of Bcl‐2 and IAP Family Members

Pachymic acid (PA) is a lanostane‐type triterpenoid derived from Poria cocos mushroom that possess various biological effects such as anti‐cancer, antiinflammatory and anti‐metastasis effects. In this study, we investigated the anti‐cancer effects of PA in EJ bladder cancer cells. The results showed that PA significantly inhibited proliferation of EJ cells in a dose‐dependent manner. PA induced accumulation of sub‐G1 DNA content (apoptotic cell population), apoptotic bodies and chromatin condensation and DNA fragmentation in EJ cells in a dose‐dependent manner. PA also induces activation of caspase‐3, ‐8 and ‐9, and subsequent cleavage of poly (ADP‐ribose) polymerase, and significantly suppressed the inhibitor of apoptosis protein family proteins in a dose‐dependent manner. Furthermore, PA activates Bid and induced the loss of mitochondrial membrane potential (ΔΨ_m) with up‐regulated pro‐apoptotic proteins (Bax and Bad), down‐regulated anti‐apoptotic proteins (Bcl‐2 and Bcl‐xL) and cytochrome c release. In turn, PA increased the generation of reactive oxygen species (ROS); also, the ROS production was blocked by N‐acetyl‐L‐cysteine. The expressions of TNF‐related apoptosis inducing ligand and death receptor 5 were up‐regulated by PA in a dose‐dependent manner, suggesting extrinsic pathway also involved in PA‐induced apoptosis. This study provides evidence that PA might be useful in the treatment of human bladder cancer. Copyright © 2015 John Wiley & Sons, Ltd.     

[6]‐Shogaol,a Novel Chemopreventor in 7,12‐Dimethylbenz[a]anthracene‐induced Hamster Buccal Pouch Carcinogenesis

Oral cancer is a major cause of morbidity and mortality in developing countries. Despite advances in chemotherapy for the cancer management, the survival rate has not yet been improved. Dietary nutrient has been receiving a lot of attention and interest in the chemotherapeutic development. [6]‐Shogaol is a major bioactive compound identified in ginger that possesses many pharmacological properties. The aim of the present study is to investigate the effect of [6]‐shogaol on 7,12‐dimethylbenz[a]anthracene‐induced hamster buccal pouch (HBP) carcinogenesis. Oral squamous cell carcinoma induced in HBP by painting with 0.5% 7,12‐dimethylbenz(a)anthracene (DMBA), thrice in a week for 16 weeks. We observed 100% tumour incidence, decreased levels of lipid peroxidation, antioxidant, and phase II detoxification enzymes (GST, GR and GSH) in DMBA‐induced hamsters. Further, enhanced activity of phase I enzymes (cytochrome p450 and b5) and over‐expression of mutant p53, Bcl‐2 and decreased expression of wild type p53 and Bax were noticed in DMBA‐induced hamsters. Our results indicated that [6]‐shogaol (10, 20 and 40 mg/kg body weight) treated with DMBA‐painted hamsters, considerably reversed tumour incidence, improved antioxidant status, phase II detoxification enzymes, and also inhibit lipid peroxidation and phase I enzymes. Moreover, [6]‐shogaol inhibits mutant p53 and Bcl‐2 expression and significantly restored normal p53, Bax levels. Thus, we concluded that [6]‐shogaol prevents DMBA‐induced HBP carcinogenesis through its antioxidant as well as modulating apoptotic signals. Copyright © 2016 John Wiley & Sons, Ltd.     

Pongapin and Karanjin,furanoflavanoids of Pongamia pinnata,induce G2/M arrest and apoptosis in cervical cancer cells by differential reactive oxygen species modulation,DNA damage,and nuclear factor kappa‐light‐chain‐enhancer of activated B cell signaling

In this study, the antitumor activity of two furanoflavanoid derivatives, Pongapin and Karanjin, was evaluated in comparison with Plumbagin, a plant‐derived polyphenol with proven antitumor activity. The compounds differentially inhibit the growth of different cancer cell lines (most effective on HeLa cells), with very low inhibitory effect on the growth of normal mouse embryonic fibroblast cell line. Pongapin like Plumbagin could significantly increase the intracellular reactive oxygen species (ROS) in the HeLa cells by stabilization of nuclear factor of kappa light polypeptide gene enhancer in B‐cells inhibitor (I‐κB) expression and reduction of nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) expression. In contrast, Karanjin could decrease ROS level by inhibition of I‐κB degradation resulting restriction of NF‐κB nuclear translocation. Pongapin and Plumbagin significantly increased DNA damage‐induced p53 expression and p21 nuclear expression. However, Karanjin treatment showed low DNA damage with increased p53 expression. The compounds induced G2/M arrest and increase in SubG1 population, indicating induction of apoptosis. Apoptosis was further validated by acridine orange/ethidium bromide dual staining and terminal deoxynucleotidyl transferase dUTP nick‐end labeling assay in HeLa cells after treatment with the compounds. The compounds induced caspase‐dependent apoptosis through induction of Bax/Bcl‐2 ratio either through increased expression of Bax by Pongapin and Plumbagin or low expression of Bcl‐2 by Karanjin. Thus, Pongapin and Karanjin may be potential natural anticancer agents in the future, like Plumbagin.