Curcumin inhibits human lung large cell carcinoma cancer tumour growth in a murine xenograft model

Curcumin can decrease viable cells through the induction of apoptosis in human lung cancer NCI‐H460 cells in vitro. However, there are no reports that curcumin can inhibit cancer cells in vivo. In this study, NCI‐H460 lung tumour cells were implanted directly into nude mice and divided randomly into four groups to be treated with vehicle, curcumin (30 mg/kg of body weight), curcumin (45 mg/kg of body weight) and doxorubicin (8 mg/kg of body weight). Each agent was injected once every 4 days intraperitoneally (i.p.), with treatment starting 4 weeks after inoculation with the NCI‐H460 cells. Treatment with 30 mg/kg and 45 mg/kg of curcumin or with 8 mg/kg of doxorubicin resulted in a reduction in tumour incidence, size and weight compared with the control group. The findings indicate that curcumin can inhibit tumour growth in a NCI‐H460 xenograft animal model in vivo. Copyright © 2010 John Wiley & Sons, Ltd.     

Apoptotic Effect of Galbanic Acid via Activation of Caspases and Inhibition of Mcl‐1 in H460 Non‐Small Lung Carcinoma Cells

Galbanic acid (GBA), a major compound of Ferula assafoetida, was known to have cytotoxic, anti‐angiogenic and apoptotic effects in prostate cancer and murine Lewis lung cancer cells; the underling apoptotic mechanism of GBA still remains unclear so far. Thus, in the present study, the apoptotic mechanism of GBA was investigated mainly in H460 non‐small cell lung carcinoma (NSCLC) cells because H460 cells were most susceptible to GBA than A549, PC‐9 and HCC827 NSCLC cells. Galbanic acid showed cytotoxicity in wild EGFR type H460 and A549 cells better than other mutant type PC‐9 and HCC827 NSCLC cells. Also, GBA significantly increased the number of Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive cells and sub G1 population in H460 cells. Western blotting revealed that GBA cleaved poly (ADP‐ribose) polymerase (PARP), activated Bax and caspase 9, attenuated the expression of Bcl‐2, Bcl‐x_L, and Myeloid cell leukemia 1 (Mcl‐1) in H460 cells. However, interestingly, overexpression of Mcl‐1 blocked the ability of GBA to exert cytotoxicity, activate caspase9 and Bax, cleave PARP, and increase sub G1 accumulation in H460 cells. Overall, these findings suggest that GBA induces apoptosis in H460 cells via caspase activation and Mcl‐1 inhibition in H460 cells as a potent anticancer agent for NSCLC treatment. Copyright © 2015 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.     

Emodin Regulates Apoptotic Pathway in Human Liver Cancer Cells

Emodin, a natural anthraquinone, has been reported to possess antiproliferative effects in many cancer cell lines. However, anticancer mechanism against human liver cancer remains unclear. In this study, we observed that emodin induced apoptosis in HepG2 cells and caused a significant accumulation of cells in the G1 phase. Western blot data showed that emodin treatment caused the increasing of release of cytochrome c into cytosol from mitochondria and the activation of caspase‐8 and caspase‐9, which suggest that the intrinsic and extrinsic pathways could be involved. Emodin treatment also resulted in a dose‐dependent accumulation of intracellular reactive oxygen species. Furthermore, emodin increased the protein level of p53 and decreased the protein level of NF‐κB/p65 in HepG2 cells, which indicated these two regulators might play a role in emodin‐induced apoptosis. Computational modeling showed that emodin could directly bind to the BH3 domain of Bcl‐2 through forming one hydrogen bond with Ala146 residue in Bcl‐2. From these examinations, emodin not only significantly downregulated expression of Bcl‐2 but also inhibited the heterodimerization of Bcl‐2 with Bax because of strong interaction between emodin and Bcl‐2. These suggest that emodin induces apoptosis in liver cancer cell line through a multifaceted complex cascade of events. Copyright © 2012 John Wiley & Sons, Ltd.     

Neferine,an alkaloid from lotus seed embryo targets HeLa and SiHa cervical cancer cells via pro‐oxidant anticancer mechanism

Apoptosis and autophagy are important processes that control cellular homeostasis and have been highlighted as promising targets for novel anticancer drugs. This study aims to investigate the inhibitory effects and mechanisms of Neferine (Nef), an alkaloid from the lotus seed embryos of Nelumbo nucifera (N. nucifera), as a dual inducer of apoptosis and autophagy through the reactive oxygen species (ROS) activation in cervical cancer cells. Nef and N. nucifera extract suppressed the cell viability of HeLa and SiHa cells in a dose‐dependent manner. Importantly, Nef showed minimal toxicity to normal cells. Furthermore, Nef inhibited anchorage‐independent growth, colony formation and migration ability of cervical cancer cells. Nef induces mitochondrial apoptosis by increasing pro‐apoptotic protein bax, cytochrome‐c, cleaved caspase‐3 and caspase‐9, poly‐ADP ribose polymerase (PARP) cleavage, DNA damage (pH₂AX) while downregulating Bcl‐2, procaspase‐3 and procaspase‐9, and TCTP. Of note, apoptotic effect by Nef was significantly attenuated in the presence of N‐acetylcysteine (NAC), suggesting pro‐oxidant activity of this compound. Nef also promoted autophagy induction through increasing beclin‐1, atg‐4, atg‐5 and atg‐12, LC‐3 activation, and _P62/SQSTM1 as determined by western blot analysis. Collectively, these results demonstrate that Nef is a potent anticancer compound against cervical cancer cells through inducing apoptosis and autophagic pathway involving ROS.     

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.     

Antiproliferative effect of benzophenones and their influence on cathepsin activity

The antiproliferative activity of two prenylated benzophenones isolated from Rheedia brasiliensis, the triprenylated garciniaphenone and the tetraprenylated benzophenone 7‐epiclusianone, was investigated against human cancer cell lines. The antiproliferative activity on melanoma (UACC‐62), breast (MCF‐7), drug‐resistant breast (NCI‐ADR), lung/non‐small cells (NCI460), ovarian (OVCAR 03), prostate (PC03), kidney (786‐0), lung (NCI‐460) and tongue (CRL‐1624 and CRL‐1623) cancer cells was determined using spectrophotometric quantification of the cellular protein content. The effect of these benzophenones on the activity of cathepsins B and G was also investigated. Garciniaphenone displayed cytostatic activity in all cell lines, whereas 7‐epiclusianone showed a dose‐dependent cytotoxic effect. The IC₅₀ values for cell proliferation revealed that 7‐epiclusianone is more active than garciniaphenone against most of the cell lines. Furthermore, the antiproliferative effects demonstrated by garciniaphenone and 7‐epiclusianone were related to their cathepsin inhibiting properties. In conclusion, 7‐epiclusianone is a promising naturally occurring agent which displays multiple inhibitory effects which may be working in concert to inhibit cancer cell proliferation in vitro. The putative pathway by which 7‐epiclusianone affects cancer cell development may involve cathepsin inhibition. Copyright © 2009 John Wiley & Sons, Ltd.     

c‐Jun N‐terminal Kinase‐Dependent Endoplasmic Reticulum Stress Pathway is Critically Involved in Arjunic Acid Induced Apoptosis in Non‐Small Cell Lung Cancer Cells

Though arjunic acid, a triterpene isolated from Terminalia arjuna, was known to have antioxidant, antiinflammatory, and cytotoxic effects, its underlying antitumor mechanism still remains unclear so far. Thus, in the present study, the molecular antitumor mechanism of arjunic acid was examined in A549 and H460 non‐small cell lung cancer (NSCLC) cells. Arjunic acid exerted cytotoxicity by 3‐[4, 5‐dimethylthiazol‐2‐yl]‐2, 5‐diphenyl tetrazolium bromide (MTT) assay and significantly increased sub‐G1 population in A549 and H460 cells by cell cycle analysis. Consistently, arjunic acid cleaved poly (ADP‐ribose) polymerase (PARP), activated Bax, and phosphorylation of c‐Jun N‐terminal kinases (JNK), and also attenuated the expression of pro‐caspase‐3 and Bcl‐2 in A549 and H460 cells. Furthermore, arjunic acid upregulated the expression of endoplasmic reticulum (ER) stress proteins such as IRE1 α, ATF4, p‐eIF2α, and C/EBP homologous protein (CHOP) in A549 and H460 cells. Conversely, CHOP depletion attenuated the increase of sub‐G1 population by arjunic acid, and also JNK inhibitor SP600125 blocked the cytotoxicity and upregulation of IRE1 α and CHOP induced by arjunic acid in A549 and H460 cells. Overall, our findings suggest that arjunic acid induces apoptosis in NSCLC cells via JNK mediated ER stress pathway as a potent chemotherapeutic agent for NSCLC.     

A p‐Menth‐1‐ene‐4,7‐diol (EC‐1) from Eucalyptus camaldulensis Dhnh. Triggers Apoptosis and Cell Cycle Changes in Ehrlich Ascites Carcinoma Cells

Anticancer activities of p‐menth‐1‐ene‐4,7‐diol (EC‐1) isolated from Eucalyptus camaldulensis Dhnh. were studied on Ehrlich ascites carcinoma (EAC) cells by MTT (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5 diphenyl tetrazolium bromide) assay. Anticancer activities also analyzed in EAC‐bearing mice by assessment of cancer growth inhibition, changes in cancer volume, changes in life span, and hematological parameters. Apoptosis was analyzed by fluorescence microscope, DNA fragmentation assay, and flow cytometry. The expression of apoptosis‐related genes, Bcl‐2, Bcl‐X, PARP‐1, p53, and Bax, were analyzed using polymerase chain reaction (PCR). EC‐1 significantly inhibited proliferation of EAC cells in vivo and restored the altered hematological parameters of EAC‐bearing mice. Cytological observation by fluorescence microscope showed apoptosis of EAC cells upon treatment with EC‐1. Also, DNA fragmentation assay revealed EAC cells' apoptosis following EC‐1 treatment. Increased mRNA expressions of p53 and Bax genes and negative expressions of Bcl‐2 and Bcl‐X were observed in cells treated with EC‐1. These findings confirmed the induction of apoptosis by EC‐1. In addition, MTT assay showed dose‐dependent anticancer activity of EC‐1 against EAC cell. Cell cycle analysis revealed that EC‐1 treatment caused suppression of EAC cells at S phase. To conclude, EC‐1 is a novel anticancer compound and showed antiproliferative and apoptotic activities in cellular and mice models. Copyright © 2015 John Wiley & Sons, Ltd.     

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.     

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.     

Curcumin Inhibits Proliferation and Induces Apoptosis of Human Colorectal Cancer Cells by Activating the Mitochondria Apoptotic Pathway

Curcumin, a natural plant extract from Curcuma longa, is known for its anti‐carcinogenic and chemopreventive effects on a variety of experimental cancer models. In this study, we evaluated the effects of curcumin and elucidated its mechanism in human colorectal carcinoma cells. Cell viability assay showed that curcumin significantly inhibited the growth of LoVo cells. Curcumin treatment induced the apoptosis accompanied by ultra‐structural changes and release of lactate dehydrogenase in a dose‐dependent manner. Moreover, treatment with 0–30 µg/mL curcumin decreased the mitochondrial membrane potential and activated the caspase‐3 and caspase‐9 in a dose‐ and time‐dependent manner. Nuclear and annexin V/PI staining showed that curcumin induced the apoptosis of LoVo cells. FACS analysis revealed that curcumin could induce the cell cycle arrest of LoVo cells at the S phase. Furthermore, western blotting analysis indicated that curcumin induced the release of cytochrome c, a significant increase of Bax and p53 and a marked reduction of Bcl‐2 and survivin in LoVo cells. Taken together, our results suggested that curcumin inhibited the growth of LoVo cells by inducing apoptosis through a mitochondria‐mediated pathway. Copyright © 2012 John Wiley & Sons, Ltd.     

Modulating Bcl-2 family proteins and caspase-3 in induction of apoptosis by paeoniflorin in human cervical cancer cells

Paeoniflorin (PF), the principal bioactive component in the paeony root, has been used alone or combined with other herbs for many years in traditional Chinese medicine. New studies have shown that PF possesses an antitumor effect. However, the effect of PF on human cervical cancer cells has not been reported previously. This study determined the effect of PF on human cervical cancer cell line (HeLa) cells by the methyl thiazolyl tetrazolium (MTT) assay, flow cytometry with annexin V‐fluorescein isothiocyanate (FITC)/propidium iodide (PI) technology, the transmission electron microscope (TEM) and immunocytochemical technique. After treatment with PF, the proliferation of HeLa cells was inhibited in a dose and time‐dependent manner (p < 0.05). The apoptosis rate of HeLa cells increased with ascending concentrations of PF (p < 0.05) and the proportion of HeLa cells in S phase showed an increasing trend also. Typical apoptotic changes of HeLa cells exposed to PF were seen under the TEM. Meanwhile, there was a decrease in the expression of Bcl‐2 and an enhancement in the expression of Bax and caspase‐3 genes compared with the control group (p < 0.05). In conclusion, PF can induce significantly the apoptosis of HeLa cells, which may be demonstrated by the down‐regulation of anti‐apoptosis gene Bcl‐2 and the up‐regulation of pro‐apoptosis genes Bax and caspase‐3. Copyright © 2011 John Wiley & Sons, Ltd.     

Morin enhances auranofin anticancer activity by up‐regulation of DR4 and DR5 and modulation of Bcl‐2 through reactive oxygen species generation in Hep3B human hepatocellular carcinoma cells

Evidence suggests that auranofin (AF) exhibits anticancer activity by inhibiting thioredoxin reductase (TrxR). Here, in this study, we have investigated the synergistic effects of AF and morin and their mechanism for the anticancer effects focusing on apoptosis in Hep3B human hepatocellular carcinoma cells. We assessed the anticancer activities by annexin V/PI double staining, caspase, and TrxR activity assay. Morin enhances the inhibitory effects on TrxR activity of AF as well as reducing cell viability. Annexin V/PI double staining revealed that morin/AF cotreatment induced apoptotic cell death. Morin enhances AF‐induced mitochondrial membrane potential (ΔΨm) loss and cytochrome c release. Further, morin/AF cotreatment upregulated death receptor DR4/DR5, modulated Bcl‐2 family members (upregulation of Bax and downregulation of Bcl‐2), and activated caspase‐3, ‐8, and ‐9. Morin also enhances AF‐induced reactive oxygen species (ROS) generation. The anticancer effects results from caspase‐dependent apoptosis, which was triggered via extrinsic pathway by upregulating TRAIL receptors (DR4/DR5) and enhanced via intrinsic pathway by modulating Bcl‐2 and inhibitor of apoptosis protein family members. These are related to ROS generation. In conclusion, this study provides evidence that morin can enhance the anticancer activity of AF in Hep3B human hepatocellular carcinoma cells, indicating that its combination could be an alternative treatment strategy for the hepatocellular carcinoma.     

Genistein Mitigates Radiation-induced Testicular Injury

The present study investigated the radioprotective effect of a multifunctional soy isoflavone, genistein, with the testicular system. Genistein was administered (200 mg/kg body weight) to male C3H/HeN mice by subcutaneous injection 24 h prior to pelvic irradiation (5 Gy). Histopathological parameters were evaluated 12 h and 21 days post‐irradiation. Genistein protected the germ cells from radiation‐induced apoptosis (p < 0.05 vs vehicle‐treated irradiated mice at 12 h post‐irradiation). Genistein significantly attenuated radiation‐induced reduction in testis weight, seminiferous tubular diameter, seminiferous epithelial depth and sperm head count in the testes (p < 0.05 vs vehicle‐treated irradiated mice at 21 days post‐irradiation). Repopulation and stem cell survival indices of the seminiferous tubules were increased in the genistein‐treated group compared with the vehicle‐treated irradiation group at 21 days post‐irradiation (p < 0.01). The irradiation‐mediated decrease in the sperm count and sperm mobility in the epididymis was counteracted by genistein (p < 0.01), but no effect on the frequency of abnormal sperm was evident. Reactive oxygen species (ROS) were evaluated using DCFDA method and exposure to irradiation elevated ROS levels in the testis and genistein treatment resulted in a significant attenuation of radiation‐induced ROS production. The results indicate that genistein protects from testicular dysfunction induced by gamma‐irradiation by an antiapoptotic effect and recovery of spermatogenesis. Copyright © 2011 John Wiley & Sons, Ltd.     

Xanthorrhizol Induces Apoptosis Through ROS‐Mediated MAPK Activation in Human Oral Squamous Cell Carcinoma Cells and Inhibits DMBA‐Induced Oral Carcinogenesis in Hamsters

Xanthorrhizol, a natural sesquiterpenoid compound isolated from Curcuma xanthorrhiza Roxb, has been known to inhibit the growth of human colon, breast, liver and cervical cancer cells. In this study, xanthorrhizol decreased cell viability, induced apoptosis and decreased the level of full‐length PARP in SCC‐15 oral squamous cell carcinoma (OSCC) cells. A decrease in cell viability and PARP degradation was not prevented by treatment with the caspase inhibitor Z‐VAD‐fmk in xanthorrhizol‐treated cells. Xanthorrhizol treatment elevated intracellular Ca²⁺ and ROS levels in SCC‐15 cells. Treatment with a Ca²⁺ chelator, EGTA/AM, did not affect xanthorrhizol‐ induced cytotoxicity, but cell viability was partly recovered by treatment with endogenous antioxidant, GSH, or hydroxy radical trapper, MCI‐186. Furthermore, the viability of xanthorrhizol‐treated SCC‐15 cells was significantly restored by treatment with SB203580 and/or SP600125 but not significantly by PD98059 treatment. Xanthorrhizol‐induced activation of p38 MAPK and JNK was blocked by MCI‐186. Finally, xanthorrhizol suppressed the number of tumors in buccal pouches and increased the survival rate in hamsters treated with 7,12‐dimethylbenz[a]anthracene. In conclusion, xanthorrhizol may induce caspase‐independent apoptosis through ROS‐mediated p38 MAPK and JNK activation in SCC‐15 OSCC cells and prevent chemical‐induced oral carcinogenesis. Therefore, xanthorrhizol seems to be a promising chemopreventive agent. Copyright © 2012 John Wiley & Sons, Ltd.     

Bioactivity‐guided Isolation of Cytotoxic Sesquiterpene Lactones of Gochnatia polymorpha ssp. floccosa

Phytochemical study of Gochnatia polymorpha (Less) Cabr. ssp. floccosa Cabr. trunk bark, guided by antiproliferative assays on 10 human cancer cell lines and the VERO cell line, yielded six known compounds identified as the triterpene bauerenyl acetate, the guaianolide 11α,13‐dihydrozaluzanin C and the dimeric guaianolides 10‐desoxygochnatiolide A, gochnatiolide A, 8‐hydroxi‐10‐desoxygochnatiolide A and 8‐hydroxigochnatiolide A. Extracts, fractions of extracts and isolated compounds were tested in vitro against a panel of human cancer cell lines, including U251 (glioma, CNS), UACC‐62 (melanoma), MCF‐7 (breast), NCI‐ADR/RES (drug‐resistant ovarian), 786.0 (kidney), NCI‐H460 (lung, no small cells), PC‐3 (prostate), OVCAR‐3 (ovarian), HT‐29 (colon), K562 (leukemia) and against the VERO no cancer cell line. Bauerenyl acetate was inactive, while 11α,13‐dihydrozaluzanin C showed weak activity against UACC62 and the VERO cell line. The most active compounds were 10‐desoxygochnatiolide A and gochnatiolide A, which inhibited the growth of kidney, melanoma, ovarian‐resistant and glioma cell lines with values of TGI (total growth inhibition) varying 0.21–1.09 µg/mL. This is the first report about cytotoxic activity of dimeric lactones against cell lines. Copyright © 2011 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.