The effect of xanthorrhizol on the expression of matrix metalloproteinase‐1 and type‐I procollagen in ultraviolet‐irradiated human skin fibroblasts

Matrix metalloproteinases (MMPs) are key regulators of the skin photoaging process that is set in motion by exposure to ultraviolet (UV) irradiation. This skin damage results from UV‐induced generation of reactive oxygen species, which are associated with upregulation of MMPs and decreased collagen synthesis. We investigated the effects of xanthorrhizol, isolated from Curcuma xanthorrhiza, on the expression of MMP‐1 and type‐I procollagen in UV‐irradiated human skin fibroblasts. Fibroblasts cultured in the presence or absence of purified xanthorrhizol or C. xanthorrhiza extract were irradiated with UV (20 mJ/cm²), and MMP‐1 and type‐I procollagen levels were measured using Western blot analysis. Xanthorrhizol (0.001–0.1 µM ) and C. xanthorrhiza extract (0.01–0.5 µg/mL) induced a significant, dose‐dependent decrease in the expression of MMP‐1 protein, and increased the expression of type‐1 procollagen. At a concentration of 0.1 µM , xanthorrhizol nearly completely abrogated MMP‐1 expression. The MMP‐1‐suppressing and type‐1 procollagen‐inducing effects of xanthorrhizol treatment were greater than those of epigallocatechin 3‐O‐gallate (EGCG), which is known to be a natural anti‐aging agent. These results suggest that xanthorrhizol is a potential candidate for the prevention and treatment of skin aging. Copyright © 2009 John Wiley & Sons, Ltd.     

Reactive Oxygen Species‐Mediated Activation of AMP‐Activated Protein Kinase and c‐Jun N‐terminal Kinase Plays a Critical Role in Beta‐Sitosterol‐Induced Apoptosis in Multiple Myeloma U266 cells

Although beta‐sitosterol has been well known to have anti‐tumor activity in liver, lung, colon, stomach, breast and prostate cancers via cell cycle arrest and apoptosis induction, the underlying mechanism of anti‐cancer effect of beta‐sitosterol in multiple myeloma cells was never elucidated until now. Thus, in the present study, the role of reactive oxygen species (ROS) in association with AMP‐activated protein kinase (AMPK) and c‐Jun N‐terminal kinase (JNK) pathways was demonstrated in beta‐sitosterol‐treated multiple myeloma U266 cells. Beta‐sitosterol exerted cytotoxicity, increased sub‐G₁ apoptotic population and activated caspase‐9 and ‐3, cleaved poly (ADP‐ribose) polymerase (PARP) followed by decrease in mitochondrial potential in U266 cells. Beta‐sitosterol promoted ROS production, activated AMPK, acetyl‐CoA carboxylase (ACC) and JNK in U266 cells. Also, beta‐sitosterol attenuated the phosphorylation of AKT, mammalian target of rapamycin and S6K, and the expression of cyclooxygenase‐2 and VEGF in U266 cells. Conversely, AMPK inhibitor compound C and JNK inhibitor SP600125 suppressed apoptosis induced by beta‐sitosterol in U266 cells. Furthermore, ROS scavenger N‐acetyl L‐cysteine attenuated beta‐sitosterol‐mediated sub‐G₁ accumulation, PARP cleavage, JNK and AMPK activation in U266 cells. Overall, these findings for the first time suggest that ROS‐mediated activation of cancer metabolism‐related genes such as AMPK and JNK plays an important role in beta‐sitosterol‐induced apoptosis in U266 multiple myeloma cells. Copyright © 2013 John Wiley & Sons, Ltd.     

Coriolus versicolor‐derived protein‐bound polysaccharides trigger the caspase‐independent cell death pathway in amelanotic but not melanotic melanoma cells

We have investigated the potential cell death mechanism promoted by Coriolus versicolor fungus‐derived protein‐bound polysaccharides (PBPs) in melanoma cells. Knowing that melanogenesis has the potential to affect the tumor behavior and melanoma therapy outcome, the cytotoxic effects of PBPs were evaluated in human SKMel‐188 melanoma cell line, whose phenotype, amelanotic versus pigmented, depends on the concentration of melanin precursors in the culture medium. Our results showed that inhibitory effect of PBPs (100 and 200 μg/ml) towards melanoma cells is inversely associated with the pigmentation level. This cytotoxicity induced in nonpigmented melanoma cells by PBPs was caspase‐independent; however, it was accompanied by an increased intracellular reactive oxygen species (ROS) generation. The ROS production was controlled by c‐Jun N‐terminal kinase (JNK) because SP600125, a JNK inhibitor, significantly reduced ROS generation and protected cells against PBPs‐induced death. We also found that PBPs‐induced lactate dehydrogenase release in amelanotic melanoma cells was abolished by co‐treatment with receptor‐interacting serine/threonine‐protein kinase 1 inhibitor, implying engagement of this kinase in PBPs‐induced death pathway. The results suggest that PBPs induce an alternative programmed cell death, regulated by receptor‐interacting protein‐1 and ROS and that this process is modified by melanin content in melanoma cells. These findings are remarkable when considering the use of commercially available Coriolus versicolor by patients who suffer from melanoma cancer.     

Triggering of p38 MAPK and JNK Signaling is Important for Oleanolic Acid‐Induced Apoptosis via the Mitochondrial Death Pathway in Hypertrophic Scar Fibroblasts

Hypertrophic scarring is characterized by collagen overproduction and excessive deposition of extracellular matrix. No consensus arises currently about the best therapeutics to produce complete and permanent improvement of scars with few side effects. In the present study, the mechanism of oleanolic acid (OA)‐induced apoptosis in hypertrophic scar fibroblasts (HSFs) was investigated for the first time. OA activated the protein phosphorylation of p38 MAPK and JNK but not ERK. OA did not antagonize the inhibitory effects of SB203580 on p38 MAPK pathway activity but sharply enhanced JNK phosphorylation when HSFs were pretreated with SB203580. Similarly, the inhibition of JNK signal pathway activation by pretreatment with SP600125 facilitated the protein phosphorylation of p38 MAPK caused by OA. Inhibition of p38 MAPK and/or JNK by inhibitors significantly enhanced cell viability and OA only partially depressed the increased cell viability. Moreover, OA increased Bax translocation, MMP loss, mitochondrial cytochrome c and AIF release, Bax and caspase‐3 protein expression and the ratio of Bax to Bcl‐2, decreased Bcl‐2 protein expression, and elevated the mRNA expression of Apaf‐1, caspase‐9, and capase‐3. These results suggest that OA elicits apoptosis through triggering of p38 MAPK and JNK signaling and activation of the mitochondrial death pathway. OA might be a good and useful natural drug against hypertrophic scars. Copyright © 2014 John Wiley & Sons, Ltd.     

Paris saponin VII induces cell cycle arrest and apoptosis by regulating Akt/MAPK pathway and inhibition of P‐glycoprotein in K562/ADR cells

Paris saponinVII (PSVII) is a steroidal saponin isolated from the roots and rhizomes of Trillium tschonoskii Maxim. We found that PSVII could inhibit the growth of adriamycin‐resistant human leukemia cells (K562/ADR) in a dose‐dependent manner. Furthermore, the molecular mechanism underlying the cytotoxicity and downregulation of P‐glycoprotein (P‐gp) expression by PSVII was clarified. PSVII significantly suppressed cell proliferation by cell cycle arrest in the G0/G1 phase, which was associated with an obvious decrease in cyclin B1/D1 and CDK2/4/6 protein expression. Moreover, PSVII could attenuate mitochondrial membrane potential, increase the expression of apoptosis‐related proteins, such as Bax and cytochrome c, and decrease the protein expression levels of Bcl‐2, caspase‐9, caspase‐3, PARP‐1, and p‐Akt. We also found that JNK, ERK1/2, and p38 were regulated by PSVII in K562/ADR cells. And further studies indicated that the decrease in the reactive oxygen species level inhibited intrinsic P‐gp expression. Therefore, PSVII‐induced apoptosis in K562/ADR cells was associated with Akt/MAPK and the inhibition of P‐gp. In addition, PSVII induced a robust autophagy in K562/ADR cells as demonstrated by the degradation of LC3‐I. These results provide a biochemical basis for possible clinical applications of PSVII in the treatment of leukemia.     

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.     

Acacetin‐induced cell apoptosis in head and neck squamous cell carcinoma cells: Evidence for the role of muscarinic M3 receptor

Aacacetin, a plant flavone has shown antitumor efficacy recently. However, its associated mechanisms are poorly known. We hypothesized that the muscarinic M3 receptor (M₃R), which is highly expressed in some cancer tissue, is related to the antitumor effect of acacetin in head and neck squamous cell carcinoma (HNSCC) cells. Our results showed that 12.5‐ to 200‐μM acacetin inhibited cell viability in dose‐ and time‐dependent manners in HNSCC cells, but a relative higher concentration was needed for oral adenoid cystic carcinoma cells. M₃R expression level was higher in HNSCC cells than that in adenoid cystic carcinoma cells. Flow cytometry and electron microscopy confirmed acacetin‐induced cell apoptosis in 22B cells, a HNSCC cell line. Acacetin promoted mitochondrial cytochrome c release and caspase 9, 3 processing. Knocking down of M₃R expression by specific siRNA significantly prevented the acacetin‐induced cell viability damage, cell apoptosis, and caspase 3 activation. Besides, M₃R was also involved in acacetin‐induced elevation of reactive oxygen species and intracellular calcium ([Ca²⁺]_i). These data indicate that acacetin‐induced cell apoptosis in HNSCC cells may through M₃R related calcium signaling and caspase 3 activation. Acacetin is a potent natural antitumor reagent especially for the tumor cells, which highly expressed M₃R.     

紫苏叶水提物对阿霉素致HK-2细胞氧化损伤的保护及机制

目的:探讨阿霉素(ADR)诱导人肾小管上皮细胞(HK-2)发生氧化损伤后,紫苏叶水提取物(PFAE)对其细胞活性、氧化损伤标记物及细胞凋亡等关键因子的影响。方法:ADR刺激HK-2细胞建立损伤模型,使用N-乙酰半胱氨酸(NAC)或不同浓度PFAE(5,15,45 g·L~(-1))干预后,采用细胞增殖/毒性检测(CCK-8)法检测细胞存活率,结合光镜下细胞形态变化,筛选出PFAE保护细胞的最佳浓度。后续实验分为6组:空白组,ADR(0.05 g·L~(-1))组,PFAE(15 g·L~(-1))组,ADR+PFAE(0.05+15)g·L~(-1)组,NAC(0.81 g·L~(-1))组,ADR+NAC(0.05+81)g·L~(-1)组。检测细胞匀浆中的丙二醛(MDA),超氧化物歧化酶(SOD)和细胞总抗氧化能力,2',7'-二氯荧光黄双乙酸盐(DCFH-DA)荧光探针检测细胞内活性氧(ROS)水平,流式细胞术及脱氧核糖核苷酸末端转移酶(TUNEL)染色法检测细胞凋亡率,蛋白免疫印迹法(Western blot)检测细胞线粒体凋亡相关蛋白B淋巴细胞瘤-2基因(Bcl-2),Bcl-2相关X蛋白(Bax),半胱氨酸天冬氨酸蛋白酶9和3(Caspase-9,Caspase-3),聚腺苷二磷酸-核糖聚合酶(PARP)包括其剪切体的表达,及丝裂原活化蛋白激酶(MAPK)信号转导通路中p38丝裂素活化蛋白激酶(p38 MAPK),细胞外信号调节激酶(ERK),c-Jun氨基端激酶(JNK)及其磷酸化蛋白的表达。结果:与空白组比较,ADR组的细胞活性显著降低(P0.01),与ADR组比较,5,15 g·L~(-1)的PFAE和NAC能促进细胞的增殖(P0.01)。与空白组比较,ADR组抗氧化能力和SOD水平显著降低(P0.01),MDA和ROS的水平显著增高(P0.01),与ADR组比较,ADR+PFAE组和ADR+NAC组抗氧化能力和SOD水平显著升高(P0.01),MDA和ROS的水平显著下降(P0.01)。与空白组比较,ADR组细胞凋亡率上升(P0.01),凋亡相关蛋白Bax/Bcl-2,cleaved Caspase-9/Caspase-9,cleaved Caspase-3/Caspase-3,cleaved PARP/PARP水平显著上升(P0.01),MAPKs通路中的p38 MAPK,ERK和JNK的磷酸化蛋白表达明显增高(P0.05,P0.01);与ADR组比较,PFAE或NAC干预后减轻了细胞凋亡率,降低了凋亡蛋白的相对比值,并且抑制了MAPK信号通路中p38 MAPK,ERK蛋白的磷酸化(P0.01),但对磷酸化的JNK蛋白表达无影响。结论:PFAE可以减轻ADR诱导的HK-2细胞氧化损伤,并发挥抗氧化作用,通过线粒体凋亡途径和ERK/p38 MAPK信号通路来抑制细胞凋亡。     

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.     

Corosolic Acid Triggers Mitochondria and Caspase‐dependent Apoptotic Cell Death in Osteosarcoma MG‐63 Cells

The response of osteosarcoma MG‐63 cells to corosolic acid treatment has been investigated. The results showed that corosolic acid significantly inhibited cell viability in both a dose and a time dependent manner. It was found that corosolic acid increased the Bax/Bcl‐2 ratio by up‐regulating Bax expression, disrupted mitochondrial membrane potential and triggered the release of cytochrome c from mitochondria into the cytoplasm. Corosolic acid treatment triggered the activation of caspase‐8, 9 and 3. The apoptosis was obviously inhibited by pretreatment with a general caspase inhibitor, z‐VAD‐FMK. Moreover, pretreatment of CsA, a cyclophilin D ligand that inhibits mitochondria potential uncoupling, prevented the activation of caspase‐9 and caspase‐3, but not caspase‐8, and the apoptosis of MG‐63 cells, triggered by corosolic acid. All these results indicated that corosolic acid‐induced apoptosis was associated with the activation of caspases via a mitochondrial pathway. Copyright © 2011 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.     

Astragalus polysaccharides exerts anti‐infective activity by inducing human cathelicidin antimicrobial peptide LL‐37 in respiratory epithelial cells

Astragalus polysaccharides (APS), one of the major active components in Astragalus membranaceus, is an effective immunomodulator used in the treatment of immunological diseases in China. However, the anti‐infective action and mechanism of APS is not fully known. In the present study, we found that APS induced the expression of human cathelicidin antimicrobial peptide LL‐37, a key host anti‐infective molecule, in both mRNA and protein levels in respiratory epithelial cells HBE16 and A549. Furthermore, the lysate and supernatant from APS‐treated HBE16 cells both exhibited an obvious antibacterial action, which was partially neutralizated by LL‐37 monoclonal antibody. In addition, APS also significantly elevated the phosphorylation of p38 MAPK and JNK and caused the degradation of IκBα. Specific inhibitors of p38 MAPK, JNK, or NF‐κB obviously abolished APS‐induced LL‐37 synthesis and antibacterial activity, respectively. Taken together, our results confirmed the enhancement of APS on LL‐37 induction and antibacterial action in respiratory epithelial cells, which may be attributed to activation of p38 MAPK/JNK and NF‐κB pathways. Furthermore, these results also supported the clinical application of APS in the treatment of infectious diseases.     

The Novel p53‐Dependent Metastatic and Apoptotic Pathway Induced by Vitexin in Human Oral Cancer OC2 Cells

Vitexin, identified as apigenin‐8‐C‐D‐glucopyranoside, a natural flavonoid compound found in certain herbs such as hawthorn herb, has been reported to exhibit anti‐oxidative, anti‐inflammatory, anti‐metastatic and antitumor properties. The aim of this study was to investigate the possible existence of p53‐dependent pathway underlying vitexin‐induced metastasis and apoptosis in human oral cancer cells, OC2 cells. Vitexin decreased cell viability significantly. Meanwhile, the expression of tumor suppressor p53 and a small group of its downstream genes, p21 ^WAF1 and Bax, were upregulated. The p53 inhibitor pifithrin‐α (PFT‐α) knockdown of the signaling of p53 led vitexin to lose its antitumor effect and inhibited the expression of p53 downstream genes, p21^WAF1 and Bax. Vitexin had anti‐metastatic potential accompanied with increasing plasminogen activator inhibitor 1 (PAI‐1) accumulation and decreasing matrix metalloproteinase‐2 expression. Our present study evidenced, by using p53 inhibitor PFT‐α, PAI‐1 and peroxisome proliferator‐activated receptor γ are downstream genes of p53 in vitexin‐induced signaling. MAPK inhibitor PD98059 decreased the OC2 cells viability significantly. The expression of p53 and its downstream genes p21 ^WAF1 and Bax were enhanced by blocking the activation of p42/p44 MAPK in response to treatment with vitexin. Moreover, p42/p44 MAPK played a negative role in p53‐dependent metastasis and apoptosis. We give evidence for the first time that the novel p53‐dependent metastatic and apoptotic pathway induced by vitexin in human oral cancer OC2 cells. Copyright © 2012 John Wiley & Sons, Ltd.     

Retracted: Baicalin relieves TNF‐α‐evoked injury in human aortic endothelial cells by up‐regulation of miR‐145

Hypertension is recognized to be associated with low‐grade inflammation. Baicalin (BAI) is reported to possess various pharmacological including anti‐inflammatory activities. This research explored the molecular mechanism by which BAI functions in human aortic endothelial cells (HAECs). HAECs were pretreated with BAI. Cell viability, apoptosis, and expressions of crucial proteins were respectively evaluated using cell counting kit‐8 assay, flow cytometry, and western blot. Productions of cytokines were respectively assessed employing quantitative real‐time polymerase chain reaction and enzyme‐linked immunosorbent assay. Cell transfection was utilized to alter miR‐145 expression. The expressions of proteins participated in JNK and p38MAPK pathways were analyzed utilizing western blot. TNF‐α inducement successfully evoked inflammatory injury in HAECs, exhibiting as prominently suppressed viability, while facilitated apoptosis and productions of cytokines. However, BAI pretreatment significantly ameliorated TNF‐α‐triggered inflammatory injuries. Besides, miR‐145 expression was markedly inhibited by TNF‐α inducement, while notably elevated by BAI pretreatment. Although miR‐145 overexpression had no significant influence on apoptosis, miR‐145 silence observably reversed BAI pretreatment‐evoked protective influences on TNF‐α‐induced HAECs, as well as the inhibited impacts on the levels of key proteins involved in JNK and p38MAPK pathways. This investigation illustrated that BAI relieved TNF‐α‐triggered injuries through upregulating miR‐145 via suppressing JNK and p38MAPK pathways.     

Anthocyanidin attenuates myocardial ischemia induced injury via inhibition of ROS‐JNK‐Bcl‐2 pathway: New mechanism of anthocyanidin action

Despite treatment options available to date, myocardial ischemia (MI) remains the leading cause of death worldwide. Studies are focused on finding effective therapeutic strategies against MI injury. Growing interest has been developed in natural compounds possessing medicinal properties with scarcer side effects. Here, we have evaluated the cardioprotective potential of anthocyanidin against MI injury and explored its underlying protective mechanism. Left anterior descending coronary artery was ligated to induce MI in mice. Neonatal mice cardiomyocytes were treated with H₂O₂ to induce oxidative stress (a major contributor to MI injury) in vitro. Anthocyanidin pretreatment significantly reduced the infarct size, preserved the cell viability, and protected against ischemia‐induced cardiac injury in treatment groups compared with the H₂O₂‐treated group in vitro. Measurement of reactive oxygen species (ROS) validated the strong antioxidant potential of anthocyanidin, as significant reduction in oxidative stress was observed in anthocyanidin‐pretreated groups. Mechanistically, pretreatment with anthocyanidin significantly subdued the activation of JNK (to p‐JNK) and elevated Bcl‐2 levels. Both in vivo and in vitro findings suggest that anthocyanidin can induce a state of myocardial resistance against ischemic insult. We have provided the experimental evidence for inhibition of ROS/p‐JNK/Bcl‐2 pathway being the underlying mechanism of action of anthocyanidin. Our results support the use of anthocyanidin as therapeutic strategy against MI injury.     

Phloroglucinol Protects INS‐1 Pancreatic β‐cells Against Glucotoxicity‐Induced Apoptosis

Decreasing numbers, and impaired function, of pancreatic β‐cells are key factors in the development of type 2 diabetes. This study was designed to investigate whether phloroglucinol protected pancreatic β‐cells against glucotoxicity‐induced apoptosis using a rat insulinoma cell line (INS‐1). High glucose treatment (30 mM) induced INS‐1 cell death; however, the level of glucose‐induced apoptosis was significantly reduced in cells treated with 100‐μM phloroglucinol. Treatment with 10–100‐μM phloroglucinol increased cell viability and decreased intracellular levels of reactive oxygen species, nitric oxide, and lipid peroxidation dose‐dependently in INS‐1 cells pretreated with high glucose. Furthermore, phloroglucinol treatment markedly reduced the protein expression of Bax, cytochrome c, and caspase 9, while increasing anti‐apoptotic Bcl‐2 protein expression. Cell death type was examined using annexin V/propidium iodide staining, revealing that phloroglucinol markedly reduced high glucose‐induced apoptosis. These results demonstrated that phloroglucinol could be useful as a potential therapeutic agent for the protection of pancreatic β‐cells against glucose‐induced apoptosis. Copyright © 2015 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.     

Effect of xanthorrhizol,xanthorrhizol glycoside and trachylobanoic acid isolated from cachani complex plants upon the contractile activity of uterine smooth muscle

Xanthorrhizol, xanthorrhizol glycoside, and trachylobanoic acid, compounds isolated from medicinal plants that are grouped in the complex known as Cachani have been shown to inhibit the tonic contraction of rat uterus induced by: (a) depolarizing K⁺ solution (60 mM ), (b) CaCl₂ (1 mM ), and (c) BAY K 8644 (0.3 µM ) in a concentration‐dependent manner (1–30 µg/mL). The inhibitory potency was displayed as follows: xanthorrhizol > xanthorrhizol glycoside > trachylobanoic acid. These results suggest that the assayed compounds might block voltage operated calcium influx in myometrial cells as they displayed a calcium‐antagonistic activity. This effect is not due to peripheral receptor activation (β₂‐adrenergic, H₂‐histaminergic) as neither propranolol nor cimetidine modified the inhibitory effect of the compounds assayed. This is the first report showing that plants belonging to the Cachani complex may contain uterine smooth muscle bioactive substances. Copyright © 1999 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.