Curcumin and tetrahydrocurcumin induce cell death in Ara‐C‐resistant acute myeloid leukemia

Most anticancer agents induce cancer cell death; however, multidrug‐resistant cancers often lead to treatment failure. The effective use of curcumin as an anticancer agent has been demonstrated in clinical trials. Tetrahydrocurcumin, a major curcumin metabolite, exhibits pharmacological activities similar to those of curcumin. Curcumin induces cell death mainly through the apoptosis pathway, and tetrahydrocurcumin induces cell death mainly via an autophagy pathway in HL60 cells. Here, we investigated whether curcumin and tetrahydrocurcumin can induce apoptosis‐ and autophagy‐mediated cell deaths in Ara‐C‐resistant cancer cells, respectively. The results demonstrated that curcumin and tetrahydrocurcumin induced cell death by apoptosis and autophagy, respectively, in Ara‐C‐resistant HL60 cells. Thus, curcumin and tetrahydrocurcumin have potential applications in the treatment of acute myeloid leukemia with Ara‐C resistance.     

白藜芦醇联合姜黄素对SMMC-7721肝癌细胞作用

目的:观察白藜芦醇联合姜黄素对体外人肝癌细胞SMMC-7721增殖和凋亡的影响及相关信号通路.方法:不同浓度白藜芦醇、姜黄素及两药联合干预SMMC-7721细胞,MTT法检测细胞增殖,流式细胞术检测细胞凋亡、Hoechst 33258染色检测细胞凋亡形态变化,比色法检测半胱氨酸天冬氨酸蛋白酶(caspase)-3,caspase-8,caspase-9酶活性,Western blot法检测半胱氨酸天冬氨酸蛋白酶切割底物(PARP).结果:与对照组相比,白藜芦醇、姜黄素单独或联合作用SMMC-7721细胞均可抑制SMMC-7721细胞增殖,两药联合后抑制作用更显著.白藜芦醇、姜黄素联合较单独用药可增强SMMC-7721细胞凋亡,呈现凋亡形态改变,白藜芦醇、姜黄素及联合组细胞凋亡率分别为( 17.39±1.41)％,(14.96±2.23)％,(25.36±2.68)％;同时提高SMMC-7721细胞caspase-3,caspase-8及caspase-9活性,促使PARP蛋白剪辑.结论:白藜芦醇、姜黄素联合使用可增强对人肝癌细胞SMMC-7721的抗癌作用,并可能与caspase-8,caspase-9/caspase-3/PA RP信号通路介导细胞凋亡相关.     

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.     

抗癌中药单体对肿瘤细胞自噬的调控

自噬是细胞内能量代谢和自我更新的机制,参与细胞诸多生理病理过程,维持机体内稳态。近年来研究发现,自噬与肿瘤的发生发展密切相关,参与调控肿瘤的形成、增殖、转移以及能量代谢等诸多方面。自噬对肿瘤的调控是一个复杂的动态过程,自噬能抑制早期肿瘤的生成,促进晚期肿瘤的发展。目前自噬已成为肿瘤研究领域的新热点,越来越多的研究表明,中草药及其有效成分具有调控肿瘤细胞自噬水平的作用。相对应于自噬在肿瘤发生发展中的复杂角色,抗癌中药有效成分的作用亦具有多面性,或诱导肿瘤细胞发生自噬引起细胞死亡、抑制肿瘤转移;或抑制自噬,增强肿瘤对药物的敏感性;甚至可能在不同肿瘤类型中表现出截然相反的自噬性死亡或保护性自噬作用。目前调控肿瘤自噬水平的中药有效成分研究主要集中在具有抗肿瘤作用的皂苷、生物碱、多酚、黄酮和内酯类化合物,既可以通过诱导细胞自噬达到抗肿瘤的效果,也可以通过抑制细胞自噬发挥抑瘤作用。因此,本文对抗癌中药单体在调节肿瘤细胞自噬方面的研究进展做一综述,有助于研制以自噬为靶点的抗肿瘤药物,为抗肿瘤药物研发提供新方向。     

Curcumin promotes burn wound healing in mice by upregulating caveolin‐1 in epidermal stem cells

We aimed to explore the effect of curcumin on epidermal stem cells (ESCs) in regulating wound healing and the underlying molecular mechanism. We treated mouse ESCs isolated from skin tissues with curcumin, and then assessed the proliferation ability of cells induced by epidermal growth factor using cell counting kit‐8 assay. The pluripotency of ESCs was evaluated as well through examination of Nanog expression in ESCs. Further, mice with skin burns were treated with ESCs with or without curcumin pretreatments. Histological evaluations were then preformed to determine wound scores, cell proliferation, reepithelialization, and capillary density in wounds. Curcumin treatment promoted the proliferative ability of ESCs and conditioned medium from curcumin‐treated ESCs enhanced human umbilical vein endothelial cell (HUVEC) tube formation. We also found curcumin treatment elevated caveolin‐1 expression in ESCs, which was required for the beneficial effect of curcumin on ESC proliferation and HUVEC tube formation. Next, using a mouse model of burn wound healing, curcumin‐treated ESCs exhibited enhanced wound closure, which also required caveolin‐1 expression. Our current study demonstrates the beneficial effect of curcumin on burn wound healing in mice, which is mediated by upregulating caveolin‐1 in ESCs, and supports the potential therapeutic role of curcumin in ESC‐based treatment against skin wound healing.     

乌药挥发油通过AMPK/mTOR信号通路诱导胃癌AGS细胞凋亡和自噬

目的 研究乌药挥发油对人胃癌细胞AGS凋亡和自噬的的影响,并探讨腺苷酸活化蛋白激酶（AMPK）/哺乳动物雷帕霉素靶蛋白（mTOR）信号通路在其中的调控作用。方法 利用水蒸气蒸馏法提取乌药挥发油,采用噻唑蓝（MTT）比色法检测乌药挥发油对人胃癌细胞AGS细胞活力的影响,并根据半抑制浓度（IC₅₀）确定最佳给药浓度与时间,用于后续研究;设置空白组、乌药挥发油低、中、高质量浓度组（0、15、30、60 mg·L^-1）及阳性药环磷酰胺（CTX）组（350 mg·L^-1）。用不同浓度的乌药挥发油处理AGS细胞48 h,采用细胞集落形成实验检测细胞增殖能力的变化、流式细胞仪检测细胞周期的变化、细胞划痕实验检测细胞迁移能力的变化、苏木素-伊红（HE）染色观察细胞形态的变化、Annexin-V/碘化丙啶（PI）双染法检测AGS细胞凋亡率、吖啶橙（AO）染色观察自噬水平的变化、蛋白免疫印迹法（Western blot）检测自噬效应蛋白Beclin-1、p62、微管相关蛋白1轻链3（LC3）、B细胞淋巴瘤因子-2（Bcl-2）、Bcl-2相关X蛋白（Bax）、剪切的胱天蛋白酶-3（cleaved Caspase-3）、剪切的多聚ADP-核糖聚合酶（cleaved PARP）、单磷酸腺苷活化蛋白激酶（AMPK）、磷酸化AMPK（p-AMPK）、雷帕霉素机械靶蛋白（mTOR）及磷酸化mTOR（p-mTOR）蛋白表达水平的变化。结果 与空白组比较,AGS细胞经乌药挥发油干预24、48 h,细胞活性被明显抑制（P<0.05,P<0.01）,呈浓度和时间依赖性;乌药挥发油各浓度组细胞增殖与迁移能力明显降低（P<0.05,P<0.01）,且随浓度的上升抑制能力越明显;乌药挥发油将AGS细胞周期阻滞于G₂/M期（P<0.05,P<0.01）,呈浓度依赖性;乌药挥发油各浓度组出现细胞圆化,体积变小并伴随凋亡小体形成等现象,细胞凋亡率明显增加（P<0.05,P<0.01）;随着乌药挥发油浓度的增加,自噬体数量增加致红色荧光逐渐增强,提示自噬水平的提升;乌药挥发油各浓度组Beclin-1、LC3 Ⅱ/LC3 Ⅰ、cleaved Caspase-3、cleaved PARP、Bax/Bcl-2及AMPK蛋白表达水平明显升高（P<0.05,P<0.01）;p62与p-mTOR蛋白表达水平明显降低（P<0.05,P<0.01）。结论 乌药挥发油通过调节AMPK/mTOR信号通路诱导AGS细胞凋亡和自噬介导的生长抑制。     

Coadministration of Erlotinib and Curcumin Augmentatively Reduces Cell Viability in Lung Cancer Cells

Resistance to erlotinib in lung cancer cases includes T790M mutant epidermal growth factor receptor and c‐Met gene amplification, but other unknown mechanisms account for about 30% of the resistance. Activation of the nuclear factor kappa B (NFkappaB)‐related pathways in association with the reduction in ikappaB level may be one of such potential mechanisms. It is known that curcumin inhibits the inducible activation of NFkappaB at least in part by sustaining ikappaB expression level. Therefore, we evaluated the effects of coadministration of erlotinib and curcumin on lung cancer cells. We found that erlotinib and curcumin augmentatively reduced cell viability. Studies in PC9 cells showed that induction of apoptosis was involved. Expression of ikappaB was elevated in PC9 cells by curcumin administration, and pretreatment with siRNAs for ikappaB significantly attenuated the reduction in cell viability after coadministration of erlotinib and curcumin. Furthermore, coadministration of erlotinib and/or curcumin augmentatively attenuated the growth of PC9 tumors in mice. These results suggested the existence of an augmentative tumor growth inhibitory effect between erlotinib and curcumin, and this effect was at least in part mediated by the increase in the expression of ikappaB induced by curcumin. Copyright © 2013 John Wiley & Sons, Ltd.     

Lipid‐Lowering Effects of Curcumin in Patients with Metabolic Syndrome: A Randomized,Double‐Blind,Placebo‐Controlled Trial

Human studies of curcumin extract on lipid‐lowering effect have not been completely investigated and have had controversy results. This study tested the effect of daily curcumin extract for 12 weeks on weight, glucose, and lipid profiles in patients with metabolic syndrome. Sixty‐five patients were randomized into two groups; 33 patients taking curcumin extract capsule (630 mg thrice daily) and 32 patients taking a placebo capsule thrice daily for 12 weeks. At 12 weeks after the curcumin extract consumption, the level of high‐density lipoprotein cholesterol (HDL‐C) significantly increased from 40.96 ± 8.59 to 43.76 ± 2.79 mg/dL (p < 0.05), and the level of low‐density lipoprotein cholesterol (LDL) was significantly reduced (120.55 ± 36.81 to 106.51 ± 25.02 mg/dL, p < 0.05). The triglyceride‐lowering effect, a reduction of 65 mg/dL, was also found in this study. In subgroups analysis, the consumption of curcumin may have a lowering cholesterol effect in male patients and an increasing HDL‐C effect in female patients, both of which result in a decrease of T‐Chol/HDL‐C ratio. The intake of the curcumin extract of 1890 mg/day for 12 weeks was associated with lipid‐lowering effect but did not improve weight and glucose homeostasis in the patients with metabolic syndrome. Daily curcumin consumption may be an alternative choice to modify cholesterol‐related parameters, especially in metabolic syndrome patients. Copyright © 2014 John Wiley & Sons, Ltd.     

Turmeric Toxicity in A431 Epidermoid Cancer Cells Associates with Autophagy Degradation of Anti‐apoptotic and Anti‐autophagic p53 Mutant

The keratinocyte‐derived A431 Squamous Cell Carcinoma cells express the p53R273H mutant, which has been reported to inhibit apoptosis and autophagy. Here, we show that the crude extract of turmeric (Curcuma longa), similarly to its bioactive component Curcumin, could induce both apoptosis and autophagy in A431 cells, and these effects were concomitant with degradation of p53. Turmeric and curcumin also stimulated the activity of mTOR, which notoriously promotes cell growth and acts negatively on basal autophagy. Rapamycin‐mediated inhibition of mTOR synergized with turmeric and curcumin in causing p53 degradation, increased the production of autophagosomes and exacerbated cell toxicity leading to cell necrosis. Small‐interference mediated silencing of the autophagy proteins BECLIN 1 or ATG7 abrogated the induction of autophagy and largely rescued p53 stability in Turmeric‐treated or Curcumin‐treated cells, indicating that macroautophagy was mainly responsible for mutant p53 degradation. These data uncover a novel mechanism of turmeric and curcumin toxicity in chemoresistant cancer cells bearing mutant p53. Copyright © 2014 John Wiley & Sons, Ltd.     

姜黄素对人白血病K562细胞凋亡的影响

Ｋ５６２细胞对多种化疗药物诱导凋亡具有抗性，本文以ＡＯ／ＥＢ染色法、细胞分光光度术、ＤＮＡ凝胶电泳及电镜观察等方法，发现姜黄素可显著诱导Ｋ５６２细胞凋亡，提示该药对治疗慢性粒细胞性白血病可能有价值。     

从自噬角度研究雷公藤甲素引起HepG2细胞肝毒性的机制

目的:探讨雷公藤甲素(TP)对HepG2细胞的过氧化损伤及对自噬的调控作用。方法:将质量浓度为0.003 2,0.016,0.08,0.4,2 g·L~(-1)的TP作用于体外培养的HepG2细胞48 h,另设空白组做对比,采用噻唑蓝(MTT)法检测细胞生长活性,采用酶联免疫吸附测定(ELISA)法检测超氧化物歧化酶(SOD),谷胱甘肽过氧化物酶(GSH-Px)的活性,采用蛋白质免疫印迹(Western blot)法检测自噬相关蛋白微管相关蛋白轻链3(LC3Ⅱ)与Beclin1蛋白的表达情况,用免疫荧光法检测自噬相关蛋白LC3的表达情况。结果:与空白组比较,随着TP质量浓度的增加,HepG2活性下降(P0.05,P0.01);检测细胞上清中SOD,GSH-Px的活性,均较空白组降低(P0.05,P0.01);Western blot表明TP可上调LC3Ⅱ与Beclin1蛋白水平的表达(P0.05,P0.01),免疫荧光法同样表明TP能够引起自噬相关蛋白LC3表达的增多(P0.05,P0.01),均具有一定的浓度依赖性。结论:一定质量浓度的TP可造成肝细胞损伤,其损伤机制可能与过氧化损伤以及过氧化损伤导致的自噬过度激活有关。     

Comparative Oral Absorption of Curcumin in a Natural Turmeric Matrix with Two Other Curcumin Formulations: An Open‐label Parallel‐arm Study

Curcuminoids are the major bioactive molecules in turmeric, and poor bioavailability deters them from being the major components of many health and wellness applications. This study was conducted to assess the bioavailability of a completely natural turmeric matrix formulation (CNTMF) and compare its bioavailability with two other commercially available formulations, namely, curcumin with volatile oil (volatile oil formulation) and curcumin with phospholipids and cellulose (phospholipid formulation) in healthy human adult male subjects (15 each group) under fasting conditions. Each formulation was administrated orally as a single 500‐mg dose in capsule form, and blood samples were analyzed by liquid chromatography mass spectrometry at various time intervals up to 24 h. The ingestion of the CNTMF was very well absorbed and resulted in a mean curcuminoids plasma C_max of 170.14 ng/mL (T_max = 4 h) compared with 47.54 ng/mL and 69.63 ng/mL for the volatile oil (T_max = 3 h) and phospholipid (T_max = 2.25 h) formulations, respectively. The extent of absorption of total curcuminoids in the blood for the CNTMF was 6× greater than volatile oil formulation and 5× greater than phospholipids formulation. The results of this study indicate that curcumin in a natural turmeric matrix exhibited greater bioavailability than the two comparator products. Copyright © 2017 John Wiley & Sons, Ltd.     

The Role of Curcumin Administration in Patients with Major Depressive Disorder: Mini Meta‐Analysis of Clinical Trials

Major depression is a common, recurrent, and chronic disease that negatively affects the quality of life and increases the risk of mortality. Several studies have demonstrated that curcumin, the yellow‐pigmented substance of the turmeric, possesses antidepressant properties. The aim of this review is to meta‐analytically assess the antidepressant effect of curcumin in patients with major depressive disorders. We extensively searched the literature until August 2015. The random‐effect model was used to calculate the pooled standardized difference of means (SMD). Subgroup analyses were also performed to examine the effect of different study characteristics on the overall model. Six clinical trials met the inclusion criteria. Overall, curcumin administration showed a significantly higher reduction in depression symptoms [SMD = ?0.34; 95% confidence interval (CI) = ?0.56, ?0.13; p = 0.002]. Subgroup analyses showed that curcumin had the highest effect when given to middle‐aged patients (SMD = ?0.36; 95% CI = ?0.59; ?0.13; p = 0.002), for longer duration of administration (SMD = ?0.40; 95% CI = ?0.64, ?0.16; p = 0.001), and at higher doses (SMD = ?0.36; 95% CI = ?0.59, ?0.13; p = 0.002). The administration of new formulation of curcumin (BCM‐95) had non‐significantly higher effect on depression as compared with the conventional curcumin–piperine formula. We conclude that there is supporting evidence that curcumin administration reduces depressive symptoms in patients with major depression. Copyright © 2015 John Wiley & Sons, Ltd.     

姜黄素对Raji细胞体外抗癌作用的实验研究

目的研究姜黄素对Raji细胞体外抗癌作用及其机制,对比研究其对RaIi细胞和人单个核细胞的细胞毒性。方法用MTT法检测姜黄素对Raji细胞及人单个核细胞增殖的影响,Annexin—V／PI双标流式术、缺口末端标记法检测姜黄素对Raji细胞及人单个核细胞凋亡的影响,PI单标流式细胞术测定姜黄素对Raji细胞DNA含量分布的影响。结果(1)姜黄素对Raji细胞具有明显的增殖抑制作用。(2)姜黄素可以时间和剂量依赖性方式诱导Raji细胞凋亡。(3)姜黄素组Raji细胞周期发生变化,细胞周期被阻滞于G0／G1和G2／M期,S期比例减少。(4)姜黄素对人单个核细胞无明显抑制增殖和诱导凋亡作用。结论姜黄素能够调控Raji细胞的细胞周期并诱导其凋亡,从而抑制Raji细胞增殖;姜黄素对人单个核细胞无明显细胞毒作用,而选择性作用于肿瘤细胞。     

Effect of Curcumin Against Pentylenetetrazol‐Induced Seizure Threshold in Mice: Possible Involvement of Adenosine A1 Receptors

Curcumin, obtained from Curcuma longa, has been in use for manifold human disorders. The present study explores the effect of curcumin against pentylenetetrazol (PTZ) seizure threshold in mice. The possible involvement of adenosine receptor(s) mechanism was also investigated. Minimal dose of PTZ (i.v., mg/kg) needed to induce different phases of convulsions were recorded as an index of seizure threshold. Curcumin (20–120 mg/kg, p.o.) produced an increase in seizure threshold for convulsions induced by PTZ i.v. infusion. The anticonvulsant effect of curcumin (80 mg/kg) was prevented by 8‐phenyltheophylline (0.5 mg/kg, i.p., non‐selective adenosine receptor antagonist) and 8‐cyclopentyl‐1,3‐dipropylxanthine (5 mg/kg, i.p., adenosine A₁ receptor antagonist) but not by 8‐(3‐cholorostryl)caffeine (4 mg/kg, i.p., adenosine A_2A receptor antagonist). Further, 5′‐N‐ethylcarboxamidoadenosine (0.005 mg/kg, i.p., non‐selective A₁/A₂ receptor agonist), or N⁶‐cyclohexyladenosine (0.2 mg/kg, i.p., adenosine A₁ receptor agonist), was able to potentiate the anticonvulsant action of curcumin. In contrast, 5′‐(N‐cyclopropyl) carboxamidoadenosine (0.1 mg/kg, i.p., adenosine A_2A receptor agonist) failed to potentiate the effect of curcumin. This study demonstrated the anticonvulsant effect of curcumin against PTZ i.v. seizure threshold via a direct or indirect activation of adenosine A₁ but not A_2A receptors in mice. Thus, curcumin may prove to be an effective adjunct in treatment of convulsions. Copyright © 2013 John Wiley & Sons, Ltd.     

Potential Role of Curcumin Against Biofilm‐Producing Organisms on the Skin: A Review

Turmeric root (Curcuma longa) is predominantly used as a spice, but has also long been known to possess antimicrobial, analgesic, antiinflammatory, and anticancer properties. One predominant group of active compounds in turmeric are curcuminoids, namely bright yellow‐pigmented curcumin. While modern science has yet to fully investigate the therapeutic claims of turmeric and its derivatives, results have proven promising in decreasing pain and inflammation in arthritis, improving insulin sensitivity in diabetes, and even curing a variety of infections. The purpose of this review is to discuss the potential for curcumin as an agent against microbial infections, with a special focus on the skin and in the development of bacterial biofilms. Curcumin has demonstrated bactericidal efficacy against a variety of infections when administered with antibiotics in several clinical studies, with consistent antimicrobial activity demonstrated in vitro, as well as in urinary tract infections, gingival infections, and chronic wound infections. Hypothesized mechanisms of action include curcumin's ability to perturb bacterial membranes, disturb protofillament assembly, and even impair bacterial virulence factors. Further investigation is needed to fully understand which organisms are most susceptible to the effects of curcumin and how curcumin can be implemented in dermatology to treat skin conditions such as chronic wounds and acne vulgaris. Copyright © 2017 John Wiley & Sons, Ltd.     

Curcumin I Mediates Neuroprotective Effect Through Attenuation of Quinoprotein Formation,p‐p38 MAPK Expression,and Caspase‐3 Activation in 6‐Hydroxydopamine Treated SH‐SY5Y Cells

6‐Hydroxydopamine (6‐OHDA) selectively enters dopaminergic neurons and undergoes auto‐oxidation resulting in the generation of reactive oxygen species and dopamine quinones, subsequently leading to apoptosis. This mechanism mimics the pathogenesis of Parkinson's disease and has been used to induce experimental Parkinsonism in both in vitro and in vivo systems. In this study, we investigated the effects of curcumin I (diferuloylmethane) purified from Curcuma longa on quinoprotein production, phosphorylation of p38 MAPK (p‐p38), and caspase‐3 activation in 6‐OHDA‐treated SH‐SY5Y dopaminergic cells. Pretreatment of SH‐SY5Y with curcumin I at concentrations of 1, 5, 10, and 20 μM, significantly decreased the formation of quinoprotein and reduced the levels of p‐p38 and cleaved caspase‐3 in a dose‐dependent manner. Moreover, the levels of the dopaminergic neuron marker, phospho‐tyrosine hydroxylase (p‐TH), were also dose‐dependently increased upon treatment with curcumin I. Our results clearly demonstrated that curcumin I protects neurons against oxidative damage, as shown by attenuation of p‐p38 expression, caspase‐3‐activation, and toxic quinoprotein formation, together with the restoration of p‐TH levels. This study provides evidence for the therapeutic potential of curcumin I in the chemoprevention of oxidative stress‐related neurodegeneration. Copyright © 2013 John Wiley & Sons, Ltd.     

Garcinone E Blocks Autophagy Through Lysosomal Functional Destruction in Ovarian Cancer Cells

Background: High proliferative rate of cancer cells requires autophagy to maintain nutrient supply and intracellular homeostasis. As a result, impairing autophagic flux could be a novel strategy of cancer therapy. Aims and Objectives: In this study, the mechanism of a xanthone derivative isolated from Garcinia mangostana, garcinone E(GE), was investigated. Materials and Methods: Fluorescence assay was used to observe the accumulation and location of autophagosome and lysosome. Flow cytometry with Lyso-tracker red, MDC, and AO staining were applied to evaluate the lysosome accumulation and cellular acidity. Western blot and RT-qPCR were performed to evaluate the protein and mRNA levels, respectively. Results: GE could cause enhancement of LC3 II and p62 and the accumulation of autophagosome and lysosome. Meanwhile, it limited the protein level of Rab7, increased lysosomal pH, and inhibited the maturation of lysosomal hydrolases such as Cathepsin L, therefore blockaded the fusion of autophagosome and lysosome. Moreover, GE acted as a TFEB modulator by downregulating its protein level, which might contribute to autophagy dysfunction in ovarian cancer cells. Conclusions: GE interfered autophagosome–lysosome fusion in cancer cells, which demonstrated its application as an autophagy regulator and a potential therapeutic agent.     

Fangchinoline Induces G1 Arrest in Breast Cancer Cells Through Cell‐Cycle Regulation

Fangchinoline, an alkaloid derived from the dry roots of Stephaniae tetrandrine S. Moore (Menispermaceae), has been shown to possess cytotoxic, anti‐inflammatory, and antioxidant properties. In this study, we used Fangchinoline to inhibit breast cancer cell proliferation and to investigate its underlying molecular mechanisms. Human breast cancer cell lines, MCF‐7 and MDA‐MB‐231, were both used in this study. We found that Fangchinoline significantly decreased cell proliferation in a dose‐dependent manner and induced G1‐phase arrest in both cell lines. In addition, upon analysis of expression of cell cycle‐related proteins, we found that Fangchinoline reduced expression of cyclin D1, cyclin D3, and cyclin E, and increased expression of the cyclin‐dependent kinase (CDK) inhibitors, p21/WAF1, and p27/KIP1. Moreover, Fangchinoline also inhibited the kinase activities of CDK2, CDK4, and CDK6. These results suggest that Fangchinoline can inhibit human breast cancer cell proliferation and thus may have potential applications in cancer therapy. Copyright © 2013 John Wiley & Sons, Ltd.