Curcumin ameliorates impaired insulin/IGF signalling and memory deficit in a streptozotocin-treated rat model

Increased serum insulin levels and reduced peripheral insulin activities seen in insulin resistance syndrome are associated with age-dependent cognitive impairment and Sporadic Alzheimer’s Disease (SAD), suggesting a disturbance in the insulin signalling system in the brain and possibly being one of the causes of dementia. Therefore, the streptozotocin (STZ)-induced animal may be an appropriate model for the investigation of SAD and related dementia. This study was designed to investigate the beneficial effect of Curcumin (CUR), a neuroprotective agent, on intracerebroventricular (ICV) STZ-induced cognitive impairment in rats. For this purpose, adult male Wistar rats were bilaterally ICV injected with STZ (3 mg/kg). An artificial cerebrospinal fluid (aCSF) was given to the control group (SHAM) instead of STZ on days 1 and 3. Learning and memory performance were assessed using the “passive avoidance task” and the “Morris water maze test”. After confirmation of acquisition impairment with these tests, the STZ group was divided into two subgroups: STZ + vehicle (Vh) and STZ + CUR. The rats in the SHAM and STZ + Vh groups were administered intraperitoneally with 0.5 ml Vh and the rats in the STZ + CUR group were treated intraperitoneally with CUR (300 mg kg⁻¹ day⁻¹ in Vh) for 10 days starting from the 25th day after STZ injection. The Morris water maze test was reapplied on the 35th day after STZ injection and all of the rats were sacrificed on day 36 for quantitation of IGF-1 and for histopathological evaluation. Rats in the STZ + CUR group were found to have a higher performance in cognitive tests than rats in the STZ + Vh group (P < 0.01). In parallel with the cognitive tests, IGF-1 levels were decreased in all of the STZ-injected groups (1.78 ± 0.34) compared to the SHAM group (3.46 ± 0.41). In contrast, CUR treatment significantly increased IGF-1 levels (P < 0.001). The degree of neuronal loss decreased after CUR treatment compared to the SHAM group (P < 0.02). These results clearly indicate that CUR treatment is effective in reducing the cognitive impairment caused by STZ in rats, and may be a potential therapeutic agent for altering neurodegeneration in SAD.     

Proteomic analysis identifies proteins associated with curcumin-enhancing efficacy of irinotecan-induced apoptosis of colorectal cancer LOVO cell

Objective: We wish to implement a proteomics-based approach to pick and identify the proteins associated with curcumin enhancing efficacy of irinotecan inducing apoptosis of colorectal cancer LOVO cells, and further explore their synergy mechanism by bioinformatics. Methods: A colorectal cancer cell line (LOVO cell) treated by curcumin combined with irinotecan in different ways respectively was used as our comparative model. Protein spots were analyzed through MALDI-TOF/TOF. The location and function of differential protein spots were analyzed through UniProt database. Protein-protein interactions were examined through String software. Results: A total of 54 protein spots differentially expressed with 1.5-fold difference were picked, 11 of which were repeated. They mainly were involved in intracellular calcium pathways, cellular respiratory chain pathway and intracellular redox reaction pathways of LOVO cell. According to the function of various protein points, combining with varying curves of protein points in each treatment groups, we selected five interesting protein spots, 4 of which exists Protein-protein interactions, and they were close to the formation and reduction of disulfides in intracellular endoplasmic reticulum (ER). Conclusion: We selected preliminary but comprehensive data about differential expression protein spots of LOVO cell. Among these, the five interesting differential expression protein spots identified in this study may provide new insight into LOVO cell therapeutic biomarkers. Curcumin may suppress GSTM5 expression to enhance the lethal effect of irinotecan on LOVO cells, and maybe their combination via the affection of PDI and PRDX4 to disturb the formation and reduction of disulfides results in inducing apoptosis of LOVO cell.     

Possible Links between Intestinal Permeablity and Food Processing: A Potential Therapeutic Niche for Glutamine

Increased intestinal permeability is a likely cause of various pathologies, such as allergies and metabolic or even cardiovascular disturbances. Intestinal permeability is found in many severe clinical situations and in common disorders such as irritable bowel syndrome. In these conditions, substances that are normally unable to cross the epithelial barrier gain access to the systemic circulation. To illustrate the potential harmfulness of leaky gut, we present an argument based on examples linked to protein or lipid glycation induced by modern food processing. Increased intestinal permeability should be largely improved by dietary addition of compounds, such as glutamine or curcumin, which both have the mechanistic potential to inhibit the inflammation and oxidative stress linked to tight junction opening. This brief review aims to increase physician awareness of this common, albeit largely unrecognized, pathology, which may be easily prevented or improved by means of simple nutritional changes.     

姜黄素对兔颈动脉斑块稳定性及EPCs活力的影响

目的:观察姜黄素对颈动脉斑块稳定性及内祖皮细胞(EPCs)的影响。方法:将30只新西兰兔随机分为空白对照组、模型组及姜黄素组,各10只,其中空白对照组予普通饲料喂养,模型组予喂养高脂饲料,姜黄素组予喂养高脂饲料+100 mg/d姜黄素。连续喂养12周后HE染色法观察3组西兰兔主动脉内膜斑块厚度、外周血总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL-C)水平以及利用MTT法测定人纤维EPCs细胞迁徙及增殖活性。结果:1)血脂水平:与空白组比较,模型组及姜黄素组TC、TG及LDL-C均升高(P0.05),HDL-C降低(P0.05),其中姜黄素干预后上述指标有明显改善(P0.05)。2)形态学变化:空白对照组颈动脉壁厚薄均匀,结构均匀,模型组及姜黄素均出现动脉管腔狭窄,动脉内膜增厚,其中姜黄素组较模型组改善。3)EPCs增殖情况:与空白组比较,模型组及姜黄素OD值均降低(P0.05),与模型组比较,姜黄素OD有所上调(P0.05)。4)EPCs迁徙能力:空白对照组各时间点划痕愈合率均显著高于其余2组(P0.05),其中姜黄素组各时间点划痕愈合率均高于模型组(P0.05)。结论:姜黄素由明显抗动脉粥样硬化作用,其作用机制可能与促进EPCs增殖及迁徙有关。     

Colon carcinogenesis: Influence of Western diet-induced obesity and targeting stem cells using dietary bioactive compounds

Colon cancer strikes more than 1 million people annually and is responsible for more than 500,000 cancer deaths worldwide. Recent evidence suggests that the majority of malignancies, including colon cancer are driven by cancer stem cells (CSCs) that are resistant to current chemotherapeutic approaches leading to cancer relapse. Wnt signaling plays a critical role in colon stem cell renewal and carcinogenesis. Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), a Wnt target gene, and aldehyde dehydrogenase 1 B1 (ALDH1B1) are good markers for normal and malignant human colon stem cells. Diet contributes to 20% to 42% of all human cancers and 50% to 90% of colon cancer. Recent evidence shows that the Western diet has a causative link to colon cancer; however, mechanisms of action are not fully elucidated. Western diet-induced obesity elevates systemic insulin-like growth factor-1 and insulin levels, which could lead to elevated proliferation and suppressed apoptosis of CSCs through PI3K/AKT/Wnt pathway. Although conventional chemotherapy targets the PI3K/AKT pathways and can significantly reduce tumor size, it fails to eliminate CSCs and has serious side effects. Dietary bioactive compounds such as grape seed extract, curcumin, lycopene, and resveratrol have promising chemopreventive effects, without serious side effects on various types of cancers due to their direct and indirect actions on CSC self-renewal pathways such as the Wnt pathway. Understanding the role of CSCs in diet-induced colon cancer will aid in development of evidence-based dietary chemopreventive strategies and/or therapeutic agents targeting CSCs.     

丹参酚酸B和姜黄素抑制大鼠肝星状细胞细胞外信号调节激酶的磷酸化

目的研究丹参酚酸B(SAB)和姜黄素(Cur)对大鼠肝星状细胞(HSC)增殖、活化和细胞外信号调节激酶(ERK)的作用。方法培养大鼠HSC-T6,使用SAB和Cur处理细胞,采用MTT法检测药物对细胞增殖的影响。收集裂解细胞并抽提细胞总蛋白,10%聚丙烯酰胺凝胶电泳分离蛋白,采用Western blot法检测药物对细胞表达α平滑肌肌动蛋白(α-SMA)、I型胶原、ERK和磷酸化ERK的影响。结果Cur剂量依赖性地抑制大鼠HSC的增殖和活化,SAB和Cur显著降低α-SMA的表达水平(P<0.01);SAB对I型胶原的分泌无影响(P>0.05)而Cur显著减少I型胶原的分泌(P<0.05)。SAB和Cur对ERK表达水平都没有显著影响(P>0.05),但是显著降低了磷酸化ERK的表达水平(P<0.01 vs.P<0.05)。结论SAB和Cur能够抑制HSC的增殖、活化和ERK的磷酸化。     

姜黄素诱导乳腺癌MCF-7细胞凋亡

目的 研究姜黄素对人乳腺癌细胞株MCF-7细胞增殖抑制和诱导凋亡作用.方法 MTT法检测姜黄素对MCF-7细胞的增殖抑制作用;流式细胞术(FCM)PI单染检测细胞周期;Annexin V/PI双染法检测细胞凋亡;Western blot法检测Bcl-2和Bax蛋白的表达.结果 姜黄素对MCF-7细胞生长有明显抑制作用,并呈剂量、时间依赖性;姜黄素能使MCF-7细胞阻滞在G1/S期,可以诱导细胞凋亡,Bax蛋白表达上调,而Bcl-2的表达减少.结论 姜黄素对人乳腺癌MCF-7细胞的增殖具有显著的抑制作用并可诱导细胞凋亡.其分子作用机制可能与其上调Bax基因表达水平的同时下调Bcl-2基因表达水平,从而诱导细胞凋亡有关.     

Antiangiogenic and growth inhibitory effects of synthetic novel 1, 5-diphenyl-1,4 pentadiene-3-one-3-yl-ethanone pyridine curcumin analogues on Ehrlich ascites tumor in vivo

In the present investigation we have synthesized novel substituted dienone pyridine ethanone curcumin analogues 3a and 3b by nucleophilic substitution reactions with 2-bromo-1-pyridine-3-yl ethanone and characterized by ¹H nuclear magnetic resonance (NMR), infrared IR, mass, and CHNS analysis. The compounds demonstrated tumor growth inhibition and antiangiogenic effects against mouse Ehrlich ascites tumor in vivo and suppressed neovascularization in a chorio allantoic membrane model.     

姜黄素对人胚肺成纤维细胞的生长抑制及细胞外基质合成的影响

目的:研究姜黄素对体外培养人胚肺成纤维细胞(HEF-5)MRC-5增殖、胶原表达和周期分布的影响。方法:体外培养MRC-5细胞,用姜黄素处理,分为正常对照组和10、20、30、40、50、60μmol/L姜黄素组。于37℃继续培养24 h后,用四甲基偶氮唑蓝(MTT)法检测细胞增殖情况,用天狼猩红染色法测定细胞内胶原的表达,用流式细胞仪检测细胞周期的变化。结果:姜黄素呈剂量和时间依赖性抑制MRC-5细胞的增生(P<0.05),并降低胶原的生成(P<0.05),流式细胞仪检测结果显示,细胞主要停滞于G1期。结论:姜黄素能抑制MRC-5细胞的增殖和胶原的增加,并使细胞周期停滞在G1期,提示姜黄素可能通过抑制MRC-5细胞的增殖来减少细胞外基质积聚,从而发挥其抗肺纤维化的作用。     

姜黄素脂质体在大鼠体内药代动力学研究

目的研究姜黄素脂质体口服液在大鼠体内的药代动力学行为。并与游离姜黄素溶液进行比较,评价姜黄素脂质体药代动力学特征。方法大鼠灌胃给药,摘眼球取血,HPLC测定血药浓度;采用3P87药代软件模拟房室模型并计算药代动力学参数。结果当姜黄素的给药量1次接近300 mg/kg时,其药代动力学过程为非线性动力学过程。结论姜黄素脂质体口服液比姜黄素混悬液入血速度明显加快,有利于机体的吸收,并且消除减慢,血液中浓度高,在组织中分布广。