Flavonoids and stilbenoids as a promising arsenal for the management of chronic arsenic toxicity

Rapid industrial and technological development has impacted ecosystem homeostasis strongly. Arsenic is one of the most detrimental environmental toxins and its management with chelating agents remains a matter of concern due to associated adverse effects. Thus, safer and more effective alternative therapy is required to manage arsenic toxicity. Based on existing evidence, native and indigenous plant-based active biomolecules appear as a promising strategy to mitigate arsenic-induced toxicity with an acceptable safety profile. In this regard, various phytochemicals (flavonoids and stilbenoids) are considered important classes of polyphenolic compounds with antioxidant and chelation effects, which may facilitate the removal of arsenic from the body more effectively and safely with regard to conventional approaches. This review presents an overview of conventional chelating agents and the potential role of flavonoids and stilbenoids in ameliorating arsenic toxicity. This report may provide a roadmap for identifying novel prophylactic/therapeutic strategies for managing arsenic toxicity.     

白藜芦醇治疗结直肠癌的机制研究进展

【摘要】白藜芦醇是一种天然的多酚化合物，有预防心血管疾病，预防衰老，抗炎，抗癌等作用。该文总结了近年来白藜芦醇作用于结直肠癌的机制的研究进展，为白藜芦醇的进一步研究提供依据。     

Resveratrol attenuates high-fat diet-induced non-alcoholic steatohepatitis by maintaining gut barrier integrity and inhibiting gut inflammation through regulation of the endocannabinoid system

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白藜芦醇对氧糖剥夺/再复氧损伤后体外小胶质细胞极化的影响

目的 探讨白藜芦醇对氧糖剥夺/再复氧损伤（OGD/R）后小胶质细胞极化的影响。方法 对体外培养的N9小胶质细胞进行氧糖剥夺150 min，复氧培养24 h。实验分为正常组、对照组和白藜芦醇预处理24 h组。细胞计数盒-8(CCK-8)法检测细胞活力，硫代巴比妥酸（TBA）和水溶性四唑盐（WST-1）法分别检测细胞上清液中丙二醛（MDA）含量和总超氧化物歧化酶（SOD）活性，免疫荧光法检测核因子-E2-相关因子2（Nrf2）的核移位，Western blotting和Real-time PCR法检测CD206、诱导型一氧化氮合酶（iNOS）、Nrf2、血红素加氧酶1（HO-1）和苯醌还原酶（NQO1）蛋白和mRNA表达水平。 结果 OGD/R损伤后，白藜芦醇组细胞活力、SOD活力、CD206、Nrf2、HO-1、NQO1蛋白或mRNA表达均显著高于对照组（P<0.05,n=3），而MDA含量和iNOS蛋白或mRNA表达均显著低于对照组（P<0.05,n=3），白藜芦醇组Nrf2 蛋白较对照组明显移位到细胞核。 结论 白藜芦醇预处理可能通过增强Nrf2的激活，调控M1/M2型小胶质细胞极化，从而减轻OGD/R后小胶质细胞的氧化应激损伤。     

Lycopene and resveratrol ameliorate zinc oxide nanoparticles-induced oxidative stress in Nile tilapia,Oreochromis niloticus

Industrial products contained nano-zinc oxide (ZnONP) can gain access to the aquaculture environment causing hazardous effects on the living biota. Therefore, this work was planned to examine the ameliorative effects of dietary supplementation of lycopene (LYC) and/or resveratrol (RES) against ZnONP toxicity in Nile tilapia. Five groups with 20 fish each were used; Control, received tap water only; ZnONP group, was intoxicated with ZnONP (50 mg/L); ZnONP-LYC group, was exposed to ZnONP and LYC (500 mg/ kg of the diet); ZnONP-RES group, was exposed to ZnONP and RES (50 mg/kg of the diet); ZnONP-LYC-RES group, was exposed to ZnONP and a combination of LYC and RES. The experiment was continued for 30 days. Fish blood and tissues were then assembled for determination of liver and kidney function and oxidative stress status in liver, kidney, and gills tissue. Results revealed a considerable elevation of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), cholesterol, urea, and creatinine with a noticeable lowering of total proteins and albumin serum levels in response to ZnONP intoxication. In addition, there were significant increase in malondialdehyde (MDA) and reduction in the reduced-glutathione (GSH) levels and superoxide dismutase (SOD) and catalase (CAT) activities. However, treatment with LYC and/or RES ameliorated the ZnONP-inflicted oxidative stress which possibly attributed to their beneficial antioxidant activities.     

Resveratrol improves the therapeutic efficacy of bone marrow-derived mesenchymal stem cells in rats with severe acute pancreatitis

ObjectiveBone marrow-derived mesenchymal stem cells (BMSCs) are effective in the treatment of severe acute pancreatitis (SAP), but their therapeutic effects could still be improved. In order to optimize the clinical application of BMSCs, we adopted the strategy of resveratrol (Res) pretreatment of BMSCs (Res-BMSCs) and applied it to a rat model of sodium taurocholate (NaT)-induced acute pancreatitis.MethodsSAP was induced by injection of 3% NaT into the pancreatic duct and successful induction of SAP occurred after 12 h. Rats were treated with BMSCs, Res or BMSCs primed with Res at 40 mmol/L, Vandetanib (ZD6474) daily oral dosages of 50 mg/kg vandetanib.ResultsRes stimulated BMSCs to secrete vascular endothelial growth factor A (VEGFA), activated the downstream phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, and inhibited pancreatic cell apoptosis. In addition, conditioned medium (CM) from Res-BMSCs enhanced the proliferation of human umbilical vein endothelial cells (HUVECs) in vitro, increased resistance to apoptosis and promoted the expression of angiogenesis-related proteins CD31, VEGF and VEGFR2 in pancreatic tissue, but Vandetanib partly abolished these effects by blocking the VEGFA- mediated pathway.ConclusionResveratrol-preprocessed BMSCs can activate the PI3K/AKT signaling pathway in pancreatic cells and HUVECs through paracrine release of VEGFA; thus, achieving the therapeutic effect of resisting apoptosis of pancreatic cells and promoting regeneration of damaged blood vessels. Res pretreatment may be a new strategy to improve the therapeutic effect of BMSCs on SAP.     

Resveratrol-loaded PLGA nanoparticles mediated programmed cell death in prostate cancer cells

Resveratrol (RL), a natural polyphenol, is known for its diverse biological effects against various human cancer cell lines. But low aqueous solubility, poor bioavailability, and stability limit its efficacy against prostate cancer. In this study polymeric nanoparticles encapsulating resveratrol (RLPLGA) were designed and their cytotoxic and mode of apoptotic cells death against prostate cancer cell line (LNCaP) was determined. Nanoparticles were prepared by solvent displacement method and characterized for particle size, TEM, entrapment efficiency, DSC and drug release study. RLPLGA exhibited a significant decrease in cell viability with 50% and 90% inhibitory concentration (IC₅₀ and IC₉₀) of 15.6?±?1.49 and 41.1?±?2.19?μM respectively against the LNCaP cells. This effect was mediated by apoptosis as confirmed by cell cycle arrest at G1-S transition phase, externalization of phosphatidylserine, DNA nicking, loss of mitochondrial membrane potential and reactive oxygen species generation in LNCaP cells. Furthermore, significantly greater cytotoxicity to LNCaP cells was observed with nanoparticles as compared to that of free RL at all tested concentrations. RLPLGA nanoparticles presented no adverse cytotoxic effects on murine macrophages even at 200?μM. Our findings support the potential use of developed resveratrol loaded nanoparticle for the prostate cancer chemoprevention/ chemotherapy with no adverse effect on normal cells.     

白藜芦醇通过抑制Akt/mTOR信号通路活性促进肺癌细胞自噬发挥抗肿瘤效应的研究

目的 探讨白藜芦醇对肺癌细胞生长活性的抑制效应及可能的机制。方法 稳定培养肺癌细胞系H292,分别加入含10、20、40 μmol·L^-1白藜芦醇的培养基进行干预,采用CCK-8、流式细胞术、细胞集落形成实验检测白芦藜醇对H292细胞生长活性的影响,采用免疫荧光、Western blotting检测白藜芦醇对细胞Akt/mTOR信号通路相关蛋白的影响。结果 （1） CCK-8检测结果显示,白藜芦醇对H292细胞增殖有明显抑制作用（P<0.05）,且呈时间和剂量依赖性,同时对H292细胞周期有明显影响,能阻滞细胞周期于G₂/M期。（2）白藜芦醇可明显抑制H292细胞集落形成（P<0.05）,并呈剂量依赖性。（3） Western blotting检测结果显示,白藜芦醇以剂量依赖的方式诱导H292细胞中LC3-II的累积。免疫荧光检测发现,白藜芦醇可诱导细胞核和线粒体中GFP-LC3显著增加。（4）自噬抑制剂3-MA能有效减弱白藜芦醇对H292细胞活力的抑制作用,溶酶体酸化抑制剂Bafilomycin A1则可促进白藜芦醇导致的LC3-II累积。（5）白藜芦醇可下调H292细胞中p-Akt、p-P70S6K、p-mTOR蛋白的表达（P<0.05）,而对Akt、P70S6K、mTOR蛋白的表达无明显影响（P>0.05）。结论 白藜芦醇可通过抑制Akt/mTOR信号通路抑制肺癌细胞的增殖。