Resveratrol,a natural phytoalexin,normalizes hyperglycemia in streptozotocin-nicotinamide induced experimental diabetic rats

Resveratrol is a polyphenolic phytoalexin produced in appreciable amounts as a secondary metabolite in grapevines in response to fungal infections. Based on the present knowledge, it appears to be a promising bioactive natural molecule with potential applications in phytotherapy or pharmacology. The present study was aimed to evaluate the antidiabetic properties of resveratrol in streptozotocin-nicotinamide induced experimental diabetes in rats. The diabetic rats orally treated with resveratrol (5 mg kg⁻¹ b.w d⁻¹) for 30 days resulted in significant (p < 0.05) decrease in the levels of blood glucose, glycosylated hemoglobin, blood urea, serum uric acid, serum creatinine and diminished activities of pathophysiological enzymes such as aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP). The antihyperglycemic nature of resveratrol is also evidenced from the improvement in the levels of plasma insulin and hemoglobin. Further, the results are comparable with glyclazide, an oral standard drug. Thus, the present findings suggest that resveratrol may be considered as an effective therapeutic agent for the treatment of diabetes mellitus.     

Hepatoprotective effects of antioxidants in chronic hepatitis C

We have read with interest the paper published in issue 2, volume 16 of World Journal of Gastroenterology 2010 by Nakamura et al, demonstrating that the antioxidant resveratrol (RVT) enhances hepatitis C virus (HCV) replication, consequently, they conclude that RVT is not a suitable antioxidant therapy for HCV chronic infection. The data raise some concern regarding the use of complementary and alternative medicine since the most frequent supplements taken by these patients are antioxidants or agents that m...     

白藜芦醇在动脉粥样硬化治疗中的抗炎抗氧化及抗增殖作用研究进展

白藜芦醇是一种多酚类化合物,具有广泛的生理药理学作用,如抗炎症、抗氧化及抗增殖等多种生物活性,但目前其作用机制尚未完全明确。近年研究表明,白藜芦醇主要通过调控白细胞介素6/信号转导及转录活化因子3、核因子κB及分裂原活化蛋白激酶等关键信号转导通路达到其抗炎、抗氧化作用,主要通过抑制哺乳动物雷帕霉素靶蛋白信号通路作用达到其抗增殖作用。     

白藜芦醇调控癫痫持续状态大鼠海马内源性巯醇抗氧化剂(酶)的作用

目的 探讨白藜芦醇(Res)在氯化锂联合重复低剂量匹罗卡品诱导癫痫持续状态大鼠模型中的抗氧化作用及其机制.方法 54只SD大鼠随机分为 3 组:对照组、癫痫模型组和Res治疗组,采用氯化锂联合重复低剂量匹罗卡品腹腔注射制备癫痫持续状态大鼠模型,Res治疗组同时给予白藜芦醇预防性治疗.对大鼠按痫性分级标准进行行为学观测;...     

白藜芦醇对离心运动后骨骼肌微损伤的修复

背景：白藜芦醇是一种天然的抗氧化剂和自由基廓清剂,具有清除自由基、减轻脂质过氧化等重要药理作用,目前有关白藜芦醇在减轻骨骼肌损伤、促进损伤修复方面的研究尚不多见。 目的：观察白藜芦醇对离心运动后骨骼肌超微结构损伤、血清丙二醛和肌细胞浆Ca2+浓度的影响。 设计、时间及地点：对照观察动物实验,于2007-08/2008-06在南方医科大学完成。 材料：成年雄性SD大鼠72只,实验室适应性喂养3 d后随机分为蒸馏水组(n=40)、白藜芦醇组(n=32)。白藜芦醇制剂购自湖南省洪江华光生物有限公司。 方法：白藜芦醇组大鼠每日腹腔注射1次白藜芦醇制剂60 mg/kg,蒸馏水组大鼠腹腔注射等量蒸馏水,连续2周。2周后,将大鼠在动物跑台上进行一次性下坡跑运动,速度为16 m/min,下坡坡度为16°,5 min运动,2 min休息,总运动时间为120 min。运动过程中采用人工驱赶和声刺激,不使用电刺激。 主要观察指标：于运动前、运动后即刻、运动后24,48,72 h电镜下观察比目鱼肌纤维Z线,TAB法测定血清丙二醛和流式细胞仪检测肌细胞浆Ca2+浓度。 结果：与蒸馏水组比较,白藜芦醇组镜下肌纤维损伤程度减轻,骨骼肌细胞Z线异常百分率在运动后即刻、运动后24,48,72 h比蒸馏水组分别降低了50.34%,52.67%,52.65%和53.26%(P < 0.05),离心运动引起的血清丙二醛升高程度分别下降了27.7%,29.56%,34.38%和27.79%(P < 0.05),胞浆Ca2+浓度分别降低了27.53%,25.84%,22.14%和11.62% (P < 0.05)。 结论：白藜芦醇可降低离心运动后血清丙二醛浓度和肌细胞浆Ca2+浓度,减轻运动导致的肌肉损伤。     

白藜芦醇上调糖尿病大鼠脂肪组织PPAR-γ及GluT-4蛋白表达

目的 探讨白藜芦醇改善糖尿病大鼠脂肪组织胰岛素敏感性及降血糖的作用机制.方法 雄性Wistar大鼠随机分为对照组(NC,n=15)及糖尿病造模组(DM,n=40),DM组成模后随机分为糖尿病模型组(DM-C,n=15)和糖尿病白藜芦醇治疗组(DM-T,n=15).DM-T组予白藜芦醇5.0 mg/(kg·d)-1灌胃1...     

trans-Resveratrol inhibits H2O2-induced adenocarcinoma gastric cells proliferation via inactivation of MEK1/2-ERK1/2-c-Jun signalling axis

In this report we investigate the signalling pathway activated by H₂O₂ in human adenocarcinoma gastric cells (AGS) and we evaluate the anti-proliferative action of the natural stilbene trans-resveratrol. We demonstrate that H₂O₂ accelerates cell growth and induces a prompt MEK1/2-ERK1/2 activation. Such events are also associated with the activation of c-Jun and its translocation into the nuclear compartment. A specific inhibitor of ERK1/2 phosphorylation by MEK1/2 (U0126) abrogates these phenomena. On the contrary, specific inhibition of JNK activity does not influence H₂O₂-mediated growth, suggesting that cell proliferation likely proceeds via MEK1/2-ERK1/2-Jun signalling axis. trans-Resveratrol is also able to completely suppress the increase in proliferation. We demonstrate that this property is not due to its antioxidant capacity but rather due to a specific inhibition of ERK1/2 phosphorylation by MEK1/2 and repression of c-Jun activation.     

白藜芦醇衍生物(BTM-0512)在大鼠体肠吸收特性研究

目的:研究白藜芦醇衍生物[(E)-3,5,4′-三甲氧基-1,2-二苯乙烯(BTM-0512)]在大鼠肠道的吸收特性。方法:采用大鼠在体肠循环实验,考察不同的药物浓度、肠段及胆汁对吸收参数的影响。BTM-0512在大鼠肠循环液中的药物浓度采用HPLC法测定;循环液中酚红浓度采用UV法测定。结果:在肠道正常PH值情况下,低、中、高3个浓度的BTM-0512的吸收速率常数(K_a)分别为0.6290、0.5329(扎胆管)、0.5330(未扎胆管)、0.6791h~(-1),表明不同浓度BTM-0512在肠道的吸收速率常数相近,且胆汁对BTM-05 12肠道吸收没有影响(P>0.05);在十二指肠、空肠、回肠、结肠的吸收速率常数分别为0.9492、0.5216、0.3835、0.1185 h~(-1),统计结果显示,不同肠段间吸收有明显差异(P<0.05)。结论:BTM-0512在肠道内是以被动扩散的方式被吸收,呈现一级动力学过程。因BTM-0512在整肠段均有吸收,剂型设计时可考虑肠溶制剂。