Different parts of the medicinal plant Tamarindus indica L. are full of phytochemicals that are able to reduce elevated blood pressure, blood sugar and lipids. These pharmacological effects are due to the presence of antioxidant type compounds in those parts of the plant. This study was aimed to explore the molecular mechanism of anti-obesity effects of ethanolic extract of T. indica L. leaves (TILE) through the evaluation of biochemical parameters and gene expression analysis in high-fat diet (HFD) consuming Wistar rats. Male Wistar rats were supplied with a standard diet (SD), or HFD, or HFD with 100 mg/kg or 200 mg/kg or 400 mg/kg TILE for 8 weeks. The body weight, liver weight, fat weight, plasma lipids, and oxidative stress-related parameters were measured. The transcript levels of different adipogenesis related transcription factors, lipogenic enzymes, and lipolytic enzymes were also evaluated by quantitative real-time PCR. Phytochemical analysis demonstrated that TILE is enriched with a substantial level of polyphenols (287.20 ± 9.21 mg GAE/g extract) and flavonoids (107.52 ± 11.12 mg QE/g extract) which might be the reason of significant antioxidant and radical scavenging activities. Feeding of TILE (400 mg/kg/day) to HFD-fed rats increased activity of superoxide dismutase and catalase which is reflected as a significant reduction of oxidative stress markers like nitric oxide and malondialdehyde. TILE (400 mg/kg/day) feeding also down-regulated the mRNA levels of proadipogenic transcription factors including liver X receptor alpha (LXRα), peroxisome proliferator-activated receptor gamma (PPARγ), and sterol regulatory element-binding protein 1c (SREBP1c) in diet-induced obese rats. As a consequence of this, the mRNA level of lipogenic enzymes like acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), diacylglycerol acyltransferase (DGAT), and HMG-CoA reductase was down-regulated with a parallel up-regulation of the transcript level of lipolytic enzyme, hormone-sensitive lipase (HSL). Observations from this study indicate that antioxidant-rich TILE can reduce HFD-induced body weight, fat weight and liver weight as well as blood lipids through down-regulating the gene expression of proadipogenic transcription factors and lipogenic enzymes with a concerted diminution of the gene expression of lipolytic enzyme, HSL.

中文翻译：

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富含抗氧化剂的罗望子Ta叶片提取物通过调节基因表达减少高脂饮食诱导的大鼠肥胖

药用植物罗望子（Tamarindus indica L.）的不同部位都充满了能够降低血压，血糖和脂质的植物化学物质。这些药理作用是由于在植物的那些部分中存在抗氧化剂类型的化合物。本研究旨在通过对食用高脂饮食（Wistar大鼠）的高脂饮食（HFD）的生化参数进行评估和基因表达分析，探讨T树乙醇提取物（TILE）抗肥胖作用的分子机制。向雄性Wistar大鼠提供标准饮食（SD），HFD或100 mg / kg或200 mg / kg或400 mg / kg TILE的HFD，持续8周。测量体重，肝脏重量，脂肪重量，血浆脂质和氧化应激相关参数。不同脂肪形成相关转录因子的转录水平，还通过定量实时PCR评估了脂肪形成酶和脂解酶。植物化学分析表明，TILE富含大量多酚（287.20±9.21 mg GAE / g提取物）和类黄酮（107.52±11.12 mg QE / g提取物），这可能是重要的抗氧化剂和自由基清除活性的原因。向HFD喂养的大鼠饲喂TILE（400 mg / kg /天）可增加超氧化物歧化酶和过氧化氢酶的活性，这反映为氧化应激标记物（如一氧化氮和丙二醛）的显着减少。TILE（400 mg / kg / day）喂养还下调了促脂肪转录因子的mRNA水平，包括肝X受体α（LXRα），过氧化物酶体增殖物激活受体γ（PPARγ），饮食诱导的肥胖大鼠体内的固醇调节元素结合蛋白1c（SREBP1c）。因此，脂肪酶的mRNA水平如乙酰辅酶A羧化酶（ACC），脂肪酸合酶（FAS），二酰基甘油酰基转移酶（DGAT）和HMG-CoA还原酶被下调，而平行的上调脂解酶，激素敏感性脂肪酶（HSL）的转录水平。这项研究的观察结果表明，富含抗氧化剂的TILE可以通过下调促脂肪形成转录因子和脂肪酶的基因表达，同时协调基因表达的减少，从而降低HFD诱导的体重，脂肪重量，肝脏重量以及血脂脂分解酶HSL 脂肪酸合成酶（FAS），二酰基甘油酰基转移酶（DGAT）和HMG-CoA还原酶被下调，而脂解酶，激素敏感性脂肪酶（HSL）的转录水平被平行上调。这项研究的观察结果表明，富含抗氧化剂的TILE可以通过下调促脂肪形成转录因子和脂肪酶的基因表达，同时协调基因表达的减少，从而降低HFD诱导的体重，脂肪重量，肝脏重量以及血脂脂分解酶HSL 脂肪酸合成酶（FAS），二酰基甘油酰基转移酶（DGAT）和HMG-CoA还原酶被下调，而脂解酶，激素敏感性脂肪酶（HSL）的转录水平被平行上调。这项研究的观察结果表明，富含抗氧化剂的TILE可以通过下调促脂肪形成转录因子和脂肪酶的基因表达，同时协调基因表达的减少，从而降低HFD诱导的体重，脂肪重量，肝脏重量以及血脂脂分解酶HSL