Department of Clinical Pharmacology, TN Medical College and BYL Nair Charitable Hospital, Mumbai Central, Mumbai - 400 008, India.
Indian J Pharmacol. 2013 Jan-Feb;45(1):30-3. doi: 10.4103/0253-7613.106431.
Measurement of glucose uptake into peripheral tissue is an important mechanism to assess Insulin sensitivity. The present in vitro study was conducted to evaluate the Insulin sensitizing activity of Phyllanthus emblica (Pe), Tinospora cordifolia (Tc) and Curcuma longa (Cl) by assessing glucose uptake activity in a 3T3L1 adipocyte model.
The 3T3 L1 fibroblast cells were differentiated to adipocytes, using a cocktail of insulin, isobutyl-1-methylxanthine and dexamethazone. These adipocytes were initially treated with different concentrations of the selected plants following which 2-deoxy glucose uptake was estimated using a radioactive assay. The effects of plants on glucose uptake both in the presence and absence of insulin was evaluated and compared with pioglitazone, a known insulin sensitizer.
Pe and Tc per se significantly stimulated glucose uptake in 3T3-L1 adipocytes in a dose dependent manner with maximal effect at higher concentrations (200 μg/ml). The effect of both Pe and Tc at 200 μg/ml was comparable to insulin and greater than pioglitazone. Cl per se stimulated glucose uptake with maximal effect at 50 μg/ml. However, this effect was lesser as compared to insulin with higher concentrations inhibiting glucose uptake. When combined with insulin, an antagonist effect was observed between Pe, Tc and insulin indicating a possible plant-drug interaction while Cl in combination with insulin showed an increase in the glucose uptake as compared to Cl alone.
The results suggest that one of the mechanisms for the anti-diabetic effect of Pe, Cl and Tc may be through an insulin sensitizing effect (stimulation of glucose uptake into adipocytes). Further studies using other target sites viz. skeletal muscle and hepatocytes models and in an insulin resistant state would help substantiate this conclusion.
测量外周组织对葡萄糖的摄取是评估胰岛素敏感性的重要机制。本体外研究旨在通过评估 3T3L1 脂肪细胞模型中的葡萄糖摄取活性，来评估 Phyllanthus emblica（Pe）、Tinospora cordifolia（Tc）和 Curcuma longa（Cl）的胰岛素增敏活性。
3T3L1 成纤维细胞用胰岛素、异丁基-1-甲基黄嘌呤和地塞米松混合物分化为脂肪细胞。这些脂肪细胞最初用选定植物的不同浓度处理，然后用放射性测定法估计 2-脱氧葡萄糖摄取。评估了植物对葡萄糖摄取的影响，包括在存在和不存在胰岛素的情况下，并将其与已知的胰岛素增敏剂吡格列酮进行比较。
Pe 和 Tc 本身以剂量依赖性方式显著刺激 3T3L1 脂肪细胞中的葡萄糖摄取，在较高浓度（200μg/ml）时达到最大效应。Pe 和 Tc 在 200μg/ml 时的作用与胰岛素相当，大于吡格列酮。Cl 本身以 50μg/ml 的最大效应刺激葡萄糖摄取。然而，与胰岛素相比，这种作用较小，较高浓度抑制葡萄糖摄取。当与胰岛素联合使用时，Pe、Tc 和胰岛素之间观察到拮抗作用，表明可能存在植物-药物相互作用，而 Cl 与胰岛素联合使用时与 Cl 单独使用相比，葡萄糖摄取增加。
结果表明，Pe、Cl 和 Tc 的抗糖尿病作用的一种机制可能是通过胰岛素增敏作用（刺激脂肪细胞摄取葡萄糖）。使用其他靶位点（即骨骼肌和肝细胞模型）和在胰岛素抵抗状态下进行的进一步研究将有助于证实这一结论。
