Gorelick Jonathan, Rosenberg Rivka, Smotrich Avinoam, Hanuš Lumír, Bernstein Nirit
Judea Regional Research and Development Center, Kiryat Arba, Israel.
Institute of Soil Water and Environmental Sciences, Volcani Center, POB 6, 50-250, Israel.
Phytochemistry. 2015 Aug;116:283-289. doi: 10.1016/j.phytochem.2015.02.029. Epub 2015 Mar 18.
Withania somnifera, known in India as Asghawhanda, is used traditionally to treat many medical problems including diabetes and has demonstrated therapeutic activity in various animal models as well as in diabetic patients. While much of W. somnifera's therapeutic activity is attributed to withanolides, their role in the anti-diabetic activity of W. somnifera has not been adequately studied. In the present study, we evaluated the anti-diabetic activity of W. somnifera extract and purified withanolides, as well as the effect of various elicitors on this activity. W. somnifera leaf and root extracts increased glucose uptake in myotubes and adipocytes in a dose dependent manner, with the leaf extract more active than the root extract. Leaf but not root extract increased insulin secretion in basal pancreatic beta cells but not in stimulated cells. Six withanolides isolated from W. somnifera were tested for anti-diabetic activity based on glucose uptake in skeletal myotubes. Withaferin A was found to increase glucose uptake, with 10μM producing a 54% increase compared with control, suggesting that withaferin A is at least partially responsible for W. somnifera's anti-diabetic activity. Elicitors applied to the root growing solutions affected the physiological state of the plants, altering membrane leakage or osmotic potential. Methyl salicylate and chitosan increased withaferin A content by 75% and 69% respectively, and extracts from elicited plants increased glucose uptake to a higher extent than non-elicited plants, demonstrating a correlation between increased content of withaferin A and anti-diabetic activity.
印度人参（Withania somnifera）在印度被称为Ashwagandha，传统上用于治疗包括糖尿病在内的多种医学问题，并且在各种动物模型以及糖尿病患者中都显示出治疗活性。虽然印度人参的许多治疗活性归因于睡茄内酯，但它们在印度人参抗糖尿病活性中的作用尚未得到充分研究。在本研究中，我们评估了印度人参提取物和纯化的睡茄内酯的抗糖尿病活性，以及各种诱导剂对该活性的影响。印度人参叶和根提取物以剂量依赖的方式增加了肌管和脂肪细胞中的葡萄糖摄取，叶提取物比根提取物更具活性。叶提取物而非根提取物增加了基础胰腺β细胞中的胰岛素分泌，但在刺激细胞中没有增加。基于骨骼肌管中的葡萄糖摄取，对从印度人参中分离出的六种睡茄内酯进行了抗糖尿病活性测试。发现Withaferin A可增加葡萄糖摄取，10μM时与对照相比增加了54%，这表明Withaferin A至少部分负责印度人参的抗糖尿病活性。施加到根系生长溶液中的诱导剂影响了植物的生理状态，改变了膜通透性或渗透势。水杨酸甲酯和壳聚糖分别使Withaferin A含量增加了75%和69%，诱导植物的提取物比未诱导植物在更高程度上增加了葡萄糖摄取，这表明Withaferin A含量的增加与抗糖尿病活性之间存在相关性。
