α-Amylase catalyses the hydrolysis of starch and ultimately producing glucose. Controlling the catalytic activity of this enzyme reduces glucose production in the postprandial stage, which could be a therapeutic benefit for people with diabetes. This study was conducted to evaluate α-amylase inhibition for utilizing the crude extracts of some medicinal plants traditionally used in Nepal for the treatment of diabetes and its related complications. Microtiter plate approach has been used to assess inhibitory activities of in vitro α-amylase of methanolic extracts of thirty-two medicinal plants. A starch tolerance test was used in rats to investigate the in vivo study of the methanolic extract concerning glibenclamide as the positive control. Acacia catechu, Dioscorea bulbifera, and Swertia chirata exhibited inhibitory activity against α-amylase and with IC50 values; 49.9, 296.1, and 413.5 μg/mL, respectively. Kinetics study revealed that all the extracts displayed a mixed type of inhibition pattern, with Ki values ranging from 26.6–204.2 μg/mL. Free radical scavenging activity was again re-examined and found prominent in extracts of A. catechu. Likewise, A. catechu and S. chirata showed significant reduction of blood glucose concentration up to 30 min after oral dose of 250 mg/kg (F (4, 20) = 4.1, p = .048), and (F (4, 20) = 4.1, p = .036), respectively. Enzymatic assay for α-amylase inhibition using extracts was successfully evaluated. Also, the in-vitro and in-vivo study model revealed that medicinal plants could be a potent source of α-amylase inhibition. So, they could serve as potential candidates for future drug development strategies for curing diabetes with minimal or no adverse side effects.

中文翻译：

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尼泊尔药用植物治疗糖尿病的α-淀粉酶抑制活性的评估

α-淀粉酶催化淀粉的水解并最终产生葡萄糖。控制此酶的催化活性可减少餐后阶段的葡萄糖生成，这可能对糖尿病患者具有治疗益处。这项研究旨在评估α-淀粉酶的抑制作用，以利用尼泊尔传统上用于治疗糖尿病及其相关并发症的某些药用植物的粗提物。微量滴定板法已用于评估32种药用植物的甲醇提取物的体外α-淀粉酶的抑制活性。在大鼠中进行了淀粉耐受性试验，以研究以格列本脲为阳性对照的甲醇提取物的体内研究。刺槐相思，薯os，和Swertia chirata表现出对α-淀粉酶的抑制活性，IC50值；分别为49.9、296.1和413.5μg/ mL。动力学研究表明，所有提取物均表现出混合类型的抑制模式，Ki值为26.6–204.2μg/ mL。再次清除自由基清除活性，发现其在儿茶曲霉提取物中很显着。同样，在口服250 mg / kg剂量后的30分钟内，儿茶曲霉和奇异曲霉显示血糖浓度显着降低（F（4，20）= 4.1，p = .048）和（F（4， 20）= 4.1，p = .036）。使用提取物的酶法测定α-淀粉酶抑制作用已成功评估。同样，体外和体内研究模型表明，药用植物可能是抑制α-淀粉酶的有效来源。所以，