Phytomedicine and Phytochemistry Group, Oxidative Stress Research Centre, Department of Biomedical Sciences, Faculty of Health & Wellness Sciences, Cape Peninsula University of Technology, Bellville 7535, South Africa.
DSI/Mintek Nanotechnology Innovation Centre, Biolabels Node, Department of Biotechnology, University of the Western Cape, Bellville 7530, South Africa.
Molecules. 2020 Nov 26;25(23):5546. doi: 10.3390/molecules25235546.
The plant has been used traditionally to treat diabetes mellitus. Scientific evidence supporting the antidiabetic effects of this plant's active ingredient-vindoline has not been fully evaluated. In this study, extracts of and vindoline were tested for antioxidant activities, alpha amylase and alpha glucosidase inhibitory activities and insulin secretory effects in pancreatic RIN-5F cell line cultured in the absence of glucose, at low and high glucose concentrations. The methanolic extract of the plant showed the highest antioxidant activities in addition to the high total polyphenolic content ( < 0.05). The HPLC results exhibited increased concentration of vindoline in the dichloromethane and the ethylacetate extracts. Vindoline showed noticeable antioxidant activity when compared to ascorbic acid at < 0.05 and significantly improved the in vitro insulin secretion. The intracellular reactive oxygen species formation in glucotoxicity-induced cells was significantly reduced following treatment with vindoline, methanolic and the dichloromethane extracts when compared to the high glucose untreated control ( < 0.05). Plant extracts and vindoline showed weaker inhibitory effects on the activities of carbohydrate metabolizing enzymes when compared to acarbose, which inhibited the activities of the enzymes by 80%. The plant extracts also exhibited weak alpha amylase and alpha glucosidase inhibitory effects.
该植物传统上被用于治疗糖尿病。尚未充分评估支持该植物活性成分长春碱具有抗糖尿病作用的科学证据。在这项研究中,在无葡萄糖、低葡萄糖和高葡萄糖浓度下培养的胰腺 RIN-5F 细胞系中,测试了 和长春碱的提取物的抗氧化活性、α-淀粉酶和α-葡萄糖苷酶抑制活性以及胰岛素分泌作用。该植物的甲醇提取物除了总多酚含量高(<0.05)外,还显示出最高的抗氧化活性。HPLC 结果显示,在二氯甲烷和乙酸乙酯提取物中长春碱的浓度增加。与抗坏血酸相比,长春碱表现出明显的抗氧化活性,当浓度低至 <0.05 时,还显著改善了体外胰岛素分泌。与未经高葡萄糖处理的对照相比,长春碱、甲醇和二氯甲烷提取物处理后,糖毒性诱导细胞中的活性氧形成明显减少(<0.05)。与抑制酶活性达 80%的阿卡波糖相比,植物提取物和长春碱对碳水化合物代谢酶活性的抑制作用较弱。植物提取物也表现出较弱的α-淀粉酶和α-葡萄糖苷酶抑制作用。