Ibrahim Mohammed Auwal, Koorbanally Neil Anthony, Islam Shahidul
Acta Pol Pharm. 2016 Sep;73(5):1235-1247.
Vitex doniana is an important African medicinal plant traditionally used for the treatment of many diseases including type 2 diabetes (T2D). In this study, ethyl acetate, ethanol and aqueous extracts of the stem bark, root and leaf of V. doniana were analyzed for in vitro anti-oxidative activity and the results indicated that the ethanolic extract of the leaves had the best anti-oxidative activity. Subsequently, the ethanolic extract of the leaves was partitioned between hexane, dichloromethane, ethyl acetate and water. The aqueous fraction had a significantly ( p < 0.05) higher phenolics content and also showed the best anti-oxidative activity within the fractions. Furthermore, the aqueous fraction demonstrated significantly (p < 0.05) more potent inhibitory activities against α-glucosidase and α-amylase than other fractions. Steady state kinetics analysis revealed that the aqueous fraction inhibited both (α-glucosidase and (α-amylase activities in a non-competitive manner with inhibition binding constant (Ki) values of 5.93 and 167.44 μg/mL, respectively. Analysis of the aqueous fraction by GC-MS showed the presence of resorcinol, 4-hydroxybenzoic acid, 3,4,5-trimethoxyphenol and 2,4'-dihydroxychalcone identified by their mass fragmentation patterns and comparison to standard spectra. The results obtained in this study showed that V doniana leaves have a good in vitro anti-T2D potential possibly elicited through phenolics.
钝叶黄荆是一种重要的非洲药用植物，传统上用于治疗包括2型糖尿病（T2D）在内的多种疾病。在本研究中，对钝叶黄荆茎皮、根和叶的乙酸乙酯、乙醇和水提取物进行了体外抗氧化活性分析，结果表明叶的乙醇提取物具有最佳的抗氧化活性。随后，叶的乙醇提取物用己烷、二氯甲烷、乙酸乙酯和水进行分配。水相部分的酚类含量显著更高（p<0.05），并且在各部分中也表现出最佳的抗氧化活性。此外，水相部分对α-葡萄糖苷酶和α-淀粉酶的抑制活性比其他部分显著更强（p<0.05）。稳态动力学分析表明，水相部分以非竞争性方式抑制α-葡萄糖苷酶和α-淀粉酶的活性，抑制结合常数（Ki）值分别为5.93和167.44μg/mL。通过GC-MS对水相部分进行分析，结果显示存在间苯二酚、4-羟基苯甲酸、3,4,5-三甲氧基苯酚和2,4'-二羟基查耳酮，通过它们的质谱裂解模式并与标准光谱进行比较来鉴定。本研究获得的结果表明，钝叶黄荆叶具有良好的体外抗2型糖尿病潜力，可能是通过酚类物质发挥作用。
