Iheagwam Franklyn Nonso, Israel Emmanuel Nsedu, Kayode Kazeem Oyindamola, De Campos Opeyemi Christianah, Ogunlana Olubanke Olujoke, Chinedu Shalom Nwodo
Department of Biochemistry, Covenant University, Canaanland, P.M.B. 1023 Ota, Ogun State, Nigeria.
Covenant University Public Health and Wellbeing Research Cluster (CUPHWERC), Covenant University, Canaanland, P.M.B. 1023 Ota, Ogun State, Nigeria.
Evid Based Complement Alternat Med. 2019 Sep 5;2019:6316231. doi: 10.1155/2019/6316231. eCollection 2019.
leaves are used in managing both diabetes mellitus and its complications in Southwest Nigeria. However, its inhibitory activity on enzymes implicated in diabetes is not very clear. This study investigated the inhibitory properties and mode of inhibition of leaf extracts on enzymes associated with diabetes. The study also identified some bioactive compounds as well as their molecular interaction in the binding pocket of these enzymes. Standard enzyme inhibition and kinetics assays were performed to determine the inhibitory effects of aqueous extract (TCA) and ethanol extract (TCE) of leaves on -glucosidase and -amylase activities. The phytoconstituents of TCA and TCE were determined using GC-MS. Molecular docking of the phytocompounds was performed using Autodock Vina. TCA and TCE were the most potent inhibitors of -glucosidase (IC = 3.28 ± 0.47 mg/mL) and -amylase (IC = 0.24 ± 0.08 mg/mL), respectively. Both extracts displayed a mixed mode of inhibition on -amylase activity, while mixed and noncompetitive modes of inhibition were demonstrated by TCA and TCE, respectively, on -glucosidase activity. The GC-MS analytic chromatogram revealed the presence of 24 and 22 compounds in TCE and TCA, respectively, which were identified mainly as phenolic compounds, terpenes/terpenoids, fatty acids, and other phytochemicals. The selected compounds exhibited favourable interactions with the enzymes compared with acarbose. Overall, the inhibitory effect of on -amylase and -glucosidase may be ascribed to the synergistic action of its rich phenolic and terpene composition giving credence to the hypoglycaemic nature of leaves.
在尼日利亚西南部，树叶被用于治疗糖尿病及其并发症。然而，其对与糖尿病相关酶的抑制活性尚不清楚。本研究调查了树叶提取物对与糖尿病相关酶的抑制特性和抑制模式。该研究还鉴定了一些生物活性化合物及其在这些酶结合口袋中的分子相互作用。进行了标准酶抑制和动力学测定，以确定树叶水提取物（TCA）和乙醇提取物（TCE）对α-葡萄糖苷酶和α-淀粉酶活性的抑制作用。使用气相色谱-质谱联用仪（GC-MS）测定TCA和TCE的植物成分。使用Autodock Vina对植物化合物进行分子对接。TCA和TCE分别是α-葡萄糖苷酶（IC₅₀ = 3.28 ± 0.47 mg/mL）和α-淀粉酶（IC₅₀ = 0.24 ± 0.08 mg/mL）最有效的抑制剂。两种提取物对α-淀粉酶活性均表现出混合抑制模式，而TCA和TCE对α-葡萄糖苷酶活性分别表现出混合抑制和非竞争性抑制模式。GC-MS分析色谱图显示，TCE和TCA中分别存在24种和22种化合物，主要鉴定为酚类化合物、萜类/萜类化合物、脂肪酸和其他植物化学物质。与阿卡波糖相比，所选化合物与酶表现出良好的相互作用。总体而言，树叶对α-淀粉酶和α-葡萄糖苷酶的抑制作用可能归因于其丰富的酚类和萜类成分的协同作用，这证实了树叶的降血糖特性。
