Alpha-Amylase and Alpha-Glucosidase Enzyme Inhibition and Antioxidant Potential of 3-Oxolupenal and Katononic Acid Isolated from Nuxia oppositifolia
Alpha-Amylase and Alpha-Glucosidase Enzyme Inhibition and Antioxidant Potential of 3-Oxolupenal and Katononic Acid Isolated from Nuxia oppositifolia
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DOI：
10.3390/biom10010061
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发表时间：
2020-01-01
期刊：
影响因子：
5.5
通讯作者：
AlAjmi, Mohamed F.
中科院分区：
文献类型：
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作者：
Alqahtani, Ali S.;Hidayathulla, Syed;AlAjmi, Mohamed F.
女侠在许多阿拉伯国家传统上用于治疗糖尿病；然而，缺乏科学证据。因此，本研究探讨了植物提取物及其纯化化合物的抗糖尿病和抗氧化活性。采用双溶剂体系对槐叶甲醇粗提物进行了分离。用硅胶柱层析法纯化了正己烷馏分，得到了katononic acid和3-oxolupenal等化合物。采用α -淀粉酶和α -葡萄糖苷酶抑制法测定其抗糖尿病活性。采用2,2-二苯基-1-吡啶肼（DPPH）和2,2 '-氮基-双（3-乙基苯并噻唑-6-磺酸）（ABTS）清除率测定抗氧化能力。此外，酶（α -淀粉酶和α -葡萄糖苷酶）和配体（3-羟戊二醛和katononic酸）之间的相互作用通过荧光猝灭和分子对接研究。对淀粉酶抑制作用的IC50值分别为46.2 μ g/mL （101.6 μ M）和52.4 μ g/mL （119.3 μ M）。3-吲哚酚（62.3 μ g/mL或141.9 μ M）对α -葡萄糖苷酶的抑制作用强于卡顿酸（88.6 μ g/mL或194.8 μ M）。在抗氧化活性方面，相对极性的粗提物和正丁醇部位具有最大的DPPH和ABTS清除活性。然而，纯化的化合物的抗氧化活性在低到中等范围内。分子对接研究证实，3-羟戊二醛和katononic酸与α -淀粉酶和α -葡萄糖苷酶的活性位点残基都有很强的相互作用。荧光猝灭结果还表明，3-羟戊二醛和katononic酸对α -淀粉酶和α -葡萄糖苷酶都有很好的亲和力。本研究为该植物治疗2型糖尿病提供了初步资料。
Nuxia oppositifolia is traditionally used in diabetes treatment in many Arabian countries; however, scientific evidence is lacking. Hence, the present study explored the antidiabetic and antioxidant activities of the plant extracts and their purified compounds. The methanolic crude extract of N. oppositifolia was partitioned using a two-solvent system. The n-hexane fraction was purified by silica gel column chromatography to yield several compounds including katononic acid and 3-oxolupenal. Antidiabetic activities were assessed by alpha-amylase and alpha-glucosidase enzyme inhibition. Antioxidant capacities were examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2 '-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) scavenging assays. Further, the interaction between enzymes (alpha-amylase and alpha-glucosidase) and ligands (3-oxolupenal and katononic acid) was followed by fluorescence quenching and molecular docking studies. 3-oxolupenal and katononic acid showed IC50 values of 46.2 mu g/mL (101.6 mu M) and 52.4 mu g/mL (119.3 mu M), respectively against the amylase inhibition. 3-oxolupenal (62.3 mu g/mL or 141.9 mu M) exhibited more potent inhibition against alpha-glucosidases compared to katononic acid (88.6 mu g/mL or 194.8 mu M). In terms of antioxidant activity, the relatively polar crude extract and n-butanol fraction showed the greatest DPPH and ABTS scavenging activity. However, the antioxidant activities of the purified compounds were in the low to moderate range. Molecular docking studies confirmed that 3-oxolupenal and katononic acid interacted strongly with the active site residues of both alpha-amylase and alpha-glucosidase. Fluorescence quenching results also suggest that 3-oxolupenal and katononic acid have a good affinity towards both alpha-amylase and alpha-glucosidase enzymes. This study provides preliminary data for the plant's use in the treatment of type 2 diabetes mellitus.