Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy.
J Pharm Pharmacol. 2021 Aug 12;73(9):1240-1249. doi: 10.1093/jpp/rgab057.
This study aims to investigate antidiabetic activity of several Vernonia amygdalina extracts to study their potential use in medicine.
Aqueous and ethanol extracts were obtained by maceration and Soxhlet extraction from roots and leaves of V. amygdalina. The extracts were tested as inhibitors of α-glucosidase activity and of advanced glycation end products (AGEs) formation. Further, radical scavenging activity was examined detecting the oxygen radical absorbance capacity, while the potential cytotoxicity of extracts was estimated with MTT assay.
In aqueous and ethanol extracts, several polyphenolic compounds were identified; in detail, (-)-catechin and luteolin were found in leaf extracts, while caffeic acid, chlorogenic acid and the terpenoid vernodalol were recognized in root extracts. Regarding antidiabetic activity, the aqueous root extracts efficiently inhibited α-glucosidase activity in a concentration-dependent manner (IC50 = 5.6 µg/ml and 39.8 µg/ml, respectively of macerated and Soxhlet extracts), whereas those obtained from leaves exhibited lower potency. Furthermore, AGEs formation was reduced by all V. amygdalina extracts starting from 10 µg/ml.
The aqueous extracts of V. amygdalina roots obtained by maceration and Soxhlet extraction show remarkable anti-α-glucosidase activity, and all extracts have favourable antiglycation and antioxidant activities.
本研究旨在探讨几种马缨丹提取物的抗糖尿病活性，以研究其在医学中的潜在用途。
采用浸渍法和索氏提取法从马缨丹的根和叶中提取水提物和醇提物。将提取物作为α-葡萄糖苷酶活性抑制剂和晚期糖基化终产物（AGEs）形成抑制剂进行测试。此外，通过检测氧自由基吸收能力来检测自由基清除活性，同时通过 MTT 测定法估计提取物的潜在细胞毒性。
在水提物和醇提物中，鉴定出几种多酚类化合物；具体而言，在叶提取物中发现了（-）-儿茶素和木樨草素，而在根提取物中发现了咖啡酸、绿原酸和萜类化合物 vernodalol。关于抗糖尿病活性，水提的马缨丹根提取物以浓度依赖的方式有效地抑制α-葡萄糖苷酶活性（浸渍和索氏提取的 IC50 值分别为 5.6 µg/ml 和 39.8 µg/ml），而叶提取物的抑制作用较低。此外，所有马缨丹提取物均能从 10 µg/ml 开始减少 AGEs 的形成。
通过浸渍法和索氏提取法获得的马缨丹根的水提物显示出显著的抗α-葡萄糖苷酶活性，并且所有提取物均具有良好的抗糖化和抗氧化活性。
