Study of the Extraction and Hypolipidemic Mechanism of Steviosides from Stevia rebaudiana Leaves

摘要

In order to understand the hypolipidemic mechanism of steviosides from Stevia rebaudiana leaves, we optimised ratio of solid to liquid, extraction temperatures, extraction times, time to obtain optimal extraction conditions. Under the optimal condition (solid to liquid 1:20, extraction temperature 80?C, and extraction times 4h, time 4), the experimental yield of steviosides was gave the best results (8.637±0.27%). The SVS-2 were obtained by a DEAE-52 cellulose column and Sephadex G-15 column chromatography. The SVS-2 was characterised through FT-IR spectroscopy, NMR spectroscopy, HPLC-PAD-MS analysis by comparison with a stevioside standard. In vitro test, the steviosides can decrease liver TC, TG and serum TG, TC level and increased swimming time of rats fed with high-fat diets. Therefore, the results suggest that steviosides had a high hypolipidemic activity and could be used as a potential therapeutic agent for hyperlipidemia.