Optimization of β-sitosterol from SWIETENIA MAHAGONI seeds extract using supercritical carbon dioxide (SC-CO2) extraction and its anti-diabetic activities

Abstract

Swietenia mahagoni is broadly used in traditional remedies. It contains several bioactive compounds such as ß-sitosterol. The aim of this study is to investigate the effect of supercritical carbon dioxide (SC-CO2) extraction conditions (pressure and temperature) on oil yield and ß-sitosterol content from switenia mahagoni seeds and to analyze the anti-diabetic activities of switenia mahagoni seeds extract. Swietenia mahagoni seeds extracts were obtained by SC-CO2 extraction at pressures of 20-30 MPa and temperatures of 40-60 °C. The optimization process was done by a three-level factorial design with a response surface methodology using Statistica software 7.0 (StatSoft, EUA). Quantification of ß-sitosterol content was performed by using a high performance liquid chromatography conducted on C18 reversed phase Kinetex Biphenyl column using methanol: acetonitrile (60:40 v/v) as mobile phase. The oil yields at different conditions obtained were analyzed with a-glucosidase and a-amylase inhibition assays. One way analysis was used for statistical significance by using Statistica software 7.0 (StatSoft, EUA) and IC50 (extract concentration causing 50% enzyme inhibitory) was determined by using GraphPad Prism 6.0 software. The experimental data of SC-CO2 extraction obtained were fitted to a second-order polynomial model and the obtained oil yields were between 1.5-14.5%, while ß- sitosterol content obtained were 3.1-9.2 mg/g. The highest inhibition of a- glucosidase and a-amylase enzymes were 98.4% ± 0.2 and 34.9% ± 1.2, respectively. The best conditions within the studied ranges were 30 MPa and 40 °C to extract ß- sitosterol in the highest amount. All conditions for extraction of swietenia mahagoni seeds were potent to a-glucosidase inhibitory assay but showed a weak inhibition toward a-amylase inhibitory assay. These findings implied that swietenia mahagoni seeds extract containing ß-sitosterol, could be an effective natural anti-diabetic agent.