Investigation of β-Sitosterol and Prangol Extracted from Achillea Tenoifolia Along with Whole Root Extract on Isolated Rat Pancreatic Islets

The genus Achillea (Asteraceae) consisting of important medicinal species, growing wildly in Iran, of which A. tenuifolia is found in Iran-o-Turan regions. Regarding the traditional use of Achillea species for treatment of diabetes and also lack of information on phyto-constituents of A. tenuifolia underground parts, in this study anti-diabetic activity of the plant have been reported. In order to find the main active components, underground parts of the plant were extracted with water and fractioned by hexane, ethyl acetate, and methanol and the separation of the main compounds were carried out via medium pressure liquid chromatography (MPLC). Also, anti-diabetic effects of the extract were investigated on rat pancreatic islets. The root extract of the plant as well as the compound β-sitosterol showed moderate α-amylase inhibitory activity, however prangol did not suppress the enzyme activity. The results of islet cells’ bio-function assays revealed that the herb root extract was able to increase the secretion of insulin in high concentration (10 mg/mL) and improved the cell viability with no toxicity in all doses. Furthermore, the herbal extract could reduce the levels of reactive oxygen species (ROS) and lipid peroxidation (LPO). The plant extract also significantly decreased the enzyme activity for both caspase-3 and -9 and increased the antioxidant capacity of the isolated cells. Taking together, preparations or extracts from the underground parts of the plant are good candidates for further anti-diabetic investigation and clinical trials.