Antidiabetic Synergetic Effects of Plant Extract-Mixtures in Streptozotocin- Diabetes Rats

This study investigates the effects of Psidium guajava L. leaf (Pg), Lagerstroemia speciosa L. leaf (Ls) and mixture A (Pg, Ls, Morus indica L. leaf extract, Pinus densiflora needles extract, Acanthopanax sen-ticosus M. root extract) on streptozotocin (STZ)-diabetes rats. For four weeks, STZ-diabetes rats were fed crystallized extracts of Pg, Ls, and mixture A. Compared to the diabetic control group, extracts of Pg, Ls, and mixture A decreased glucose levels in rats by 20%, 14 % and 24 % respectively. These extracts also decreased the level of total cholesterol, triglyceride and free fatty acid, compared to the diabetic control group, while effectively increasing levels of insulin and high-density lip-oprotein-cholesterol. These results showed that mixture A had greater antihyperglycemic, anti-hyperlipidemic, and insulin-increasing effects than the Pg and Ls extracts. Mixture A also showed better restoration of damaged beta cell function compared to Pg and Ls extracts. Therefore, it was proved that mixture A provides a beneficial synergistic effect when compared with Pg and Ls ex-tracts used individually. Key words: STZ-diabetes rats, antihyperglycemic effect, antihyperlipidemic effect, synergistic effec