Antidiabetic and antilipidemic effect of eremanthin from Costus speciosus (Koen.)Sm., in STZ-induced diabetic rats

The increasing prevalence of diabetes mellitus worldwide is an issue of major socio-economic concern. Diabetes mellitus is a complex and a multifarious group of disorders that disturbs the metabolism of carbohydrates, fat and protein. Medicinal plants play an important role in the management of diabetes mellitus especially in developing countries. Costus speciosus is widely used in Indian medicine to treat various diseases. Eremanthin was isolated from C. speciosus. The structure was identified using gas chromatography–mass spectrometry (GC–MS) analysis. Eremanthin was administered to streptozotocin (STZ) (50 mg/kg bw) induced diabetic male Wistar rats at different doses (5, 10, 20 mg/kg bw) for 60 days. Plasma glucose level was significantly (p < 0.05) reduced in a dose dependent manner when compared to the control. In addition, oral administration of eremanthin (20 mg/kg bw) significantly decreased glycosylated hemoglobin (HbA1c), serum total cholesterol, triglyceride, LDL-cholesterol and at the same time markedly increased plasma insulin, tissue glycogen, HDL-cholesterol and serum protein. Eremanthin also restored the altered plasma enzyme (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alkaline phosphatase and acid phosphatase) levels to near normal. Results of this experimental study indicated that eremanthin possessed hypoglycemic and hypolipidemic activities and hence it could be used as a drug for treating diabetes.