Hypoglycemic and Hypolipidemic Effects of Aqueous Extracts of Ajuga iva and Centaurium erythreae on a Rodent Model of Metabolic Syndrome

Aim: The aim of the study was to investigate hypoglycemic and hypolipidemic activities of aqueous extracts of Centaurium erythraea (CnE) and Ajuga iva (AjI) after daily oral dosing for 60 days in a rodent model of metabolic syndrome (MetS). Materials and Methods: Meriones shawi rats were fed a high caloric diet and forced to limited physical activity for 180 days to develop obesity, hyperglycemia and hyperlipidemia (OHH) as a model of MetS. After administration of single oral doses of test substances [extracts of CnE (250 mg/kg) and AjI (150 mg/kg), and reference drug [glibenclamide (GLB; 3 mg/kg)] to OHH rats, plasma levels of glucose, insulin, Total Cholesterol (TC), and Triglycerides (TG) were measured. In the sub-chronic study, the effect of daily oral dosing of test substances for 60 days to OHH rats, on Body Weight (BW), plasma glucose, insulin, TC, Low Density Lipoprotein (LDL)-cholesterol, High Density Lipoprotein (HDL)-cholesterol, TG, and free fatty acids were determined; insulin resistance (IR as HOMA-IR and QUICKI) and atherosclerotic index were calculated. Results and Conclusion: Meriones shawi rats developed OHH, hyperinsulinemia, IR and dyslipidemia- typical components of MetS. Single doses of test substances decreased only hyperglycemia. In the sub-chronic study, the test substances reduced plasma glucose, insulin, TC and LDL-cholesterol, as well as HOMA-IR and atherosclerotic index (AjI-extract > CnE-extract > GLB); plasma level of TG decreased with AjI only. These two plants may have the potential to be used therapeutically in the treatment of diabetes and possibly MetS, since, previous toxicological studies have shown a wide margin of safety for AjI and CnE.