ABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: The use of an aqueous extract of coriander (Coriandrum sativum L.; Apiaceae, Umbelliferae) seeds (CS-extract) in Moroccan traditional treatment of diabetes remains to be experimentally validated. AIM OF THE STUDY: The study aim was to investigate potential hypoglycemic (and hypolipidemic) activity of CS-extract after a single oral dose and after daily dosing for 30 days (sub-chronic study) in normal and obese-hyperglycemic-hyperlipidemic (OHH) Meriones shawi rats. MATERIALS AND METHODS: After a single oral dose of CS-extract (20mg/kg; predetermined as optimum), plasma glucose, insulin, total cholesterol (TC), and triglycerides (TG) were measured in normal and OHH rats (hypercaloric diet and forced limited physical activity); glibenclamide (GLB; 2.5mg/kg) was used as reference. In the sub-chronic study, the effect of CS-extract and GLB (at the above doses) on body weight (BW), plasma glucose, insulin, TC, LDL-cholesterol, HDL-cholesterol, TG, urea and creatinine was determined in normal and OHH rats; insulin resistance (IR as HOMA-IR), atherosclerotic and cardioprotective indices were calculated. RESULTS: A single dose of CS-extract or GLB suppressed hyperglycemia in OHH rats, and normo-glycemia was achieved at 6-h post-dose; there was no effect on lipids, TG or insulin, but IR decreased significantly. The hypoglycemic effect was lower in normal rats. In the sub-chronic study in OHH rats, the test substances (CS-extract>GLB) reduced plasma glucose (normoglycemia on Day 21), insulin and IR, TC, LDL-cholesterol, and TG. Atherosclerotic index decreased while cardioprotective indices increased only by CS-extract, with no effect on BW, urea or creatinine. CONCLUSION: Sub-chronic administration of CS-extract in OHH Meriones shawi rats normalized glycemia and decreased the elevated levels of insulin, IR, TC, LDL-cholesterol and TG. Since, the CS-extract decreased several components of the metabolic syndrome and decreased atherosclerotic and increased cardioprotective indices, CS-extract may have cardiovascular protective effect. The present study validates the traditional use of coriander in diabetes.