Antihyperglycemic and hypolipidaemic effects of the methanolic extract of Saudi mistletoe ( Viscum schimperi Engl.)

Abstract

The current study evaluated the antihyperglycemic and hypolipidaemic effects of methanolic extract of Viscum schimperi Engl. whole parts in streptozotocin (STZ)-induced diabetic rats. The antihyperglycemic activity was evaluated by measuring the fasting blood glucose level (BGL) and by applying the oral glucose tolerance test (OGTT) in diabetic rats. In addition, the effect of the extract on blood plasma insulin was measured as well as its effect on tissue glycogen contents in muscle and liver. The hypolipidaemic effect was evaluated by assaying triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein-cholesterol (LDL-C). Diabetic male Wistar rats of a same age group were treated orally once a day for 4 weeks with a dose of 500 mg/kg bw of methanolic extract. Fasting BGL was measured on the 7th, 14th, 21st and 28th days, while plasma insulin levels were measured at the end of the 28th day. Maximum reduction in BGL of 37% was observed at the 4th week. Furthermore, there was a significant increase in plasma insulin, by 321.6%. The hypolipidaemic effect was demonstrated by significant reductions in plasma TC (32.6%), in TG (32.2%) and in LDL-C (27.2%); and an increase in HDL-C of 171.5%. The present data suggest that V. schimperi has both antihyperglycemic and hypolipidaemic effects with high insulin-secreting activity.