Anti-diabetic effects of Allium cepa (onions) aqueous extracts on alloxan-induced diabetic Rattus novergicus

Abstract

The hypoglycaemic and hypolipidaemic effects of the increasing dosages of Allium cepaaqueous extracts on alloxan - induced diabetic Rattus novergicus for possible use in the management of diabetes mellitus was investigated. Diabetes mellitus was induced in 54 out of a total of 63 adult R. novergicus using 150 mg/kg of alloxan monohydrate. Increasing dosages (200, 250 and 300 mg/kg) of A. cepa aqueous extracts were given to the diabetic rats for six weeks while the control rats got either normal saline (1 ml) or increasing dosages of glibenclamide (2.5, 3.8 and 5.0 mg/kg) during the same period. Blood glucose level, total serum lipids and total serum cholesterol were assessed with routine methods. F-LSD was employed to test significant differences (P < 0.05) among treatment means. Increasing dosages of A. cepa aqueous extracts produced a dose-dependent significant (P < 0.05) reductions in the blood glucose levels, total serum lipid and total serum cholesterol when compared with that of the control rats. The most effective percentage reduction in blood glucose level, total serum lipids and cholesterol were observed at 300 mg/kg. From the experimental findings, it is possible to conclude that A. cepa studied exhibited promising hypoglycaemic and hypolipidaemic activity in alloxan-induced diabetic rats. It’s hypoglycaemic and hypolipidaemic effects could represent a protective mechanism against the development of hyperglycaemia and hyperlipidaemia characteristic of diabetes mellitus. Key words: Allium cepa, hypoglycaemia, hypolipidaemia, alloxan diabetic rats.