ABSTRACT
The study aimed to investigate the antidiabetic and lipid profile effects of the combination of Vernonia amygdalina (Bitter Leaf) and Ocimum gratissimum (Scent Leaf) leaf extracts on alloxan-induced diabetic rats. The study was conducted using mature leaves of Vernonia amygdalina and Ocimum gratissimum collected from Iguodia Community, Ovia North East Local Government Area, Edo State, Nigeria. The extracts were prepared by maceration in distilled water, evaluated at 100 and 200 mg/kg doses daily administered orally to diabetic rats over a 14-day period. Rats were divided into 5 groups of 4 each, the first were normal rats given distilled water orally daily for 14 days, the 2nd to 5th groups were diabetic rats induced using alloxan 150mg/kg intraperitoneal single dose. The 2nd group which were untreated diabetic rats were given distilled water while the 3rd to 5th groups which were diabetics were given 100, 200 mg/kg of both extracts while the 5th received gilbenclamide 5mg/kg respectively. All administration were done orally and daily for 14 days.
Diabetes was confirmed with a blood glucose level greater or equal to 200 mg/dl from blood samples obtained via the tail vein. Blood glucose levels were measured at various intervals, and on the 7th and 14th days following extract administration, while lipid profile parameters were determined at the end of the study. The percentage yield of the aqueous extract of leaves of Vernonia amygdalina and Ocimum gratissimum were 5.75% and 4.47%, respectively.
The combined use of both extracts demonstrated significant (p<0.05) hypoglycemic activity, comparable to the antidiabetic drug glibenclamide and in comparison with the untreated diabetic rats. Blood glucose levels in the diabetic rats treated with the extracts showed a rapid normalization compared to the untreated diabetic rats. Additionally, extracts combination significantly (p<0.05) reduced the total cholesterol levels at both doses used in comparison with the untreated diabetic rats. A significant increase in HDL level (p<0.05) was also noted on treatment of diabetic rats in comparison with the untreated diabetic rats.
In conclusion this study confirms the ethnomedicinal practice of combining bitter and scent leaves as done in folk medicine for the management of diabetes mellitus. Further research is however required to identify the active phytoconstituents and clarify the mechanisms underlying these effects.
