Hypoglycaemic Effects of Combined Administration of Gongronema latifolium and Odontonema strictum on Diabetic Wistar Rats

Abstract

Prevalence of diabetes mellitus, as well as therapeutic limitations with the available standard treatment options, necessitated the investigation of G. latifolium and O. strictum, two locally recognized herbal plants, as an alternative source of treatment. Acute toxicity test for the leaf extracts of G. latifolium and O. strictum was conducted using twenty-four mice of two groups, with zero deaths after twenty-four hours for either group of leaf extracts. The results indicated that LD50 for G. latifolium and O. strictum is greater than 5000 mg kg-1 of body weight. The effect of combined aqueous leaf extracts of G. latifolium and O. strictum on alloxan-induced diabetic rats was investigated for 28 days. A total of 35 male rats were placed in five groups, tagged NC, DC, MET, GLOS I and GLOS II, with each having seven (7) animals. NC was the normal control group; they were fed with rat chow and water. Diabetes was induced in rats in DC, MET, GLOS I and GLOS II by a single intraperitoneal injection of 150 mg kg-1of alloxan monohydrate. DC served as the diabetic control; they did not receive any treatment. MET received orally 150 mg kg-1 of metformin. GLOS I received 50 mg kg-1 bodyweight of G. latifolium and 50 mg kg-1 bodyweight of O. strictum, while GLOS II received 100 mg kg-1 bodyweight of G. latifolium and 100 mg kg-1 bodyweight of O. strictum. Changes in bodyweight, blood glucose levels, liver enzymes, urea and creatinine, lipid profile and oxidative stress markers were determined using standard methods. A significant increase (p<0.05) was recorded in the body weight, while a significant decrease (p<0.05) was observed in the blood glucose levels of diabetic rats treated with 100 and 200 mg kg-1 of combined extracts when compared to untreated diabetic rats. There was a significant reduction in the liver enzymes, urea, creatinine, lipid profile and oxidative stress markers of GLOS I and GLOS II rats treated with the combined extracts when compared with rats in the NC and DC groups. The results suggested that the combined aqueous extracts of G. latifolium and O. strictum have hypoglycaemic, hepatoprotective and antioxidant effects on alloxan–induced diabetic rats, hence, can be used as a herbal treatment for diabetes.