Antihyperglycaemic and Safety Evaluation of the Combination Effect of Selected Plants in Diabetic Animal Models

Abstract

Background: Hyperglycemia is a common side effect of untreated diabetes, and it can result in long-term damage to specific body organs. Several herbs including Vernonia amygdalina, Ocimum gratissimum, and Allium sativum have been used to treat hyperglycemia in Nigeria. There has not been any systematic research on the toxicity and efficacy of synergistically combining three plant options. As a result, this study aims to investigate the toxicological profile and anti-hyperglycemic capabilities of the combination of three different medicinal plants in treating Type 2 diabetes.

Materials and Methods: Ethanol extract was prepared from the combination of equal proportions of leaves of Vernonia amygdalina, Ocimum gratissimum, and bulbs Allium sativum. Acute and sub-chronic toxicity (90 days) were carried out using standard protocols. Freshly prepared streptozotocin (50 mg per kg body weight) was injected intraperitoneally into rats after an overnight fast. Graded doses of the extract (100, 200, 400, and 800 mg/kg) were administered orally to separate groups alongside 200 mg/kg pretreated and control groups for 21 days. The serum obtained after the sacrifice was evaluated for biochemical, insulin secretion, leptin and antioxidant enzyme assays and a histopathological examination was carried out.

Results: Toxicity profile results showed that the combined extract is safe (> 5000 mg/kg) for use. This was corroborated by findings from the biochemical assays. The extract exhibited significant (p > 0.05) anti-hyperglycaemic potential at different doses, especially at 200 mg/kg bw in diabetic rat models. WBC decreased, platelet, MCV increased, liver function enzymes, total bilirubin, urea reduced, HDL increased, antioxidant enzymes, insulin increased and leptin reduced significantly (p > 0.05) respectively. No congestion or atrophy was observed in the histopathological examination.

Conclusion: This combined extract formulation is thus suggested as a source of bioactive compounds for targeted use in the development of a new antidiabetic phytomedicine.