ABSTRACT
Objective: To study toxicity, anti-diabetic and cardiovascular effects of hydro-ethanolic extracts of Parinari curatellifolia seed extract and Aristolochia vogelii roots extract and (1:1) mixture of the above two extracts. Materials and Methods: Twenty Wister strain albino rats were randomly assigned to four groups; A, B, C and D with each consisting of five animals received extracts as follows: Group I, P. curatellifolia and A. vogelli mixture (1:1) (500 mg/kg bwt); Group II, A. vogelli (500 mg/kg bwt); Group III, P. curatellifolia seed extract (500 mg/kg bwt); Group IV, 0.5 ml (2% w/v) acacia solution and served as control. After 30 min, the animals were each administered orally with 40% (w/v) glucose at a dose of 1ml /100 g bwt. Blood glucose levels were then monitored at 30, 60, and 120 min. intervals and reported as the average glucose level of each group. Another set of twenty five rats (diabetic rats) were randomly distributed into five groups of five animals each while the additional sixth group was the positive control consisting of five normal rats. Treatments were as follows: Group I, diabetic treated with A. vogelli at a dose of 500 mg/kg bwt; Group II, diabetic treated with P. curatellifolia at a dose of 500 mg/kg bwt; Group III, diabetic treated with glibenclamide 600μg /kg bwt; Group IV, diabetic treated with mixture of Parinari curatellifolia and A. vogelli (1:1) (500 mg/kg bwt); Group V, diabetic untreated (control negative) while group VI was the positive control. Results: A significant reduction in postprandial sugar level was observed after 30 min in all treatments. The extracts individually and in combined form also showed effective decrease in plasma glucose levels on the diabetic rats. There were significant reductions (p<0.05) in low density lipoprotein (LDL)-cholesterol levels and significant increase (p<0.05) in high density lipoprotein (HDL)–cholesterol in the treated diabetic group compared to the negative control. Furthermore, significant reductions in aspartate aminotransferases (AST) and alanine aminotransferases (ALT) levels were observed in the treated diabetic animals compared to the untreated. Also significant reduction in the creatinine and increase in the protein levels respectively were observed in the treated diabetic groups. Conclusion: The results showed that the respective extracts and the extract mixture had both good hypoglycaemic activity and beneficial effects on cardiovascular risk factors.