Effect of Ethanolic Leaf Extract of Psidium guajava Linn. (Guava) in Alloxan-Induced Diabetic Rats

Effect of water – soluble components of ethanolic leaf extract of Psidium guajava Linn. on blood glucose and cholesterol levels in alloxan-induced diabetic male albino wistar rats was evaluated. A total of 30 male albino wistar rats were randomized into 4 groups. Ten (10) animals each were randomly assigned to groups 1 and 2 and 5 each for groups 3 and 4. Group 1 animals were induced with 150 mg of alloxan/kg body weight of animal, after which they were administered 400 mg of extracts/kg body weight of animal. Group 2 animals serving as diabetic control were administered only 150 mg of alloxan/kg body weight of animal, no extract was given. Group 3 animals received only 400 mg of extract/kg body weight of animal while Group 4 animals served as normal control and were given distilled water in place of the extract. Extracts were administered twice daily and treatments lasted for 10 consecutive days. Blood samples were collected for analysis every two days from the tail tips of the rats. Results obtained showed that there were significant (p < 0.05) reductions in blood glucose and cholesterol levels in the diabetic treated rats (Group 1) when compared with the diabetic control rats (Group 2). However, administration of the extract did not show any hypoglycaemic effect on the normal rats (p ？ 0.05) compared with the control. The results suggest that leaf extract of P. guajava Linn. is antihyperglycaemic and not hypoglycaemic. In view of the fact that it also showed significant antihypercholesterolaemia, P. guajava Linn. may be a potential antidiabetic agent.