Effects of a Fraction of the Methanol Extract of the Seeds of Abrus Precatorius on Malondialdehyde and Antioxidant Levels of Alloxan-Induced Diabetic Rats

Introduction: The aim of this study is to evaluate the effect of fraction 2 (F2) of methanol extract of the seeds of Abrus precatorius on malondialdehyde and antioxidant level of alloxan-induced diabetic Wistar albino rats.

Materials and Methods: The methanol extract of the seeds of A. precatorius Linn Fabaceae was fractionated by Sephadex G15. Diabetes was induced by a single intraperitoneal administration of alloxan at a dose of 150 mg/kg bodyweight. The phytochemical analysis and the biochemical parameters were investigated using standard diagnostic methods.

Results: Both qualitative and quantitative analysis of F2 revealed the presence of high amounts of alkaloids (2000 ± 80 mg/100 g), flavonoids (158 ± 17.6 mg/100 g) and tannins (258 ± 45 mg/100 g) but low concentration of saponins (18.3 ± 2.43 mg/100 g). The malondialdehyde (MDA) level of all the test groups and the group treated with the standard drug decreased significantly (p<0.05) compared with that of untreated diabetic group. However, the catalase activity in all the test groups significantly increased (p<0.05) while the activity of superoxide dismutase increased significantly (p<0.05) in groups administered 20mg/kg of the fraction and the group pre-treated with 10mg/kg of the fraction compared with the diabetic untreated group. Similarly, the result revealed a significant increase (p<0.05) in non-enzymatic antioxidants such as reduced glutathione and vitamin E of the rats treated with graded doses of F2 while vitamin C showed significant (p<0.05) increase in normal control groups and pre-treated groups compared with the diabetic untreated. Studies on membrane stabilization using hypotonicity-induced red blood cell haemolysis revealed that the F2 of the methanol extract of the seeds of A. precatorius Linn inhibited haemolysis in a dose-dependent manner.

Conclusion: The results obtained from this study revealed that the F2 fraction of the methanol extract of A. precatorius contain important phytochemicals found in the Fraction 2 (F2) however showed improvement in antioxidant defence as well as has a stabilizing effect on the membrane.