Effect of Methanol Extract of Mangifera indica Linn. Kernel on Partially Purified Phospholipase A2 (PLA2) from Venom of Naja nigricollis: An in vitro Study

摘要

This study was aimed at evaluating the effect of methanol extract of Mangifera indica on phospholipase A2 from Naja nigricollis. Phospholpase A_2 was first isolated from the venom of Naja nigricollis and then partially purified using ion-exchange and gel filtration chromatography. The inhibition effect of methanol extract of Mangifera indica kernel against PLA_2 was investigated. The extracted PLA_2 showed purification folds of 2.85 and 13.15 for ion-exchange and gel filtration chromatography respectively while the percentage yields are 44.12 and 70% for ion-exchange and gel filtration chromatography, respectively. Extract of Mangifera indica kernel showed peak inhibition of 66.67 and 90.00% on the partially purified PLA2 using arithmetic and geometric variations in the concentrations of the extract, respectively. The concentrations of the extract (inhibitor) at which 50% of the enzyme activity was inhibited (IC_(50)) are 6.67 and 2.5 mg mL~(-1) for arithmetic and geometric progression, respectively. The double reciprocal plot of the enzyme in the presence of the extract at 8 and 32 mg mL~(-1) revealed K_M values of 0.29 and 0.28 mg mL~(-1) and Vmax values of 6.70 μmoles min~(-1) and 4.5 μmoles min~(-1), respectively while K_M and V_(max) of 0.29 mg mL~(-1) and 7.6 μmoles min~(-1), respectively were obtained in the absence of the extract which suggests non-competitive inhibition. Phytochemical analysis of Mangifera indica kernel extract revealed the presence of alkaloids, carbohydrates, tannins, flavonoids, saponins and glycosides. The results of this study suggest that Mangifera indica extract is a potential anti-venom agent against Naja nigricollis.