Dammarane triterpene saponin from Bacopa monniera as the superoxide inhibitor in polymorphonuclear cells

The hydroalcoholic extract of the whole plant of Bacopa monniera Wettst. (Scrophulariaceae), exhibited an inhibitory effect on superoxide released from polymorphonuclear (PMN) cells in the nitroblue tetrazolium (NBT) assay. The major saponin bacoside A(3) was found to be responsible for this effect in the herb. This compound showed 85, 91.66, 91.66, and 83 % inhibitions of NBT reduction at the concentrations of 200, 100, 50, and 25 microg/ml, respectively, with an IC(50) value of 10.22 microg/ml. These inhibitory effects were compared with those of the standard positive controls, quercetin and ascorbic acid with IC(50) of 111 and 14.16 microg/ml, respectively. Another major saponin bacopasaponin C was found to be much less potent as compared to bacoside A(3) whereas the remaining two mixtures of saponins were found to be inactive.