Gastric H+, K+-ATPase Inhibition, and Antioxidant Properties of Selected Commonly Consumed Vegetable Sources

Abstract

Oxidative stress and upregulation of gastric H+, K+-ATPase enzyme activity have been known to cause ulcer pathogenicity for which safer drugs are yet to be identified. Aqueous extracts of seven commonly consumed vegetable sources were screened for inhibition of H+, K+-ATPase and antioxidant activities. Results indicated that Z. officinale (Ginger) followed by M. arvensis (Pudina) are potent gastroprotective sources with inhibition of H+, K+-ATPase of IC50 of 18.3 ± 0.7 and 25.2 ± 0.9 μg gallic acid equivalents/ml respectively, which is almost equivalent or better than the known inhibition of H+, K+-ATPase—Omeprazole (IC50 ˜27 μg/ml). Further, all these vegetable extracts showed multi-potent antioxidant activity, such as free radical scavenging, reducing power ability, and inhibition of lipid peroxidation, which are required to inhibit complex steps of ulcerations. On the basis of the absolute amounts and potency of inhibition of H+, K+-ATPase as well as antioxidant activity of individual phenolic acids, the relative percentage contribution of phenolic acids from different vegetable extracts to both inhibition of H+, K+-ATPase and antioxidant activity was calculated and data revealed that gentisic and protocatechuic acid contributes significantly to both inhibition of H+, K+-ATPase and antioxidant activity.