Inhibitory actions of berberine on growth and arylamine N- acetyltransferase activity in strains of Helicobacter pylori from peptic ulcer patients

Abstract

N-acetyltransferase (NAT)-catalyzed reactions can result in activation or detoxification of arylamine carcinogens. Studies were conducted to examine the dose effects of berberine on inhibition of growth versus arylamine NAT activities in strains of Helicobacter pylori collected from peptic ulcer patients. An inhibition-of growth study on H. pylori demonstrated that berberine elicited a dose-dependent growth inhibition in the H. pylori cultures. The results on the NAT activity was determined using acetyl coenzyme A recycling assay and high pressure liquid chromatography. Cytosols or suspensions of H. pylori with or without selected concentrations of berberine cotreatment showed different percentages of 2-aminofluorene and p- aminobenzoic acid acetylation. The data indicated that there was decreased NAT activity associated with increased levels of berberine in the H. pylori cytosols and suspensions. The apparent values of Km and Vmax also decreased after cotreatment of berberine in both examined systems. This report is the first finding of berberine inhibition of arylamine NAT activity in strains of H. pylori.