Antimicrobial activity of Mahonia aquifolium and two of its alkaloids against oral bacteria

Abstract

Extracts or alkaloids isolated from Mahonia aquifolium exhibit antimicrobial activity against Gram-positive and Gram-negative bacteria, fungi, and protozoa. In this study the bacteriostatic and bacteriocidal activities of a M. aquifolium extract and two of its major alkaloids, berberine chloride and oxyacanthine sulphate, were tested in vitro against nine different oral bacteria. Minimum inhibitory concentrations were in the range from 0.125% for berberine chloride, and from 0.0156% to > 0.0625% for oxyacanthine sulphate. The values for the minimum bactericidal concentrations were in the same range, indicating that the test substances most probably acted in a bactericidal manner. The most susceptible bacterium against all three test substances was Porphyromonas gingivalis.