RESUMO
The inhibitory activity of berberine on the DNA single-strand cleavage induced by hydrogen peroxide and cytochrome c was measured. Berberine effectively inhibited single-strand cleavage of DNA and its effectiveness was concentration-dependent. As the berberine concentration increased, the inhibitory activity against the DNA single-strand cleavage increased. The treatments with 1, 5, 10, 50, and 100 microM berberine showed 7.7, 10.8, 32.2, 39.5, and 51.6% inhibition of DNA cleavage. This inhibitory activity of berberine against the DNA single-strand cleavage has never been reported previously. The inhibitory activity of berberine against DNA cleavage was stronger than caffeic acid and ascorbic acid. Berberine did not show strong hydroxyl radical scavenging activity, but showed strong superoxide anion radical quenching ability.