Inhibitory activity of berberine on DNA strand cleavage induced by hydrogen peroxide and cytochrome c

The inhibitory activity of berberine on the DNA single-strand cleavage indu ced by hydrogen peroxide and cytochrome c was measured. Berberine effective ly inhibited single-strand cleavage of DNA and its effectiveness was concen tration-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 muM berberine showed 7.7, 10.8, 32.2, 39.5, and 51.6% inhibition of DNA cleavage. This inhibitory activity of berberine aga inst the DNA single-strand cleavage has never been reported previously. The inhibitory activity of berberine against DNA cleavage was stronger than ca ffeic acid and ascorbic acid. Berberine did not show strong hydroxyl radica l scavenging activity, but showed strong superoxide anion radical quenching ability.