Inhibitory Effects of Extracts of Osidium guajava L. and Agaricus blazei Murill on DNA Polymerase Activity

Abstract

We have been screening selective inhibitors of eukaryotic DNA polymerases from natural food materials. A 50% ethanol leaf extract (“Gaba-leaves 1”) of a higher plant, Osidium guajava L., inhibited activities of DNA polymerases α (replicative polymerase) and λ (repair-related polymerase), and the purified fraction obtained by hydrophobic chromatography (“Gaba-leaves 2” was a stronger inhibitor than Gaba-leaves 1. We also found that the extract of a well-known mushroom possessing anti-cancer activity, Agaricus blazei Murill (“Agaricus”) inhibited the activity of DNA polymerases. A mixture of Gaba-leaves and Agaricus stimulated the inhibitory activity of DNA polymerase α, and decreased the inhibitory activity of DNA polymerase λ.