The frequencies of sister chromatid exchanges (SCE) in human lymphocyte cultures were studied under various conditions such as free-radical loading by hypoxanthine-xanthine oxidase (HX-XO) system, which is a well known generator of superoxide, and SCE suppression by specific herb extracts, Scutellaria baicalensis and Rosa multiflora T., added to the system. Intraindividual comparison of SCE frequencies showed a significant increase in an HX-XO group, though interindividual variations were great.
Meanwhile, with the addition of these extracts, the SCE frequencies decreased dramatically. These results indicate that both Scutellaria baicalensis and Rosa multiflora T. are able to reduce the magnitude of free radical impairment to cultured human lymphocyte chromatin structures.
These extracts showed themselves to have a suppression effect on the SCE frequencies in human lymphocytes exposed to free radical generator system of HX-XO, because their effects appeared to be constant even among different individuals. It would be interesting to further examine a role of other oxygen radicals as PMA, producing SCEs in human lymphocytes and to clarify the mechanism by which these herb extracts inhibit SCEs generated by free radicals.
