Investigation of DNA damage in lymphocytes exposed to benzathine penicillin G.

Abstract

Benzathine penicillin G (BPG) is a widely used antibiotic for treatment or prophylaxis of certain infectious diseases. Previous in vivo studies using sister chromatid exchange (SCE) frequency and comet assay, had showed that long-term administration of benzathine penicillin G may cause some degree of DNA damage in children with rheumatic fever. Because DNA damage has also been reported in various connective tissue disorders, to rule out the possible effects of underlying disease on DNA integrity, 3-day-cultured lymphocytes obtained from nine healthy individuals were exposed to BPG at different concentrations (0.002, 0.02 and 0.1 micro g/mL), and sister chromatid exchange frequencies were studied. The mean SCE frequency per metaphase was calculated from 20 selected cells for each individual. The incidence of SCE frequency did not differ when all groups were compared. Comparing between each concentration group, exposure to BPG did not cause a dose-dependent increase in SCE frequency (Student's t-test, P > 0.05). Insignificant changes (P > 0.05) in SCE, within the 3-day exposure to BPG, may suggest that DNA damage did not occur. Short-term exposure to BPG does not have toxic effects on DNA. In contrast, this preliminary study should be supported by other genotoxicity assays, expanding the exposure time to longer periods, in order to exclude rapid DNA repair mechanisms. and a possible role of underlying disease on DNA integrity should not be ignored.