Protective effect of vitamin C and or vitamin E on micronuclei induction by rifampicin in mice
Rifampicin which is a known antituberculous agent has been reported to induce both chromosomal breakage and numerical chromosomal abnormalities. This study was carried out to determine the mutagenicity of rifampicin and more importantly to investigate the protective roles of antioxidants-vitamin C and E individually and in-combination therapy against rifampicin mutagenicity using micronucleus assay. Therapeutic concentrations of rifampicin alone (9mg/kg), rifampicin plus vitamin E (5mg/kg), rifampicin plus vitamin C (8mg/kg) and rifampicin plus vitamin C plus vitamin E were administered orally for 28 consecutive days using 6 mice in each group. The negative and positive control mice received same volume of distilled water and cyclophosphamide (40 mg/kg) intraperitoneally 6 hours before sacrifice, respectively. The results showed rifampicin alone treated group to demonstrate significant (P<0.05) increase in the proportion of micronucleated polychromatic erythrocyte (MPCE) to polychromatic erythrocyte (PCE) compared with the negative control group while a significant decrease (P≤0.05) in the proportion of MPCE to PCE was demonstrated in the rifampicin plus vitamin E; rifampicin plus vitamin C plus E and rifampicin plus vitamin C groups compared with cyclophosphamide treated group and rifampicin treated group. These findings suggest that rifampicin has damaging effects on the deoxyribonucleic acid (DNA). However, co-administration of rifampicin and antioxidants (vitamin C and E) has protective effect on the damaging potentials of rifampicin.