Chrysin (CHR) is a food-based bioactive ingredient whereas, sodium arsenite (SA) is one of the major contaminant in drinking water. When ingested, SA contributes to tissue damage due to bioactivation by S-adenosyl methionine (SAM)-dependent methyltransferase. Hence, the needs to nullify this effect by investigating the potentials of CHR on SA-induced genotoxicity in rats. The experiment was divided into two successive stages (ameliorative and preventive, curative studies) for 1 week. Rats were divided into four groups: distilled water, 10mg/kg SA, 10mg/kg CHR and co-administration. In stage 2, the experimental groups were given either CHR or SA for 1 week, and treated in reversed order for additional week. Lipid peroxidation, protein carbonyl and DNA fragmentation in liver, blood brain and bone marrow cells micronucleus were assayed for using standard protocols. Molecular docking of SAM-dependent methyltransferase in the presence of CHR was conducted. CHR significantly ( p < 0.05) decreased the level of lipid peroxidation, protein carbonyls and DNA fragmentation in blood, liver and brain tissues as against group treated with SA. It also significantly ( p<0.05) reduced the level of micronuclei generated in bone marrow cells. The effects of CHR were shown to be ameliorative, preventive and curative in nature. Furthermore, CHR was able to dock (with binding energy of -24.81 kcal/mol and predicted inhibition kinetic constant (Ki) of 0.959 µM) into the active site of SAM-dependent methyltransferase with strong hydrogen bond and hydrophobic interactions. The study might have unravelled the potentials of CHR against SA-induced chromosomal and DNA damage, which might be due to inhibition of SAM-dependent methyltransferase.
Keywords: DNA damage; S-adenosyl methionine-dependent methyltransferase; Sodium arsenite; chrysin; modelling.