Attenuation of genotoxicity, oxidative stress, apoptosis and inflammation by rutin in benzo(a)pyrene exposed lungs of mice: Plausible role of NF-κB, TNF-α and Bcl-2

Background: Benzo(a)pyrene [B(a)P] is an environmental contaminant and potential carcinogenic agent that causes lung injuries which leads to lung cancer. Rutin, a well-known flavonoid present in various natural sources, possesses biological activities such as anti-oxidative and anti-inflammatory properties. The aim of this study was to evaluate the protective effects of rutin against B(a)P-induced genotoxicity, oxidative stress, apoptosis and inflammation in Swiss albino mice. Methods: Pretreatment of rutin was given by oral gavage at doses of 40 and 80 mg/kg body weight (b.wt.) for 7 days before the administration of a single oral dose of B(a)P (125 mg/kg b.wt.). The ameliorative effect of rutin on oxidative stress, apoptotic and inflammatory markers in lung tissues and genotoxicity was studied using an alkaline unwinding assay and DNA fragmentation. Results: B(a)P enhanced lipid peroxidation, xanthine oxidase, H₂O₂ generation and lactate dehydrogenase (LDH) activity; depleted activities of anti-oxidant enzymes and glutathione content; induced DNA strand breaks and fragmentation; disrupted normal histopathological architecture and also showed abnormal expression of NF-κB, COX-2, IL-6, TNF-α and Bcl-2. Rutin pretreatment caused a significant reduction in lipid peroxidation and LDH activity; increased glutathione content; restored antioxidant enzyme activity; reduced DNA strand breaks and fragmentation; modulated the expression of inflammatory, and apoptotic markers and restored the histopathological structure. Conclusions: The findings of the present study supported the protective effect of rutin against B(a)P-induced lung toxicity and genotoxicity.