The effect of melatonin on benzo(a)pyrene-induced renal toxicity in mice

Benzo(a)pyrene is a ubiquitous environmental contaminant, which could induce renal injury. It is reported that melatonin has a protective effect against multiple organ injuries by regulating oxidative stress, apoptosis, and autophagy. The aim of this study was to estimate the melatonin effects on benzo(a)pyrene renal toxicity in mice and the possible molecular mechanisms involved in this model. Thirty male mice were allocated to five groups and treated with benzo(a)pyrene (75 mg/kg, oral gavage) and/or melatonin (10 and 20 mg/kg, intraperitoneally). The oxidative stress factors were evaluated in renal tissue. The levels of apoptotic (the Bax/Bcl-2 ratio and caspase-3) and autophagic (the LC3 II/I, Beclin-1, and Sirt1) proteins were examined using Western blot. Following the administration of benzo(a)pyrene, malondialdehyde, caspase-3 and the Bax/Bcl-2 ratio increased in renal tissue, while Sirt1, Beclin-1, and the LC3 II/I ratio diminished. Interestingly, the co-administration of 20 mg/kg melatonin along with benzo(a)pyrene reduced the oxidative stress markers, apoptotic and autophagic proteins. Collectively, melatonin exhibited a protective effect against benzo(a)pyrene-induced renal injury through the suppression of oxidative stress and apoptosis and the inhibition of Sirt1/autophagy pathway.