Potential ameliorative effects of epigallocatechin-3-gallate against cigarette smoke exposure induced renal and hepatic deficits.

The environmental pollution caused by cigarette smoke (CS) seriously endangers people's health. Epigallocatechin-3-gallate (EGCG) is the most abundant catechin in green tea. In this study, rats were exposed to CS for 90 days. Kidney function was evaluated by detecting the levels of serum creatinine and blood urea nitrogen. Liver function was evaluated by detecting the activities of alanine aminotransferase and aspartate transaminase. The renal and hepatic oxidative stress and inflammation were assessed by detecting the levels of malondialdehyde, reduced glutathione, antioxidant enzymes (superoxide dismutase and glutathione peroxidase) and proinflammatory cytokines. Organ fibrosis was evaluated by observing collagen deposition via masson staining, by examining the hydroxyproline level, by measuring the mRNA levels of fibrosis-associated genes collagen (Col)-1A1 and Col-3A1, as well as by assessing the activity of profibrotic TGF-β1 pathway. Additionally, renal and hepatic epithelial-mesenchymal transition (EMT) were evaluated. It was observed that EGCG ameliorated the renal and hepatic oxidative stress, inflammation, EMT, as well as inhibited the activation of TGF-β1 signaling pathway induced by CS. These results showed that EGCG could attenuate CS-induced renal and hepatic fibrosis.