Diacerein ameliorates amiodarone-induced pulmonary fibrosis via targeting the TGFβ1/α-SMA/Smad3 pathway

This study is aimed at investigating the possible protective effect of diacerein (DIA) against AMD-induced pulmonary fibrosis in rats. Rats were classified into 4 groups: a normal group that received distilled water, control group that received AMD (100 mg/kg, p.o.) for 21 days to induce pulmonary fibrosis, and 2 treatment groups that received diacerein, in 2 dose levels (50 and 100 mg/kg, p.o., respectively) in addition to AMD (100 mg/kg, p.o.), for 21 days. Lung function test was assessed using a spirometer; serum and tissue were collected. Biochemical, real-time PCR, histopathological, and immunohistopathological analyses were carried out. AMD reduced tidal volume (TV), peripheral expiratory rate (PER), forced vital capacity (FVC), serum reduced glutathione (GSH) levels, Beclin, and LCII, while it elevated transform growth factor (TGF-β1) gene expression, serum malondialdehyde (MDA) level, alpha-smooth muscle actin (α-SMA), Smad3, phosphorylated signal transducer and activator of transcription (p-STAT3), and p62 lung content. Also, AMD elevated tumor necrosis factor-alpha (TNF-α) and caspase-3 protein expression. DIA elevated TV, PER, FVC, serum GSH level, Beclin, and LCII, while it reduced TGF-β1 gene expression, serum MDA level, α-SMA, Smad3, p-STAT-3, and p62 lung content. Moreover, DIA reduced TNF-α and caspase-3 protein expression. DIA attenuated AMD-induced pulmonary fibrosis via alleviating the TGF1/α-SMA/Smad3 pathway, reducing STAT-3 activation, and combating oxidative stress and inflammation in addition to promoting autophagy and abrogating apoptosis.