Preventive Effect of 3,3'-dimethoxy-4,4'-dihydroxy-stilbene Triazole on Pulmonary Fibrosis through Inhibition of Inflammation and Down-regulation of TGF-b Signaling Pathway

In the present study effect of 3,3'-dimethoxy-4,4'-dihydroxy-stilbene triazole (STT) on plmonary fibrosis development was investigated in vitro in primary lung fibroblasts as well as in vivo in mice model. The results demonstrated that STT treatment effectively inhibited the TGF-β1 induced increase in expression of α-SMA and collagen I proteins in PLFs. STT treatment effectively reversed the TGF-β1 induced increase in expression of LOXL2 protein and phosphorylation of Smad2/3 proteins. Treatment of PLFs with STT reversed the TGF-β1-induced increase in expression of NOX4 and suppression of p-AMPK protein. In mice model of pulmonary fibrosis STT treatment significantly inhibited the BLM-mediated decrease in body weight and survival rate. The BLM induced increase in pulmonary index in mice was also effectively inhibited on treatment with STT. Treatment of the mice with STT inhibited the BLM-induced increase in α-SMA and Col I protein expression in pulmonary tissues. The BLM-induced increase in TGF-β1 protein expression in pulmonary tissues of the mice was inhibited on treatment with STT. Treatment with STT effectively promoted the AMPK activation in lung tissues of the BLM administered mice. In summary, the present study demonstrates that STT treatment prevents TGF-β1 induced up-regulation of α-SMA, collagen I, LOXL2 protein expression and targets phosphorylation of Smad2/3 proteins in PLFs. Moreover, it inhibits TGF-β1-induced increase in expression of NOX4 and reverses TGF-β1-mediated suppression in expression of p-AMPK protein. Therefore, STT inhibits fibrosis development in vitro as well as in vivo and therefore can be investigated further as a therapeutic agent for the treatment of lung fibrosis.