Total extract of Yupingfeng attenuates bleomycin-induced pulmonary fibrosis in rats

Yupingfeng is a Chinese herbal compound used efficaciously to treat respiratory tract diseases. Total glucosides of Yupingfeng have been proven effective in anti-inflammation and immunoregulation. Nevertheless, the role of total extract of Yupingfeng (YTE) in pulmonary fibrosis (PF), a severe lung disease with no substantial therapies, remains unknown. Present study was conducted to elucidate the anti-fibrotic activity of YTE. The rat PF model was induced by intratracheal administration of bleomycin (BLM, 5 mg/kg), and YTE (12 mg/kg/d) was gavaged from the second day. At 14 and 28 days, the lungs were harvested and stained with H&E and Masson's trichrome. The content of hydroxyproline (HYP) and type I collagen (Col-I) were detected, while the protein expression of high-mobility group box 1 (HMGB1), transforming growth factor-beta 1 (TGF-β1), Col-I and α-smooth muscle actin (α-SMA) were analyzed by immunohistochemistry or Western blot. As observed, YTE treatment attenuated the alveolitis and fibrosis induced by BLM, reduced the loss of body weight and increase of lung coefficient. Meanwhile, YTE strongly decreased the levels of HYP and Col-I, and reduced the over-expression of HMGB1, TGF-β1, Col-I and α-SMA. In conclusion, YTE could ameliorate BLM-induced lung fibrosis by alleviating HMGB1 activity and TGF-β1 activation, suggesting therapeutic potential for PF.