In addition, it has been shown that salidroside reduced serum hydroxyproline, collagen type IV and malondialdehyde levels in lung tissues of mice with bleomycin-induced pulmonary fibrosis, while TGF-β1 levels in serum and lung tissues were significantly reduced, and pulmonary solids and collagen deposition were alleviated (Liu et al., 2017a). Here, TGFB1 is linked to pulmonary fibrosis.