Water extract of Osmanthus fragrans attenuates TGF-β1-induced lung cellular fibrosis in human lung fibroblasts cells

Abstract

Introduction: Idiopathic interstitial pneumonia, also known as idiopathic pulmonary fibrosis, is a type of diffuse parenchymal lung disease of unknown etiology. Osmanthus Fragrans, referred to as sweet olives, possesses various functions, including neuro-protection, the scavenging of free radicals, and anti-oxidation. Transforming growth factor beta (TGF-?) is a vital growth factor that is essential for regulating cell growth, differentiation, immune-regulation, and extracellular matrices. This study investigates the mechanism underlying water extract of Osmanthus fragrans on the regulation of pulmonary cellular fibrosis. Materials and Methods: The HFL-1 cells, human lung fibroblasts, were cultured with 5 ng/mL of TGF-?1 for 24 h. After the induction of cellular fibrosis, 200 ?g/mL water extract of Osmanthus fragrans was added and cultured for another 24 h. Subsequently, the enzyme-linked immunosorbent assay was performed to quantify the extracellular fibronectin, and Western blot analysis was conducted to examine the expression of TGF-?1 and its downstream SMAD proteins. Results: The findings indicated that 200 ?g/mL of water extract of Osmanthus fragrans significantly attenuates TGF-?1-induced increase in fibronectin. In addition, Osmanthus fragrans dramatically suppresses TGF-?1-induced increases in the expression of pSmad2/3. Conclusion: We propose that water extract of Osmanthus fragrans is a potential fibrosis antagonist for lung fibroblasts. Thus, water extract of Osmanthus fragrans may exert its beneficial effects through suppressing post-receptor signaling of TGF-?1 and restoring lung fibroblasts cells character by blocking the expression of pSmad2/3.