The efficacy of plant extract and bioactive compounds approaches in the treatment of pulmonary fibrosis: A systematic review

Pulmonary fibrosis (PF) is a lethal, chronic and progressive respiratory disease leading to interstitial lung damage and serious breathing problems. The pathogenic mechanism involves activation, migration, proliferation and differentiation of fibroblasts into myofibroblats inducing extracellular matrix accumulation that destroy lung parenchyma. Available antifibrotic treatment options are limited to Pirfenidone and Nintedanib that prevent deterioration without an improvement of this disease. The use of plant extracts and natural bioactive compounds for the treatment of PF has been known for more than thirty years in China. Nowadays, phytotherapy has gained a considerable attention in the treatment of PF both in vivo and in vitro using bleomycin (BLM)-induced lung inflammation, oxidative stress and pulmonary fibrosis in rats. In this review, we aimed to focus on the protective effects and the mechanisms of action of several plant extracts described by various research works for the treatment of PF.