Repurposing of carvedilol to alleviate bleomycin-induced lung fibrosis in rats: Repressing of TGF-β1/α-SMA/Smad2/3 and STAT3 gene expressions

Idiopathic pulmonary fibrosis (IPF) is the most widely studied interstitial lung disease. IPF eventually leads to respiratory insufficiency, lung cancer, and death. Carvedilol (CAR) is a third-generation β-adrenergic receptor antagonist with an α1-blocking effect. CAR demonstrates antifibrotic activities in various experimental models of organ fibrosis. Aims: This work is designed to explore the possible alleviating effects of CAR on bleomycin (BLM)-induced lung fibrosis in rats. Main methods: The BLM rat model of lung fibrosis was achieved by intratracheal delivery of a single dose of 5 mg/kg of BLM. Seven days following BLM injection, either prednisolone or CAR was orally administered at doses of 10 mg/kg once daily for 21 days to the rats. The actions of CAR were evaluated by lung oxidant/antioxidant parameters, protein concentration and total leucocyte count (TLC) in bronchoalveolar lavage fluid (BALF), fibrosis regulator-related genes along with the coexistent lung histological changes. Key findings: CAR effectively decreased lung malondialdehyde level, increased superoxide dismutase activity, declined both protein concentration and TLC in BALF, downregulated TGF-β1/α-SMA/Smad2/3 and STAT3 gene expressions, and repaired the damaged lung tissues. Significance: CAR conferred therapeutic potential against BLM-induced lung fibrosis in rats, at least in part, to its antioxidant, anti-inflammatory, and antifibrotic activities. CAR could be utilized as a prospective therapeutic option in patients with lung fibrosis in clinical practice.