Abstract
Pulmonary fibrosis (PF) is a respiratory disease that causes serious respiratory problems. The effects of French marine pine bark extract (Pycnogenol®), with antioxidant and anti-inflammatory properties, were investigated on lung fibrosis in polyhexamethylene guanidine (PHMG)-treated mice. Mice were separated into four groups (n = 6): vehicle control (VC, saline 50 μl); PHMG (1.1 mg/kg); PHMG + Pycnogenol® (0.3 mg/kg/day); and PHMG + Pycnogenol® (1 mg/kg/day). PF was induced via intratracheal instillation of PHMG. Treatment with PHMG decreased body weight and increased lung weight, both of which were improved by treatment with PHMG + Pycnogenol® (1 mg/kg). Enzyme-linked immunosorbent assay, western blotting, and PCR revealed that Pycnogenol® attenuated PHMG-induced increase in inflammatory cytokines and fibrosis-related factors in a dose-dependent manner. Finally, histopathological analysis revealed reduced inflammation/fibrosis in the PHMG + Pycnogenol® (1 mg/kg) group. Collectively, the results indicate that Pycnogenol® can be used to treat PF as it hinders fibrosis progression by inhibiting inflammatory responses in the lungs of PHMG-treated mice.