Effects of a Hydrolyzed Lignin Derivative on Bleomycin-Induced Pulmonary Fibrosis in Mice

Female C57BL/J mice with pulmonary fibrosis induced by injections of bleomycin (20 mg/kg intraperitoneally, 8 times for 4 weeks) were treated with a lignin derivative-based composition BP-C3 (80 mg/kg, daily intragastric administrations for 4 weeks). Bleomycin treatment increased the severity of pulmonary fibrosis (Ashcroft score increased from 1.43±0.20 to 4.17±0.48) and the percentage of α-SMA⁺ tissue (from 15.22±1.01 to 33.12±2.30%) and DNA-synthetizing nuclei (from 1.05±0.14 to 3.38±0.375). After treatment with BP-C3, we observed a tendency to a decrease in Ashcroft score (to 3.40±0.51) and a significant decrease in the percentage of α-SMA⁺ tissue to 24.30±1.70%; the percentage of DNA-synthetizing nuclei decreased to a lesser extent (to 3.03±0.22%). These results suggest that BP-C3 has a moderate antifibrotic activity.