Protection of bleomycin-induced fibrosis and inflammation by taurine

Taurine has been shown to protect against lung injury induced by various oxidants including ozone, nitrogen dioxide, amiodarone, and paraquat and to protect against bleomycin-induced lung injury in combination with niacin. In this study, Spraque-Dawley rats were treated with 5% taurine in the drinking water for 10 days prior to bleomycin instillation. Fibrosis in the rats pretreated with taurine (BT) was absent, along with fewer inflammatory infiltrates compared to the untreated rats (BW). A significant decrease in the number of PMNs and a decrease in hydroxyproline levels were found in the bronchoalveolar lavage fluid in the BT group compared to the BW group. By immunohistochemical staining, inducible nitric oxide synthase was evident in the lungs of bleomycin-treated rats, and minimal when rats were treated with taurine. Tumor necrosis factor-alpha (TNF-α) as measured by immunohistochemical staining, was present in lungs of both taurine-treated and untreated rats, but was more abundant in the BW group compared to the BT group. In addition, decreased ICAM presentation was detected by EM immunogold staining in the BT group compared to the BW group. These data demonstrate that rats pretreated with 5% taurine in their drinking water prior to bleomycin instillation are protected from fibrosis, inflammatory infiltrates, as well as nitric oxide and TNF-α production, which are hallmarks of bleomycin lung injury.