Curcumin inhibition of bleomycin-induced pulmonary fibrosis in rats

Curcumin, an anti-inflammatory, antioxidant, was evaluated for its ability to suppress bleomycin (BLM)-induced pulmonary fibrosis in rats. A. single i ntratracheal instillation of BLM (0.75 U 100(-1) g, sacrificed 3, 5, 7, 14 and 28 days post-BLM) resulted in significant increases in total cell numbe rs, total protein, and angiotensin-converting enzyme (ACE), and alkaline ph osphatase (AKP) activities in bronchoalveolar lavage fluid. Animals with fi brosis had a significant increase in lung hydroxyproline content. Alveolar macrophages from BLM-administered rats elaborated significant increases in tumour necrosis factor (TNF)-alpha release, and superoxide and nitric oxide production in culture medium. Interestingly, oral administration of curcum in (300 mg kg(-1) 10 days before and daily thereafter throughout the experi mental time period) inhibited BLM-induced increases in total cell counts an d biomarkers of inflammatory responses in BALE. In addition, curcumin signi ficantly reduced the total lung hydroxyproline in BLM rats. Furthermore, cu rcumin remarkably suppressed the BLM-induced alveolar macrophage production of TNF-alpha, superoxide and nitric oxide. These findings suggest curcumin as a potent anti-inflammatory and anti-fibrotic agent against BLM-induced pulmonary fibrosis in rats.