Abstract
In this study, we investigated whether oxidant/antioxidant imbalance in bleomycin (BLM)-instilled lungs would be prevented by curcumin. A single intratracheal injection of bleomycin (5 mg/kg body weight) to rats induced acute lung injury accompanied by significant increases in biochemical markers and inflammatory cell accumulation in bronchoalveolar lavage fluid and increased lung levels of myeloperoxidase (MPO) and intercellular adhesion molecule-1 (ICAM-1) 7 days after bleomycin administration. Also, bleomycin instillation led to leukocytes accumulation and fibrotic changes in the lung interstitium. Lung levels of thiobarbituric acid reactive substances (TBARS), conjugated dienes and protein carbonyls were increased at 7 and 14 days after bleomycin administration. In addition, increases in lung antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, glutathione reductase and glutamate cysteine ligase were noticed 7 and 14 days after BLM administration. Curcumin (300 mg/kg body weight, one week before and daily thereafter for 14 days) treatment significantly inhibited bleomycin-induced increases in lung lavage fluid biomarkers, histopathological changes, lung lipid peroxidation products and restored the levels of antioxidant enzymes to normal values. These findings indicate that curcumin is capable of inhibiting bleomycin-induced lung injury through inhibition of oxidative stress and perturbations in pulmonary antioxidant defense mechanisms.
Keywords: Antioxidant, Bleomycin, Curcumin, Lipid peroxidation, Lung injury, Oxidative stress
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