ABSTRACT
Nicotine is an alkaloid that is responsible for most of the dangerous effects of cigarette smoking on the human body. Curcumin is a component of turmeric that is a yellow spice derived from the plant Curcuma longa and has anti-inflammatory, antioxidant, and antimalignant properties. The aim of this work is to study the protective role of curcumin against the cytotoxic effect of nicotine on the lungs of adult male mice using light and electron microscopes. Thirty adult male mice were used in this study. They were divided into three groups. The first group was considered as the control, the second group received a subcutaneous injection of nicotine at a dose of 2.5 mg/kg/day for 1 month, and the third group received a subcutaneous nicotine injection at a dose of 2.5 mg/kg/day and oral curcumin at a dose of 80 mg/kg/day for 1 month. At the end of the experiment, the animals were sacrificed and specimens of the lungs were extracted and processed for examination by light and electron microscopy. In the nicotine-treated group, thickening of the interalveolar septa with narrowing of air spaces was observed, thick abnormal elastic fibers and many collagenous fibers were deposited in lung interstitium, and an apparent increase in the number of pneumocytes type 11 cells with exhausted lamellar bodies was observed. Concomitant administration of nicotine and curcumin resulted in partial recovery from these toxic effects. Curcumin can be used to decrease the harmful effects of nicotine on the lungs in both active and passive smokers