Kalpana C, Sudheer AR, Rajasekharan KN, Menon VP
Correspondence: Dr Venugopal P Menon, cmrana@sify.com
ABSTRACT
Introduction Tobacco consumption is one of the leading preventable causes of death and disease worldwide. Nicotine, a major toxic component of tobacco, has been identified as an important risk factor for lung-related diseases. Increasing evidence demonstrates that oxidative stress plays a crucial aetiological role in the development of lung-related diseases. The present study aims at evaluating the protective role of curcumin and a synthetic analogue of curcumin (BDMC-A) on nicotine-induced oxidative stress.
Methods Male albino rats of Wistar strain were used for the experimental study. Lung toxicity was induced by subcutaneous injection of nicotine at a dose of 2.5 mg/kg body weight (five days a week, for 22 weeks) and curcuminoids were given simultaneously by intragastric intubation for 22 weeks. Measurement of lipid peroxidation indices, thiobarbituric acid reactive substances and hydroperoxides, nitric oxide and antioxidants, such as superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, vitamin E and vitamin C, were used as biomarkers for testing the antioxidant potential of the drugs.
Results Oxidative stress, as evidenced by lipid peroxidation indices, was significantly increased in nicotine-treated groups. Administration of curcumin and BDMC-A abrogated this effect. The antioxidant status which was decreased in nicotine was effectively modulated by both curcumin and BDMC-A treatment. However, the reduction in oxidative stress was more pronounced in BDMC-A treatment groups compared to those treated with curcumin.
Conclusion The present study suggests that BDMC-A exerts its protective effect by modulating the extent of lipid peroxidation and augmenting the antioxidant defence system.
Keywords: antioxidants, curcumin, curcumin analogue, lipid peroxidation, lung toxicity, nicotine
Singapore Med J 2007; 48(2): 124–130