title: Protective effect of ferulic acid on nicotine-induced DNA damage and cellular changes in cultured rat peripheral blood lymphocytes: a comparison with N-acetylcysteine.
abstract: Nicotine is the major pharmacologically active substance in cigarette smoke and plays an important etiological role in the development of lung cancer. Incidence of cancer may be related to oxidative damage to host genome by nicotine. These oxidative actions may be modified by the phytochemicals present in food. The present study describes the protective effect of ferulic acid (FA), a naturally occurring nutritional compound on nicotine-induced DNA damage and cellular changes in cultured rat peripheral blood lymphocytes in comparison with N-acetylcysteine (NAC), a well-known antioxidant. One-hour exposure of lymphocytes to nicotine at the doses of 0.125, 0.25, 0.5, 1, 2, 3 and 4 mM induced a statistically significant dose-dependent increase in the levels of thiobarbituric acid reactive substances (TBARS), a lipid peroxidative marker and decrease in the levels of reduced glutathione (GSH), an important endogenous antioxidant. The lowest concentration eliciting significant damage was 1 mM nicotine and maximum damage was observed with 3 mM concentration. Hence, the test concentration was fixed at 3 mM nicotine. We have used 5 different doses of FA (10, 50, 100, 150 and 300 microM) and NAC (0.25, 0.5, 1, 2 and 4 mM) to test their protective effects. In all the groups, FA and NAC showed a dose-dependent inhibitory effect. Maximum protection was observed at the dose of 150 microM FA and 1mM NAC. So, 150 microM FA and 1mM NAC were used for further studies. There was a significant increase in the levels of lipid peroxidative index (TBARS and hydroperoxides (HP)), severity of DNA damage (evaluated by comet assay) in nicotine-treated group, which were significantly decreased in FA and NAC-treated groups. Nicotine treatment significantly decreased the endogenous antioxidant status viz., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), GSH, vitamin A, E and C. Co-administration of FA and NAC to nicotine-treated lymphocytes showed a significant increase in the antioxidant status. The protective effect of FA was merely equal to that of NAC effect. FA and NAC treatment alone did not produce any toxicity to the normal lymphocytes at their effective doses. On the whole, there is overwhelming evidence that FA has the ability to modulate DNA damage and a variety of cellular changes that occur during nicotine-induced toxicity in rat peripheral blood lymphocytes.
authors.affiliation: Department of Biochemistry and Biotechnology, Faculty of Science, Center for Micronutrient Research, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India.
authors.forename: Adluri Ram
authors.initials: AR
authors.lastname: Sudheer
authors.forename: Shanmugavelu
authors.initials: S
authors.lastname: Muthukumaran
authors.forename: Chandran
authors.initials: C
authors.lastname: Kalpana
authors.forename: Marimuthu
authors.initials: M
authors.lastname: Srinivasan
authors.forename: Venugopal Padmanabhan
authors.initials: VP
authors.lastname: Menon
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002478:Cells, Cultured; D020552:Comet Assay; D003373:Coumaric Acids / Q000494:pharmacology*; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D009538:Nicotine / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D018722:Nicotinic Agonists / Q000633:toxicity*; D051381:Rats
chemical_list: D000975:Antioxidants; D003373:Coumaric Acids; D016166:Free Radical Scavengers; D018722:Nicotinic Agonists; D009538:Nicotine; C004999:ferulic acid; D000111:Acetylcysteine