Protective effect of tomato against N-methyl-N'-nitro-N-nitrosoguanidine-induced in vivo clastogenicity and oxidative stress.
OBJECTIVE
Chemoprevention by dietary constituents has emerged as a cost-effective approach to control the incidence of gastric cancer, the second most common malignancy worldwide, and a major cause of mortality in Chennai, India. Identification of dietary agents with chemopreventive potential requires prescreening in animal models. We evaluated the modifying effects of tomato paste against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced genetic damage and oxidative stress in male Swiss mice.


METHODS
Quantitation of bone marrow micronuclei, extent of lipid peroxidation, and the status of the antioxidants reduced glutathione, glutathione peroxidase, and glutathione S-transferase in the stomach and liver of Swiss albino mice were used to monitor the protective effects of tomato. Three different doses of tomato (0.5, 1, and 2 g/kg of body weight) were administered intragastrically for 5 d consecutively followed by intragastric intubation of MNNG 1.5 h after the final administration.


RESULTS
Increased frequency of micronuclei and enhanced lipid peroxidation were accompanied by compromised antioxidant defenses in MNNG-treated rats. Pretreatment of tomato paste at the concentration of 1 and 2 g/kg of body weight significantly decreased micronuclei and lipid peroxidation and enhanced reduced glutathione-dependent antioxidant and detoxifying enzymes.


CONCLUSIONS
Our results demonstrate that tomato protects against the clastogenic effects of MNNG by decreasing micronucleated polychromatic erythrocytes and lipid peroxidation and enhancing antioxidant status.
Department of Biochemistry, Faculty of Science, Annamalai University, Tamil Nadu, India.
Balaiya
B
Velmurugan
Vaidhyanathan
V
Bhuvaneswari
Suresh K
SK
Abraham
Siddavaram
S
Nagini
D000818:Animals; D001854:Bone Marrow Cells / Q000187:drug effects; D018890:Chemoprevention / Q000379:methods; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005753:Gastric Mucosa / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D018551:Solanum lycopersicum; D008297:Male; D008769:Methylnitronitrosoguanidine / Q000633:toxicity*; D051379:Mice; D015162:Micronucleus Tests / Q000379:methods; D009152:Mutagenicity Tests / Q000379:methods; D009153:Mutagens / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D028321:Plant Preparations / Q000627:therapeutic use*; D013270:Stomach / Q000187:drug effects / Q000201:enzymology
D009153:Mutagens; D028321:Plant Preparations; D008769:Methylnitronitrosoguanidine; D005979:Glutathione Peroxidase; D005982:Glutathione Transferase; D005978:Glutathione