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Objective: Combination chemoprevention by dietary agents is a promising approach toward cancer control. Many dietary agents are known to prevent experimental mutagenesis and carcinogenesis by modulating xenobiotic-metabolizing enzymes. The present study evaluated the combinatorial chemopreventive effects of tomato and garlic on hamster buccal pouch carcinogenesis induced by 7,12-dimethylbenz[a]anthracene (DMBA)., Methods: Hamsters were assigned to one of four groups. The right buccal pouches of animals in group 1 were painted with 0.5% DMBA three times a week. The right buccal pouches of animals in group 2 were painted with DMBA and received intragastric administration of a combined dose of tomato and garlic on days alternate to DMBA application. Animals in group 3 were given chemopreventive agents alone. Animals in group 4 served as controls. Levels of phase I and II enzymes and the frequency of bone marrow micronuclei were used as biomarkers of chemoprevention., Results: All the hamsters painted with DMBA alone developed buccal pouch carcinomas that exhibited increased activities of xenobiotic-metabolizing enzymes associated with increased frequencies of bone marrow micronuclei. In the liver, an increase in phase I enzymes was accompanied by compromised phase II detoxification activities. Combined administration of tomato and garlic effectively suppressed the incidence and mean tumor burden of hamster buccal pouch carcinomas. In addition, tomato and garlic combination significantly decreased phase I enzymes and increased phase II enzyme activities in the pouch and liver with a decreased incidence of bone marrow micronuclei., Conclusion: From these results, we suggest that modulation of xenobiotic-metabolizing enzymes exerted by tomato and garlic combination plays a key role in mitigating the mutagenic and carcinogenic effects of DMBA.

Background: Effective combinations of dietary agents are promising candidates for cancer chemoprevention because of their safety and the fact that they are not perceived as medicine. The present study was designed to investigate the apoptosis-inducing effect of combined administration of tomato and garlic during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis., Methods: Hamsters were divided into four groups. The right buccal pouches of animals in group 1 were painted with 0.5% DMBA three times a week. Animals in group 2 painted with DMBA as in group 1, received in addition intragastric administration of a combined dose of tomato and garlic on days alternate to DMBA application. Group 3 animals were given chemopreventive agents alone. Animals in group 4 served as control. All the animals were sacrificed after an experimental period of 14 weeks. DNA fragmentation and the apoptosis-associated proteins-Bcl-2, Bax, Bim, P53 as well as caspases 8 and 3 were used as markers of apoptosis., Results: Topical application of DMBA for 14 weeks resulted in well-developed squamous cell carcinomas (SCCs) associated with increased expression of Bcl-2 and decreased expression of Bax, Bim, P53 and caspases 8 and 3. Combined administration of tomato and garlic significantly inhibited the development of HBP carcinomas and induced apoptosis. This was evidenced by downregulation of Bcl-2 and upregulation of Bax, Bim, P53 and caspases 8 and 3., Conclusion: The induction of apoptosis may be one of the mechanisms through which functional foods such as tomato and garlic exert their anticancer properties.

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., Conclusion: Our results demonstrate that tomato protects against the clastogenic effects of MNNG by decreasing micronucleated polychromatic erythrocytes and lipid peroxidation and enhancing antioxidant status.

Chemoprotection by dietary agents is a promising strategy for cancer prevention. The aim of the present study was to evaluate the combined effect of tomato and garlic against 7,12-dimethylbenz-[a]anthracene (DMBA)-induced genetic damage and oxidative stress in 12-14-week-old male Swiss albino mice. The animals were randomized into experimental and control groups and divided into eight groups of five animals each. Group 1 animals were injected intraperitoneally with 35 mg/kg body weight DMBA suspended in peanut oil as a single dose. Groups 2-4 animals received tomato (500 mg/kg body weight), garlic (125 mg/kg body weight) and a combination of tomato and garlic for 5 days by gavage, respectively, followed by DMBA 1.5 h after the final feeding. The doses of tomato and garlic correspond to the average human daily consumption. Animals in groups 5, 6 and 7 received tomato alone, garlic alone and tomato + garlic combination, respectively, for 5 days. Group 8 animals received the same volume of water and served as control. The incidence of bone marrow micronuclei and the extent of lipid peroxidation and the concentrations of antioxidants glutathione, glutathione peroxidase and glutathione-S-transferase were measured in the liver, 48 h after DMBA exposure. Increased frequency of micronuclei and enhanced lipid peroxidation accompanied by compromised antioxidant defenses were observed in DMBA-treated animals. Although pretreatment with tomato or garlic significantly reduced the frequency of DMBA-induced bone marrow micronuclei, the combination of tomato and garlic exhibited more profound effect in inhibiting DMBA-induced genotoxicity and oxidative stress. We suggest that a broad spectrum of antimutagenic and anticlastogenic effects can be achieved through an effective combination of functional foods such as tomato and garlic.

This study was designed to investigate the protective role of pretreatment with graded doses of freshly prepared tomato paste against 7,12-dimethylbenz[a]anthracene (DMBA)-induced genetic damage and oxidative stress in male Swiss mice. The incidence of bone marrow micronuclei and the extent of hepatic lipid peroxidation and the antioxidants glutathione, glutathione peroxidase, and glutathione S-transferase were monitored. Three different concentrations (0.5, 1, and 2 g/kg body weight) of tomato paste were tested for their anticlastogenic effects against DMBA (35 mg/kg body weight). Increased frequency of micronuclei and enhanced lipid peroxidation accompanied by compromised antioxidant defenses were observed in DMBA-treated animals. Pretreatment with all three doses of tomato paste significantly reduced the frequencies of DMBA-induced micronuclei and oxidative stress. These findings demonstrate that administration of tomato paste protects against the clastogenic effects of DMBA by decreasing lipid peroxidation and enhancing the antioxidant status.