Altered expression of anti and proapoptotic proteins during chemoprevention of hamster buccal pouch carcinogenesis by tomato and garlic combination.
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.


CONCLUSIONS
The induction of apoptosis may be one of the mechanisms through which functional foods such as tomato and garlic exert their anticancer properties.
Bhuvaneswari
V
V
Department of Biochemistry, Faculty of Science, Annamalai University, Annamalainagar-608 002, Tamil Nadu, India.
Rao
K S
KS
Nagini
S
S
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis; D001551:Benz(a)Anthracenes / Q000737:chemistry; D020169:Caspases / Q000378:metabolism; D006224:Cricetinae; D053938:DNA Fragmentation / Q000187:drug effects; D004195:Disease Models, Animal; D005737:Garlic / Q000737:chemistry*; D015870:Gene Expression / Q000187:drug effects*; D018551:Solanum lycopersicum / Q000737:chemistry*; D009062:Mouth Neoplasms / Q000378:metabolism / Q000517:prevention & control*; D010936:Plant Extracts / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism
D000972:Antineoplastic Agents, Phytogenic; D001551:Benz(a)Anthracenes; D010936:Plant Extracts; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; C046810:7,12-dihydroxymethylbenz(a)anthracene; D020169:Caspases