Bhuvaneswari V, Rao K S, Nagini S
Department of Biochemistry, Faculty of Science, Annamalai University, Annamalainagar-608 002, Tamil Nadu, India.
Clin Chim Acta. 2004 Dec;350(1-2):65-72. doi: 10.1016/j.cccn.2004.07.002.
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.
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.
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.
The induction of apoptosis may be one of the mechanisms through which functional foods such as tomato and garlic exert their anticancer properties.
膳食因子的有效组合因其安全性以及不被视为药物这一事实，有望成为癌症化学预防的候选物。本研究旨在调查在7,12-二甲基苯并[a]蒽（DMBA）诱导的仓鼠颊囊（HBP）癌变过程中，番茄和大蒜联合给药的凋亡诱导作用。
将仓鼠分为四组。第1组动物的右侧颊囊每周用0.5% DMBA涂抹三次。第2组动物如第1组一样涂抹DMBA，此外在与DMBA涂抹日交替的日子里接受番茄和大蒜联合剂量的胃内给药。第3组动物单独给予化学预防剂。第4组动物作为对照。在14周的实验期后，处死所有动物。DNA片段化以及凋亡相关蛋白——Bcl-2、Bax、Bim、P53以及半胱天冬酶8和3被用作凋亡标记物。
局部应用DMBA 14周导致了发育良好的鳞状细胞癌（SCC），伴有Bcl-2表达增加以及Bax、Bim、P53和半胱天冬酶8和3表达降低。番茄和大蒜联合给药显著抑制了HBP癌的发展并诱导了凋亡。这通过Bcl-2的下调以及Bax、Bim、P53和半胱天冬酶8和3的上调得以证明。
凋亡诱导可能是番茄和大蒜等功能性食品发挥其抗癌特性的机制之一。
