Human dietary exposure to
benzo(a)pyrene (BaP) has generated interest with regard to the association of BaP with gastrointestinal
carcinogenesis. Since
colon cancer ranks third among
cancer-related mortalities, it is necessary to evaluate the effect of
phytochemicals on
colon cancer initiation and progression. In this study, we investigated the preventive effects of
resveratrol (RVT) on BaP-induced colon
carcinogenesis in Apc(Min) mouse model. For the first group of mice, 100 μg BaP/kg
body weight was administered to mice in
peanut oil via oral gavage over a 60-day period. For the second group, RVT was coadministered with BaP at a dose of 45 μg/kg. For the third group, RVT was administered for 1 week prior to BaP exposure for 60 days. Jejunum, colon and liver were collected at 60 days post BaP and RVT exposure;
adenomas in jejunum and colon were counted and subjected to histopathology. RVT reduced the number of colon
adenomas in BaP+RVT-treated mice significantly compared to that in mice that received BaP alone. While dysplasia of varying degrees was noted in colon of BaP-treated mice, the dysplasias were of limited occurrence in RVT-treated mice. To ascertain whether the
tumor inhibition is a result of altered BaP-induced toxicity of
tumor cells, growth, apoptosis and proliferation of
adenocarcinoma cells were assessed posttreatment with RVT and BaP. Cotreatment with RVT increased apoptosis and decreased cell proliferation to a greater extent than with BaP alone. Overall, our observations reveal that RVT inhibits colon
tumorigenesis when given together with BaP and holds promise as a therapeutic agent.