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Description:
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The present study was carried out to examine the chemopreventive effects of
curcumin and green tea polyphenols on the hamster cheek pouch carcinogenesis model .
This model of oral carcinogenesis has been widely used in chemoprevention studies ,
however , these studies have been limited to the use of DMBA as the carcinogenic
agent . We have developed a protocol of carcinogenesis in the hamster cheek pouch
using B[a]P , a broadly distributed environmental carcinogen , formed as a by -product of
the combustion of organic materials including cigarette smoke . B[a]P - induced tumors
in the hamster cheek pouch are primarily endophytic squamous cell carcinomas that
closely resemble squamous cell carcinomas of the human oral mucosa . The cheek
pouch of male Syrian hamsters were treated topically for eight weeks with 0 .6 %
curcumin , 6 .0 % curcumin , 2 .5 % green tea polyphenols , or 5 .0 % green tea polyphenols ,
3 times per week 30 minutes prior to the application of 2 .0 % B[a]P .
The animals were sacrificed 24 hours and 72 hours after the last treatments .
Short -term mechanistic markers of malignant progression were used to determine
effects of each compound . Cellular proliferation , assessed by bromodeoxyuridine
(Brdu ) incorporation , p53 protein accumulation , and apoptotic activity were evaluated .
The results of the present study demonstrated that 0 .6 % curcumin and 2 .5 % green tea
polyphenols had strong inhibitory effects on cellular proliferation and p53 protein
accumulation . And 6 .0 % curcumin and 5 .0 % green tea polyphenols appeared to induce
apoptosis . Our data suggest that curcumin and green tea polyphenols may have a
plausible chemopreventive effect on oral carcinogenesis in the hamster cheek pouch
model . |