Inhibition of Cell Proliferation and Induction of Apoptosis During Azoxymethane Induced Colon Carcinogenesis by Black Tea.
Tea (Camellia sinensis) is one of the most popular beverages, consumed worldwide. The health promoting properties of tea have been attributed to its antioxidative polyphenolic constituents and their oxidative products. The aim of the present study was to evaluate the chemopreventive efficacy of a black tea infusion on azoxymethane induced colonic preneoplastic lesions, the aberrant crypt foci in Sprague-Dawley rats. Rats were injected with azoxymethane (15mg/kg.b.w.) and received oral administration of 1% and 2% (w/v) tea infusions from the 1(st)day of carcinogen application. The treatment was continued for 12 weeks. The colons were then assessed for aberrant crypt foci and compared with the untreated carcinogen control group. In situ cell proliferation and in situ apoptosis were also estimated using Brdu incorporation and the TUNEL method, respectively. Aberrant crypt foci were reduced significantly (by 44% in the 1% tea-treated and by about 40% in 2% tea-treated group). Significant decrease in proliferation and increase in apoptosis suggest a possible interplay between the two processes resulting in inhibition of colon carcinogenesis by black tea.
Sengupta
Archana
A
Dept. of Cancer Chemoprevention, Chittaranjan National Cancer Institute, Kolkata- 700026, India. archanadi1@rediffmail.com
Ghosh
Samit
S
Das
Sukta
S