Tea polyphenols inhibit cyclooxygenase-2 expression and block activation of nuclear factor-kappa B and Akt in diethylnitrosoamine induced lung tumors in Swiss mice.
BACKGROUND
Due to lack of validated screening methods and hence poor prognosis, treatment of lung cancer has not still improved up to the expectations. Therefore, risk of lung cancer needs to be minimized by efficient preventive measures. Tea (Camellia sinensis) and its bioactive polyphenols have been associated with prevention of human cancer for several organs. Thus, intake of tea polyphenols seems to be a viable mean to control lung cancer burden. In the present study, we studied the chemopreventive effects of green tea polyphenols (GTP) and black tea polyphenols (BTP) against diethylnitrosoamine (DEN) induced lung tumors in Swiss albino mice.


RESULTS
Chemopreventive potential of tea polyphenols, was recorded as evident by, low incidence of alveologenic tumors in lungs of animals at tested doses (0.1% and 0.2% of both GTP and BTP) when compared with DEN (20 mg/kg b wt) treated animals. As a mechanism of cancer chemoprevention cellular signaling pathways were also targeted. GTP and BTP treatment inhibited the expression of Akt, cyclooxygenase-2 and inactivated nuclear factor-kappa B via blocking phosphorylation and subsequent degradation of IkappaB alpha.


CONCLUSIONS
Thus, the study suggests that polyphenolic constituents of both cultivars of tea, i.e. green and black, have chemopreventive effects in DEN induced lung tumorigenesis in Swiss albino mice.
Roy
Preeti
P
Proteomics Laboratory, Indian Institute of Toxicology Research, (Council of Scientific & Industrial Research), P.O. Box 80, M.G. Marg, Lucknow, 226001, India.
Nigam
Nidhi
N
Singh
Madhulika
M
George
Jasmine
J
Srivastava
Smita
S
Naqvi
Hasnain
H
Shukla
Yogeshwer
Y
D000818:Animals; D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004052:Diethylnitrosamine; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008175:Lung Neoplasms / Q000139:chemically induced / Q000188:drug therapy*; D008297:Male; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D010636:Phenols / Q000008:administration & dosage / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D059808:Polyphenols; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D013662:Tea
D016588:Anticarcinogenic Agents; D005419:Flavonoids; D016328:NF-kappa B; D010636:Phenols; D059808:Polyphenols; D013662:Tea; D004052:Diethylnitrosamine; D051546:Cyclooxygenase 2; D051057:Proto-Oncogene Proteins c-akt