Black Tea Polyphenols Restrict Benzopyrene-induced Mouse Lung Cancer Progression through Inhibition of Cox-2 and Induction of Caspase-3 Expression

Abstract

Lung cancer is one of the leading causes of cancer related death in most developed and many developing countriesof the world. Due to lack of validated screening methods and poor prognosis, treatment of lung cancer has notimproved significantly over the last two decades. Therefore the risk of the disease needs to be minimized by preventivemeasures. One approach for lung cancer prevention envisages reversal or restriction of precancerous lesions bychemopreventive intervention. It demands a deeper understanding of the pathogenesis of the disease and identificationof the ideal point of intervention. In the present investigation, tea components, epigallocatechin gallate (EGCG) andtheaflavins (TF) were assessed for their chemopreventive potential when administered in the post initiation phase oflung carcinogenesis in an experimental mouse model. Histopathological changes in lungs of mice administeredbenzo(a)pyrene (BP) were followed serially and correlated with the expression of Cox-2, caspase-3 and caspase-7,which play key roles in histopathogenesis of neoplasia. The observations strongly indicate that both EGCG and TFcan influence the expression of these genes to modulate the process of carcinogenesis, resulting in delayed onset andlowered incidence of pre-invasive lung lesions.