In normal state of a cell, endogenous antioxidant enzyme system maintains the level of reactive oxygen species generated by mitochondrial respiratory chain.

Tea polyphenols are secondary metabolites of tea plants and are well known for beneficial health effects. They can protect from a variety of illnesses including cancers. Tea polyphenols can prevent cancer by modulating epigenetic aberrations taking place in DNA methylation, histone modifications, and micro-RNAs. By altering these epimutations, they regulate chromatin dynamics and expression of genes those induce or suppress cancer formation. However, majority of the studies in existing literature are carried out for green tea polyphenols rather than black tea polyphenols despite the fact that black tea is the most commonly consumed form of tea (78%) followed by green tea (20%) and other forms of tea. Research findings indicate that tea polyphenols may be potential source from which drugs with less side effects and affordable price can be developed.

A survey was conducted to determine the cancer profile in Nainital and adjoining districts of Uttarakhand. Epidemiological information was collected from the records of patients with confirmed cancer cases. A total of 354 cases were studied for the year 2010. Lung cancer was found to be leading cancer type (17.23%) overall. Breast cancer was most prevalent in females (22.29%) followed by cervical (14.86%) and ovarian cancers (13.51%). Men were mainly suffering from tobacco- and alcohol-related cancers, e.g., lungs (26.21%), larynx (11.16%), oropharynx (9.7%), oral cavity (6.79%), and esophagus (6.79%). Cancers of unknown primary site (1.41%) were also detected.

Phase I metabolic enzyme CYP1A1 plays an important role in xenobiotics metabolism and has been extensively studied as a cancer risk biomarker. CYP1A1 is polymorphic and its four variants, e.g., CYP1A1* 2 A, CYP1A1* 2C, CYP1A1* 3 and CYP1A1* 4 with trivial names m1, m2, m3, and m4 respectively, are most commonly studied for cancer link. Gene- gene interaction studies combining polymorphisms of this enzyme with those of phase II detoxifying enzymes, especially glutathione S- transferases (GSTs) revealed greater risk for cancer susceptibility. Variants of CYP1A1 have also been found to be associated with chemotherapeutic adverse- effects. Results of these studies, however, remained largely contradictory mainly because of lack of statistical power due to involvement of small sample size. Strongly powered experimental designs involving gene- gene, gene- environment interactions are required in order to validate CYP1A1 as reliable cancer- biomarker.

Background:Null genetic polymorphism of Glutathione S-transferase T1 (GSTT1) and -463 G>A promoter polymorphism of myeloperoxidase (MPO) were studied for association with lung cancer.Materials and Methods:In a case- control study 26 lung cancer patients and 33 healthy individuals from hilly Kumaun region of northern India were investigated. DNA was extracted from peripheral blood. GSTT1 null polymorphism was detected by duplex PCR, and MPO polymorphism was detected by performing PCR-RFLP.Results:An increased but statistically non- significant risk for lung cancer was found for GSTT1 null genotype. No association for MPO -463G>A genotype was evident.Conclusion:Further study with large sample size may reveal such association in this population.