Black Tea: Phytochemicals, Cancer Chemoprevention and Clinical Studies.
Crit Rev Food Sci Nutr. 2015 Nov 11:0. Epub 2015 Nov 11. PMID: 26561007
Brahma N Singh
Tea (Camellia sinensis L.) is the most popular flavored, functional, and therapeutic non-alcoholic drink that consumes by two-thirds of the world's population. Black tea leaves are reported to contain thousands of bioactive constituents such as polyphenols, amino acids, volatile compounds, and alkaloids which exhibit a range of promising pharmacological property. Due to strong antioxidant property, black tea inhibits the development of various cancers by regulating oxidative damage of biomolecules, endogenous antioxidants, and pathways of mutagen and transcription of antioxidant gene pool. Regular drinking of phytochemicals-rich black tea is linked to regulate several molecular targets including COX-2, 5-LOX, AP-1, JNK, STAT, EGFR, AKT, Bcl2, NF-κB, Bcl-xL, caspases, p53, FOXO1, TNFα, PARP, and MAPK may be the basis for how dose black tea prevent and cure cancer. In vitro and preclinical studies support the anti-cancer activity of black tea, however its effect under human trails is uncertain, though more clinical experiments are needed atmolecular levels to understand its anti-cancer property. This review discusses the current knowledge on phytochemistry, chemopreventive activity, and clinical applications of black tea in order to reveal its anti-cancer effect.