title: Studies on black tea (Camellia sinensis) extract as a potential antioxidant and a probable radioprotector.
abstract: Positive health effects of tea (Camellia sinensis) on a wide range of physiological problems and diseases are well known and are in part due to its copious antioxidant content. The effect of black tea extract (BTE), which is rich in polyphenolic antioxidants, against the consequences of radiation exposure has not been properly identified. The functional properties of BTE were analyzed and its radioprotective effect on V79 cells was explored in the present study. BTE scavenged free radicals and inhibited Fenton reaction-mediated 2-deoxyribose degradation and lipid peroxidation in a dose-dependent fashion, establishing its antioxidant properties. The radioprotective effects of BTE on strand break induction in pBR322 plasmid DNA were 100 % at 80 μg/ml and higher. In V79 cells, BTE was effective in decreasing the frequency of radiation-induced micronucleated cells and the yields of reactive oxygen species (ROS) and also in restoring the integrity of cellular mitochondrial membrane potential significantly. BTE exerted maximum protection against radiation-induced damage in V79 at a dose of 5 μg/ml. Due to the functional properties of BTE-flavonoids, which have been identified by HPLC, it is envisaged that the key player in radioprotection is elimination of ROS.
authors.affiliation: School of Biotechnology and Biological Sciences, West Bengal University of Technology, Kolkata, West Bengal, India.
authors.forename: Sandip
authors.initials: S
authors.lastname: Pal
authors.forename: Chabita
authors.initials: C
authors.lastname: Saha
authors.forename: Subrata Kumar
authors.initials: SK
authors.lastname: Dey
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D028241:Camellia sinensis; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000187:drug effects; D004249:DNA Damage; D005419:Flavonoids / Q000032:analysis; D005720:Gamma Rays / Q000009:adverse effects*; D017665:Hydroxyl Radical / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D015162:Micronucleus Tests; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000494:pharmacology*; D010957:Plasmids; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D011837:Radiation-Protective Agents; D017382:Reactive Oxygen Species; D017665:Hydroxyl Radical; D004247:DNA