PROTECTIVE EFFECTS OF TEA POLYPHENOLS AGAINST OXIDATIVE DAMAGE TO RED-BLOOD-CELLS

Citation
Ln. Grinberg et al., PROTECTIVE EFFECTS OF TEA POLYPHENOLS AGAINST OXIDATIVE DAMAGE TO RED-BLOOD-CELLS, Biochemical pharmacology, 54(9), 1997, pp. 973-978
Citations number
30
Categorie Soggetti
Pharmacology & Pharmacy",Biology
Journal title
ISSN journal
00062952
Volume
54
Issue
9
Year of publication
1997
Pages
973 - 978
Database
ISI
SICI code
0006-2952(1997)54:9<973:PEOTPA>2.0.ZU;2-X
Abstract
Tea polyphenols (TPP) from black and green teas were evaluated for the ir antioxidant effects on normal red blood cells (RBC) and beta-thalas semic RBC membranes challenged with exogenous oxidants in vitro. The T PP of both types protected RBC against primaquine-induced lysis; they also protected the whole cells and the membranes against H2O2-induced lipid peroxidation so that about 80% protection was reached at [TPP] = 10 mu g/mL. TPP from black tea at the same concentration protected no rmal RBC from morphological alterations caused by the peroxide treatme nt. The mechanism of the effects of TPP was investigated using a chemi cal system generating (OH)-O-. (iron + ascorbic acid). TPP from both b lack and green teas inhibited the (OH)-O-. fluxes in a concentration-d ependent manner, indicating the possibility of iron chelation by TPP. Spectrophotometric titration revealed that TPP could stoichiometricall y bind ferric iron to form a redox-inactive Fe-TPP complex. Quantitati ve analysis suggests that one or more major catechins from the TPP pre parations are the likely iron-binding compounds accounting for the ant ioxidant effects of TPP on RBC. (C) 1997 Elsevier Science Inc.