Iron-chelating and free-radical scavenging activities of microwave-processed green tea in iron overload.
Secondary iron overload is found in beta-thalassemia (thal) patients because of increased dietary iron absorption and multiple blood transfusions. Excessive iron catalyzes free-radical generation, leading to oxidative damage and vital organ dysfunction. Non-transferrin-bound iron (NTBI) detected in thalassemic plasma is highly toxic and chelatable. Though used to treat iron overload, desferrioxamine (DFO) and deferiprone (L1) also have adverse effects. Green tea (GT) shows many pharmacological effects, particularly antioxidative and iron-chelating capacities. This study was performed to investigate the ability of GT extracts to reduce plasma NTBI concentration and oxidative stress in vitro. The Fe(3+) was found to bind to GT crude extract and form a complex. Green tea crude extract time- and dose-dependently decreased plasma NTBI concentration and counteracted the increase of oxidative stress in both Fe(2+)-EDTA-treated human plasma and erythrocytes. Green tea is a bifunctional natural product that could be relevant for management of iron overload and oxidative stress.
Srichairatanakool
Somdet
S
Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Thailand. mdbci@yahoo.com
Ounjaijean
Sakaewan
S
Thephinlap
Chonthida
C
Khansuwan
Udompun
U
Phisalpong
Chada
C
Fucharoen
Suthat
S
D000975:Antioxidants / Q000494:pharmacology; D028241:Camellia sinensis / Q000737:chemistry* / Q000528:radiation effects; D002392:Catechin / Q000031:analogs & derivatives / Q000032:analysis / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D003890:Desiccation; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D004912:Erythrocytes / Q000187:drug effects*; D005290:Ferric Compounds / Q000097:blood / Q000493:pharmacokinetics; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006358:Hot Temperature; D006801:Humans; D066298:In Vitro Techniques; D007501:Iron / Q000097:blood; D007502:Iron Chelating Agents / Q000494:pharmacology*; D019190:Iron Overload / Q000188:drug therapy*; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects; D008872:Microwaves; D009566:Nitrates / Q000097:blood / Q000493:pharmacokinetics; D018384:Oxidative Stress / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology* / Q000528:radiation effects; D010949:Plasma / Q000187:drug effects*; D013662:Tea / Q000737:chemistry* / Q000528:radiation effects; D017086:beta-Thalassemia / Q000097:blood*
D000975:Antioxidants; D005290:Ferric Compounds; D016166:Free Radical Scavengers; D007502:Iron Chelating Agents; D009566:Nitrates; D010936:Plant Extracts; D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate; D007501:Iron; C025302:ferric nitrate