title: Epigallocatechin-3-gallate protects rat brain mitochondria against cadmium-induced damage.
abstract: Many health claims have been made about the medicinal benefits of drinking green tea, including neuroprotection. This study mainly focuses on Epigallocatechin 3-gallate (EGCG), a potent antioxidant, which is abundantly found in green tea. Cadmium [Cd(2+)] is a toxic pollutant that leads to neurotoxicity in both animals and humans. Although the entrance of Cd(2+) in the adult central nervous system is limited, developmental neurotoxicity has been evidenced as result of the blood-brain barrier (BBB) immaturity. Moreover, high Cd(2+) levels are known to impair BBB function. Furthermore, the molecular mechanisms related to its neurotoxic properties remain unknown. This study evaluates the potential protective effect of the major green tea polyphenol, EGCG, against Cd(2+)-induced mitotoxicity under in vitro conditions, using mitochondrial-enriched fractions from rat brain. Co-incubation of EGCG with Cd(2+) prevented the Cd(2+)-induced mitochondrial dysfunction (capacity to reduce MTT to formazan). In addition, EGCG completely prevented mitochondrial lipid peroxidation induced by Cd(2+) but did not affect non protein thiols levels. Spectroscopic studies have shown EGCG able to form a chemical complex with Cd(2+), in an equimolar ratio. In this study we demonstrate EGCG effectiveness in protecting against Cd(2+)-induced mitochondrial dysfunction and lipid peroxidation probably due to its antioxidant and chelating effects.
authors.affiliation: Postgraduate Programme of Biochemistry, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil. renata.abib@terra.com.br
authors.forename: Renata Torres
authors.initials: RT
authors.lastname: Abib
authors.forename: Kaite Cristiane
authors.initials: KC
authors.lastname: Peres
authors.forename: Anderson Machado
authors.initials: AM
authors.lastname: Barbosa
authors.forename: Tanara Vieira
authors.initials: TV
authors.lastname: Peres
authors.forename: Angela
authors.initials: A
authors.lastname: Bernardes
authors.forename: Lizandra Maria
authors.initials: LM
authors.lastname: Zimmermann
authors.forename: André
authors.initials: A
authors.lastname: Quincozes-Santos
authors.forename: Haidi D
authors.initials: HD
authors.lastname: Fiedler
authors.forename: Rodrigo Bainy
authors.initials: RB
authors.lastname: Leal
authors.forename: Marcelo
authors.initials: M
authors.lastname: Farina
authors.forename: Carmem
authors.initials: C
authors.lastname: Gottfried
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002614:Chelating Agents / Q000494:pharmacology*; D005562:Formazans / Q000737:chemistry; D005978:Glutathione / Q000032:analysis; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013778:Tetrazolium Salts / Q000737:chemistry; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
chemical_list: D002614:Chelating Agents; D005562:Formazans; D018696:Neuroprotective Agents; D013778:Tetrazolium Salts; D017392:Thiobarbituric Acid Reactive Substances; D002104:Cadmium; C079782:MTT formazan; D002392:Catechin; C045651:epigallocatechin gallate; D005978:Glutathione