title: Tea epigallocatechin-3-gallate increases 8-isoprostane level and induces caudal regression in developing rat embryos.
abstract: Tea is the most common beverage after water. Concerns have been raised about the safety of tea during pregnancy, especially for embryo development. We aimed at studying the effects of active tea components on developing embryos by in vitro rat embryo culture. Rat embryos during early organogenesis were cultivated in serum supplemented with one of the tea catechins. Developmental hallmarks and malformations (Mal) in the developing embryos were compared and evaluated by a standard morphological scoring system. The embryotoxicity of each tea catechin was classified according to the European Center for the Validation of Alternative Methods. Cell viability was assessed by supervital dye staining, apoptosis by TUNEL assay, and peroxidation by the 8-isoprostane EIA method. We found that (+)-catechin had the least effect on developing embryos (Mal(50)=715.1 mg/L; IC50(Mal)=435 mg/L), whereas (-)-epigallocatechin gallate had the most adverse effect (Mal(50)=54.2 mg/L; IC50(Mal)=45.8 mg/L). The major malformation in affected embryos included caudal retardation with abnormal axial flexion and delayed hind-limb formation. All catechins were classified as nonembryotoxic except (-)-epigallocatechin gallate, which was classified as weakly embryotoxic. With (-)-epigallocatechin gallate, increased numbers of nonviable and apoptotic cells in the malformed embryos were associated with increased embryo 8-isoprostane.
authors.affiliation: Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Shatin, New Territories, Hong Kong. ccwang@cuhk.edu.hk
authors.forename: Chi Chiu
authors.initials: CC
authors.lastname: Wang
authors.forename: Kai On
authors.initials: KO
authors.lastname: Chu
authors.forename: Wai Sing
authors.initials: WS
authors.lastname: Chong
authors.forename: Wai Ying
authors.initials: WY
authors.lastname: Li
authors.forename: Chi Pui
authors.initials: CP
authors.lastname: Pang
authors.forename: Alisa S W
authors.initials: AS
authors.lastname: Shum
authors.forename: Tze Kin
authors.initials: TK
authors.lastname: Lau
authors.forename: Michael Scott
authors.initials: MS
authors.lastname: Rogers
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives* / Q000633:toxicity; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000378:metabolism; D004622:Embryo, Mammalian / Q000187:drug effects*; D005260:Female; D020287:In Situ Nick-End Labeling; D010936:Plant Extracts / Q000633:toxicity; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013662:Tea / Q000737:chemistry / Q000633:toxicity
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D013662:Tea; C075750:8-epi-prostaglandin F2alpha; D002392:Catechin; D015237:Dinoprost; C045651:epigallocatechin gallate