title: Effects of oolong tea on plasma antioxidative capacity in mice loaded with restraint stress assessed using the oxygen radical absorbance capacity (ORAC) assay.
abstract: In the present study, we investigated the antioxidative effect of oolong tea in vitro and in vivo using the oxygen radical absorbance capacity (ORAC) assay. An oolong tea extract, catechin and related compounds suppressed the oxidation of fluorescence induced by AAPH in a dose-dependent manner, that is, they prolonged the antioxidant time in vitro. Oral administration of the oolong tea extract to mice treated with restraint stress increased ORAC activity in plasma as compared with a stress control group. The extract also increased plasma vitamin C levels, and there was a good relationship between ORAC activity and the vitamin C level in plasma. The elevation of plasma ORAC and vitamin C level may have been related to the stress-relieving effect of oolong tea. These effects are probably due to the antioxidative properties of the tea. Thus, these findings suggested that oolong tea has beneficial effects on health related to its antioxidative action.
authors.affiliation: Institute of Traditional Chinese Medicine and Natural Products, Jinan University, Guangzhou, China. Hiroshi_Kurihara@suntory.co.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kurihara
authors.forename: Harukazu
authors.initials: H
authors.lastname: Fukami
authors.forename: Sumio
authors.initials: S
authors.lastname: Asami
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Toyoda
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nakai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shibata
authors.forename: Xin-Sheng
authors.initials: XS
authors.lastname: Yao
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000097:blood*; D012149:Restraint, Physical; D013312:Stress, Physiological / Q000097:blood*; D013662:Tea
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D013662:Tea; D001205:Ascorbic Acid