title: Green tea extract improves endurance capacity and increases muscle lipid oxidation in mice.
abstract: Green tea contains a high level of polyphenolic compounds known as catechins. We investigated the effects of green tea extract (GTE), which is rich in catechins, on endurance capacity, energy metabolism, and fat oxidation in BALB/c mice over a 10-wk period. Swimming times to exhaustion for mice fed 0.2-0.5% (wt/wt) GTE were prolonged by 8-24%. The effects were dose dependent and accompanied by lower respiratory quotients and higher rates of fat oxidation as determined by indirect calorimetry. In addition, feeding with GTE increased the level of beta-oxidation activity in skeletal muscle. Plasma lactate concentrations in mice fed GTE were significantly decreased after exercise, concomitant with increases in free fatty acid concentrations in plasma, suggesting an increased lipid use as an energy source in GTE-fed mice. Epigallocatechin gallate (EGCG), a major component of tea catechins, also enhanced endurance capacity, suggesting that the endurance-improving effects of GTE were mediated, at least in part, by EGCG. The beta-oxidation activity and the level of fatty acid translocase/CD36 mRNA in the muscle was higher in GTE-fed mice compared with control mice. These results indicate that GTE are beneficial for improving endurance capacity and support the hypothesis that the stimulation of fatty acid use is a promising strategy for improving endurance capacity.
authors.affiliation: Biological Science Laboratories, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan. murase.takatoshi@kao.co.jp
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Murase
authors.forename: Satoshi
authors.initials: S
authors.lastname: Haramizu
authors.forename: Akira
authors.initials: A
authors.lastname: Shimotoyodome
authors.forename: Azumi
authors.initials: A
authors.lastname: Nagasawa
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tokimitsu
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology; D000818:Animals; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000187:drug effects; D005227:Fatty Acids / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D050356:Lipid Metabolism; D008297:Male; D008660:Metabolism / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D018482:Muscle, Skeletal / Q000378:metabolism*; D009929:Organ Size / Q000187:drug effects; D010084:Oxidation-Reduction / Q000187:drug effects; D010807:Physical Endurance / Q000187:drug effects*; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D013550:Swimming; D013662:Tea / Q000737:chemistry*
chemical_list: D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D010936:Plant Extracts; D012333:RNA, Messenger; D013662:Tea; D019344:Lactic Acid; D002392:Catechin; C045651:epigallocatechin gallate