Green tea extract improves endurance capacity and increases muscle lipid oxidation in mice

Murase, Takatoshi; Haramizu, Satoshi; Shimotoyodome, Akira; Nagasawa, Azumi; Tokimitsu, Ichiro

doi:10.1152/ajpregu.00693.2004

Cited by 172 publications

(161 citation statements)

References 46 publications

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“…EGCG can modulate insulin secretion and insulin sensitivity (16,17). EGCG has also been shown in skeletal muscle to promote fatty acid oxidation (18). Furthermore, EGCG has been suggested to reduce blood pressure through enhancing vascular endothelial function and insulin sensitivity (19).…”

Section: Epigallocatechin-3-gallate (Egcg)mentioning

confidence: 99%

Epigallocatechin-3-gallate (EGCG), A Green Tea Polyphenol, Suppresses Hepatic Gluconeogenesis through 5′-AMP-activated Protein Kinase

Collins

Liu

et al. 2007

Journal of Biological Chemistry

305

224

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Epigallocatechin-3-gallate (EGCG), a main catechin of green tea, has been suggested to inhibit hepatic gluconeogenesis. However, the exact role and related mechanism have not been established. In this study, we examined the role of EGCG in hepatic gluconeogenesis at concentrations that are reachable by ingestion of pure EGCG or green tea, and are not toxic to hepatocytes. Our results show in isolated hepatocytes that EGCG at relatively low concentrations (<1 M) inhibited glucose production via gluconeogenesis and expression of key gluconeogenic genes. EGCG was not toxic at these concentrations while demonstrating significant cytotoxicity at 10 M and higher concentrations. EGCG at 1 M or lower concentrations effective in suppressing hepatic gluconeogenesis did not activate the insulin signaling pathway, but activated 5-AMP-activated protein kinase (AMPK). The EGCG suppression of hepatic gluconeogenesis was prevented by blockade of AMPK activity. In defining the mechanism by which EGCG activates AMPK, we found that the EGCG activation of AMPK was mediated by the Ca 2؉ /calmodulin-dependent protein kinase kinase (CaMKK). Furthermore, our results show that the EGCG activation of AMPK and EGCG suppression of hepatic gluconeogenesis were both dependent on production of reactive oxygen species (ROS), which was a known activator of CaMKK. Together, our results demonstrate an inhibitory role for EGCG in hepatic gluconeogenesis and shed new light on the mechanism by which EGCG suppresses gluconeogenesis.

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Section: Epigallocatechin-3-gallate (Egcg)mentioning

confidence: 99%

Epigallocatechin-3-gallate (EGCG), A Green Tea Polyphenol, Suppresses Hepatic Gluconeogenesis through 5′-AMP-activated Protein Kinase

Collins

Liu

et al. 2007

Journal of Biological Chemistry

305

224

View full text Add to dashboard Cite

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“…[21][22][23] Briefly, we used an acrylic pool (length Â width Â depth: 90 Â 45 Â 45 cm 3 ) filled with water to a depth of 38 cm. The current in the pool was generated by a pump (type C-P60H; Hitachi, Tokyo, Japan), and the strength was adjusted using a valve.…”

Section: Swimming Exmentioning

confidence: 99%

“…23 Hence, repeated exposure to increased plasma fatty acids during Ex might produce adaptive changes that stimulate lipid catabolism. Catecholamines released from sympathetic nerves promote lipid mobilization and thermogenesis via b3-adrenoreceptors.…”

Section: Obesity Suppression and Tea Catechins T Murase Et Almentioning

confidence: 99%

Reduction of diet-induced obesity by a combination of tea-catechin intake and regular swimming

et al. 2005

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Objective: Obesity is a metabolic disorder resulting from imbalance between metabolizable energy intake and energy expenditure. It is known to be a strong risk factor for lifestyle-related diseases. Here, we investigated the effects of long-term intake of tea catechins (Cat) in combination with regular exercise (Ex) on the development of obesity in C57BL/6 mice. Design: We compared body weight, adipose tissue mass, plasma parameters and b-oxidation activity in mice fed a low-fat diet (5% triglyceride (TG); LF), a high-fat diet (30% TG; HF), a HF diet supplemented with 0.5% (w/w) tea Cat, a HF diet in addition to swimming Ex or a HF diet plus 0.5% tea Cat in addition to swimming Ex (Cat þ Ex) for 15 weeks. Oxygen consumption and respiratory quotients were measured using indirect calorimetry. Results: Tea-Cat intake in combination with swimming Ex suppressed HF diet-induced body-weight gain by 18 and 22%, respectively, compared to Ex and tea-Cat intake on their own. Visceral fat accumulation and the development of hyperinsulinemia and hyperleptinemia were also reduced in the HF þ Cat þ Ex group. Muscular b-oxidation activity in this group was 69 and 52% higher, respectively, than that in the HF and HF þ Cat groups. Lipid oxidation, determined using indirect calorimetry, was higher in the HF þ Cat þ Ex group, suggesting increased lipid utilization at the individual level. Conclusion: These results indicate that intake of tea Cat, together with regular Ex helps to reduce diet-induced obesity. This effect might be attributed, at least in part, to the activation of whole-body energy metabolism.

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“…28) In addition, Murase et al reported that green tea extract, which contains high levels of polyphenolic compounds, increased fatty acid beta-oxidation in the liver and muscles of mice. 29,30) Li et al also showed that green tea leaf extract enhanced hepatic expression of lipolytic transcriptional factor PPAR-alpha and improved lipid homeostasis in a fructose-fed insulin-resistant hamster model. 31) In addition, previous reports have indicated that BBL contains a variety of phenolic compounds, such as chlorogenic acid, quercetin, caffeic acid, and procyanidins, and has oxygen radical absorbance capacity and antileukaemic activity.…”

mentioning

confidence: 98%

Effect ofVaccinium ashei readeLeaves on Lipid Metabolism in Otsuka Long-Evans Tokushima Fatty Rats

Nagao

Higa

Shirouchi

et al. 2008

Bioscience, Biotechnology, and Biochemistry

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The effects of blueberry leaf (BBL) on lipid metabolism were studied in obese rats. Feeding of BBL lowered levels of serum lipids and C-reactive protein and alleviated hepatic triglyceride accumulation in the rats. The hypolipidemic effect might be attributable to a reduction of lipogenesis and enhancement of lipolysis in the liver. These results suggest the use of blueberry leaf as a dietary hypolipidemic component.Key words: Vaccinium ashei reade; blueberry leaf; lipid metabolism; Otsuka Long-Evans Tokushima Fatty ratLifestyle-related diseases, such as hyperlipidemia, arteriosclerosis, diabetes mellitus, and hypertension, are widespread and increasingly prevalent diseases in industrialized countries, and they contribute to increases in cardiovascular morbidity and mortality. 1,2) Accompanied by rapid increases in the numbers of elderly people, this is important not only medically but also socioeconomically. Although the pathogenesis of lifestyle-related diseases is complicated and the precise mechanisms have not yet been elucidated, obesity has emerged as a major cardiovascular risk factor according to epidemiologic studies. [3][4][5] Obesity is defined as an increased mass of adipose tissue, and its prevalence and severity are markedly increasing in westernized countries. Otsuka Long-Evans Tokushima Fatty (OLETF) rats develop a syndrome with multiple metabolic and hormonal disorders that shares many features with human obesity. 6-9) OLETF rats have hyperphagia because they lack receptors for cholecystokinin, and become obese, developing hyperlipidemia, fatty liver, and type-2 diabetes. In this study, we examined effects of blueberry leaf (BBL) on lipid metabolism in obese OLETF rats.Vaccinium ashei reade (blueberry) belongs to the Ericaceae plant group, and infusions of its leaf are used as a folk medicine treatment for lifestyle-related diseases in Europe. 10,11) Martineau et al. demonstrated anti-diabetic properties of the Canadian lowbush blueberry in vitro. 11) Recently, we reported that blueberry leaf revealed strong inhibitory effects on angiotensinconverting enzyme activity in vitro, and that feeding of blueberry leaf suppressed the development of essential hypertension in spontaneously hypertensive rats in vivo. 12) The effects of blueberry leaf on lipid metabolism, however, have not been fully evaluated.To determine the physiological function of BBL, we evaluated the effect of BBL feeding on hepatic enzyme activities in relation to lipid metabolism in obese OLETF rats.Four-week-old male OLETF rats were provided by the Tokusima Research Institute (Otsuka Pharmaceutical, Tokushima, Japan). The rats were housed individually in metal cages in a temperature-controlled room (24 C) under a 12-h light/dark cycle. After a 1-week adaptation period on a powder chow diet (CE-2, Clea Japan, Tokyo), they were assigned to three groups (six rats each), each fed one of three diets: (i) a semisynthetic diet containing (in weight %) casein, 20; corn oil, 7; cornstarch, 15; vitamin mixture (AIN-76Ô), 1; mineral mixture ...

show abstract

Green tea extract improves endurance capacity and increases muscle lipid oxidation in mice

Cited by 172 publications

References 46 publications

Epigallocatechin-3-gallate (EGCG), A Green Tea Polyphenol, Suppresses Hepatic Gluconeogenesis through 5′-AMP-activated Protein Kinase

Epigallocatechin-3-gallate (EGCG), A Green Tea Polyphenol, Suppresses Hepatic Gluconeogenesis through 5′-AMP-activated Protein Kinase

Reduction of diet-induced obesity by a combination of tea-catechin intake and regular swimming

Effect ofVaccinium ashei readeLeaves on Lipid Metabolism in Otsuka Long-Evans Tokushima Fatty Rats

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