Green tea changes serum and liver metabolomic profiles in mice with high‐fat diet‐induced obesity

SCOPE: Green tea (GT) consumption helps to prevent and control obesity by stimulating hepatic lipid metabolism. However, GT-induced changes in serum and liver metabolomes associated with the anti-obesity effects are not clearly understood. The aim of this study was to identify and validate metabolomic profiles in the livers and sera of GT-fed obese mice to elucidate the relationship between GT consumption and obesity prevention. METHODS AND RESULTS: Serum and liver metabolites were analyzed in mice fed normal diet, high-fat diet (HFD), HFD with GT, and HFD with crude catechins, using LC-quadrupole TOF MS. The addition of 1% GT to HFD reduced adipose tissue and the levels of blood triglycerides, glucose, insulin, and leptin elevated in HFD-fed mice. We proposed an HFD-induced obesity pathway and validated it by investigating the key regulatory enzymes of mitochondrial β-oxidation: carnitine palmitoyltransferase-1 and -2, acyl-coenzyme A dehydrogenase, and acetyl-coenzyme A acyltransferase. The results showed that HFD-induced abnormal mitochondrial β-oxidation was moderated by the consumption of caffeine- and theanine-enriched GT. CONCLUSION: Results of LC/MS-based metabolomic analysis of obese mice showed changes associated with abnormal lipid and energy metabolism, which were alleviated by GT intake, indicating the mechanism underlying the anti-obesity effects of GT.