Guoan Luo

Bio: Guoan Luo is an academic researcher from Tsinghua University. The author has contributed to research in topics: Epigallocatechin gallate & Fermented tea. The author has an hindex of 3, co-authored 3 publications receiving 101 citations.

Anti-obesity and hypolipidemic effects of Fuzhuan brick tea water extract in high-fat diet-induced obese rats

Abstract: Background Fuzhuan brick tea is a kind of microbial fermented tea, which has received increasing attention in recent years owing to its benefits for human health. In this study, the anti-obesity and hypolipidemic effects of Fuzhuan brick tea water extracts (FTEs) were investigated. Results FTEs consisted of 204.07 ± 3.38 mg g−1 polyphenol, 109.20 ± 1.36 mg g−1 flavonoids, and others. The FTEs significantly suppressed the increase of body weight and accumulation of adipose tissue, and reduced the level of serum triacylglycerol, total cholesterol and low-density lipoprotein (LDL) cholesterol in obese rats fed a high-fat diet. Moreover, FTEs attenuated the gene expression of sterol regulatory element binding protein-1c, fatty acid synthase and CCAAT/enhancer binding protein α, which is related to lipogenic metabolism. In contrast, the gene expressions of enzymes involved in energy expenditure and lipodieresis including hepatic peroxisome proliferator-activated receptor α, carnitine palmitoyltransferase 1a and LDL receptor gene expression were increased by FTE treatment. Conclusions Our study demonstrates that FTEs have anti-obesity and hypolipidemic functions, suggesting that it might be effective for treatment of obesity and hyperlipemia.

Proteomic analysis of the inhibitory effect of epigallocatechin gallate on lipid accumulation in human HepG2 cells

Abstract: Background (−)-Epigallocatechin-3-gallate (EGCG), the most abundant catechin found in green tea, effectively reduces body weight and tissue and blood lipid accumulation. To explore the mechanism by which EGCG inhibits cellular lipid accumulation in free fatty acid (FFA) induced HepG2 cell culture, we investigated the proteome change of FFA-induced HepG2 cells exposed to EGCG using two-dimensional gel electrophoresis and mass spectrometry.

Inhibiting effects of epigallocatechin gallate (EGCG) on the formation of age pigment in vitro and in vivo

Abstract: Lipofuscin age pigment is often considered as a hallmark of aging, which shows an accumulation rate inversely correlated with longevity and it is primarily composed of carbonyl-amino cross linked protein residues. The purpose of this study is to determine whether epigallocatechin gallate (EGCG) would inhibit the formation of age pigment in both MDA-modified human serum albumin and D-galactose-induced aging mice models by using spectrofluorometry, HPLC-PDA, FTIR spectrometer, SEM and TEM observation. Results showed that EGCG could inhibit the formation of age pigment in vitro and in vivo. The structure-activity relationship suggested that besides anti-oxidative stress and trapping the reactive unsaturated aldehydes, the inhibiting effects were correlated with the galloyl D-ring of tea catechins on neutralizing the amino-carbonyl cross-linking reaction. Key words: Epigallocatechin gallate (EGCG), age pigment, galloyl group, amino-carbonyl cross-linking products.

Kudingcha and Fuzhuan Brick Tea Prevent Obesity and Modulate Gut Microbiota in High-Fat Diet Fed Mice.

Abstract: Scope Kudingcha (KDC) from Ilex kudingcha and Fuzhuan brick tea (FBT) are popular beverages in China, and their preventive and therapeutic roles in metabolic disorders have been reported. However, the relationship between the gut microbiota modulatory effects of KDC and FBT and prevention of obesity is still not clearly understood. Methods and results KDC and FBT are tested individually for their capacities to prevent obesity and modulate the gut microbiota in high-fat diet (HFD) fed C57BL/6J mice. The results show that both KDC and FBT supplementation could modulate oxidative injury, inflammation, lipid metabolism, and reduce HFD induced obesity significantly. Both KDC and FBT could enhance the diversity of gut microbiota. KDC could reduce the relative abundance of Erysipelotrichaceae, while FBT could reduce the ratio of Firmicutes to Bacteroidetes and enhance the relative abundance of Bifidobacteriaceae. Conclusion These findings suggest that KDC and FBT could attenuate features of the metabolic syndrome in HFD-fed mice, which might be due to the modulation of gut microbiota by KDC and FBT.

Brick dark tea: a review of the manufacture, chemical constituents and bioconversion of the major chemical components during fermentation

Abstract: Brick dark tea is a unique brick-formed tea compressed from the older, coarse and rough leaves and branches of Camellia sinensis var. sinensis and C. sinensis var. assamica mainly in Hunan, Sichuan and Yunnan provinces in China. Researches on brick dark tea have become increasingly popular owing to its special health benefits. A series of biochemical reactions occur during the special production—microbial fermentation stage and multitudinous components have been detected. Many of the functional components have been isolated and identified from brick dark tea. In this paper, modern manufacturing techniques about different kinds of brick dark tea and their effects on transformation of the chemical constituents, as well as the chemical components were reviewed and discussed.