Effects of Theabrownin from Pu‐erh Tea on the Metabolism of Serum Lipids in Rats: Mechanism of Action

Abstract

Theabrownin (TB), one of the main bioactive components in pu-erh tea, has a significant blood lipid-lowering effect in hyperlipidemic rats. Therefore, it was hypothesized that TB would regulate the activity of key enzymes involved in lipid metabolism and accelerate the catabolism of exogenous cholesterol in rats fed a high fat diet. A total of 90 Sprague-Dawley rats were randomly divided into a normal control group (Group I), a high fat diet group (Group II), and high-fat diet plus TB group (Group III). A total of 10 rats were selected from each group and killed at 15, 30, or 45 d after starting the study for analysis. After feeding 45 d, the contents of TC, TG, and LDL-C levels in Group II were increased by 54.9%, 93.1%, and 134.3% compared with those in Group III, respectively, and the content of HDL-C in Group II was decreased by 55.7%. These effects were inhibited in the rats in Group III, which exhibited no significant differences in these levels compared with Group I, indicating that TB can prevent hyperlipidemia in rats fed a high fat diet. TB enhanced the activity of hepatic lipase and hormone-sensitive triglyceride lipase (HSL) and increased the HSL mRNA expression in liver tissue and epididymis tissue. The HL activity in serum of Group III was increased by 147.6% compared with that in Group II. The content of cholesterol and bile acid in the feces of rats was increased by 21.11- and 4.08-fold by TB. It suggested that TB could promote the transformation and excretion of dietary cholesterol of rats in vivo.

Oxidized tea polyphenols prevent lipid accumulation in liver and visceral white adipose tissue in rats

“…Depending on their degree of fermentation, OTPs are known as theaflavins (TFs), thearubigin (TRs) and theabrownins (TBs) [17]. Theaflavins are the least oxidized tea polyphenols and are present in high concentrations in black tea, whereas theabrownins are highly oxidized tea polyphenols and the main bioactive component in pu-erh tea [18]. The TFs and TRs associated with black tea have been reported to have several health benefits, such as anti-obesity, hypocholesterolaemic and anti-diabetic properties [19][20][21][22][23].…”

Theagalloflavic Acid, a New Pigment Derived from Hexahydroxydiphenoyl Group, and Lignan Oxidation Products Produced by Aerobic Microbial Fermentation of Green Tea

“…Based on these spectroscopic and chemical results, the structure of yellow pigment 1 was determined as shown in Fig. 1 and named 4.63, H-7, H-7′), which were closely related to that of pinoresinol with a symmetric structure. 29) An important difference was observed in the aromatic region: two metacoupled aromatic doublets (H-2, H-2′) indicated the presence of a 3,4-dihydroxy-5-methoxy aromatic group.…”

“…In some parts of East Asia, aerobic and anaerobic microbial fermentation is applied to green tea or boiled tea leaves to produce tea products, which also decrease catechin concentrations. Although the importance of catechin degradation products has been reported recently, [2][3][4] little is known about the chemistry of products in fermented tea because of their complexity. Our research group has reported studies of enzymatic oxidation of catechins in black tea production [5][6][7] and hydrogenation of catechins in anaerobic microbial fermentation of green tea.…”

Isolation, Identification, and Biotransformation of Teadenol A from Solid State Fermentation of Pu-erh Tea and In Vitro Antioxidant Activity

“…Flavonoids [16], theabrownin (TB) [17,18], gallic acid (GA) [19], and statin [20] have anti-obesity/hypolipidemic effects and regulate lipid metabolism. Caffeine (CAF) [21] and polysaccharides [22,23] have blood glucose-lowering effects, and 8-C N-ethyl-2-pyrrolidinone substituted flavan-3-ols [24], ethanol-soluble pigment [25], polysaccharides [23,26], and phenolic compounds [27] (including GA, (+)-catechin, (-)-epicatechin, (-)-epicatechin-3-O-gallate, (-)-epigallocatechin-3-O-gallate (-)-epiafzelechin-3-O-gallate, kaempferol, and quercetin) have antioxidant properties.…”