The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 13 No.
5 • October 2010
Theabrownin May Be the Main Bioactive Molecule in Pu-erh Tea;
Has Significant Blood Lipid-Lowering Effects
Although pu-erh tea is made from Camillia sinensis, the same plant whose leaves are used to derive white, green, oolong, and black teas, it is produced by different, more complex and often lengthy fermentation and heat treatment processes resulting in a tea with a different flavor and some differences in component ingredients as compared to the other teas. Pu-erh tea has been shown to have anti-obesity, hypolipidemic, and hypocholesterolemic effects. Recently, a paper has identified an ingredient, theabrownin, that may be the main bioactive component in pu-erh tea. This rust-brown colored pigment is also found in black tea but at lower concentrations (4% to 9% in black tea as compared to 10% to 14% in pu-erh tea).
Recent studies performed by and cited by the authors of paper #2 have shown that theabrownin (TB) fractionated from pu-erh tea has a significant blood lipid-lowering effect, reducing serum triglyceride, total cholesterol and low density lipoprotein (LDL), while increasing HDL in rats fed a high fat diet (though not in those on a normal diet). The authors hypothesized that these effects were a result of alterations by TB in key enzymes involved in lipid metabolism and/or on cholesterol breakdown and excretion. (The authors explain that the high fat test diet contained added fat and cholesterol and also had small amounts of bile salts added to “help” the rats to absorb the cholesterol contained in the diets because rats do not absorb cholesterol very well, not nearly as well as rabbits. Next time, they say, they will use rabbits! Perhaps they did not have enough money to do so this time.)
The results showed that the rats fed TB-supplemented high fat diet were prevented from developing the diet-induced increases in serum total cholesterol, triglycerides, and LDL cholesterol as compared to the rats fed the high fat diet without TB. The TB-supplemented high fat diet fed rats also maintained their HDL at the same level as the control rats fed the regular (no added fat and cholesterol and no added bile salts) diet, and had HDL more than twice that of the decreased levels in the unsupplemented rats fed the high fat diet. TB supplementation caused an increase in the activity of hepatic lipase and hormone- sensitive triglyceride lipase, which the authors propose is important in the cholesterol reducing effects of the TB.
Theabrownin Dramatically Increased Excretion of Cholesterol
The feces of the TB-supplemented high fat diet fed rats had greatly increased levels of cholesterol and bile acids (21.11- and 4.08-fold greater, respectively) as compared to the unsupplemented high fat diet fed rats, thus demonstrating a huge increase by TB in the excretion of cholesterol. Moreover, TB “alleviated and slowed” the liver pathology (fatty liver) that ordinarily occurs in rats fed a high fat diet and indeed was induced in the rats on the high fat diet without TB.
Though we subscribe to many scientific journals, including some (such as Lipids and J Lipid Res) that are specifically devoted to research on lipids, we do not often find research on pu-erh tea (most of which is done in China and published in Chinese). We hope that there will be more such research; we are particularly interested in its lipogenesis (fat synthesis) inhibiting effects, which is why we include pu-erh tea in our special selection of teas formulation for helping reach and maintain a healthy body fat content.
- Ku et al. Application of metabolomics in the analysis of manufacturing type of pu-erh tea and composition changes with different postfermentation year. J Agric Food Chem 58:345-352 (2010).
- Gong et al. Effects of theabrownin from pu-erh tea on the metabolism of serum lipids in rats: mechanism of action. J Food Sci 75(6):H182-H189 (2010).
- Way et al. Pu-erh tea attenuates hyperlipogenesis and induces hepatoma cells growth arrest through activating AMP- activated protein kinase (AMPK) in human HepG2 cells. J Agric Food Chem 57:5257-5264 (2009).
- Hou et al. Pu-erh tea aqueous extracts lower atherosclerotic risk factors in a rat hyperlipidemia model. Exp Gerontol 44:434-439 (2009).