Effects of Zijuan pu-erh tea theabrownin on metabolites in hyperlipidemic rat feces by Py-GC/MS

This study investigated the effects of intragastric infusion with Zijuan pu-erh tea theabrownin (ZPTB) on ZPTB metabolites in rat feces, and the relationship between fecal metabolites and lipid metabolism in rats. Fifty Sprague-Dawley rats were randomly assigned to five intervention treatments: a normal diet alone (group I), high-lipid diet alone (group II), high-lipid diet combined with low-dose ZPTB intragastric infusion (group III), high-lipid diet combined with medium-dose ZPTB infusion (group IV), and high-lipid diet combined with high-dose ZPTB infusion (group V). Fecal samples were collected 72 h after intervention and freeze-dried to constant weight. Curie-point pyrolysis-gas chromatography/mass spectroscopy (Py-GC/MS) showed that fecal samples from the different groups contained different metabolites and at varying concentrations. The normal control group, high-lipid model group, and the low-, medium-, and high-dose ZPTB infusion groups had 47 (42.0% of all MS-identified metabolites with structural match qualities greater than 80%), 49 (66.72%), 41 (68.18%), 43 (66.6%), and 29 (58.39%) common metabolites to all groups. Ten metabolites were unique to groups consuming the high-lipid diet. Nine, 13, and 13 metabolites were unique to the low-, medium-, and high-dose ZPTB infusion group, respectively. These results demonstrate that Py-GC/MS can effectively detect marker metabolites in feces. The results also suggest that ZPTB increases the cholesterol-to-bile acids conversion in hepatocytes and stimulates the fecal excretion of cholesterol and its metabolites (bile acids, lipids, acids). Therefore, ZPTB may be effective at regulating lipid metabolism in animals and lowering the serum levels of total cholesterol, low-density cholesterol, and triglycerides.