Efficacy and safety of Chinese black tea (Pu-Ehr) extract in healthy and hypercholesterolemic subjects

Background/Aims: Water-extracted Chinese black tea (Pu-Ehr) exerts a precipitating effect on mixed bile salt micelles in foods. The amount of black tea extract (BTE) effective for hypercholesterolemia (HC) was examined in humans. Materials and Methods: Animals (test 1) and humans (tests 2-5) were given BTE in the following studies: (test 1) an acute 2-week toxicity test conducted in mice with 2,000 mg/kg BTE or saline; (test 2) a dose-finding 8-week toxicity study with excessive BTE ingestion (0.75 or 1 g/day) in 10 healthy and 10 borderline HC subjects; (test 3) a 1-day acute toxicity test using a ( 10 g) single-bolus study (n = 10); (test 4) a 5-week long-term safety test (5 g/day, n = 11), and (test 5) a 4-month noncomparative study in 21 HC patients ingesting 1 g/day. Results: The safety study showed no changes in hematological or relevant biochemical parameters in both mice and humans in the acute and long-term toxicity tests. In test 5, significant reductions in total and low-density lipoprotein cholesterol levels accompanied by significant decreases in body weight were observed without affecting other biochemical parameters. Conclusions: BTE significantly reduced blood cholesterol levels in humans and may prove safe and useful in preventing and improving metabolic syndrome-induced arteriosclerosis and/or obesity. Copyright c 2008 S. Karger AG, Basel.