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.