Green Tea Catechins -Pharmacokinetic Properties and Health Beneficial Effects

Abstract

In this review, we provide information on thepharmacokinetic properties of green tea catechins and their beneficial health effects. The major catechins in green tea are (-)-epicatechin (EC), its hydroxyl deriv. (-)-epigallocatechin (EGC), and their gallic acid esters, (-)-epicatechin-3-gallate (ECg) and (-)-epigallocatechin-3-gallate (EGCg). We developed an anal. method for detn. of the presence of green tea catechins in human serum using ion-pair HPLC with electrochem. detection to est. the pharmacokinetic parameters of target catechins. The Cmax values indicated that catechin absorption was relatively low. One of the gallatedcatechins, EGCg, had a longer half-life than the non-gallatedcatechins. Green tea catechins, in particular, have attracted attention as cancer preventive agents in terms of their low toxicity and being readily available to the general population. Several epidemiol. studies revealed that green tea consumption reduces cancer incidence. Numerous in vitro cell culture studies have shown that EGCg, which is defined as a major green tea catechin contributing to green tea's anticancer effects, inhibits cell growth concomitant with induction of apoptosis. We have previously found that the cell death-inhibiting gene, Bcl-xL, was decreased by EGCg. These results support the hypothesis that EGCg regulates cytoplasmic NF-κB and subsequently induction of apoptosis. Green tea consumption may also play a role in preventing other lifestyle diseases, such as cardiovascular diseases and stroke, due to its hypocholesterolemic and hypotensive activities. In conclusion, habitual green tea drinking may promote human health by preventing lifestyle-related diseases. [on SciFinder(R)]