(-)-Epigallocatechin-3-gallate Inhibits Human and Rat Renal Organic Anion Transporters.

Organic anion transporter 1 (OAT1, SLC22A6) and 3 (OAT3, SLC22A8) are multispecific drug transporters highly expressed on the basolateral membranes of the renal proximal tubules. OAT1 and OAT3 mediate the tubular secretion of clinically significant drugs; thus, they influence the pharmacokinetics of drugs and further determine their efficacy and toxicity. OAT1 and OAT3 are also the target of drug-drug interactions. In this study, we examined the effects of the tea catechin (-)-epigallocatechin-3-gallate (EGCG) on human (h) and rat (r) OAT1 and OAT3 using the fluorescent organic anion 6-carboxyfluorescein (6-CF) and hOAT1-, hOAT3-, rOat1-, or rOat3-expressing HEK293 cells and on renal elimination of 6-CF in rats. 6-CF is transported by hOAT1, hOAT3, rOat1, and rOat3. 6-CF is urinary excreted by Oats in rats. EGCG, a dominant catechin in green tea leaf, inhibits human and rat OAT1 and OAT3 and reduces the renal elimination of 6-CF in rats. Our findings are useful for the assessment of food-drug interactions mediated by renal OATs.