Differential Effects of Chrysin on Nitrofurantoin Pharmacokinetics Mediated by Intestinal Breast Cancer Resistance Protein in Rats and Mice

Purpose. The activities of breast cancer resistance protein (Bcrp/ABCG2) as well as P-glycoprotein (P-gp) and drug-metabolizing enzymes can be inhibited by several flavonoids or drugs in rats. However, the species, sex and regional differences of effects of flavonoids on Bcrp/ABCG2 in rats and mice remain unclear, although Bcrp, like P-gp, is also important in controlling drug absorption and disposition. Methods. We used chrysin as a model flavonoid because it possesses anti-inflammatory and antioxidative properties and is used as a dietary supplement. We examined the pharmacokinetics of nitrofurantoin, a specific Bcrp substrate, after oral or intravenous administration in rats and mice treated with chrysin. Bcrp mRNA levels were measured in liver, kidney, duodenum, jejunum and ileum in rats and mice. Results. Oral chrysin increased plasma concentrations of nitrofurantoin in rats but not mice. Intraperitoneal injection of chrysin into rats or mice had little effect on the elimination of nitrofurantoin. The AUC(0-t) in female mice was 1.5-2.0 folds higher than in male mice after oral and intravenous administration of nitrofurantoin. Absorption of nitrofurantoin from apical to basal sides was significantly increased by chrysin in both duodenum and jejunum as well as in ileum in rat small intestine. Conclusions. Chrysin-nitrofurantoin interactions it takes place in the small intestine and occur in rats, but not in mice, possibly due to the higher levels of Bcrp in the small intestine in rats as compared with mice.