Description
6,7-dihydroxy Bergamottin (6,7-DHB) is a potent inhibitor of CYP3A4 (IC50 = 25 μM). It appears to be the primary compound in grapefruit juice that is responsible for inhibition of testosterone 6β-hydrolase activity. Ingestion of grapefruit juice during treatment regimes with drugs normally metabolized by cytochrome P450 enzymes of the CYP3A subfamily results in a substantial increase in plasma concentration of these agents. However, giving a patient grapefruit juice or just 6,7-DHB could be advantageous in cases where a drug is metabolized too quickly by CYP3A4.
Uses
6′,7′-dihydroxybergamottin has been used to study its effect on the inhibition of cytochrome P450 (CYP)-mediated triazolam hydroxylation in dog liver microsomes.
Uses
A minor metabolite of Bergamottin (B318400). Metabolization of Bergamottin by cytochromes P 450 2B6 and 3A5.
Uses
A minor metabolite of Bergamottin. Metabolization of Bergamottin by cytochromes P 450 2B6 and 3A5.
Definition
ChEBI: 6',7'-Dihydroxybergamottin is a member of psoralens.
Biochem/physiol Actions
CYP3A4 inhibitor.
in vitro
6,7-dhb significantly blocked the testosterone 6β-hydrolase in human liver microsomes and human cyp3a4 expressed in escherichia coli membrane in a time- and concentration-dependent manner. furthermore, 6,7-dhb proved to be a potent nadph- and time-dependent inhibitor of cyp3a4 [1]. 6,7-dhb concentration-dependently inhibited nifedipine (nfp) oxidation in hepg2-gs-3a4 cell, a cell line from hepatoblastoma with overexpression of human cyp3a4 [2].
in vivo
male wistar-st rats were intraduodenally administered with 6,7-dhb at a dose of 3.4 mg/ml. after 4 hours, 6,7-dhb had no significant effects on the nfp plasma concentrations, suggesting that 6,7-dhb had no pharmacokinetic effect on the rats [3].
References
[1]. bellevue, f., woster, p., edwards, d., he, k., & hollenberg, p. synthesis and biological evaluation of 6′,7′-dihydroxybergamottin (6,7-dhb), a naturally occurring inhibitor of cytochrome p450 3a4. bioorganic & medicinal chemistry letters. 1997; 7(20): 2593-2598.
[2]. araki, n., tsuruoka, s., hasegawa, g., yanagihara, h., omasa, t., & enosawa, s. et al. inhibition of cyp3a4 by 6′,7′-dihydroxybergamottin in human cyp3a4 over-expressed hepg2 cells. journal of pharmacy and pharmacology. 2012; 64(12): 1715-1721.
[3]. mohri, k., & uesawa, y. effects of furanocoumarin derivatives in grapefruit juice on nifedipine pharmacokinetics in rats. pharmaceutical research, 2001;18(2):177-182.
