Pharmacokinetic interaction study of sulphasalazine in healthy subjects and the impact of curcumin as an in vivo inhibitor of BCRP.
BACKGROUND AND PURPOSE An ATP-binding cassette (ABC) transporter, breast cancer resistance protein (BCRP)/ABCG2, limits oral bioavailability of sulphasalazine. Here we examined the effect of curcumin, the principal curcuminoid of turmeric, on oral bioavailability of microdoses and therapeutic doses of sulphasalazine in humans. EXPERIMENTAL APPROACH Effects of curcumin were measured on the ATP-dependent sulphasalazine uptake by hBCRP-expressing membrane vesicles and on oral bioavailability of sulphasalazine in wild-type and Bcrp(-/-) mice. Eight healthy Japanese subjects received an oral dose of sulphasalazine suspension (100 µg) or tablets (2 g) alone or after curcumin tablets (2 g). Uptake of sulphasalazine was studied in HEK293 cells transfected with the influx transporter (OATP)2B1. KEY RESULTS Curcumin was a potent hBCRP inhibitor in vitro (K(i) 0.70 ± 0.41 µM). Curcumin increased the area under the curve (AUC)(0-8) of plasma sulphasalazine eightfold in wild-type mice at 300 and 400 mg·kg(-1), but not in Bcrp(-/-) mice. Curcumin increased AUC(0-24) of plasma sulphasalazine 2.0-fold at microdoses and 3.2-fold at therapeutic doses in humans. Non-linearity of the dose-exposure relationship was observed between microdoses and therapeutic doses of sulphasalazine. Sulphasalazine was a substrate for OATP2B1 (K(m) 1.7 ± 0.3 µM). Its linear index (dose/K(m)) at the therapeutic dose was high and may saturate OATP2B1. CONCLUSIONS AND IMPLICATIONS Curcumin can be used to investigate effects of BCRP on oral bioavailability of drugs in humans. Besides the limited dissolution, OATP2B1 saturation is a possible mechanism underlying non-linearity in the dose-exposure relationship of sulphasalazine.
Laboratory of Molecular Pharmacokinetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
Hiroyuki
H
Kusuhara
Hidetoshi
H
Furuie
Akihiro
A
Inano
Akihiro
A
Sunagawa
Saiko
S
Yamada
Chunyong
C
Wu
Shinya
S
Fukizawa
Nozomi
N
Morimoto
Ichiro
I
Ieiri
Mariko
M
Morishita
Kiminobu
K
Sumita
Hiroshi
H
Mayahara
Takuya
T
Fujita
Kazuya
K
Maeda
Yuichi
Y
Sugiyama
D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001682:Biological Availability; D003474:Curcumin / Q000494:pharmacology*; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D057809:HEK293 Cells; D006801:Humans; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D027361:Organic Anion Transporters / Q000235:genetics; D012460:Sulfasalazine / Q000097:blood / Q000493:pharmacokinetics*; D014162:Transfection
D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; C501412:Abcg2 protein, mouse; D018076:DNA, Complementary; D027361:Organic Anion Transporters; C450859:SLCO2B1 protein, human; D012460:Sulfasalazine; D003474:Curcumin