Screening of OATP1B1/3 and OCT1 inhibitors in cryopreserved hepatocytes in suspension

Eur J Pharm Sci. 2010 Jul 11;40(4):282-8. doi: 10.1016/j.ejps.2010.03.023. Epub 2010 Apr 8.


Drug-drug interactions involving hepatic drug transporters may have clinical consequences and jeopardize development of promising drug candidates. Organic anion transporting polypeptides (OATP/Oatp) and the organic cation transporters (OCT/Oct) are among the most important transporters involved in xenobiotic uptake in the liver. In the present study, 179 molecules have been tested as inhibitors of the uptake of estradiol-17betaD-glucuronide (E(2)17betaG), substrate of OATP1B1/3 (rOatp), or 1-methyl-4-phenylpyridinium (MPP+), substrate of OCT1 (rOct1), into suspended cryopreserved hepatocytes from humans and rats. Uptake was assessed in 96-well plates by measuring intracellular accumulation of radioactive substrate in hepatocytes in presence or absence of inhibitor. In rat hepatocytes 140 compounds were identified as inhibitors (inhibition at 20 microM > or = 30%) of E(2)17betaG uptake and 77 compounds inhibitors of MPP+ uptake. The most potent inhibitors of rOatp and rOct1 were dantrolene sodium (K(i)=2 +/- 9 microM) and bepridil (K(i)=14 +/- 2 microM), respectively. In human hepatocytes, the most potent inhibitors of E(2)17betaG and MPP+ uptake were capsazepine (K(i)=14 +/- 5 microM) and cyproheptadine (K(i)=19+/-3 microM), respectively. Structure-activity relationship (SAR) analysis of all tested compounds suggested that lipophilicity, polarity, pK(a) and the number of hydrogen bond donors and acceptors play a role in their interaction with the transporters investigated. The method used here is a simple tool to screen large number of compounds as inhibitors of the uptake of substrates into suspended hepatocytes.

MeSH terms

  • 1-Methyl-4-phenylpyridinium / pharmacokinetics*
  • Animals
  • Bepridil / pharmacology
  • Biological Transport / drug effects
  • Capsaicin / analogs & derivatives
  • Capsaicin / pharmacology
  • Cryopreservation
  • Cyproheptadine / pharmacology
  • Dantrolene / pharmacology
  • Drug Evaluation, Preclinical
  • Drug Interactions
  • Enzyme Inhibitors / pharmacology*
  • Estradiol / analogs & derivatives*
  • Estradiol / pharmacokinetics
  • Hepatocytes / drug effects*
  • Hepatocytes / enzymology
  • Hepatocytes / metabolism
  • Humans
  • Isoenzymes / antagonists & inhibitors
  • Liver-Specific Organic Anion Transporter 1
  • Organic Anion Transporters / antagonists & inhibitors*
  • Organic Anion Transporters, Sodium-Independent / antagonists & inhibitors*
  • Rats
  • Solute Carrier Organic Anion Transporter Family Member 1B3
  • Species Specificity
  • Structure-Activity Relationship


  • Enzyme Inhibitors
  • Isoenzymes
  • Liver-Specific Organic Anion Transporter 1
  • Organic Anion Transporters
  • Organic Anion Transporters, Sodium-Independent
  • SLCO1B1 protein, human
  • SLCO1B3 protein, human
  • Solute Carrier Organic Anion Transporter Family Member 1B3
  • estradiol-17 beta-glucuronide
  • Cyproheptadine
  • Estradiol
  • Bepridil
  • Dantrolene
  • capsazepine
  • 1-Methyl-4-phenylpyridinium
  • Capsaicin