Organic Anion Transporting Polypeptides (OATPs) and pharmaconutrition

Y Coleman,

June 26, 2023

Organic Anion Transporting Proteins (OATPs) are influx transporters ie transport substrates from blood into organs and cells. OATPs can transport compounds that are relatively large and have a high degree of albumin binding under physiological conditions; they also mediate xenobiotic uptake.

In conjunction with the Organic Anion Transporters (OATs), the OATPs are important in hepatobiliary transport, renal secretion, intestinal absorption, and brain penetration of various compounds.


 – inducers – increase OATP activity; currently none have been identified.

 – inhibitors – slow or stop the rate of activity and transport.

– modulators – are compounds that interact with the OATPs to either enhance or reduce their activity.

– substrates – are compounds the OATPs transport; can also be inhibitors.

OATP Isoforms

There are 11 known isoforms of which –

  • OATP1B1 + OATP1B3 have been studied extensively,
  • OATP1A2 + OATP2B1 have limited data,
  • the other 7 polypeptides are not well defined.

Summary of nutrition-related findings for the 11 known isoforms –



has either a direct or indirect role in bile salt transport.


all major organs including intestines, liver, kidney, lung, bile duct, retina, placenta, prostate, testes, brain and Blood Brain Barrier.


retinoids, T4, T3, thyroxine, epicatechin gallate.


include flavonoids, Ginkgo flavonoids, apigenin, kaempferol, quercetin, fruit juice, naringin (in grapefruit and orange juice), hesperidin, grapefruit compounds (at a commonly consumed volume), apple juice, Camellia sinensis extract, epicatechin gallate, epigallocatechin gallate, catechins in green tea, pomelo juice.


Included in drug discovery processes to minimise drug-drug interactions


offers both monophasic (one binding site) and biphasic (two binding sites) capabilities.


basolateral surface of hepatocytes (liver), kidney, intestine, blood-brain barrier, placenta, however there are many claims that this transporter is liver-specific transporter under normal physiological conditions.


T4, T3, vitamin D3-glucuronide.