Rat organic cation transporter 1 / Oct1

evidence_span

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experimental_model

Rat Oct1-transfected CHO uptake kinetics and Oct1-knockout mouse tissue distribution

exposure

Intravenous metformin in Oct1(-/-) and Oct1(+/+) mice; buformin and phenformin compared in vitro

limitations

Transporter assignment in rodents. Affinities are assay values, not human tissue concentrations, and renal handling was governed by other transporters in this model.

nutrient_topic

Metformin research collection; topical membership is not evidence of a direct clinical effect, and pharmacological exposure is not dietary intake. · Metformin

organism

Rat transporter in CHO cells; mouse in vivo

plain_language

Other biguanides use the same carrier, and they bind it more tightly than metformin does.

primary_references

[metformin-p12130709] Involvement of organic cation transporter 1 in hepatic and intestinal distribution of metformin. (2002). https://pubmed.ncbi.nlm.nih.gov/12130709/ DOI: 10.1124/jpet.102.034140

tissue_or_cell_type

Liver, small intestine and kidney

transport_effect

raises Buformin transported into the expressing cell with a Km of 49 micromolar.

transport_pool

the expressing cell Buformin transported into the expressing cell with a Km of 49 micromolar.

Metformin: transport, molecular targets, gut mechanisms and nutrient interactions (2026-09-19) · lines 73–84

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Rat Oct1-transfected CHO uptake kinetics and Oct1-knockout mouse tissue distribution · source_derived_draft · unverified_draft

### metformin-rat-oct1-buformin Rat Oct1 also transported buformin with a Km of 49 microM, a higher affinity than for metformin. Condition category: normal nutrient_topic: Metformin research collection; topical membership is not evidence of a direct clinical effect, and pharmacological exposure is not dietary intake. plain_language: Other biguanides use the same carrier, and they bind it more tightly than metformin does. organism: Rat transporter in CHO cells; mouse in vivo tissue_or_cell_type: Liver, small intestine and kidney experimental_model: Rat Oct1-transfected CHO uptake kinetics and Oct1-knockout mouse tissue distribution limitations: Transporter assignment in rodents. Affinities are assay values, not human tissue concentrations, and renal handling was governed by other transporters in this model. exposure: Intravenous metformin in Oct1(-/-) and Oct1(+/+) mice; buformin and phenformin compared in vitro evidence_span: {"source_cache": "artifacts/metformin-research/12130709.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2bd4b1f58d2b0b30807a1a521298f4713a86049a53f62cfc5d6463927644d82b", "start_char": 0, "end_char": 1411, "text_sha256": "2bd4b1f58d2b0b30807a1a521298f4713a86049a53f62cfc5d6463927644d82b"} [metformin-p12130709] Involvement of organic cation transporter 1 in hepatic and intestinal distribution of metformin. (2002). https://pubmed.ncbi.nlm.nih.gov/12130709/ DOI: 10.1124/jpet.102.034140

evidence_span

{"source_cache": "artifacts/metformin-research/12130709.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2bd4b1f58d2b0b30807a1a521298f4713a86049a53f62cfc5d6463927644d82b", "start_char": 0, "end_char": 1411, "text_sha256": "2bd4b1f58d2b0b30807a1a521298f4713a86049a53f62cfc5d6463927644d82b"}

experimental_model

Rat Oct1-transfected CHO uptake kinetics and Oct1-knockout mouse tissue distribution

exposure

Intravenous metformin in Oct1(-/-) and Oct1(+/+) mice; buformin and phenformin compared in vitro

limitations

Transporter assignment in rodents. Affinities are assay values, not human tissue concentrations, and renal handling was governed by other transporters in this model.

nutrient_topic

Metformin research collection; topical membership is not evidence of a direct clinical effect, and pharmacological exposure is not dietary intake. · Metformin

organism

Rat transporter in CHO cells; mouse in vivo

plain_language

Other biguanides use the same carrier, and they bind it more tightly than metformin does.

primary_references

[metformin-p12130709] Involvement of organic cation transporter 1 in hepatic and intestinal distribution of metformin. (2002). https://pubmed.ncbi.nlm.nih.gov/12130709/ DOI: 10.1124/jpet.102.034140

tissue_or_cell_type

Liver, small intestine and kidney

transport_effect

raises Phenformin transported into the expressing cell with a Km of 16 micromolar.

transport_pool

the expressing cell Phenformin transported into the expressing cell with a Km of 16 micromolar.

Metformin: transport, molecular targets, gut mechanisms and nutrient interactions (2026-09-19) · lines 86–97

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Rat Oct1-transfected CHO uptake kinetics and Oct1-knockout mouse tissue distribution · source_derived_draft · unverified_draft

### metformin-rat-oct1-phenformin Rat Oct1 also transported phenformin with a Km of 16 microM, a higher affinity than for metformin. Condition category: normal nutrient_topic: Metformin research collection; topical membership is not evidence of a direct clinical effect, and pharmacological exposure is not dietary intake. plain_language: Other biguanides use the same carrier, and they bind it more tightly than metformin does. organism: Rat transporter in CHO cells; mouse in vivo tissue_or_cell_type: Liver, small intestine and kidney experimental_model: Rat Oct1-transfected CHO uptake kinetics and Oct1-knockout mouse tissue distribution limitations: Transporter assignment in rodents. Affinities are assay values, not human tissue concentrations, and renal handling was governed by other transporters in this model. exposure: Intravenous metformin in Oct1(-/-) and Oct1(+/+) mice; buformin and phenformin compared in vitro evidence_span: {"source_cache": "artifacts/metformin-research/12130709.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2bd4b1f58d2b0b30807a1a521298f4713a86049a53f62cfc5d6463927644d82b", "start_char": 0, "end_char": 1411, "text_sha256": "2bd4b1f58d2b0b30807a1a521298f4713a86049a53f62cfc5d6463927644d82b"} [metformin-p12130709] Involvement of organic cation transporter 1 in hepatic and intestinal distribution of metformin. (2002). https://pubmed.ncbi.nlm.nih.gov/12130709/ DOI: 10.1124/jpet.102.034140

evidence_span

{"source_cache": "artifacts/metformin-research/12130709.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2bd4b1f58d2b0b30807a1a521298f4713a86049a53f62cfc5d6463927644d82b", "start_char": 0, "end_char": 1411, "text_sha256": "2bd4b1f58d2b0b30807a1a521298f4713a86049a53f62cfc5d6463927644d82b"}

experimental_model

Rat Oct1-transfected CHO uptake kinetics and Oct1-knockout mouse tissue distribution

exposure

Intravenous metformin in Oct1(-/-) and Oct1(+/+) mice; buformin and phenformin compared in vitro

limitations

Transporter assignment in rodents. Affinities are assay values, not human tissue concentrations, and renal handling was governed by other transporters in this model.

nutrient_topic

Metformin research collection; topical membership is not evidence of a direct clinical effect, and pharmacological exposure is not dietary intake. · Metformin

organism

Rat transporter in CHO cells; mouse in vivo

plain_language

The drug does not simply diffuse into a cell; a named transporter carries it.

primary_references

[metformin-p12130709] Involvement of organic cation transporter 1 in hepatic and intestinal distribution of metformin. (2002). https://pubmed.ncbi.nlm.nih.gov/12130709/ DOI: 10.1124/jpet.102.034140

tissue_or_cell_type

Liver, small intestine and kidney

transport_effect

raises Time-dependent saturable metformin uptake in CHO cells with a Km of 377 micromolar.

transport_pool

the expressing cell Time-dependent saturable metformin uptake in CHO cells with a Km of 377 micromolar.

Metformin: transport, molecular targets, gut mechanisms and nutrient interactions (2026-09-19) · lines 60–71

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Rat Oct1-transfected CHO uptake kinetics and Oct1-knockout mouse tissue distribution · source_derived_draft · unverified_draft

### metformin-rat-oct1-uptake Rat Oct1 expression produced time-dependent and saturable metformin uptake in CHO cells, with a Km of 377 microM. Condition category: normal nutrient_topic: Metformin research collection; topical membership is not evidence of a direct clinical effect, and pharmacological exposure is not dietary intake. plain_language: The drug does not simply diffuse into a cell; a named transporter carries it. organism: Rat transporter in CHO cells; mouse in vivo tissue_or_cell_type: Liver, small intestine and kidney experimental_model: Rat Oct1-transfected CHO uptake kinetics and Oct1-knockout mouse tissue distribution limitations: Transporter assignment in rodents. Affinities are assay values, not human tissue concentrations, and renal handling was governed by other transporters in this model. exposure: Intravenous metformin in Oct1(-/-) and Oct1(+/+) mice; buformin and phenformin compared in vitro evidence_span: {"source_cache": "artifacts/metformin-research/12130709.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2bd4b1f58d2b0b30807a1a521298f4713a86049a53f62cfc5d6463927644d82b", "start_char": 0, "end_char": 1411, "text_sha256": "2bd4b1f58d2b0b30807a1a521298f4713a86049a53f62cfc5d6463927644d82b"} [metformin-p12130709] Involvement of organic cation transporter 1 in hepatic and intestinal distribution of metformin. (2002). https://pubmed.ncbi.nlm.nih.gov/12130709/ DOI: 10.1124/jpet.102.034140

evidence_span

{"source_cache": "artifacts/berberine-research/25359200.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "e46385d733a3c5fc9c39b89a27ef7ca62d228258ae47bb605c6a86eca68ee8db", "start_char": 0, "end_char": 1353, "text_sha256": "e46385d733a3c5fc9c39b89a27ef7ca62d228258ae47bb605c6a86eca68ee8db"}

experimental_model

Transporter-expressing cells and intravenous rat pharmacokinetics

exposure

Intravenous metformin 2 mg/kg and berberine 10 mg/kg in rats; in-vitro concentration-response

limitations

HEK293 is the host cell, not proof that the expressed transporter is human; the indexed proteins are rat Slc22a1/Slc22a2. Intravenous rat results cannot determine an oral human interaction. Assayed substrate was metformin, not thiamine.

nutrient_topic

Berberine research collection; topical membership is not evidence of a direct dietary effect. · Berberine

organism

Rat OCT1/2 in HEK293 cells and rats; rat protein identity indexed in primary-publication chemical records

plain_language

Transport inhibition is a distinct interaction mechanism from liver CYP inhibition.

primary_references

[berberine-p25359200] Organic cation transporter-mediated drug-drug interaction potential between berberine and metformin. (2015). https://pubmed.ncbi.nlm.nih.gov/25359200/ DOI: 10.1007/s12272-014-0510-6

tissue_or_cell_type

Metformin uptake and disposition

Berberine: metabolism, nutrient connections and drug interactions (2026-09-17) · lines 766–777

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Transporter-expressing cells and intravenous rat pharmacokinetics · source_derived_draft · unverified_draft

### berberine-metformin-rat-slc22a1 Berberine inhibited rat OCT1-mediated metformin uptake in transfected cells, with reported IC50 7.28 micromolar. Condition category: normal nutrient_topic: Berberine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Transport inhibition is a distinct interaction mechanism from liver CYP inhibition. organism: Rat OCT1/2 in HEK293 cells and rats; rat protein identity indexed in primary-publication chemical records tissue_or_cell_type: Metformin uptake and disposition experimental_model: Transporter-expressing cells and intravenous rat pharmacokinetics limitations: HEK293 is the host cell, not proof that the expressed transporter is human; the indexed proteins are rat Slc22a1/Slc22a2. Intravenous rat results cannot determine an oral human interaction. Assayed substrate was metformin, not thiamine. exposure: Intravenous metformin 2 mg/kg and berberine 10 mg/kg in rats; in-vitro concentration-response evidence_span: {"source_cache": "artifacts/berberine-research/25359200.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "e46385d733a3c5fc9c39b89a27ef7ca62d228258ae47bb605c6a86eca68ee8db", "start_char": 0, "end_char": 1353, "text_sha256": "e46385d733a3c5fc9c39b89a27ef7ca62d228258ae47bb605c6a86eca68ee8db"} [berberine-p25359200] Organic cation transporter-mediated drug-drug interaction potential between berberine and metformin. (2015). https://pubmed.ncbi.nlm.nih.gov/25359200/ DOI: 10.1007/s12272-014-0510-6

evidence_span

{"source_cache": "artifacts/berberine-research/30428337.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d35cfbe70c74323ef13e51af7affae3f13a4ff7b80a1d278620b8ced217346d8", "start_char": 0, "end_char": 1775, "text_sha256": "d35cfbe70c74323ef13e51af7affae3f13a4ff7b80a1d278620b8ced217346d8"}

experimental_model

Oral rat pharmacokinetics, intestinal sacs and rat-transporter-expressing cells

exposure

Oral metformin/berberine coadministration; concentration-dependent transport assays

limitations

Route differs from the intravenous rat study. Changes in plasma, kidney tissue and excretion are separate outcomes; not proof of improved human combination efficacy.

nutrient_topic

Berberine research collection; topical membership is not evidence of a direct dietary effect. · Berberine

organism

Rats and recombinant rat OCT1, OCT2 and MATE1

plain_language

This identifies the rat transporter independently, preserving species.

primary_references

[berberine-p30428337] Organic cation transporter and multidrug and toxin extrusion 1 co-mediated interaction between metformin and berberine. (2019). https://pubmed.ncbi.nlm.nih.gov/30428337/ DOI: 10.1016/j.ejps.2018.11.010

tissue_or_cell_type

Intestinal uptake, kidney distribution and excretion

Berberine: metabolism, nutrient connections and drug interactions (2026-09-17) · lines 805–816

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Oral rat pharmacokinetics, intestinal sacs and rat-transporter-expressing cells · source_derived_draft · unverified_draft

### berberine-rat-metformin-rat-slc22a1 Berberine inhibited rat OCT1-mediated metformin transport, with IC50 18.8 micromolar. Condition category: normal nutrient_topic: Berberine research collection; topical membership is not evidence of a direct dietary effect. plain_language: This identifies the rat transporter independently, preserving species. organism: Rats and recombinant rat OCT1, OCT2 and MATE1 tissue_or_cell_type: Intestinal uptake, kidney distribution and excretion experimental_model: Oral rat pharmacokinetics, intestinal sacs and rat-transporter-expressing cells limitations: Route differs from the intravenous rat study. Changes in plasma, kidney tissue and excretion are separate outcomes; not proof of improved human combination efficacy. exposure: Oral metformin/berberine coadministration; concentration-dependent transport assays evidence_span: {"source_cache": "artifacts/berberine-research/30428337.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d35cfbe70c74323ef13e51af7affae3f13a4ff7b80a1d278620b8ced217346d8", "start_char": 0, "end_char": 1775, "text_sha256": "d35cfbe70c74323ef13e51af7affae3f13a4ff7b80a1d278620b8ced217346d8"} [berberine-p30428337] Organic cation transporter and multidrug and toxin extrusion 1 co-mediated interaction between metformin and berberine. (2019). https://pubmed.ncbi.nlm.nih.gov/30428337/ DOI: 10.1016/j.ejps.2018.11.010

experimental_model

Male spontaneously hypertensive rats; EGCG 10 mg/kg/day for 14 days and nadolol 10 mg/kg on day 14.

limitations

Rat transcription/exposure results; mRNA changes do not establish transporter protein activity or a human effect size.

nutrient_topic

EGCG collection; comparator and shared-pathway records retain their actual intervention. · Epigallocatechin-3-gallate (EGCG)

plain_language

The study measured a transporter-expression change.

primary_references

Oral epigallocatechin gallate reduces intestinal nadolol absorption via modulation of Oatp1a5 and Oct1 transcriptional levels in spontaneously hypertensive rats. · 2021 · https://pubmed.ncbi.nlm.nih.gov/34303263/ · DOI 10.1016/j.phymed.2021.153623

EGCG: receptor signaling, metabolism, nutrient interactions and discovery questions (2026-09-18) · lines 524–530

AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Male spontaneously hypertensive rats; EGCG 10 mg/kg/day for 14 days and nadolol 10 mg/kg on day 14. · source_derived_draft · unverified_draft

## egcg-hepatic-oct The study measured a transporter-expression change. EGCG pretreatment reduced the specified transporter mRNA by a reported 2.66-fold. Model: Male spontaneously hypertensive rats; EGCG 10 mg/kg/day for 14 days and nadolol 10 mg/kg on day 14. Limitations: Rat transcription/exposure results; mRNA changes do not establish transporter protein activity or a human effect size. Evidence access: primary abstract. Oral epigallocatechin gallate reduces intestinal nadolol absorption via modulation of Oatp1a5 and Oct1 transcriptional levels in spontaneously hypertensive rats. · 2021 · https://pubmed.ncbi.nlm.nih.gov/34303263/ · DOI 10.1016/j.phymed.2021.153623

experimental_model

Male spontaneously hypertensive rats; EGCG 10 mg/kg/day for 14 days and nadolol 10 mg/kg on day 14.

limitations

Rat transcription/exposure results; mRNA changes do not establish transporter protein activity or a human effect size.

nutrient_topic

EGCG collection; comparator and shared-pathway records retain their actual intervention. · Epigallocatechin-3-gallate (EGCG)

plain_language

The study measured a transporter-expression change.

primary_references

Oral epigallocatechin gallate reduces intestinal nadolol absorption via modulation of Oatp1a5 and Oct1 transcriptional levels in spontaneously hypertensive rats. · 2021 · https://pubmed.ncbi.nlm.nih.gov/34303263/ · DOI 10.1016/j.phymed.2021.153623

EGCG: receptor signaling, metabolism, nutrient interactions and discovery questions (2026-09-18) · lines 508–514

AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Male spontaneously hypertensive rats; EGCG 10 mg/kg/day for 14 days and nadolol 10 mg/kg on day 14. · source_derived_draft · unverified_draft

## egcg-ileal-oct The study measured a transporter-expression change. EGCG pretreatment reduced the specified transporter mRNA by a reported 4.03-fold. Model: Male spontaneously hypertensive rats; EGCG 10 mg/kg/day for 14 days and nadolol 10 mg/kg on day 14. Limitations: Rat transcription/exposure results; mRNA changes do not establish transporter protein activity or a human effect size. Evidence access: primary abstract. Oral epigallocatechin gallate reduces intestinal nadolol absorption via modulation of Oatp1a5 and Oct1 transcriptional levels in spontaneously hypertensive rats. · 2021 · https://pubmed.ncbi.nlm.nih.gov/34303263/ · DOI 10.1016/j.phymed.2021.153623