Scavenger receptor class B type 1 / SCARB1

cross_nutrient

false

evidence_location

Primary abstract, Methods and results; exact incubation concentrations/durations unavailable in abstract.

experimental_model

Transfected HEK-cell uptake assay; intestinal relevance tested separately

exposure

Transporter transfection and selective-inhibitor co-incubation; exact dose/time absent from abstract.

limitations

HEK overexpression is not intact human intestine; inhibitors and uptake assays do not establish clinical deficiency. In-vivo ezetimibe effect in mice was nonsignificant.

nutrient

Vitamin D2 and D3 · Vitamin D2 and D3

nutrient_topic

Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin D2 and D3

organism

Homo sapiens

plain_language

SR-BI can contribute to vitamin D3 entry into cells.

primary_references

[reboul2011] Vitamin D intestinal absorption is not a simple passive diffusion: evidences for involvement of cholesterol transporters. (2011). https://pubmed.ncbi.nlm.nih.gov/21280209/ DOI: 10.1002/mnfr.201000553

tissue_or_cell_type

HEK cell model of a candidate intestinal uptake mechanism

Vitamin D2 and D3: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 166–179

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Transfected HEK-cell uptake assay; intestinal relevance tested separately · source_derived_draft · unverified_draft

### vd-act-scarb1-uptake Expression of SR-BI in HEK cells increased cholecalciferol uptake, and its corresponding inhibitor reduced this uptake. Condition category: normal nutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect. plain_language: SR-BI can contribute to vitamin D3 entry into cells. organism: Homo sapiens tissue_or_cell_type: HEK cell model of a candidate intestinal uptake mechanism experimental_model: Transfected HEK-cell uptake assay; intestinal relevance tested separately limitations: HEK overexpression is not intact human intestine; inhibitors and uptake assays do not establish clinical deficiency. In-vivo ezetimibe effect in mice was nonsignificant. exposure: Transporter transfection and selective-inhibitor co-incubation; exact dose/time absent from abstract. cross_nutrient: false evidence_location: Primary abstract, Methods and results; exact incubation concentrations/durations unavailable in abstract. nutrient: Vitamin D2 and D3 [reboul2011] Vitamin D intestinal absorption is not a simple passive diffusion: evidences for involvement of cholesterol transporters. (2011). https://pubmed.ncbi.nlm.nih.gov/21280209/ DOI: 10.1002/mnfr.201000553

evidence_access

Primary abstract

experimental_model

Human Caco-2 inhibitor and antibody experiments.

limitations

Partial inhibition does not establish an exclusive route or clinical competition among carotenoids.

nutrient_topic

Astaxanthin collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Astaxanthin

plain_language

Different shapes of the same carotenoid used uptake machinery differently.

primary_references

Anti-Inflammatory Effects of Different Astaxanthin Isomers and the Roles of Lipid Transporters in the Cellular Transport of Astaxanthin Isomers in Caco-2 Cell Monolayers. · 2019 · https://pubmed.ncbi.nlm.nih.gov/31117505/ · DOI 10.1021/acs.jafc.9b02102

Astaxanthin: transport, membrane chemistry, signaling and nutrient interactions (2026-09-19) · lines 54–60

AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Human Caco-2 inhibitor and antibody experiments. · source_derived_draft · unverified_draft

## astaxanthin-isomer-srbi Different shapes of the same carotenoid used uptake machinery differently. SR-BI inhibitor BLT1 and an SR-BI antibody reduced all-E and 13Z astaxanthin uptake in human Caco-2 cells; neither reduced 9Z uptake in that experiment. Model: Human Caco-2 inhibitor and antibody experiments. Limitations: Partial inhibition does not establish an exclusive route or clinical competition among carotenoids. Evidence access: Primary abstract Anti-Inflammatory Effects of Different Astaxanthin Isomers and the Roles of Lipid Transporters in the Cellular Transport of Astaxanthin Isomers in Caco-2 Cell Monolayers. · 2019 · https://pubmed.ncbi.nlm.nih.gov/31117505/ · DOI 10.1021/acs.jafc.9b02102

evidence_span

{"source_cache": "artifacts/lycopene-research/18641187.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "7c71fd4fd3be9d14176bceb3c2104143269a788587feec232350a6f1c5913e3d", "start_char": 0, "end_char": 1557, "text_sha256": "7c71fd4fd3be9d14176bceb3c2104143269a788587feec232350a6f1c5913e3d"}

experimental_model

Transporter inhibition in Caco-2 cells; intestinal SR-BI transgenic mice

exposure

All-E and 5Z lycopene; mice received 0.25 g/kg diet for one month

limitations

Partial uptake inhibition is not proof of a sole transporter. Ezetimibe result is a cell assay, not a clinical drug-interaction trial.

nutrient_topic

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

organism

Human Caco-2 cells

plain_language

One intestinal lipid transporter helps lycopene enter these cells.

primary_references

[lycopene-p18641187] Lycopene absorption in human intestinal cells and in mice involves scavenger receptor class B type I but not Niemann-Pick C1-like 1. (2008). https://pubmed.ncbi.nlm.nih.gov/18641187/ DOI: 10.1093/jn/138.8.1432

tissue_or_cell_type

Intestinal epithelium and plasma

Lycopene: absorption, metabolism, nutrient connections and human outcomes (2026-09-17) · lines 104–115

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Transporter inhibition in Caco-2 cells; intestinal SR-BI transgenic mice · source_derived_draft · unverified_draft

### lycopene-srbi-uptake SR-BI antibody or BLT1 inhibited all-E and 5Z lycopene uptake by up to 60% in Caco-2 monolayers. Condition category: normal nutrient_topic: Lycopene research collection; topical membership is not evidence of a direct dietary effect. plain_language: One intestinal lipid transporter helps lycopene enter these cells. organism: Human Caco-2 cells tissue_or_cell_type: Intestinal epithelium and plasma experimental_model: Transporter inhibition in Caco-2 cells; intestinal SR-BI transgenic mice limitations: Partial uptake inhibition is not proof of a sole transporter. Ezetimibe result is a cell assay, not a clinical drug-interaction trial. exposure: All-E and 5Z lycopene; mice received 0.25 g/kg diet for one month evidence_span: {"source_cache": "artifacts/lycopene-research/18641187.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "7c71fd4fd3be9d14176bceb3c2104143269a788587feec232350a6f1c5913e3d", "start_char": 0, "end_char": 1557, "text_sha256": "7c71fd4fd3be9d14176bceb3c2104143269a788587feec232350a6f1c5913e3d"} [lycopene-p18641187] Lycopene absorption in human intestinal cells and in mice involves scavenger receptor class B type I but not Niemann-Pick C1-like 1. (2008). https://pubmed.ncbi.nlm.nih.gov/18641187/ DOI: 10.1093/jn/138.8.1432

evidence_span

{"source_cache": "artifacts/lutein-research/36863431.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "530dd42d442890be2e5cd11c18bf95c0bd850d8f67ad6682d12360dfc7f8aec0", "start_char": 0, "end_char": 1551, "text_sha256": "530dd42d442890be2e5cd11c18bf95c0bd850d8f67ad6682d12360dfc7f8aec0"}

experimental_model

SR-BI expression, tunnel mutation, binding and lipoprotein-partner assays

exposure

Wild-type or C384Y SR-BI; HDL and hepatic lipase additions

limitations

Engineered-cell mechanisms, not a clinical HDL-raising recommendation; no selective direct binding to lutein demonstrated.

nutrient_topic

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

organism

Human HEK293 cell system

plain_language

The receptor changed which pigments entered these cells.

primary_references

[lutein-p36863431] Mechanism for the selective uptake of macular carotenoids mediated by the HDL cholesterol receptor SR-BI. (2023). https://pubmed.ncbi.nlm.nih.gov/36863431/ DOI: 10.1016/j.exer.2023.109429

tissue_or_cell_type

Engineered cells without endogenous SR-BI

Lutein: metabolism, signaling and nutrient connections (2026-09-17) · lines 671–682

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · SR-BI expression, tunnel mutation, binding and lipoprotein-partner assays · source_derived_draft · unverified_draft

### lutein-srbi-cell-uptake SR-BI expression increased lutein and zeaxanthin uptake preferentially over beta-carotene. Condition category: normal nutrient_topic: Lutein research collection; topical membership is not evidence of a direct dietary effect. plain_language: The receptor changed which pigments entered these cells. organism: Human HEK293 cell system tissue_or_cell_type: Engineered cells without endogenous SR-BI experimental_model: SR-BI expression, tunnel mutation, binding and lipoprotein-partner assays limitations: Engineered-cell mechanisms, not a clinical HDL-raising recommendation; no selective direct binding to lutein demonstrated. exposure: Wild-type or C384Y SR-BI; HDL and hepatic lipase additions evidence_span: {"source_cache": "artifacts/lutein-research/36863431.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "530dd42d442890be2e5cd11c18bf95c0bd850d8f67ad6682d12360dfc7f8aec0", "start_char": 0, "end_char": 1551, "text_sha256": "530dd42d442890be2e5cd11c18bf95c0bd850d8f67ad6682d12360dfc7f8aec0"} [lutein-p36863431] Mechanism for the selective uptake of macular carotenoids mediated by the HDL cholesterol receptor SR-BI. (2023). https://pubmed.ncbi.nlm.nih.gov/36863431/ DOI: 10.1016/j.exer.2023.109429

evidence_span

{"source_cache": "artifacts/lutein-research/15554873.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3dfbef37e3c73db4732f66083063e548a1654cb759ff46392c981c50f338d8a0", "start_char": 0, "end_char": 2014, "text_sha256": "3dfbef37e3c73db4732f66083063e548a1654cb759ff46392c981c50f338d8a0"}

experimental_model

Mixed-micelle transport across Caco-2 TC-7 monolayers

exposure

Micellar lutein 1.5–15 micromolar; antibodies and BLT1

limitations

Partial inhibition supports a contribution, not an exclusive route; cell experiments do not set clinical supplement spacing.

nutrient_topic

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

organism

Human intestinal cell model

plain_language

Part of intestinal uptake used the SR-BI pathway.

primary_references

[lutein-p15554873] Lutein transport by Caco-2 TC-7 cells occurs partly by a facilitated process involving the scavenger receptor class B type I (SR-BI). (2005). https://pubmed.ncbi.nlm.nih.gov/15554873/ DOI: 10.1042/bj20040554

tissue_or_cell_type

Apical intestinal epithelial transport

Lutein: metabolism, signaling and nutrient connections (2026-09-17) · lines 476–487

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Mixed-micelle transport across Caco-2 TC-7 monolayers · source_derived_draft · unverified_draft

### lutein-srbi-intestine SR-BI antibody and BLT1 reduced lutein transport by approximately 30% and 57%, respectively. Condition category: normal nutrient_topic: Lutein research collection; topical membership is not evidence of a direct dietary effect. plain_language: Part of intestinal uptake used the SR-BI pathway. organism: Human intestinal cell model tissue_or_cell_type: Apical intestinal epithelial transport experimental_model: Mixed-micelle transport across Caco-2 TC-7 monolayers limitations: Partial inhibition supports a contribution, not an exclusive route; cell experiments do not set clinical supplement spacing. exposure: Micellar lutein 1.5–15 micromolar; antibodies and BLT1 evidence_span: {"source_cache": "artifacts/lutein-research/15554873.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3dfbef37e3c73db4732f66083063e548a1654cb759ff46392c981c50f338d8a0", "start_char": 0, "end_char": 2014, "text_sha256": "3dfbef37e3c73db4732f66083063e548a1654cb759ff46392c981c50f338d8a0"} [lutein-p15554873] Lutein transport by Caco-2 TC-7 cells occurs partly by a facilitated process involving the scavenger receptor class B type I (SR-BI). (2005). https://pubmed.ncbi.nlm.nih.gov/15554873/ DOI: 10.1042/bj20040554

evidence_span

{"source_cache": "artifacts/zeaxanthin-research/42123990.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c0b42011e7f16c3fe60d599d489d01e4b3098db9ad04856d26aca10008e995f4", "start_char": 0, "end_char": 1803, "text_sha256": "c0b42011e7f16c3fe60d599d489d01e4b3098db9ad04856d26aca10008e995f4"}

experimental_model

Micelle uptake, transporter inhibition and protein-expression assays

exposure

Free and dipalmitate xanthophyll micelles; BLT-1 and ezetimibe

limitations

Inhibitors support pathway involvement rather than exclusivity. Protein-expression changes do not prove efflux; a cell model cannot establish clinical drug spacing.

nutrient_topic

Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. · Dietary (3R,3-prime-R)-zeaxanthin

organism

Human Caco-2 monolayers

plain_language

Esterification did not remove this transporter contribution.

primary_references

[zeaxanthin-p42123990] Mechanisms of Cell Uptake and Transport of Xanthophylls in the Caco-2 Cell Model. (2026). https://pubmed.ncbi.nlm.nih.gov/42123990/ DOI: 10.3390/nu18091389

tissue_or_cell_type

Intestinal epithelial model

Zeaxanthin: metabolism, signaling and nutrient connections (2026-09-17) · lines 730–741

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Micelle uptake, transporter inhibition and protein-expression assays · source_derived_draft · unverified_draft

### zeaxanthin-srbi-ester BLT-1-sensitive uptake supported SR-BI involvement after dipalmitate exposure. Condition category: normal nutrient_topic: Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. plain_language: Esterification did not remove this transporter contribution. organism: Human Caco-2 monolayers tissue_or_cell_type: Intestinal epithelial model experimental_model: Micelle uptake, transporter inhibition and protein-expression assays limitations: Inhibitors support pathway involvement rather than exclusivity. Protein-expression changes do not prove efflux; a cell model cannot establish clinical drug spacing. exposure: Free and dipalmitate xanthophyll micelles; BLT-1 and ezetimibe evidence_span: {"source_cache": "artifacts/zeaxanthin-research/42123990.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c0b42011e7f16c3fe60d599d489d01e4b3098db9ad04856d26aca10008e995f4", "start_char": 0, "end_char": 1803, "text_sha256": "c0b42011e7f16c3fe60d599d489d01e4b3098db9ad04856d26aca10008e995f4"} [zeaxanthin-p42123990] Mechanisms of Cell Uptake and Transport of Xanthophylls in the Caco-2 Cell Model. (2026). https://pubmed.ncbi.nlm.nih.gov/42123990/ DOI: 10.3390/nu18091389

evidence_span

{"source_cache": "artifacts/zeaxanthin-research/42123990.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c0b42011e7f16c3fe60d599d489d01e4b3098db9ad04856d26aca10008e995f4", "start_char": 0, "end_char": 1803, "text_sha256": "c0b42011e7f16c3fe60d599d489d01e4b3098db9ad04856d26aca10008e995f4"}

experimental_model

Micelle uptake, transporter inhibition and protein-expression assays

exposure

Free and dipalmitate xanthophyll micelles; BLT-1 and ezetimibe

limitations

Inhibitors support pathway involvement rather than exclusivity. Protein-expression changes do not prove efflux; a cell model cannot establish clinical drug spacing.

nutrient_topic

Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. · Dietary (3R,3-prime-R)-zeaxanthin

organism

Human Caco-2 monolayers

plain_language

The shared carotenoid transporter contributed here too.

primary_references

[zeaxanthin-p42123990] Mechanisms of Cell Uptake and Transport of Xanthophylls in the Caco-2 Cell Model. (2026). https://pubmed.ncbi.nlm.nih.gov/42123990/ DOI: 10.3390/nu18091389

tissue_or_cell_type

Intestinal epithelial model

Zeaxanthin: metabolism, signaling and nutrient connections (2026-09-17) · lines 652–663

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Micelle uptake, transporter inhibition and protein-expression assays · source_derived_draft · unverified_draft

### zeaxanthin-srbi-intestinal BLT-1-sensitive uptake supported SR-BI involvement in free-zeaxanthin uptake. Condition category: normal nutrient_topic: Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. plain_language: The shared carotenoid transporter contributed here too. organism: Human Caco-2 monolayers tissue_or_cell_type: Intestinal epithelial model experimental_model: Micelle uptake, transporter inhibition and protein-expression assays limitations: Inhibitors support pathway involvement rather than exclusivity. Protein-expression changes do not prove efflux; a cell model cannot establish clinical drug spacing. exposure: Free and dipalmitate xanthophyll micelles; BLT-1 and ezetimibe evidence_span: {"source_cache": "artifacts/zeaxanthin-research/42123990.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c0b42011e7f16c3fe60d599d489d01e4b3098db9ad04856d26aca10008e995f4", "start_char": 0, "end_char": 1803, "text_sha256": "c0b42011e7f16c3fe60d599d489d01e4b3098db9ad04856d26aca10008e995f4"} [zeaxanthin-p42123990] Mechanisms of Cell Uptake and Transport of Xanthophylls in the Caco-2 Cell Model. (2026). https://pubmed.ncbi.nlm.nih.gov/42123990/ DOI: 10.3390/nu18091389

evidence_span

{"source_cache": "artifacts/zeaxanthin-research/28947101.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "8899547af674d9bc7acc413d58c440726a1469ca705aa82bc5dafd5c89aadcc2", "start_char": 0, "end_char": 1330, "text_sha256": "8899547af674d9bc7acc413d58c440726a1469ca705aa82bc5dafd5c89aadcc2"}

experimental_model

SPR and transporter overexpression

exposure

SR-BI, SCARB2/LIMP-II and CD36; HDL or LDL carriers

limitations

The study used SCARB2/LIMP-II (methods reagent AF1966), not the similarly named SCARB1 splice variant SR-BII. Reagent identity: https://www.rndsystems.com/products/human-limpii-sr-b2-antibody_af1966 . Transporter overexpression is not an oral absorption trial.

nutrient_topic

Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. · Dietary (3R,3-prime-R)-zeaxanthin

organism

Human proteins in HEK-293T cells and donor eye tissue

plain_language

A shared lipid receptor can deliver zeaxanthin.

primary_references

[zeaxanthin-p28947101] All three human scavenger receptor class B proteins can bind and transport all three macular xanthophyll carotenoids. (2017). https://pubmed.ncbi.nlm.nih.gov/28947101/ DOI: 10.1016/j.abb.2017.09.013

tissue_or_cell_type

Recombinant receptors and HEK-293T cells

Zeaxanthin: metabolism, signaling and nutrient connections (2026-09-17) · lines 587–598

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · SPR and transporter overexpression · source_derived_draft · unverified_draft

### zeaxanthin-srbi-uptake SR-BI supported zeaxanthin uptake in the transfected-cell experiment. Condition category: normal nutrient_topic: Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. plain_language: A shared lipid receptor can deliver zeaxanthin. organism: Human proteins in HEK-293T cells and donor eye tissue tissue_or_cell_type: Recombinant receptors and HEK-293T cells experimental_model: SPR and transporter overexpression limitations: The study used SCARB2/LIMP-II (methods reagent AF1966), not the similarly named SCARB1 splice variant SR-BII. Reagent identity: https://www.rndsystems.com/products/human-limpii-sr-b2-antibody_af1966 . Transporter overexpression is not an oral absorption trial. exposure: SR-BI, SCARB2/LIMP-II and CD36; HDL or LDL carriers evidence_span: {"source_cache": "artifacts/zeaxanthin-research/28947101.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "8899547af674d9bc7acc413d58c440726a1469ca705aa82bc5dafd5c89aadcc2", "start_char": 0, "end_char": 1330, "text_sha256": "8899547af674d9bc7acc413d58c440726a1469ca705aa82bc5dafd5c89aadcc2"} [zeaxanthin-p28947101] All three human scavenger receptor class B proteins can bind and transport all three macular xanthophyll carotenoids. (2017). https://pubmed.ncbi.nlm.nih.gov/28947101/ DOI: 10.1016/j.abb.2017.09.013

evidence_location

Abstract

experimental_model

Scarb1-knockout mice, intestinal brush-border vesicles and transfected COS-7 cells.

exposure

Wild-type versus Scarb1-knockout mice; high-fat feeding.

limitations

Dependence was diet/model specific; this does not establish exclusive human transport.

nutrient_topic

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

organism

Mus musculus

outcome

SCARB1 supported intestinal beta-carotene absorption in mice on a high-fat diet.

plain_language

The intestinal receptor helps beta-carotene enter the body.

primary_references

[va-vanbennekum-2005] Class B scavenger receptor-mediated intestinal absorption of dietary beta-carotene and cholesterol (2005). https://pubmed.ncbi.nlm.nih.gov/15766282/ DOI: 10.1021/bi0484320

tissue_or_cell_type

Small-intestinal brush border

transport_direction

intestinal lumen to enterocyte

Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 116–129

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Scarb1-knockout mice, intestinal brush-border vesicles and transfected COS-7 cells. · source_derived_draft · unverified_draft

### va-scarb1-beta-carotene-uptake SCARB1 supported intestinal beta-carotene absorption in mice on a high-fat diet. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: The intestinal receptor helps beta-carotene enter the body. organism: Mus musculus tissue_or_cell_type: Small-intestinal brush border experimental_model: Scarb1-knockout mice, intestinal brush-border vesicles and transfected COS-7 cells. limitations: Dependence was diet/model specific; this does not establish exclusive human transport. exposure: Wild-type versus Scarb1-knockout mice; high-fat feeding. outcome: SCARB1 supported intestinal beta-carotene absorption in mice on a high-fat diet. evidence_location: Abstract transport_direction: intestinal lumen to enterocyte [va-vanbennekum-2005] Class B scavenger receptor-mediated intestinal absorption of dietary beta-carotene and cholesterol (2005). https://pubmed.ncbi.nlm.nih.gov/15766282/ DOI: 10.1021/bi0484320

cross_nutrient

false

experimental_model

Preloaded Caco-2 TC7 monolayers

exposure

Tocopherol-preloaded cells; apical acceptor micelles; time-course Figure 4.

limitations

Apical return is distinct from basolateral secretion; acceptor availability affects the result.

nutrient_topic

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

organism

Homo sapiens

plain_language

The same receptor also helped vitamin E leave toward the gut-facing side.

primary_references

[reboul2006] Scavenger receptor class B type I (SR-BI) is involved in vitamin E transport across the enterocyte. (2006). https://pubmed.ncbi.nlm.nih.gov/16380385/ DOI: 10.1074/jbc.m509042200

tissue_or_cell_type

Intestinal epithelial cell model

Vitamin E: transport, membrane protection and nutrient interactions (2026-09-17) · lines 194–205

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Preloaded Caco-2 TC7 monolayers · source_derived_draft · unverified_draft

### ve-transport-scarb1-apical-efflux SR-BI antibody or BLT1 reduced RRR-alpha-tocopherol efflux from loaded Caco-2 TC7 cells into apical vitamin-free mixed micelles. Condition category: normal nutrient_topic: Vitamin E research collection; topical membership is not evidence of a direct dietary effect. plain_language: The same receptor also helped vitamin E leave toward the gut-facing side. organism: Homo sapiens tissue_or_cell_type: Intestinal epithelial cell model experimental_model: Preloaded Caco-2 TC7 monolayers limitations: Apical return is distinct from basolateral secretion; acceptor availability affects the result. exposure: Tocopherol-preloaded cells; apical acceptor micelles; time-course Figure 4. cross_nutrient: false [reboul2006] Scavenger receptor class B type I (SR-BI) is involved in vitamin E transport across the enterocyte. (2006). https://pubmed.ncbi.nlm.nih.gov/16380385/ DOI: 10.1074/jbc.m509042200

cross_nutrient

false

experimental_model

Differentiated Caco-2 TC7 monolayers

exposure

60-min pretreatment: antibody 3.75 µg/mL or BLT1 10 µM; 40 µM micellar RRR-alpha-tocopherol for 60 min.

limitations

Inhibitor/antibody evidence; contribution under these conditions is not the sole absorption route.

nutrient_topic

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

organism

Homo sapiens

plain_language

SR-BI helped these intestinal cells take up vitamin E.

primary_references

[reboul2006] Scavenger receptor class B type I (SR-BI) is involved in vitamin E transport across the enterocyte. (2006). https://pubmed.ncbi.nlm.nih.gov/16380385/ DOI: 10.1074/jbc.m509042200

tissue_or_cell_type

Intestinal epithelial cell model

Vitamin E: transport, membrane protection and nutrient interactions (2026-09-17) · lines 181–192

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Differentiated Caco-2 TC7 monolayers · source_derived_draft · unverified_draft

### ve-transport-scarb1-uptake Blocking SR-BI with an extracellular antibody or BLT1 reduced RRR-alpha-tocopherol uptake by human Caco-2 TC7 cells. Condition category: normal nutrient_topic: Vitamin E research collection; topical membership is not evidence of a direct dietary effect. plain_language: SR-BI helped these intestinal cells take up vitamin E. organism: Homo sapiens tissue_or_cell_type: Intestinal epithelial cell model experimental_model: Differentiated Caco-2 TC7 monolayers limitations: Inhibitor/antibody evidence; contribution under these conditions is not the sole absorption route. exposure: 60-min pretreatment: antibody 3.75 µg/mL or BLT1 10 µM; 40 µM micellar RRR-alpha-tocopherol for 60 min. cross_nutrient: false [reboul2006] Scavenger receptor class B type I (SR-BI) is involved in vitamin E transport across the enterocyte. (2006). https://pubmed.ncbi.nlm.nih.gov/16380385/ DOI: 10.1074/jbc.m509042200

evidence_location

Abstract

experimental_model

Isx, Bco1, Bco2 and Scarb1 mouse mutants; promoter binding and controlled diets.

exposure

Isx genotypes and promoter-binding experiments.

limitations

Tissue-specific regulation, not suppression in every organ.

nutrient_topic

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

organism

Mus musculus and promoter-binding preparations

outcome

ISX bound upstream SCARB1 regulatory motifs and repressed intestinal SCARB1 expression.

plain_language

The feedback factor lowers the uptake receptor.

primary_references

[va-widjajaadhi-2015] A genetic dissection of intestinal fat-soluble vitamin and carotenoid absorption (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4424956/ DOI: 10.1093/hmg/ddv072

tissue_or_cell_type

Jejunum and DNA-binding assays

Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 274–286

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Isx, Bco1, Bco2 and Scarb1 mouse mutants; promoter binding and controlled diets. · source_derived_draft · unverified_draft

### va-isx-scarb1-repression ISX bound upstream SCARB1 regulatory motifs and repressed intestinal SCARB1 expression. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: The feedback factor lowers the uptake receptor. organism: Mus musculus and promoter-binding preparations tissue_or_cell_type: Jejunum and DNA-binding assays experimental_model: Isx, Bco1, Bco2 and Scarb1 mouse mutants; promoter binding and controlled diets. limitations: Tissue-specific regulation, not suppression in every organ. exposure: Isx genotypes and promoter-binding experiments. outcome: ISX bound upstream SCARB1 regulatory motifs and repressed intestinal SCARB1 expression. evidence_location: Abstract [va-widjajaadhi-2015] A genetic dissection of intestinal fat-soluble vitamin and carotenoid absorption (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4424956/ DOI: 10.1093/hmg/ddv072

evidence_span

{"source_cache": "artifacts/lutein-research/16380385.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "410a6cc6c3325e6d2f459b06ddaf9c7b7806f9b82a918f1df02b1626f5f84074", "start_char": 0, "end_char": 1960, "text_sha256": "410a6cc6c3325e6d2f459b06ddaf9c7b7806f9b82a918f1df02b1626f5f84074"}

experimental_model

Mixed-micelle uptake in Caco-2 TC-7 cells

exposure

Alpha-tocopherol with co-incubated lutein

limitations

In vitro competition is not demonstrated vitamin E deficiency or a clinical dose-spacing rule.

nutrient_topic

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

organism

Human cell model

plain_language

Lutein and vitamin E can interact during intestinal uptake.

primary_references

[lutein-p16380385] Scavenger receptor class B type I (SR-BI) is involved in vitamin E transport across the enterocyte. (2006). https://pubmed.ncbi.nlm.nih.gov/16380385/ DOI: 10.1074/jbc.m509042200

tissue_or_cell_type

Intestinal epithelium

Lutein: metabolism, signaling and nutrient connections (2026-09-17) · lines 541–552

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Mixed-micelle uptake in Caco-2 TC-7 cells · source_derived_draft · unverified_draft

### lutein-vitamin-e-competition Co-incubated lutein reduced alpha-tocopherol uptake in Caco-2 TC-7 cells. Condition category: normal nutrient_topic: Lutein research collection; topical membership is not evidence of a direct dietary effect. plain_language: Lutein and vitamin E can interact during intestinal uptake. organism: Human cell model tissue_or_cell_type: Intestinal epithelium experimental_model: Mixed-micelle uptake in Caco-2 TC-7 cells limitations: In vitro competition is not demonstrated vitamin E deficiency or a clinical dose-spacing rule. exposure: Alpha-tocopherol with co-incubated lutein evidence_span: {"source_cache": "artifacts/lutein-research/16380385.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "410a6cc6c3325e6d2f459b06ddaf9c7b7806f9b82a918f1df02b1626f5f84074", "start_char": 0, "end_char": 1960, "text_sha256": "410a6cc6c3325e6d2f459b06ddaf9c7b7806f9b82a918f1df02b1626f5f84074"} [lutein-p16380385] Scavenger receptor class B type I (SR-BI) is involved in vitamin E transport across the enterocyte. (2006). https://pubmed.ncbi.nlm.nih.gov/16380385/ DOI: 10.1074/jbc.m509042200

availability_state

machinery_impairment Imported condition classification; unverified.

cross_nutrient

Retinoid/ISX control of a shared intestinal transporter affects vitamin E status.

evidence_location

Figure 7

experimental_model

Isx, Bco1, Bco2 and Scarb1 mouse mutants; promoter binding and controlled diets.

exposure

Females; ten weeks of AIN93G with 75 IU vitamin E/kg, with or without 50 mg zeaxanthin/kg.

limitations

Accumulation is not a clinical benefit; compound mutants had a larger effect than Isx single mutants.

nutrient_topic

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

organism

Mus musculus

outcome

Isx-deficient mice had higher hepatic alpha-tocopherol; the Isx/Bco2 double mutant showed about twice wild-type levels.

plain_language

Disrupting vitamin A feedback also changed vitamin E accumulation.

primary_references

[va-widjajaadhi-2015] A genetic dissection of intestinal fat-soluble vitamin and carotenoid absorption (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4424956/ DOI: 10.1093/hmg/ddv072

tissue_or_cell_type

Jejunum and liver

trigger_kind

machinery_impairment Imported condition classification; unverified.

Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 302–315

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Isx, Bco1, Bco2 and Scarb1 mouse mutants; promoter binding and controlled diets. · source_derived_draft · unverified_draft

### va-isx-loss-tocopherol Isx-deficient mice had higher hepatic alpha-tocopherol; the Isx/Bco2 double mutant showed about twice wild-type levels. Condition category: machinery_impairment nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Disrupting vitamin A feedback also changed vitamin E accumulation. organism: Mus musculus tissue_or_cell_type: Jejunum and liver experimental_model: Isx, Bco1, Bco2 and Scarb1 mouse mutants; promoter binding and controlled diets. limitations: Accumulation is not a clinical benefit; compound mutants had a larger effect than Isx single mutants. exposure: Females; ten weeks of AIN93G with 75 IU vitamin E/kg, with or without 50 mg zeaxanthin/kg. outcome: Isx-deficient mice had higher hepatic alpha-tocopherol; the Isx/Bco2 double mutant showed about twice wild-type levels. evidence_location: Figure 7 cross_nutrient: Retinoid/ISX control of a shared intestinal transporter affects vitamin E status. [va-widjajaadhi-2015] A genetic dissection of intestinal fat-soluble vitamin and carotenoid absorption (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4424956/ DOI: 10.1093/hmg/ddv072