Human glutathione S-transferase P1 / GSTP1

evidence_span

{"source_cache": "artifacts/sulforaphane-research/7826396.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "5dee3c3a8c8069c33fac2653f16f3521cdd17ef5e8ebddd0f82cfa3a5c95c0fe", "start_char": 0, "end_char": 989, "text_sha256": "5dee3c3a8c8069c33fac2653f16f3521cdd17ef5e8ebddd0f82cfa3a5c95c0fe"}

experimental_model

Recombinant human GST conjugation and reverse-reaction kinetics

exposure

Four isothiocyanates and GSTP1-1, GSTM1-1, GSTA1-1 and GSTM2-2

limitations

Relative enzyme rates are not whole-person clearance predictions; reverse reactions were slower and inhibited by high GSH.

nutrient_topic

Sulforaphane research collection; topical membership is not evidence of a direct dietary effect. · Sulforaphane / SFN, stereochemistry specified per study

organism

Human GST isoenzymes

plain_language

Glutathione attaches to sulforaphane during its handling.

primary_references

[sulforaphane-p7826396] Reversible conjugation of isothiocyanates with glutathione catalyzed by human glutathione transferases. (1995). https://pubmed.ncbi.nlm.nih.gov/7826396/ DOI: 10.1006/bbrc.1995.1106

tissue_or_cell_type

Isothiocyanate-glutathione chemistry

Sulforaphane: formation, electrophile sensing and nutrient connections (2026-09-17) · lines 255–266

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human GST conjugation and reverse-reaction kinetics · source_derived_draft · unverified_draft

### sulforaphane-gstp-conjugation GSTP1-1 catalyzed sulforaphane conjugation with glutathione in the human enzyme comparison. Condition category: normal nutrient_topic: Sulforaphane research collection; topical membership is not evidence of a direct dietary effect. plain_language: Glutathione attaches to sulforaphane during its handling. organism: Human GST isoenzymes tissue_or_cell_type: Isothiocyanate-glutathione chemistry experimental_model: Recombinant human GST conjugation and reverse-reaction kinetics limitations: Relative enzyme rates are not whole-person clearance predictions; reverse reactions were slower and inhibited by high GSH. exposure: Four isothiocyanates and GSTP1-1, GSTM1-1, GSTA1-1 and GSTM2-2 evidence_span: {"source_cache": "artifacts/sulforaphane-research/7826396.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "5dee3c3a8c8069c33fac2653f16f3521cdd17ef5e8ebddd0f82cfa3a5c95c0fe", "start_char": 0, "end_char": 989, "text_sha256": "5dee3c3a8c8069c33fac2653f16f3521cdd17ef5e8ebddd0f82cfa3a5c95c0fe"} [sulforaphane-p7826396] Reversible conjugation of isothiocyanates with glutathione catalyzed by human glutathione transferases. (1995). https://pubmed.ncbi.nlm.nih.gov/7826396/ DOI: 10.1006/bbrc.1995.1106

evidence_span

{"source_cache": "artifacts/sulforaphane-research/18204073.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0fcd98974f9fe12b2ca7c4326f94eddf4f20de4ac2ae6fdebb64de0efb1d8be9", "start_char": 0, "end_char": 1894, "text_sha256": "0fcd98974f9fe12b2ca7c4326f94eddf4f20de4ac2ae6fdebb64de0efb1d8be9"}

experimental_model

Transgenic transporter/enzyme comparison

exposure

Sulforaphane; GSH depletion control

limitations

Engineered cancer cells; enzyme expression and efflux can have opposing effects without being a scientific contradiction.

nutrient_topic

Sulforaphane research collection; topical membership is not evidence of a direct dietary effect. · Sulforaphane / SFN, stereochemistry specified per study

organism

Human MCF7 cells with GSTP1 and/or MRP1

plain_language

Conjugation can initially retain the exposure inside cells.

primary_references

[sulforaphane-p18204073] Expression of MRP1 and GSTP1-1 modulate the acute cellular response to treatment with the chemopreventive isothiocyanate, sulforaphane. (2008). https://pubmed.ncbi.nlm.nih.gov/18204073/ DOI: 10.1093/carcin/bgn013

tissue_or_cell_type

Intracellular retention, ARE induction and Nrf2 persistence

Sulforaphane: formation, electrophile sensing and nutrient connections (2026-09-17) · lines 1009–1020

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

### sulforaphane-gstp-retention GSTP1-1 expression alone accelerated sulforaphane/conjugate accumulation and increased ARE reporter induction. Condition category: normal nutrient_topic: Sulforaphane research collection; topical membership is not evidence of a direct dietary effect. plain_language: Conjugation can initially retain the exposure inside cells. organism: Human MCF7 cells with GSTP1 and/or MRP1 tissue_or_cell_type: Intracellular retention, ARE induction and Nrf2 persistence experimental_model: Transgenic transporter/enzyme comparison limitations: Engineered cancer cells; enzyme expression and efflux can have opposing effects without being a scientific contradiction. exposure: Sulforaphane; GSH depletion control evidence_span: {"source_cache": "artifacts/sulforaphane-research/18204073.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0fcd98974f9fe12b2ca7c4326f94eddf4f20de4ac2ae6fdebb64de0efb1d8be9", "start_char": 0, "end_char": 1894, "text_sha256": "0fcd98974f9fe12b2ca7c4326f94eddf4f20de4ac2ae6fdebb64de0efb1d8be9"} [sulforaphane-p18204073] Expression of MRP1 and GSTP1-1 modulate the acute cellular response to treatment with the chemopreventive isothiocyanate, sulforaphane. (2008). https://pubmed.ncbi.nlm.nih.gov/18204073/ DOI: 10.1093/carcin/bgn013

evidence_span

{"source_cache": "artifacts/lutein-research/21322544.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "e0362dd86389ecba7d75e2628ffcd785ea404e40a709084dd5a0749a4cfb89fa", "start_char": 0, "end_char": 1825, "text_sha256": "e0362dd86389ecba7d75e2628ffcd785ea404e40a709084dd5a0749a4cfb89fa"}

experimental_model

Recombinant binding assays and primate retinal localization

exposure

Surface plasmon resonance and immunohistochemistry

limitations

Binding does not prove net retinal delivery or clinical benefit; localization is from monkey tissue.

nutrient_topic

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

organism

Human protein and monkey retinal tissue

plain_language

The two pigments have different identified binding proteins.

primary_references

[lutein-p21322544] Identification of StARD3 as a lutein-binding protein in the macula of the primate retina. (2011). https://pubmed.ncbi.nlm.nih.gov/21322544/ DOI: 10.1021/bi101906y

tissue_or_cell_type

Retina and purified protein

Lutein: metabolism, signaling and nutrient connections (2026-09-17) · lines 138–149

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant binding assays and primate retinal localization · source_derived_draft · unverified_draft

### lutein-gstp1-distinction The study distinguishes GSTP1-associated zeaxanthin binding from StARD3-associated lutein binding. Condition category: normal nutrient_topic: Lutein research collection; topical membership is not evidence of a direct dietary effect. plain_language: The two pigments have different identified binding proteins. organism: Human protein and monkey retinal tissue tissue_or_cell_type: Retina and purified protein experimental_model: Recombinant binding assays and primate retinal localization limitations: Binding does not prove net retinal delivery or clinical benefit; localization is from monkey tissue. exposure: Surface plasmon resonance and immunohistochemistry evidence_span: {"source_cache": "artifacts/lutein-research/21322544.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "e0362dd86389ecba7d75e2628ffcd785ea404e40a709084dd5a0749a4cfb89fa", "start_char": 0, "end_char": 1825, "text_sha256": "e0362dd86389ecba7d75e2628ffcd785ea404e40a709084dd5a0749a4cfb89fa"} [lutein-p21322544] Identification of StARD3 as a lutein-binding protein in the macula of the primate retina. (2011). https://pubmed.ncbi.nlm.nih.gov/21322544/ DOI: 10.1021/bi101906y

evidence_span

{"source_cache": "artifacts/zeaxanthin-research/15355982.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "6365b1d54aafda71be4dbf6c8e5252fa6ce0af3b808d9af6fe07c37ae188ea92", "start_char": 0, "end_char": 1907, "text_sha256": "6365b1d54aafda71be4dbf6c8e5252fa6ce0af3b808d9af6fe07c37ae188ea92"}

experimental_model

Human macular protein purification and recombinant binding

exposure

Equilibrium binding and immunocytochemistry

limitations

Binding affinity is assay-specific and does not quantify uptake or clinical benefit.

nutrient_topic

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

organism

Human tissue/proteins

plain_language

A retinal binding protein selectively holds dietary zeaxanthin.

primary_references

[zeaxanthin-p15355982] Identification and characterization of a Pi isoform of glutathione S-transferase (GSTP1) as a zeaxanthin-binding protein in the macula of the human eye. (2004). https://pubmed.ncbi.nlm.nih.gov/15355982/ DOI: 10.1074/jbc.m405334200

tissue_or_cell_type

Macula and purified proteins

Zeaxanthin: metabolism, signaling and nutrient connections (2026-09-17) · lines 210–221

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human macular protein purification and recombinant binding · source_derived_draft · unverified_draft

### zeaxanthin-gstp1-binding Purified recombinant GSTP1 bound dietary zeaxanthin with apparent Kd 0.33 micromolar. Condition category: normal nutrient_topic: Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. plain_language: A retinal binding protein selectively holds dietary zeaxanthin. organism: Human tissue/proteins tissue_or_cell_type: Macula and purified proteins experimental_model: Human macular protein purification and recombinant binding limitations: Binding affinity is assay-specific and does not quantify uptake or clinical benefit. exposure: Equilibrium binding and immunocytochemistry evidence_span: {"source_cache": "artifacts/zeaxanthin-research/15355982.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "6365b1d54aafda71be4dbf6c8e5252fa6ce0af3b808d9af6fe07c37ae188ea92", "start_char": 0, "end_char": 1907, "text_sha256": "6365b1d54aafda71be4dbf6c8e5252fa6ce0af3b808d9af6fe07c37ae188ea92"} [zeaxanthin-p15355982] Identification and characterization of a Pi isoform of glutathione S-transferase (GSTP1) as a zeaxanthin-binding protein in the macula of the human eye. (2004). https://pubmed.ncbi.nlm.nih.gov/15355982/ DOI: 10.1074/jbc.m405334200

evidence_span

{"source_cache": "artifacts/zeaxanthin-research/15355982.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "6365b1d54aafda71be4dbf6c8e5252fa6ce0af3b808d9af6fe07c37ae188ea92", "start_char": 0, "end_char": 1907, "text_sha256": "6365b1d54aafda71be4dbf6c8e5252fa6ce0af3b808d9af6fe07c37ae188ea92"}

experimental_model

Human macular protein purification and recombinant binding

exposure

Equilibrium binding and immunocytochemistry

limitations

Binding affinity is assay-specific and does not quantify uptake or clinical benefit.

nutrient_topic

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

organism

Human tissue/proteins

plain_language

The stereoisomer also has a binding site.

primary_references

[zeaxanthin-p15355982] Identification and characterization of a Pi isoform of glutathione S-transferase (GSTP1) as a zeaxanthin-binding protein in the macula of the human eye. (2004). https://pubmed.ncbi.nlm.nih.gov/15355982/ DOI: 10.1074/jbc.m405334200

tissue_or_cell_type

Macula and purified proteins

Zeaxanthin: metabolism, signaling and nutrient connections (2026-09-17) · lines 223–234

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human macular protein purification and recombinant binding · source_derived_draft · unverified_draft

### zeaxanthin-gstp1-meso GSTP1 bound meso-zeaxanthin with apparent Kd 0.52 micromolar. Condition category: normal nutrient_topic: Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. plain_language: The stereoisomer also has a binding site. organism: Human tissue/proteins tissue_or_cell_type: Macula and purified proteins experimental_model: Human macular protein purification and recombinant binding limitations: Binding affinity is assay-specific and does not quantify uptake or clinical benefit. exposure: Equilibrium binding and immunocytochemistry evidence_span: {"source_cache": "artifacts/zeaxanthin-research/15355982.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "6365b1d54aafda71be4dbf6c8e5252fa6ce0af3b808d9af6fe07c37ae188ea92", "start_char": 0, "end_char": 1907, "text_sha256": "6365b1d54aafda71be4dbf6c8e5252fa6ce0af3b808d9af6fe07c37ae188ea92"} [zeaxanthin-p15355982] Identification and characterization of a Pi isoform of glutathione S-transferase (GSTP1) as a zeaxanthin-binding protein in the macula of the human eye. (2004). https://pubmed.ncbi.nlm.nih.gov/15355982/ DOI: 10.1074/jbc.m405334200

evidence_span

{"source_cache": "artifacts/zeaxanthin-research/39151780.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "e43805b4445f15c3f6490ab163d908ee7a43f475538b3160fc1ea9771cff9ab4", "start_char": 0, "end_char": 1282, "text_sha256": "e43805b4445f15c3f6490ab163d908ee7a43f475538b3160fc1ea9771cff9ab4"}

experimental_model

Confocal Raman/fluorescence imaging and expression analysis

exposure

Twelve carotenoid-related proteins; Western blot and single-cell RNA database

limitations

Localization is not proof of transport direction or rate. Regional BCO2 result differs from the 2025 study; antibody specificity, sampling and compartment remain unresolved comparison variables.

nutrient_topic

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

organism

Human donor retina and RPE

plain_language

The binding protein was concentrated where the pigments accumulate.

primary_references

[zeaxanthin-p39151780] Imaging macular carotenoids and their related proteins in the human retina with confocal resonance Raman and fluorescence microscopy. (2024). https://pubmed.ncbi.nlm.nih.gov/39151780/ DOI: 10.1016/j.exer.2024.110043

tissue_or_cell_type

Central versus peripheral retinal regions

Zeaxanthin: metabolism, signaling and nutrient connections (2026-09-17) · lines 535–546

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Confocal Raman/fluorescence imaging and expression analysis · source_derived_draft · unverified_draft

### zeaxanthin-gstp1-regional GSTP1 distribution was enriched centrally and resembled the macular carotenoid pattern. Condition category: normal nutrient_topic: Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. plain_language: The binding protein was concentrated where the pigments accumulate. organism: Human donor retina and RPE tissue_or_cell_type: Central versus peripheral retinal regions experimental_model: Confocal Raman/fluorescence imaging and expression analysis limitations: Localization is not proof of transport direction or rate. Regional BCO2 result differs from the 2025 study; antibody specificity, sampling and compartment remain unresolved comparison variables. exposure: Twelve carotenoid-related proteins; Western blot and single-cell RNA database evidence_span: {"source_cache": "artifacts/zeaxanthin-research/39151780.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "e43805b4445f15c3f6490ab163d908ee7a43f475538b3160fc1ea9771cff9ab4", "start_char": 0, "end_char": 1282, "text_sha256": "e43805b4445f15c3f6490ab163d908ee7a43f475538b3160fc1ea9771cff9ab4"} [zeaxanthin-p39151780] Imaging macular carotenoids and their related proteins in the human retina with confocal resonance Raman and fluorescence microscopy. (2024). https://pubmed.ncbi.nlm.nih.gov/39151780/ DOI: 10.1016/j.exer.2024.110043

evidence_span

{"source_cache": "artifacts/zeaxanthin-research/15949677.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194", "start_char": 0, "end_char": 1404, "text_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194"}

experimental_model

Lipid-peroxyl radical challenge in liposomes

exposure

AAPH or AMVN challenge; dietary and meso zeaxanthin

limitations

Protein-associated antioxidant synergy is demonstrated in this assay, not a clinical supplement combination.

nutrient_topic

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

organism

Cell-free system with human GSTP1

plain_language

The protein helped preserve the pigments during oxidation.

primary_references

[zeaxanthin-p15949677] Synergistic effects of zeaxanthin and its binding protein in the prevention of lipid membrane oxidation. (2005). https://pubmed.ncbi.nlm.nih.gov/15949677/ DOI: 10.1016/j.bbadis.2005.02.002

tissue_or_cell_type

Egg-yolk phosphatidylcholine liposomes

Zeaxanthin: metabolism, signaling and nutrient connections (2026-09-17) · lines 275–286

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Lipid-peroxyl radical challenge in liposomes · source_derived_draft · unverified_draft

### zeaxanthin-gstp1-stability GSTP1 association increased resistance of zeaxanthin diastereomers to chemical degradation. Condition category: normal nutrient_topic: Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. plain_language: The protein helped preserve the pigments during oxidation. organism: Cell-free system with human GSTP1 tissue_or_cell_type: Egg-yolk phosphatidylcholine liposomes experimental_model: Lipid-peroxyl radical challenge in liposomes limitations: Protein-associated antioxidant synergy is demonstrated in this assay, not a clinical supplement combination. exposure: AAPH or AMVN challenge; dietary and meso zeaxanthin evidence_span: {"source_cache": "artifacts/zeaxanthin-research/15949677.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194", "start_char": 0, "end_char": 1404, "text_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194"} [zeaxanthin-p15949677] Synergistic effects of zeaxanthin and its binding protein in the prevention of lipid membrane oxidation. (2005). https://pubmed.ncbi.nlm.nih.gov/15949677/ DOI: 10.1016/j.bbadis.2005.02.002

evidence_span

{"source_cache": "artifacts/glutathione-research/26891882.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "919a342fc31314fef155eba006fd5a61b2a0a2d93a02c4de5e122c3d25d690fc", "start_char": 0, "end_char": 1661, "text_sha256": "919a342fc31314fef155eba006fd5a61b2a0a2d93a02c4de5e122c3d25d690fc"}

experimental_model

Human PRDX6 structures, dimerization and mutagenesis

exposure

Leu145/Leu148 substitutions

limitations

PRDX6 peroxidase and phospholipase activities are distinct; this is not a clinical GSTP1-variant study.

nutrient_topic

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

organism

Human

plain_language

A glutathione transferase helps reactivate another peroxide-handling enzyme.

primary_references

[glutathione-p26891882] Peroxiredoxin 6 homodimerization and heterodimerization with glutathione S-transferase pi are required for its peroxidase but not phospholipase A2 activity. (2016). https://pubmed.ncbi.nlm.nih.gov/26891882/ DOI: 10.1016/j.freeradbiomed.2016.02.012

tissue_or_cell_type

Purified protein and proximity assays

Glutathione: metabolism, signaling and nutrient connections (2026-09-17) · lines 957–968

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human PRDX6 structures, dimerization and mutagenesis · source_derived_draft · unverified_draft

### glutathione-prdx6-gstp PRDX6 heterodimerization with piGST supports glutathionylation needed in the peroxidatic cycle. Condition category: normal nutrient_topic: Glutathione research collection; topical membership is not evidence of a direct dietary effect. plain_language: A glutathione transferase helps reactivate another peroxide-handling enzyme. organism: Human tissue_or_cell_type: Purified protein and proximity assays experimental_model: Human PRDX6 structures, dimerization and mutagenesis limitations: PRDX6 peroxidase and phospholipase activities are distinct; this is not a clinical GSTP1-variant study. exposure: Leu145/Leu148 substitutions evidence_span: {"source_cache": "artifacts/glutathione-research/26891882.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "919a342fc31314fef155eba006fd5a61b2a0a2d93a02c4de5e122c3d25d690fc", "start_char": 0, "end_char": 1661, "text_sha256": "919a342fc31314fef155eba006fd5a61b2a0a2d93a02c4de5e122c3d25d690fc"} [glutathione-p26891882] Peroxiredoxin 6 homodimerization and heterodimerization with glutathione S-transferase pi are required for its peroxidase but not phospholipase A2 activity. (2016). https://pubmed.ncbi.nlm.nih.gov/26891882/ DOI: 10.1016/j.freeradbiomed.2016.02.012

dose

Betanin 2, 10 and 20 micromolar

duration

Not specified in accessed primary abstract

evidence_access

Primary PubMed abstract; detailed exposure for PMID 23931157 additionally checked in publisher results. No uninspected full text is claimed.

evidence_scope

literature_reviewed; source-derived curation, not universally established human effects

experimental_model

Human THLE-2 non-tumour liver and HepG2 hepatoma cell lines

limitations

Responses differed by cell line. Nuclear translocation is not proof of universal transcriptional activation; kinase association does not prove direct binding. Glutathione is the shared GST substrate; this study does not show betanin raises glutathione synthesis or reverses deficiency.

nutrient_topic

Betalains collection; each molecular form, species, exposure and preparation remains explicit. · Betalains

organism

Human THLE-2 non-tumour liver and HepG2 hepatoma cell lines

plain_language

Betanin increased GSTP transcript and protein abundance in THLE-2 cells.

primary_references

Betanin, a beetroot component, induces nuclear factor erythroid-2-related factor 2-mediated expression of detoxifying/antioxidant enzymes in human liver cell lines. (2013). https://pubmed.ncbi.nlm.nih.gov/23769299/ DOI: 10.1017/S0007114513001645

route

In vitro incubation

tissue

Liver-derived cells; cytosol and nucleus

Betalains: mechanisms, molecular forms and cross-actor connections (2026-09-20) · lines 237–245

Original AI-assisted curation of twelve primary research papers; study-specific PubMed/DOI links and limitations retained. Not publisher full text. · supports · Human THLE-2 non-tumour liver and HepG2 hepatoma cell lines · source_derived_draft · unverified_draft

## betalains-gstp-expression Betanin increased GSTP transcript and protein abundance in THLE-2 cells. Model/species: Human THLE-2 non-tumour liver and HepG2 hepatoma cell lines Tissue: Liver-derived cells; cytosol and nucleus Exposure: Betanin 2, 10 and 20 micromolar Route: In vitro incubation Duration: Not specified in accessed primary abstract Limits: Responses differed by cell line. Nuclear translocation is not proof of universal transcriptional activation; kinase association does not prove direct binding. Glutathione is the shared GST substrate; this study does not show betanin raises glutathione synthesis or reverses deficiency. Primary reference: Betanin, a beetroot component, induces nuclear factor erythroid-2-related factor 2-mediated expression of detoxifying/antioxidant enzymes in human liver cell lines. (2013). https://pubmed.ncbi.nlm.nih.gov/23769299/ DOI: 10.1017/S0007114513001645

dose

Betanin 2, 10 and 20 micromolar

duration

Not specified in accessed primary abstract

evidence_access

Primary PubMed abstract; detailed exposure for PMID 23931157 additionally checked in publisher results. No uninspected full text is claimed.

evidence_scope

literature_reviewed; source-derived curation, not universally established human effects

experimental_model

Human THLE-2 non-tumour liver and HepG2 hepatoma cell lines

limitations

Responses differed by cell line. Nuclear translocation is not proof of universal transcriptional activation; kinase association does not prove direct binding.

nutrient_topic

Betalains collection; each molecular form, species, exposure and preparation remains explicit. · Betalains

organism

Human THLE-2 non-tumour liver and HepG2 hepatoma cell lines

plain_language

Betanin did not alter GSTP1 methylation in HepG2 cells.

primary_references

Betanin, a beetroot component, induces nuclear factor erythroid-2-related factor 2-mediated expression of detoxifying/antioxidant enzymes in human liver cell lines. (2013). https://pubmed.ncbi.nlm.nih.gov/23769299/ DOI: 10.1017/S0007114513001645

route

In vitro incubation

tissue

Liver-derived cells; cytosol and nucleus

Betalains: mechanisms, molecular forms and cross-actor connections (2026-09-20) · lines 247–255

Original AI-assisted curation of twelve primary research papers; study-specific PubMed/DOI links and limitations retained. Not publisher full text. · supports · Human THLE-2 non-tumour liver and HepG2 hepatoma cell lines · source_derived_draft · unverified_draft

## betalains-hepg2-methylation-null Betanin did not alter GSTP1 methylation in HepG2 cells. Model/species: Human THLE-2 non-tumour liver and HepG2 hepatoma cell lines Tissue: Liver-derived cells; cytosol and nucleus Exposure: Betanin 2, 10 and 20 micromolar Route: In vitro incubation Duration: Not specified in accessed primary abstract Limits: Responses differed by cell line. Nuclear translocation is not proof of universal transcriptional activation; kinase association does not prove direct binding. Primary reference: Betanin, a beetroot component, induces nuclear factor erythroid-2-related factor 2-mediated expression of detoxifying/antioxidant enzymes in human liver cell lines. (2013). https://pubmed.ncbi.nlm.nih.gov/23769299/ DOI: 10.1017/S0007114513001645

evidence_span

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experimental_model

Lipid-peroxyl radical challenge in liposomes

exposure

AAPH or AMVN challenge; dietary and meso zeaxanthin

limitations

Protein-associated antioxidant synergy is demonstrated in this assay, not a clinical supplement combination.

nutrient_topic

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

organism

Cell-free system with human GSTP1

plain_language

This binding-related effect persisted without glutathione.

primary_references

[zeaxanthin-p15949677] Synergistic effects of zeaxanthin and its binding protein in the prevention of lipid membrane oxidation. (2005). https://pubmed.ncbi.nlm.nih.gov/15949677/ DOI: 10.1016/j.bbadis.2005.02.002

tissue_or_cell_type

Egg-yolk phosphatidylcholine liposomes

Zeaxanthin: metabolism, signaling and nutrient connections (2026-09-17) · lines 288–299

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Lipid-peroxyl radical challenge in liposomes · source_derived_draft · unverified_draft

### zeaxanthin-gsh-independent The GSTP1–zeaxanthin protective effect did not require glutathione in this liposome experiment. Condition category: normal nutrient_topic: Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. plain_language: This binding-related effect persisted without glutathione. organism: Cell-free system with human GSTP1 tissue_or_cell_type: Egg-yolk phosphatidylcholine liposomes experimental_model: Lipid-peroxyl radical challenge in liposomes limitations: Protein-associated antioxidant synergy is demonstrated in this assay, not a clinical supplement combination. exposure: AAPH or AMVN challenge; dietary and meso zeaxanthin evidence_span: {"source_cache": "artifacts/zeaxanthin-research/15949677.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194", "start_char": 0, "end_char": 1404, "text_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194"} [zeaxanthin-p15949677] Synergistic effects of zeaxanthin and its binding protein in the prevention of lipid membrane oxidation. (2005). https://pubmed.ncbi.nlm.nih.gov/15949677/ DOI: 10.1016/j.bbadis.2005.02.002

evidence_span

{"source_cache": "artifacts/zeaxanthin-research/15949677.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194", "start_char": 0, "end_char": 1404, "text_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194"}

experimental_model

Lipid-peroxyl radical challenge in liposomes

exposure

AAPH or AMVN challenge; dietary and meso zeaxanthin

limitations

Protein-associated antioxidant synergy is demonstrated in this assay, not a clinical supplement combination.

nutrient_topic

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

organism

Cell-free system with human GSTP1

plain_language

Binding enhanced protection of the test membrane.

primary_references

[zeaxanthin-p15949677] Synergistic effects of zeaxanthin and its binding protein in the prevention of lipid membrane oxidation. (2005). https://pubmed.ncbi.nlm.nih.gov/15949677/ DOI: 10.1016/j.bbadis.2005.02.002

tissue_or_cell_type

Egg-yolk phosphatidylcholine liposomes

Zeaxanthin: metabolism, signaling and nutrient connections (2026-09-17) · lines 262–273

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Lipid-peroxyl radical challenge in liposomes · source_derived_draft · unverified_draft

### zeaxanthin-gstp1-synergy GSTP1-bound dietary zeaxanthin synergistically inhibited peroxidation induced by either radical generator. Condition category: normal nutrient_topic: Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. plain_language: Binding enhanced protection of the test membrane. organism: Cell-free system with human GSTP1 tissue_or_cell_type: Egg-yolk phosphatidylcholine liposomes experimental_model: Lipid-peroxyl radical challenge in liposomes limitations: Protein-associated antioxidant synergy is demonstrated in this assay, not a clinical supplement combination. exposure: AAPH or AMVN challenge; dietary and meso zeaxanthin evidence_span: {"source_cache": "artifacts/zeaxanthin-research/15949677.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194", "start_char": 0, "end_char": 1404, "text_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194"} [zeaxanthin-p15949677] Synergistic effects of zeaxanthin and its binding protein in the prevention of lipid membrane oxidation. (2005). https://pubmed.ncbi.nlm.nih.gov/15949677/ DOI: 10.1016/j.bbadis.2005.02.002

evidence_span

{"source_cache": "artifacts/zeaxanthin-research/15949677.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194", "start_char": 0, "end_char": 1404, "text_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194"}

experimental_model

Lipid-peroxyl radical challenge in liposomes

exposure

AAPH or AMVN challenge; dietary and meso zeaxanthin

limitations

Protein-associated antioxidant synergy is demonstrated in this assay, not a clinical supplement combination.

nutrient_topic

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

organism

Cell-free system with human GSTP1

plain_language

The two stereoisomers were not identical in this comparison.

primary_references

[zeaxanthin-p15949677] Synergistic effects of zeaxanthin and its binding protein in the prevention of lipid membrane oxidation. (2005). https://pubmed.ncbi.nlm.nih.gov/15949677/ DOI: 10.1016/j.bbadis.2005.02.002

tissue_or_cell_type

Egg-yolk phosphatidylcholine liposomes

Zeaxanthin: metabolism, signaling and nutrient connections (2026-09-17) · lines 301–312

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Lipid-peroxyl radical challenge in liposomes · source_derived_draft · unverified_draft

### zeaxanthin-meso-bound-protection GSTP1-bound meso-zeaxanthin was more protective than bound dietary zeaxanthin in this assay. Condition category: normal nutrient_topic: Zeaxanthin research collection; topical membership is not evidence of a direct dietary effect. plain_language: The two stereoisomers were not identical in this comparison. organism: Cell-free system with human GSTP1 tissue_or_cell_type: Egg-yolk phosphatidylcholine liposomes experimental_model: Lipid-peroxyl radical challenge in liposomes limitations: Protein-associated antioxidant synergy is demonstrated in this assay, not a clinical supplement combination. exposure: AAPH or AMVN challenge; dietary and meso zeaxanthin evidence_span: {"source_cache": "artifacts/zeaxanthin-research/15949677.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194", "start_char": 0, "end_char": 1404, "text_sha256": "4ed175c0b5cf937df5a37c94739b40d713261c3a99e2bebc02b3b6a37ea3f194"} [zeaxanthin-p15949677] Synergistic effects of zeaxanthin and its binding protein in the prevention of lipid membrane oxidation. (2005). https://pubmed.ncbi.nlm.nih.gov/15949677/ DOI: 10.1016/j.bbadis.2005.02.002