Human inducible nitric oxide synthase / iNOS / NOS2

dose

Indicaxanthin 5-25 micromolar with IL-1beta 25 ng/mL

duration

24 h for mediator release and permeability; earlier signaling assays

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

Differentiated human Caco-2 intestinal epithelial monolayers

limitations

No clinical IBD treatment effect or molecular binding site was established. Total thiols must not be relabeled as a specific glutathione measurement.

nutrient_topic

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

organism

Differentiated human Caco-2 intestinal epithelial monolayers

plain_language

Indicaxanthin reduced induced nitric oxide synthase expression in IL-1beta-exposed Caco-2 cells.

primary_references

Indicaxanthin inhibits NADPH oxidase (NOX)-1 activation and NF-κB-dependent release of inflammatory mediators and prevents the increase of epithelial permeability in IL-1β-exposed Caco-2 cells. (2014). https://pubmed.ncbi.nlm.nih.gov/23931157/ DOI: 10.1017/S0007114513002663

route

In vitro co-incubation

tissue

Intestinal epithelial model

Betalains: mechanisms, molecular forms and cross-actor connections (2026-09-20) · lines 287–295

Original AI-assisted curation of twelve primary research papers; study-specific PubMed/DOI links and limitations retained. Not publisher full text. · supports · Differentiated human Caco-2 intestinal epithelial monolayers · source_derived_draft · unverified_draft

## betalains-caco2-nos2 Indicaxanthin reduced induced nitric oxide synthase expression in IL-1beta-exposed Caco-2 cells. Model/species: Differentiated human Caco-2 intestinal epithelial monolayers Tissue: Intestinal epithelial model Exposure: Indicaxanthin 5-25 micromolar with IL-1beta 25 ng/mL Route: In vitro co-incubation Duration: 24 h for mediator release and permeability; earlier signaling assays Limits: No clinical IBD treatment effect or molecular binding site was established. Total thiols must not be relabeled as a specific glutathione measurement. Primary reference: Indicaxanthin inhibits NADPH oxidase (NOX)-1 activation and NF-κB-dependent release of inflammatory mediators and prevents the increase of epithelial permeability in IL-1β-exposed Caco-2 cells. (2014). https://pubmed.ncbi.nlm.nih.gov/23931157/ DOI: 10.1017/S0007114513002663

evidence_span

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experimental_model

Crystal structures of zinc-free and zinc-bound heme domains

exposure

Zinc-free versus zinc-tetrathiolate-containing structures

limitations

Direct structure is NOS2; similarity to NOS3 does not justify silently treating the proteins as identical.

nutrient_topic

Citrulline research collection; topical membership is not evidence of a direct dietary effect. · L-Citrulline

organism

Human NOS2

plain_language

The structural metal and the pterin-binding region are connected.

primary_references

[citrulline-p10409685] Crystal structures of zinc-free and -bound heme domain of human inducible nitric-oxide synthase. Implications for dimer stability and comparison with endothelial nitric-oxide synthase. (1999). https://pubmed.ncbi.nlm.nih.gov/10409685/ DOI: 10.1074/jbc.274.30.21276

tissue_or_cell_type

NOS dimer interface and pterin-binding region

Citrulline: arginine recycling, nitrogen disposal and nutrient connections (2026-09-17) · lines 606–617

AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Crystal structures of zinc-free and zinc-bound heme domains · source_derived_draft · unverified_draft

### citrulline-inos-zinc-interface The NOS2 zinc-tetrathiolate center supported intersubunit contacts and integrity of the BH4-binding site. Condition category: normal nutrient_topic: Citrulline research collection; topical membership is not evidence of a direct dietary effect. plain_language: The structural metal and the pterin-binding region are connected. organism: Human NOS2 tissue_or_cell_type: NOS dimer interface and pterin-binding region experimental_model: Crystal structures of zinc-free and zinc-bound heme domains limitations: Direct structure is NOS2; similarity to NOS3 does not justify silently treating the proteins as identical. exposure: Zinc-free versus zinc-tetrathiolate-containing structures evidence_span: {"source_cache": "artifacts/citrulline-research/10409685.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c320fb6f3fd659a2e7df4a8ddd3467a902a07b84380075d429040eaf244ccf6b", "start_char": 0, "end_char": 942, "text_sha256": "c320fb6f3fd659a2e7df4a8ddd3467a902a07b84380075d429040eaf244ccf6b"} [citrulline-p10409685] Crystal structures of zinc-free and -bound heme domain of human inducible nitric-oxide synthase. Implications for dimer stability and comparison with endothelial nitric-oxide synthase. (1999). https://pubmed.ncbi.nlm.nih.gov/10409685/ DOI: 10.1074/jbc.274.30.21276