Intervention Summary
Indole-3-carbinol (I3C) and its metabolite 3,3'-diindolylmethane (DIM) — derived from cruciferous vegetables and also produced by gut bacteria from tryptophan metabolism — as multi-mechanism agents for ovarian cancer. Three independent papers support I3C through distinct pathways: EGFR inhibition (platinum resistance), bortezomib sensitization, and cisplatin chemoprotection. This makes I3C one of the most well-triangulated supplement candidates for OC, though no human clinical trial exists yet.
Evidence
EGFR Inhibition (Dash 2015)
- I3C and DIM show significant inhibitory activity against EGFR tyrosine kinase in platinum-resistant OC (molecular docking + ADME)
- Source: dash 2015 indole 3 carbinol dim egfr ovarian cancer (computational prediction)
Bortezomib Sensitization (Taylor-Harding 2012)
- I3C sensitized OC cell lines to bortezomib; combination caused cell cycle arrest and apoptosis via ER stress and cytoskeletal disruption
- In vivo co-treatment significantly inhibited tumor growth in mice
- Source: taylor harding 2012 indole 3 carbinol bortezomib ovarian cancer (in vitro + animal model)
Cisplatin Chemoprotection (Zhu 2026)
- I3C alleviates cisplatin-induced ovarian damage by inhibiting fibrosis through TGF-beta1/Smad pathway
- Preserves ovarian function during chemotherapy
- Source: zhu 2026 indole 3 carbinol cisplatin ovarian fibrosis (animal model)
Mechanism
I3C acts through at least three independent pathways:
- EGFR kinase inhibition: Targets platinum resistance directly
- ER stress induction: Sensitizes tumor cells to proteasome inhibition
- TGF-beta1/Smad inhibition: Protects healthy ovarian tissue from chemotherapy damage
- Gut microbiome connection: I3C is an indole metabolite related to microbial tryptophan metabolism. The protective indole metabolites IPA and indoxyl sulfate (suppressed by antibiotics in OC) are in the same metabolic family.
Clinical Context
I3C is available as a dietary supplement and from cruciferous vegetable consumption. The safety profile is well-established. The gap is human clinical trial data specifically in OC — preclinical evidence across three independent mechanisms argues strongly for clinical investigation.