Compound Monograph
Casticin
Casticin (vitexicarpin) is the HPLC standardisation marker of chaste-tree (Vitex agnus-castus) fruit. Its own pharmacology is a broad but entirely preclinical anticancer literature — distinctive for a tubulin-binding, antimitotic mechanism alongside STAT3 and FOXO3a modulation — plus anti-inflammatory and immunomodulatory signals. Chaste-tree's clinical PMS/prolactin effects belong to the herb's dopaminergic diterpene extract, not to casticin.
Classification
Casticin is a flavone (methoxyflavone), part of the phenolics class. Antioxidant compounds built around one or more phenol rings — the flavonoids, tannins, phenolic acids, coumarins, and pigments behind much of a plant's protective chemistry.
Where Does It Come From? (6)
Casticin is a naturally occurring flavone (methoxyflavone), found in Chaste Tree fruit — QC standardisation marker, Vitex trifolia and Vitex rotundifolia and 4 other sources. It is well tolerated orally (low toxicity).
Pharmacology & Research
Casticin (vitexicarpin) is a hexasubstituted methoxyflavone — a relative of luteolin/apigenin and a sibling of the methoxyflavones eupatorin and jaceosidin — best known as the HPLC standardisation marker of chaste-tree fruit. The load-bearing distinction for the whole page: casticin is a QC marker, and Vitex’s human PMS/mastalgia/prolactin-lowering evidence belongs to the herb’s dopaminergic labdane diterpenes / whole-fruit extract, not to casticin 3Reference 3Chaste tree (Vitex agnus-castus) — pharmacology and clinical indicationsView study →. Casticin’s own literature is a broad but entirely preclinical anticancer dataset — distinctive for a tubulin-binding, antimitotic mechanism — plus anti-inflammatory and immunomodulatory work. No human trial has ever dosed casticin as an isolate.
- Broad preclinical anticancer activity with a distinctive mechanism: tubulin-binding/antimitotic arrest plus STAT3 suppression and FOXO3a activation across many tumour lines, with a few xenograft confirmations 4,8,11Reference 4The flavonoid casticin has multiple mechanisms of tumour cytotoxicity (a tubulin-binding agent)View study →Reference 8Casticin suppresses the carcinogenesis of small-cell lung cancer H446 cells through AMPK/FoxO3a signallingView study →Reference 11AnimalCasticin inhibits the in-vivo growth of xenograft tumours of human oral cancer SCC-4 cellsView study →.
- The honest headline: all preclinical, mostly in-vitro at µM concentrations; none of chaste-tree’s clinical trials belong to casticin (they are the extract’s diterpenes); human isolate exposure is a trivial ~0.14 mg/day marker quantity 3Reference 3Chaste tree (Vitex agnus-castus) — pharmacology and clinical indicationsView study →.
1. Anticancer
The bulk of casticin’s literature — apoptosis with G2/M or G0/G1 arrest across glioma 5Reference 5Casticin induces human glioma cell death through apoptosis and mitotic arrestView study →, leukemia 6Reference 6Casticin induces leukemic cell death through apoptosis and mitotic catastropheView study →, gallbladder 10Reference 10Casticin induces apoptosis and G0/G1 cell-cycle arrest in gallbladder cancer cellsView study →, breast, esophageal, oral, hepatocellular, ovarian and lung lines, consolidated in dedicated reviews 1,2Reference 1ReviewCasticin from Vitex species: a short review on its anticancer and anti-inflammatory propertiesView study →Reference 2An overview of the potential antineoplastic effects of casticinView study →. Mechanistically it is a tubulin-binding agent driving mitotic arrest and catastrophe 4Reference 4The flavonoid casticin has multiple mechanisms of tumour cytotoxicity (a tubulin-binding agent)View study →, it suppresses STAT3 (sensitising cells to radiation) 7Reference 7Casticin inhibits growth and enhances ionizing-radiation-induced apoptosis through suppression of the STAT3 signalling cascadeView study → and activates FOXO3a (via AMPK, and by repressing FoxM1) 8,9Reference 8Casticin suppresses the carcinogenesis of small-cell lung cancer H446 cells through AMPK/FoxO3a signallingView study →Reference 9Casticin induces growth suppression and cell-cycle arrest through activation of FOXO3a in hepatocellular carcinomaView study →, with intrinsic Bcl-2↓/Bax apoptosis retained even in p53-null cells; in-vivo support includes growth inhibition of oral-cancer SCC-4 xenografts 11Reference 11AnimalCasticin inhibits the in-vivo growth of xenograft tumours of human oral cancer SCC-4 cellsView study →.
Gap: overwhelmingly in-vitro at µM concentrations, with only small in-vivo studies and no human isolate data — the tumour-line breadth is real but hypothesis-generating, not clinical 1,4Reference 1ReviewCasticin from Vitex species: a short review on its anticancer and anti-inflammatory propertiesView study →Reference 4The flavonoid casticin has multiple mechanisms of tumour cytotoxicity (a tubulin-binding agent)View study →.
2. Anti-inflammatory / anti-allergic
Casticin blunted cigarette-smoke-induced acute lung inflammation in vivo 12Reference 12Casticin, an active compound from Vitex fructus, ameliorates cigarette-smoke-induced acute lung inflammationView study → and inhibited eosinophil migration and chemokine/adhesion-molecule expression in lung epithelial cells 13Reference 13Inhibitory effects of casticin on eosinophil migration and expression of chemokines and adhesion molecules in A549 lung epithelial cellsView study →, with NF-κB inhibition the recurring mechanism — the activity the chaste-tree notes originally attributed to casticin.
Gap: cell and small-rodent models only, with no human data (and a prominent COPD/NF-κB paper in this space is retracted and deliberately excluded here) 12,13Reference 12Casticin, an active compound from Vitex fructus, ameliorates cigarette-smoke-induced acute lung inflammationView study →Reference 13Inhibitory effects of casticin on eosinophil migration and expression of chemokines and adhesion molecules in A549 lung epithelial cellsView study →.
3. Immunomodulatory
Casticin/vitexicarpin shows bidirectional immune effects — it enhanced innate macrophage and NK-cell activity with improved survival in a leukemia mouse model 14Reference 14AnimalCasticin promotes immune responses, enhances macrophage and NK-cell activities and increases survival in leukemia BALB/c miceView study →, yet suppresses mitogen-driven lymphocyte proliferation 15Reference 15AnimalVitexicarpin, a flavonoid from the fruits of Vitex rotundifolia, inhibits mouse lymphocyte proliferationView study →.
Gap: two small preclinical models pulling in opposite directions, with no coherent human immunopharmacology 14,15Reference 14AnimalCasticin promotes immune responses, enhances macrophage and NK-cell activities and increases survival in leukemia BALB/c miceView study →Reference 15AnimalVitexicarpin, a flavonoid from the fruits of Vitex rotundifolia, inhibits mouse lymphocyte proliferationView study →.
Mechanisms
| Target / pathway | Effect | Relevant to |
|---|---|---|
| β-Tubulin / microtubules | tubulin-binding → inhibits polymerisation → mitotic (G2/M) arrest and catastrophe | anticancer (core mechanism); reproductive caution |
| p21↑ → Cdk1 inhibition; cyclin A↓ | cell-cycle arrest | anticancer |
| Bcl-2↓ / Bax; mitochondrial apoptosis; JNK | apoptosis (retained in p53-null and Pgp-overexpressing cells) | anticancer (broad lines) |
| STAT3 (incl. JAK2/STAT3) | suppressed → growth inhibition + radiosensitisation | anticancer |
| FOXO3a (via AMPK; represses FoxM1) | activated | anticancer |
| NF-κB; eosinophil migration; chemokines/adhesion molecules | inhibited | anti-inflammatory / anti-allergic |
| Macrophage / NK activity; lymphocyte proliferation | enhanced; inhibited | immunomodulatory (bidirectional) |
Pharmacokinetics
Casticin is a typical poorly-bioavailable methoxyflavone. Rat studies report low systemic exposure and rapid elimination, and metabolism work shows extensive phase-I/II biotransformation — demethylation plus glucuronidation/sulfation — consistent with high first-pass turnover 17Reference 17AnimalMetabolism studies of casticin in rats using HPLC-ESI-MSⁿView study →. The methoxy groups improve membrane permeability relative to hydroxylated flavones, but the compound is still subject to fast conjugative clearance, and there are no human pharmacokinetic data for the isolate. At herb-relevant exposure (~0.14 mg/day from a standardised chaste-tree dose), systemic casticin is negligible.
Clinical trials
There are no trials of the isolate. Casticin has never been administered to humans as a single compound for efficacy, PK or safety. All human Vitex agnus-castus trials (PMS, mastalgia, cyclical breast pain, hyperprolactinaemia, PCOS) tested the whole standardised fruit extract, and their effects are attributed to the dopaminergic diterpene fraction — casticin serves only as an HPLC standardisation marker there 3Reference 3Chaste tree (Vitex agnus-castus) — pharmacology and clinical indicationsView study →.
| Completed | Planned | Terminated | Preclinical |
|---|---|---|---|
| —(none, isolate) | — | — | Substantial(anticancer-dominated; some in-vivo) |
Last checked: July 2026.
Toxicity & Safety
Casticin’s [low] flag is chosen on the balance of evidence, with one honest caveat. No dedicated casticin toxicology of concern surfaced; the parent herb (Vitex agnus-castus) is well tolerated in trials; flavones generally show preferential toxicity toward transformed over normal cells; and human marker exposure is trivial (~0.14 mg/day). The one signal that could argue for a higher rating is casticin’s tubulin-binding/antimitotic mechanism 4Reference 4The flavonoid casticin has multiple mechanisms of tumour cytotoxicity (a tubulin-binding agent)View study → — antimitotic agents carry an intrinsic, mechanism-based concern for rapidly dividing tissues (bone marrow, gut, gonads, embryo). Because that concern is theoretical at realistic exposures and there is no observed isolate toxicology, the flag is held at [low] while the antimitotic caution is surfaced explicitly and drives a firm pregnancy verdict. Methoxyflavone CYP-modulation herb–drug-interaction potential is plausible but not well characterised for casticin specifically.
Pregnancy & lactation
Avoid. Two independent reasons converge: casticin is an antimitotic tubulin-binding agent — a mechanism class with inherent teratogenic/anti-proliferative concern for the embryo, and no reproductive-safety data exist for the isolate; and its principal source herb, chaste-tree, is hormonally active (dopaminergic, prolactin-lowering) and is itself cautioned in pregnancy and lactation.
Dosage
There is no established human dose — casticin has never been given to humans as an isolate, and all dosing in the literature is preclinical (µM in vitro; mg/kg in rodents) that does not translate. As a chaste-tree constituent, incidental intake is ~0.14 mg/day from a standardised daily dose — a QC-marker quantity, not a therapeutic one, so no human figure should be inferred.
References
- Chan EWC, et al. (2018). Casticin from Vitex species: a short review on its anticancer and anti-inflammatory properties. Journal of Integrative Medicine. https://pubmed.ncbi.nlm.nih.gov/29559215/
- Ramchandani S, et al. (2020). An overview of the potential antineoplastic effects of casticin. Molecules. https://pubmed.ncbi.nlm.nih.gov/32178324/
- Wuttke W, et al. (2003). Chaste tree (Vitex agnus-castus) — pharmacology and clinical indications. Phytomedicine. https://pubmed.ncbi.nlm.nih.gov/12809367/
- Haïdara K, et al. (2006). The flavonoid casticin has multiple mechanisms of tumour cytotoxicity (a tubulin-binding agent). Cancer Letters. https://pubmed.ncbi.nlm.nih.gov/16387422/
- Liu E, et al. (2013). Casticin induces human glioma cell death through apoptosis and mitotic arrest. Cellular Physiology and Biochemistry. https://pubmed.ncbi.nlm.nih.gov/23816816/
- Shen JK, et al. (2009). Casticin induces leukemic cell death through apoptosis and mitotic catastrophe. Annals of Hematology. https://pubmed.ncbi.nlm.nih.gov/19139893/
- Lee JH, et al. (2019). Casticin inhibits growth and enhances ionizing-radiation-induced apoptosis through suppression of the STAT3 signalling cascade. Journal of Cellular Biochemistry. https://pubmed.ncbi.nlm.nih.gov/30520154/
- Gong Q, et al. (2018). Casticin suppresses the carcinogenesis of small-cell lung cancer H446 cells through AMPK/FoxO3a signalling. Oncology Reports. https://pubmed.ncbi.nlm.nih.gov/30015975/
- He L, et al. (2013). Casticin induces growth suppression and cell-cycle arrest through activation of FOXO3a in hepatocellular carcinoma. Oncology Reports. https://pubmed.ncbi.nlm.nih.gov/23064420/
- Song XL, et al. (2017). Casticin induces apoptosis and G0/G1 cell-cycle arrest in gallbladder cancer cells. Cancer Cell International. https://pubmed.ncbi.nlm.nih.gov/28070171/
- Shang HS, et al. (2020). Casticin inhibits the in-vivo growth of xenograft tumours of human oral cancer SCC-4 cells. In Vivo. https://pubmed.ncbi.nlm.nih.gov/32871773/
- Lee H, et al. (2015). Casticin, an active compound from Vitex fructus, ameliorates cigarette-smoke-induced acute lung inflammation. International Immunopharmacology. https://pubmed.ncbi.nlm.nih.gov/26321116/
- Koh DJ, et al. (2011). Inhibitory effects of casticin on eosinophil migration and expression of chemokines and adhesion molecules in A549 lung epithelial cells. Journal of Ethnopharmacology. https://pubmed.ncbi.nlm.nih.gov/21251967/
- Lai KC, et al. (2019). Casticin promotes immune responses, enhances macrophage and NK-cell activities and increases survival in leukemia BALB/c mice. American Journal of Chinese Medicine. https://pubmed.ncbi.nlm.nih.gov/30630343/
- You KM, et al. (1998). Vitexicarpin, a flavonoid from the fruits of Vitex rotundifolia, inhibits mouse lymphocyte proliferation. Planta Medica. https://pubmed.ncbi.nlm.nih.gov/9741302/
- Alam G, et al. (2002). Tracheospasmolytic activity of viteosin-A and vitexicarpin isolated from Vitex trifolia. Planta Medica. https://pubmed.ncbi.nlm.nih.gov/12451502/
- Ling Y, et al. (2012). Metabolism studies of casticin in rats using HPLC-ESI-MSⁿ. Biomedical Chromatography. https://pubmed.ncbi.nlm.nih.gov/22407499/