Cucumis Sativus (Cucumber) Fruit Extract
Also known as Cucumber Fruit Extract, Cucumis sativus extract
“CIR Expert Panel says: safe as used in cosmetics.”
Cucumis Sativus (Cucumber) Fruit Extract (CAS 89998-01-6, EINECS 289-738-4) is the whole-fruit extract of Cucumis sativus L. (family Cucurbitaceae), prepared by extracting peeled or unpeeled cucumber fruit in glycerin/water, water/butylene glycol, or water/propylene glycol vehicles. Cucumber fruit is >96% water; the residual constituents include vitamins (notably ascorbic acid, vitamin K traces), minerals, amino acids, phenolic acids (caffeic, ferulic, chlorogenic), flavonoids (quercetin, apigenin, luteolin, kaempferol), trace cucurbitacins, phytosterols (β-sitosterol, campesterol, stigmasterol), and the iminosugar idoBR1 (Nash 2020 PMID 32656449). The CIR Expert Panel issued a final safety assessment in June 2012 (published IJT 33(2 Suppl):47S-64S, 2014, PMID 24861368) covering six Cucumis sativus-derived INCIs — Fruit Extract, Extract, Fruit, Fruit Water, Juice, Seed Extract — and concluded all are 'safe in cosmetic formulations in the present practices of use and concentration.' The assessment is the load-bearing safety source: cucumbers are FDA-listed among the 20 most consumed raw vegetables (oral safety inferred from food use); Fruit Extract was not mutagenic in the Ames assay (156-5000 µg/plate, ±metabolic activation); HRIPTs at 1% (eye lotion, n=103 and n=108) and at 5% (eye treatment mask, n=600; eye hydrogel, n=100) demonstrated no dermal sensitization; 5% formulation was not phototoxic; in vitro ocular tests (CAMVA, BCOP, EpiOcular) predicted no ocular irritation. Reported maximum leave-on use is 1% (eye lotions, face & neck products); spray products use up to 0.2%; rinse-off use ≤0.4%. Mukherjee 2013 (PMID 23098877) reviews phytochemistry and traditional dermatological use ('fresh fruit juice nourishes the skin', soothing/anti-inflammatory effect on skin irritations and sunburn). The Panel flagged cross-allergenicity with other Cucurbitaceae, ragweed pollen, and latex, plus a single occupational case report of cucumber-leaf-induced eczema in a greenhouse worker — none rising to a safety bar for cosmetic use.
CIR Expert Panel concluded Cucumis Sativus (Cucumber) Fruit Extract is SAFE for cosmetic use at present practices and concentrations (Sept 2022 QRT row Finding=S; final report IJT 33(Suppl. 2):47-64, 2014, PMID 24861368) — among the strongest regulatory clearances available for a botanical extract.
Soothing / skin-conditioning agent: documented 21-day eye-gel use study at 5% and 28-day eye-lotion use study at 1% with no dermal irritation reported; HRIPTs at 1% (n=103, n=108, n=600) and 5% (n=100) confirmed non-sensitizing (CIR FR 2012, pp. 4-5).
Anti-inflammatory mechanism: iminosugar idoBR1 isolated from cucumber fruit reduces lipopolysaccharide-induced TNF-α in human monocytes and selectively inhibits glucosylceramidase 2 (GBA2) and cytosolic β-glucosidase (Nash et al. 2020, PMID 32656449) — provides molecular plausibility for traditional topical 'soothing' claims.
Skin hydration / cosmetic vehicle: the >96% water content plus glycerin/butylene glycol vehicle commonly used in fruit-extract preparations contribute to surface hydration claims; cucumber Fruit Water reaches up to 3% in foundations.
Suitable for sensitive use cases: applied in eye-area products, baby products, and mucous-membrane formulations in the existing market without documented safety concerns at typical use concentrations.
Plant: Cucumis sativus L., family Cucurbitaceae (gourd family); INCI preparation is a glycerin- or glycol-water extract of the whole fruit. Distinct from Cucumis sativus Seed Extract (separate INCI, separate QRT row), Seed Oil (separately assessed in the 2017 plant-derived fatty oils report), and the leaf/stem (not used as cosmetic INCIs and the CIR FR's single occupational sensitization case report involved leaves).
Cross-allergenicity / IgE cross-reactivity documented with ragweed pollen, latex, and other Cucurbitaceae (celery, carrot, watermelon); systemic anaphylaxis case report in a latex-sensitized patient (CIR FR 2012 references 35-37). Topical cosmetic use has not been associated with these reactions in the assessment record.
Pesticide residue and heavy metals: CIR Expert Panel flagged the standard botanical concern that pesticide residues and heavy metals 'may be present in botanical ingredients' and that industry should continue procedures to limit these impurities prior to formulation. Not a hazard of the extract per se but an ingredient-quality consideration.
Single occupational case report (CIR FR ref 38): a greenhouse cucumber worker developed eczema after 5 months of plant contact, with positive patch reaction to cucumber leaves and stem (++ on days 2,3,7); reaction was to the LEAVES, not the fruit extract. Slight redness in 2 of 10 healthy controls. Suggests low-but-nonzero sensitization potential of plant biomass, primarily occupational.
Plant-part identity discipline: Cucumis sativus has multiple distinct INCI preparations covered by the same CIR group assessment — Fruit Extract, Extract, Fruit, Fruit Water, Juice, Seed Extract (all S in the Sept 2022 QRT) — plus Seed Oil (separately assessed S in IJT 36(Suppl. 3):51-129, 2017). This packet covers FRUIT EXTRACT specifically; formulators using Seed Extract or Seed Oil should consult the relevant separate row. The cucumber group is an 'always-safe-across-parts' species (counter-example to Calendula/Pyrus split-verdict pattern).
Modest pharmacological profile: cucumber fruit is >96% water, and active-constituent levels (cucurbitacins, polyphenols, vitamins C and K) are present in trace amounts. Cosmetic claims for 'soothing' and 'hydration' are well-supported by use history, but the bioactive evidence is correspondingly modest — the extract should not be marketed as having strong therapeutic activity equivalent to concentrated polyphenol botanicals (Camellia sinensis, Glycyrrhiza glabra).
CIR Quick Reference Table (September 2022) — Cucumis Sativus (Cucumber) Fruit Extract row: Finding=S, Citation=IJT 33(Suppl. 2):47-64, 2014
“Cucumis Sativus (Cucumber) Fruit Extract S IJT 33(Suppl. 2):47‐64, 2014”— QuickReferenceTable_AllConclusionTypes.pdf, p. 160