Effects of Sulforaphane for Skin Protection
Protects skin from UV damage
In order to verify the protective effect of sulforaphane (SFN) on the skin under UV exposure, the team of Professor Paul Talalay of Johns Hopkins University first examine the safety and efficacy of topical application of SFN. A dose-escalation safety study in healthy human subjects revealed no adverse reactions when doses as high as 340 nmol of SFN in the form of broccoli sprout extracts were applied topically to the center of a 1-cm-diameter circle drawn on the volar forearm. In subsequent efficacy studies, the results of skin punch biopsies showed that the enzyme activity of quinone oxidoreductase NQO1 increased in a dose-dependent manner.
Then, Professor Paul Talalay's team verified that SFN can mobilize cellular defense that protect skin against damage by UV radiation. Topical application of SFN-rich extracts of 3-day-old broccoli sprouts up-regulated phase 2 enzymes in the mouse and human skin, protected against UVR-induced inflammation and edema in mice, and reduced susceptibility to erythema arising from UVR in humans. In six human subjects (three males and three females, 28-53 years of age), the mean reduction in erythema across six doses of UVR (300-800 mJ/cm2 in 100 mJ/cm2 increments) was 37.7%.
A novel keloid treatment
SFN, a dietary isothiocyanate, has recently shown anti-tumor, anti-inflammatory and anti-fibrotic properties. In a study published in 2007 by Kyoto Prefecture Medical University, they evaluated the effects of SFN against keloid fibroblasts in both a single cell culture and a coculture with peripheral blood mononuclear cells (PBMC). The result indicated that SFN inhibited cell growth and reduced collagen at the mRNA and protein levels in keloid fibroblasts. This study suggests that sulforaphane may be a novel keloid treatment.
Ameliorates skin aging
In a study, researchers have investigated whether SFN may alleviate PM2.5-induced premature skin aging. In this study, SFN inhibited the development of reactive oxygen species in keratinocytes exposed to PM2.5. In keratinocyte/melanocyte cocultures, it significantly inhibited the upregulation of melanogenic paracrine mediators in keratinocytes exposed to PM2.5 and the levels of melanin in melanocytes. The results suggest that SFN mitigates PM2.5-induced premature skin aging by suppressing melanogenesis and maintaining collagen homeostasis.
In the animal experiment, male C57BL6 young (2 months) and old (21 months) mice were treated for 3 months with SFN diet (442.5 mg/kg) or control diet. The antioxidant capacities of the skin were increased in old SFN-treated animals as measured by mRNA levels of Nrf2 and its target genes NQO1and HO1. Protein expression for Nrf2 was also increased in old SFN fed animals, ROS and MMP9 protein levels were significantly decreased. Moreover, collagen deposition was improved with SFN treatment in young and structurally significantly improved in the old mice. SFN dietary supplementation therefore ameliorates skin aging through activation of the Nrf2-pathway.
References（obtained by email firstname.lastname@example.org）
 Dinkova-Kostova A T , Fahey J W , Wade K L , et al. Induction of the Phase 2 Response in Mouse and Human Skin by Sulforaphane-containing Broccoli Sprout Extracts[J]. Cancer Epidemiol Biomarkers Prev, 2007, 16(4):847-851.
 Thiers, B. H . Sulforaphane mobilizes cellular defenses that protect skin against damage by UV radiation[J]. Yearbook of Dermatology and Dermatologic Surgery, 2008, 2008:205-206.
 Horinaka, Mano, Yasuda, et al. Sulforaphane suppresses cell growth and collagen expression of keloid fibroblasts[J]. Wound repair and regeneration: official publication of the Wound Healing Society [and] the European Tissue Repair Society, 2017.
 Hjka B , Jin H , Gsl A , et al. Sulforaphane controls the release of paracrine factors by keratinocytes and thus mitigates particulate matter-induced premature skin aging by suppressing melanogenesis and maintaining collagen homeostasis[J]. Phytomedicine, 2020, 77.
 Mpab C , Eclb C , Ia B , et al. Dietary supplementation with sulforaphane ameliorates skin aging through activation of the Keap1-Nrf2 pathway[J]. The Journal of Nutritional Biochemistry, 2021.