Study 1: Resveratrol inhibits NFκB activation in normal human keratinocytes
An in-vitro study evaluated the chemopreventive ability of resveratrol against UV induced damage in cultured normal keratinocytes. The keratinocytes were irradiated with the 40 mJ/cm2 of ultraviolet B radiation and irradiation-induced activation of NFκB was measured. Treatment of keratinocytes with the resveratrol (5, 10, and 25 micro M resveratrol for 24 hours) inhibited the activation of NFkB and UV induced damage in a dose-dependent manner. Resveratrol treatment also inhibited UVB-mediated phosphorylation and degradation. The study concluded that resveratrol can support the skin tissue by inhibiting the UV-induced damage of the keratinocytes.
Adhami VM, Afaq F, Ahmad N. Suppression of ultraviolet B exposure-mediated activation of NF-kappaB in normal human keratinocytes by resveratrol. Neoplasia. 2003;5(1):74-82.
Study 2: Resveratrol inhibits melanin by post-transcriptional inhibition of melanin biosynthetic enzymes in human melanocytes
An in vitro study evaluated the effect of resveratrol on the microphthalmia-associated transcription factor (MITF) and melanin biogenic pathways in cultured melanocytes. The primary melanocytes were treated with resveratrol, and the effect of the treatment on the MITF, tyrosinase, tyrosinase-related protein-1, and dopachrome tautomerase (DCT) expression and activity were measured. The results indicated that resveratrol inhibited levels of MITF and the activities of tyrosinase and DCT. The study concluded that resveratrol has potential anti-melanin activity by modulating the pathways leading to the synthesis of melanogenic components and by inhibiting the enzyme tyrosinase of the melanin biosynthetic pathway.
Newton RA, Cook AL, Roberts DW, Leonard JH, Sturm RA. Post-transcriptional regulation of melanin biosynthetic enzymes by cAMP and resveratrol in human melanocytes. J Invest Dermatol. 2007;127(9):2216-2227.
Study 3: Resveratrol inhibits melanin synthesis in Ultraviolet B-induced pigmentation in Guinea Pigskin
In an animal study, the ability of resveratrol to inhibit the upregulation of melanogenesis in short wavelength UV induced melanin pigmentation in Guinea pig was evaluated. The guinea pigs were exposed to 390 mJ/cm2 UVB radiation on the dorsal side after the removal of the hair three times per week for two weeks. The sample containing resveratrol was applied topically onto the dorsal skin once a day for 12 days after the final UVB treatment. The melanin content of the skin tissue was measured using Fontana-Masson staining of skin sections and western blot analysis was done to analyze the levels of proteins related to melanin production. Resveratrol application efficiently reduced melanin synthesis via a reduction in tyrosinase and other related proteins of melanogenesis.
Lee TH, Seo JO, Baek SH, Kim SY. Inhibitory effects of resveratrol on melanin synthesis in ultraviolet B-induced pigmentation in Guinea pigskin. Biomol Ther (Seoul). 2014;22(1):35-40.