Antioxidants 2026, 15(6), 690; https://doi.org/10.3390/antiox15060690 (registering DOI) - 30 May 2026
Abstract
Ultraviolet A (UVA) radiation disrupts the redox balance of melanocytes and may lead to the development of melanoma, highlighting the need for new skin protection strategies. This study assessed the effect of phytocannabinoids [cannabigerol (CBG), cannabidiol (CBD), and CBG + CBD] on redox
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Ultraviolet A (UVA) radiation disrupts the redox balance of melanocytes and may lead to the development of melanoma, highlighting the need for new skin protection strategies. This study assessed the effect of phytocannabinoids [cannabigerol (CBG), cannabidiol (CBD), and CBG + CBD] on redox homeostasis in control and UVA-exposed melanocytes and in melanoma cells (SK-Mel-5). UVA radiation increased the activity of prooxidant enzymes in both melanocytes and SK-Mel-5 cells and, consequently, the level of reactive oxygen species (ROS) (approx. 2-fold). It also activated nuclear factor erythroid 2 (Nrf2), as reflected by increased expression of heme oxygenase 1 (HO-1) (melanocytes approx. 2-fold; SK-Mel-5 approx. 7-fold). Concomitantly, antioxidant mechanisms were impaired, as demonstrated by reduced superoxide dismutase (SOD1/SOD2) activity and impaired glutathione and thioredoxin function. These changes were accompanied by increased levels of oxidative damage markers (isoprostanes, 4-hydroxynonenal-4-HNE, and 4-HNE-protein adducts) (43–100%) and increased inflammatory signaling, including increased expression of nuclear factor kappa B (NF-κB) subunits (melanocytes: p52 ~2-fold, p65 ~75%; SK-Mel-5: ~4–4.5-fold) and tumor necrosis factor alpha (TNF-α; ~30%). Phytocannabinoid treatment modulated these UVA-induced changes. In SK-Mel-5 cells, phytocannabinoids normalized the activity of prooxidant enzymes and consequently reduced ROS levels (~30%). They also reduced Nrf2 activation and HO-1 expression; however, CBG increased HO-1 level in melanocytes (~25–40%). Furthermore, phytocannabinoids enhanced antioxidant defense by increasing SOD activity, particularly in melanocytes (~10–40%), and restoring the glutathione and thioredoxin systems. Markers of oxidative damage were reduced by approximately 23–37% after treatment. Furthermore, phytocannabinoids attenuated NF-κB activation (p52 ~18–28%, p65 ~25–29% in melanocytes; ~20% in SK-Mel-5), while TNF-α levels remained unchanged. The effects in non-irradiated cells were modest (<15%). These results suggest that phytocannabinoid-mediated modulation of redox balance may stabilize melanocytes exposed to UVA radiation and potentially reduce the risk of neoplastic transformation. However, the observed protective effects in SK-Mel-5 cells require further investigation and detailed molecular analysis.
Full article
(This article belongs to the Special Issue Natural Antioxidants: Multiple Mechanisms for Skin Protection and Skin Disease)
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