Antioxidant peptides (FYDQ and FVEG) derived from cricket (Acheta domesticus) protein hydrolysate enhance photoprotection and inhibit apoptosis in UVB-irradiated HaCaT keratinocytes cells

Abstract

Antioxidant peptides are extensively used in food, pharmaceuticals, and cosmetics. Two tetrapeptides, Phe-Tyr-Asp-Gln (FYDQ) and Phe-Val-Glu-Gly (FVEG), were previously identified from cricket (Acheta domesticus) protein hydrolysate. Molecular docking of these tetrapeptides showed high binding affinity to antioxidant-related proteins: Keap1, Superoxide dismutase (SOD), Catalase (CAT), GR (Glutathione reductase), and Glutathione peroxidase (GPx). In this study, FYDQ and FVEG were selected and evaluated for their protective effect against oxidative damage induced by UVB irradiation of human keratinocytes cells (HaCaT). Pretreatment with 100 μg/mL of each tetrapeptide before UVB irradiation resulted in intracellular photoprotective activity by reducing reactive oxygen species (ROS). These were accumulated by approximately two-fold compared to the UVB-irradiated HaCaT cells and restored the activity of antioxidant enzymes. Additionally, pretreatment with the tetrapeptides prior to UVB irradiation inhibited cellular apoptosis by approximately 30 % compared to the UVB-irradiated group. This was achieved by reducing the loss of mitochondrial membrane potential (MMP) by about 40 % and repressing the expression of cleaved caspase-3 and BAX by about two-fold compared to the UVB-irradiated group. FVDQ and FVEG demonstrate protective effects against UVB-induced oxidative damage through ROS scavenging leading to attenuated cellular apoptosis. Both tetrapeptides might be utilized as antioxidant components in sunscreen formulations or anti-photoaging cosmetic products.