Antioxidant peptide ETT from Isochrysis zhanjiangensis attenuate skin aging by maintaining homeostasis and promoting collagen generation

ETT (Glu-Met-Phe-Gly-Thr-Ser-Ser-Glu-Thr) isolated from Isochrysis zhanjiangensis was an antioxidant nonapeptide with the highest active site on Met 2. In this study, the investigated the anti-skin aging effect of ETT on both keratinocytes and fibroblasts, took ultraviolet B (UVB)-induced human immortalized keratinocytes (HaCaT) and hydrogen peroxide (H2O2)-induced human skin fibroblasts (BJ cells). The results showed the anti-photoaging effect of ETT on UVB-induced HaCaT cells by declining an increasing level of intracellular reactive oxygen species (ROS), activating antioxidant system via nuclear factor erythroid 2 (Nrf2)/ heme oxgenase-1 (HO-1) signaling pathway, promoting autophagy to enhancing mitochondrial membrane potential and inhibiting apoptosis. Moreover, ETT also against skin aging on H2O2-induced BJ cells by attenuating senescence and improving collagen generation via transforming growth factor β1 (TGF-β1)/Smad signaling pathway. In general, these results indicated ETT is potential to against skin aging by maintaining keratinocytes homeostasis, reducing apoptosis, attenuating fibroblasts senescence and enhancing content of collagen. [Display omitted] •ETT from Isochrysis zhanjiangensis•Anti-photoaging effect of ETT on UVB-induced HaCaT cells.•ETT is potential to against skin aging.•ETT attenuating fibroblasts senescence