The Reduction of Skin Photodamage by the Ectoine–Thermus thermophilus Cofermentation Products

ABSTRACT Background Prolonged exposure to UVB (280–320 nm) can lead to skin oxidative damage, inflammatory response, and skin cancer. Many active ingredients in the fermentation products of Thermus thermophilus have been shown to play important roles in antioxidant and anti‐UVB photodamage, such as superoxide dismutase (SOD) and photolyase. Ectoine, as one of the most prevalent compatible solutes in halophilic bacteria, can protect cells, proteins, cell membranes, and nucleic acids from external extreme environments such as high temperature, freezing, irradiation, and drying. It has been applied in the industries of fine chemicals, biomedicine, and biomanufacturing worldwide. Aims In this study, we evaluated the antioxidant activities and anti‐UVB photodamage activities of Ectoine– T. thermophilus cofermentation products (D‐Ectoine). Methods The comparison between D‐Ectoine and Ectoine was analyzed with hydroxyl radical (OH· − ) scavenging assay, superoxide anion (O 2 · − ) assay, total antioxidant capacity (T‐AOC) assay, and 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH) scavenging assay. We evaluated the antioxidant ability of D‐Ectoine by detecting malondialdehyde (MDA) levels: the activity of SOD, catalase (CAT), and glutathione peroxidase (GSH‐PX) in human skin fibroblast (HSF) cells. Inflammatory response was measured with lipopolysaccharides (LPS) induced expression of interleukin 6 (IL‐6) and interleukin 8 (IL‐8). We evaluated the protective ability of D‐Ectoine against UVB‐induced damage by detecting the content of collagen type I (Col I) and extracellular matrix metalloproteinase (MMP‐1) in the cells, and the number of cell survival, erythroid 2‐related factor 2 (Nrf2) and 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) expression in 3D skin model. Results The results showed that D‐Ectione could promote the GSH‐PX activity in HSF cells with stronger T‐AOC and DPPH scavenging capacity, reduce the expression of LPS‐induced inflammatory factors IL‐6 and IL‐8, increase Col I expression both with and without UVB and inhibit expression of MMP‐1 after UVB irradiation. In the 3D skin model, D‐Ectione could increase the number of cell survival and Nrf2 expression, and decrease 8‐OHdG expression after UVB irradiation. Conclusions These results demonstrated that D‐Ectione has protective effects against UVB‐induced skin photodamage and may contribute to the development of cosmetic products with anti‐UVB.