Fig. 5: Histological examination and biochemical detection showing robust protection of emulsion gel against UV damage on mouse skin.

a Histological images demonstrating the difference in injury of skin sections from the irradiated areas of five groups of mice collected on 3rd day. The black arrows point to the area of skin tissue necrosis. The red arrows point to the area of necrotic cell fragments with inflammatory cell infiltration. The blue arrows point to the area of epidermal cell degeneration. b The activity of CAT (an antioxidant enzyme), (c) the level of MDA (a final product of lipid peroxidation), and (d) the activity of SOD (another antioxidant enzyme) in homogenates of skin tissues from the irradiated areas of five groups of mice collected on 3rd day indicating their level of peroxidation of the skin. The levels of three inflammatory factors: (e) IL-1β, f IL-6, and (g) TNF-α in homogenates of skin tissues from the irradiated areas of five groups of mice collected on 3rd day indicating the extent of the inflammatory reaction of the skin. Data were collected based on the normalization of the UV group (UV irradiation only sample) as 100% and presented as mean ± SD of n = 3 biologically independent mice. P-values were derived from the two-sided Student’s t-test to determine the difference between the two groups, and P-values < 0.05 were defined to be statistically significant. Bla represents the blank group, that mice were neither coated with samples nor irradiated with UV spot. UV represents the UV group, that mice were treated with UV irradiation. Emu, L’Or, and Emu-G represent the emulsion, L’Oreal and emulsion gel groups, that mice were swabbed with the same amount of emulsion, L’Oreal sunscreen, and emulsion gel sample before UV irradiation, respectively.