Abstract:

The protective effect of naringin on UV-induced skin barrier damage in KM mice was studied. Twenty-five SPF KM mice were randomly divided into 5 groups: blank control group, UV model group （UV irradiation group）, positive control group （28.39 mmol/L vitamin C）, low and high-dose naringin smear groups （0.35, 3.5 mmol/L naringin）. Except for the blank control group, the other four groups of mice were simulated with sunlight ultraviolet （UVA+UVB） radiation to establish a mouse photo-damaged skin model. Before each UV irradiation, the same amount （100 μL/mouse） of naringin with the indicated dose was applied 2 h in advance. The effects of naringin on skin photodamage were investigated by testing the skin TEWL, H&E staining, Masson staining, the activities of superoxide dismutase （SOD） and catalase （CAT）, malondialdehyde （MDA） content, and the scavenging ability of reactive oxygen species （ROS） in mice skin tissues. Moreover, immunohistochemical staining （IHC staining） of filaggrin （FLG）, involucrin （IVL） and aquaporin 3 （AQP3） was used to evaluate the skin barrier-related functions of naringin against UV-damaged skin. Compared with the model group, the skin of the naringin administration group inhibited the increase in skin epidermal thickness, and the amount of collagen in the administration group increased; the low and high-dose naringin smear group could significantly reduce the loss of water in the skin of mice with UV damage （p<0.05）. Naringin significantly increased the activity of SOD and CAT （p<0.05）, significantly reduced the content of MDA （p<0.05）, and eliminated the content of ROS in the skin of mice. IHC staining study showed that the protein expression level of FLG, IVL and AQP3 increased in the naringin-administered group （p<0.05）.

Key words: naringin, UV damage, skin barrier, antioxidant