Preventive effects of Eucommia ulmoides leaf extract and its components on UVB-induced immunosuppression in mice

•Consecutive oral administration of ELE, chlorogenic acid, or geniposidic acid significantly reduced UVB-induced immunosuppression.•The treatment with chlorogenic acid or geniposidic acid decreased the serum IL-10 levels in the sensitized mice after UVB irradiation.•The plasma ROS level and the expression of skin mast cells decreased in the chlorogenic acid-treated mice.•The expression of regulatory T cell in the skin decreased in the geniposidic acid-treated mice.•As evidenced by the above, chlorogenic and geniposidic acids prevent UVB-induced immunosuppression.