The present invention provides an enhancer for enhancing the activity of oxidized protein hydrolase. The oxidized protein hydrolase activity enhancer according to the present invention contains an extract of at least one plant selected from the group consisting of Compositae Anthemis, Saururaceae Houttuynia, Rosaceae Crataegus, and Vitaceae Vitis. The oxidized protein hydrolase activity enhancer preferably contains an extract of a plant of Compositae Anthemis, an extract of a plant of Saururaceae Houttuynia, an extract of a plant of Rosaceae Crataegus, and an extract of a plant of Vitaceae Vitis. It is preferable that the plant of Compositae Anthemis is Anthemis nobilis L., the plant of Saururaceae Houttuynia is Houttuynia cordata Thunberg, the plant of Rosaceae Crataegus is Crataegus oxyacantha L., and the plant of Vitaceae Vitis is Vitis vinifera L.