The present invention provides a novel oxidized protein hydrolase activity enhancing agent. The oxidized protein hydrolase activity enhancing agent of the present invention contains at least one kind of plant extract obtained from a plant selected from the group consisting of water chestnut, stevia, rosemary, thyme, chrysanthemum, savory, mugwort, chestnut, spearmint, marjoram, peppermint, lemon balm, allspice, perilla, basil, and caraway.本發明提供一種氧化蛋白質分解酵素之新穎之活性增強劑。本發明之氧化蛋白質分解酵素活性增強劑之特徵在於包含選自由菱、甜菊、迷迭香、百里香、菊、歐洲薄荷、艾草、板栗、綠薄荷、馬郁蘭、胡椒薄荷、檸檬薄荷、眾香子、紫蘇、羅勒及葛縷子所組成之群中之至少1種植物之萃取物。
