PROBLEM TO BE SOLVED: To provide a new pharmaceutical or cosmetological drug comprising a variety of active ingredients having an action of inhibiting protein carbonylation for inhibiting skin discoloration, especially inhibiting yellowing of the skin.SOLUTION: A protein carbonylation inhibitor consists of: one or more active ingredients selected from an olive leaf extract; a hydrolyzed pea protein; and a lemon extract.COPYRIGHT: (C)2012,JPO&INPIT【課題】皮膚の変色、特に皮膚の黄色化を抑制するために、タンパク質のカルボニル化を抑制する作用を有する種々の有効成分を含んで成る新規の医薬的又は美容学的な薬剤の提供。【解決手段】オリーブ葉エキス、加水分解エンドウタンパク及びレモンエキスから選ばれる1種又は2種以上の有効成分を含んで成る、タンパク質カルボニル化抑制剤。【選択図】図3