A kind of pharmaceutical composition is disclosed for reducing damage caused by free radical. The composition includes at least one metal or its ion, at least one drug or antioxidant i.e. carrier-protected/modified, the pharmaceutical composition of carrier. The carrier, which facilitates the effect protecting activities of antioxidant enzymes, and therefore preventing, reduces environment or body fluid that antioxidant generates free radical, and extends protection, and can be used for reducing as radiation and the side effect as caused by chemotherapy.
