The present invention relates to advanced glycation end product (AGE) inhibitors or health functional foods for inhibiting an occurrence of diabetic complications, comprising a compound isolated from Morus Bark as active ingredients. Particularly, the present invention comprises a compound selected from the group consisting of mulberrofuran G, mulberrofuran K, kuwanon G, kuwanon Z, oxyresveratrol, 2',4',5,7-tetrahydroxyflavanone, morusignin L and dihydromorin isolated from Morus Bark. The compounds disclosed above inhibit the production of AGE which is a causative substance of diabetic complications. Thus, the compounds could be used as an AGE inhibitor and a health functional food for inhibiting diabetic nephropathy, diabetic retinopathy and diabetic neuropathy.