The extract of a mixture of cinnamon twig and moutan root bark, cinnamon twig and peony root, or cinnamon twig and poria according to the present invention has been confirmed to inhibit the excessive generation of advanced glycation end-products, which occurs under chronic diabetic conditions, exhibit the effect of fragmentizing a cross-link between the advanced glycation end-products and matrix proteins, have an excellent effect in inhibiting the generation of the advanced glycation end-products in a human retinal pigment epithelial cell line subjected to a hyperglycemic or aging environment, and have excellent effects in delaying, preventing, and treating diabetic complications, muscular degeneration, commotio retinae, and lower extremity edema in various animal models of diabetic complications, macular degeneration, and lower extremity edema, and thus the mixture extract can effectively be used as an active ingredient for a composition for preventing and treating diabetic complications, including diabetic retinopathy, diabetic nephropathy, and diabetic neuropathy, and angioedema, including macular (retinal) edema, macular degeneration, and varicose veins.