Composition comprising the extracts of dictyota coriaceum for prevention and treatment of cardiovascular dyscrasia

An extract of Dictyota coriaceum is provided to inhibit NAD(P)H strongly and show strong vascular relaxation effect by controlling contraction and relaxation of vascular smooth muscle, thereby being usefully used as a medicine or a health functional good for preventing and treating cardiovascular diseases. A composition for preventing and treating cardiovascular diseases selected from the group consisting of congestine heart failure, ischemia, hypertension, hypotonia, arrhythmia, heart failure, coronary restenosis and dementia comprises an extract of Dictyota coriaceum as an effective ingredient, wherein the extract is extracted by using a solvent selected from the group consisting of water, C1-4 alcohol and a mixture thereof. Further, the C1-4 alcohol is a methanol, ethanol or butanol.