Methods and compositions are disclosed for inhibiting proliferation of human colon adenocarcinoma cells, reducing pro-inflammatory molecules, adhesion molecules, and vascular smooth muscle cell proliferation, and for increasing NO production. The present invention describes the use of phenolic compositions, purified from oats or synthetically produced, to decrease the effective amount of pro-inflammatory molecules and/or cell adhesion molecules. Alternatively, an alcoholic extract or concentrate from oats can be used. The methods of the present invention can be used as a treatment or prophylaxis of a wide variety of disorders associated with inflammatory states and/or with a lack of or need for nitric oxide (NO), such as inflammatory conditions, pain, free radical associated disorders, cardiovascular diseases, autoimmune disorders, pathological platelet aggregation, pathological vasoconstriction, vascular effects of diabetes, stroke, atherosclerosis, hypertension, abnormal vasospasm, and restenosis after angioplasty.