We have analysed 53 fruits and vegetables in terms of 5 flavonoids including luteolin whis is a flavone which belong to flavonoids family. The richest source is spinach and water cress,in addition to the whole range of peppers based our analysis in Northern Ireland. Mainly luteolin is a strong antioxidant that have a possiible property to protect from heart disease. There are some suggestions for luteolin for hypertensive patients. However, the work in this area is little so do not recommend luteolin to patients at this moment and do not go with the commercials about luteolin. if you need more info about the sources of luteolin please do not hesitate. Good luck.