Another way to prevent cardiovascular disease is to correct high blood pressure. Researchers have reported that an extract of Sambiloto produced antihypertensive (blood pressure lowering) effects. The extract was given intravenously to hypertensive rats. Noradrenaline, a hormone secreted by the brain, acts to constrict blood vessels and increase heart rate, blood pressure, and blood sugar levels. Sambiloto extract inhibited the increase in blood pressure that is caused by noradrenaline. Researchers believe that Sambiloto has this antihypertensive effect because it relaxes the smooth muscle in the walls of blood vessels. This relaxation prevents the blood vessel from constricting and limiting blood flow to the heart, brain, and other organs in the body. Sambiloto keeps blood, and therefore oxygen, flowing to the brain. Diminished blood flow to the brain can cause short-term memory loss, ringing in the ears, dizziness, headaches, depression, and impaired mental performance.