Vinpocetine originally was isolated from the leaves of the periwinkle plant and is prized for its effects on brain circulation and oxygen utilization as well as acting as a blood thinner by inhibiting the clotting process. It has been used to treat blood vessel disorders of the brain due to the aging process or stroke. Vinpocetine has been referred to as a smart drug due to its nootropic capability. Nootropics constitute a large class of molecules that include drugs, supplements and various foods that boost memory functions such as attention, focus, concentration and awareness. Nootropics are thought to work by increasing the brain's supply of hormones, enzymes and,/or neurotransmitters, improving oxygen supply and/or stimulating nerve growth/repair.
As we age cerebral blood flow becomes reduced due to chronic high blood pressure, atherosclerosis and clot formation. Inadequate blood flow can result in what is known as ischemic stroke. Beyond the blocked point neurons begin to die within a few minutes due to the lack of oxygen as well as the build up of free radicals that have not been carried away. As time goes on, insufficient blood flow may bring about long-term dysfunction known as vascular dementia. Vinpocetine has been demonstrated to have a direct effect on blood vessels, blood flow and brain cells by increasing oxygen delivery and nutrient delivery as well as carry away wastes to prevent neuronal damage. Simply put, vinpocetine inhibits an enzyme associated with blood vessels that allow the blood vessels to relax making their diameters larger hence allowing for a greater blood flow to that region. More blood flow means more oxygen and nutrients will become available to that part of the brain. It also means wastes are removed more rapidly. The enzyme involved is known as a phosphodiesterase. You might be more familiar with Viagra than vinpocetine. Viagra also inhibits this enzyme and allows the vasculature of the penis to expand and fill with blood. The principle is the same. Vinpocetine also inhibits calcium channels allowing for blood vessel relaxation and greater blood flow. Interestingly, vinpocetine only affects brain blood vessels and not other vessels in the body. This is an advantage over other supplements/drugs in that the rest of the body is unaffected. The presence of vinpocetine in blood also reduces the thickness of blood by preventing red blood cells and platelets from sticking to each other allowing blood to flow easily.
The main function of vinpocetine involves its ability to increase cerebral blood flow and only cerebral blood flow. Vinpocetine does not affect blood flow in the body. The underlying mechanism involves vinpocetine's ability to inhibit an enzyme known as phosphodiesterase type 1 (PDE1) while reducing intracellular calcium concentrations. In other words, vinpocetine acts as a calcium channel blocker as well. Inhibition of this enzyme and the decrease in internal calcium levels allow for the smooth muscle cells of the vasculature to relax thus increasing their diameter (dilate) allowing for greater volume of blood to pass through. Smooth muscle cells are found in arteries but not in capillaries. This smooth muscle gives arteries great stretchability allowing for considerable changes in the amounts of blood that can flow through them. Some smooth muscle is also found in veins but to a lesser extent. Capillaries have no smooth muscle so they essentially remain the same size however keep in mind that it is in the capillaries where oxygen, nutrients and wastes are exchanged and no where else. Now that you have more blood flowing to the brain providing more oxygen and nutrients, metabolism can speed up with better utilization of glucose. Aerobic respiration requires oxygen to run it for the complete break down of the glucose molecule to generaate the energy currency of the cell known as ATP. ATP is required for most metabolic functions to run. More blood circulating through the brain brings more oxygen and glucose to tissues which increases metabolic activity allowing for the production of more transmitters enhancing memory and learning. Studies indicate oxygen and glucose uptake is greatly enhanced in areas of the brain that are damaged. And, in fact, vinpocetine helps to distribute blood where it is needed most at the time.
Vinpocetine has been studied in animals and in the petri dish where is has been demonstrated to have antioxidant properties not unlike Vitamin E. Vitamin E is essential for protecting the plasma membrane of all cells by preventing/scavenging free radicals that form on the outer surface of the membrane and vinpocetine follows in its foot steps. Basic research has demonstrated that vinpocetine has the ability to protect glial cells in the brain during hypoxic events. It has also been demonstrated to lower the level of reactive oxygen species and lipid peroxidation in membranes. So laboratory experiments provide evidence that vinpocetine has the ability to protect the brain from oxidative stress. This may prove useful in the treatment of Alzheimer’s disease and possibly Parkinson's disease. Although clinical trials are few and have small sample size, improvements in cognitive performance, focus and concentration have been observed with patients with dementia.
With vinpocetine's ability to increase cerebral blood flow along with its antioxidant properties, it is not surprising that is is used to treat chronic cerebral vascular problems. Vinpocetine may be useful in preventing future stroke complications with individuals at risk.