Parkinson's Disease and the Protective Mechanism of the Antioxidant Vitamin E

Parkinson's Disease and the protective mechanism of the antioxidant Vitamin E

Description and Risks

Parkinson's disease (PD) is a progressive movement disorder marked by tremors, rigidity, slow movements (bradykinesia), and postural instability. It is a chronic, progressive neurodegenerative disease caused by decreased production of dopamine, a neurotransmitter. Dopamine is responsible for most of the body's smooth muscle movements. As a result, motor control in Parkinson's patients is disrupted, causing anything from uncontrollable tremors to muscular stiffness to slow-as-molasses movements. (2) PD affects about 500,000 people in the United States, both men and women, with as many as 50,000 new cases each year. The disease usually begins in a person's late 50's and 60's; it causes a progressive decline in movement control, affecting the ability to control initiation, speed, and the smoothness of motion. The symptoms of PD are seen in up to 15% of those between the ages of 65-74, and almost 30% of those were between the ages of 75-84. (3)

Genetic Risks

Scientist identified two gene abnormalities present in PD patients whose families have a rate of the disease, indicating at least some evidence that the disease is inherited. Both abnormalities cause the body to produce an altered version of alpha synuclein, the protein that shows up in dense masses in the brains of Parkinson's patients. (3). But in another study in the Journal of the American Medical Association suggested heredity is a significant influence on how fast the disease will onset. Researchers identified 172 twin pairs in which at least one twin had PD. If the condition was hereditary, the rate of both twins having the disease would be lower among fraternal twins, who share some, but not all of the same genes unlike identical twins who share them all. In individuals who were diagnosed after age 50, the rate of twins who both had the disease was similar among fraternal and identical twins. In those diagnosed at 50 or younger, however, the rate was significantly lower in fraternal twins than in identical twins (2). Researchers also think that PD has environmental risks such as increase exposure to toxic chemicals such as pesticides, herbicides, or heavy metals. For example, some studies of people living in rural environments have shown a strong link with PD. In rural areas, well water is often not monitored properly and as a result, contamination from pesticides often go unnoticed. However, other studies show that this is not true, especially when rural toxins could only explain about 10% of Parkinson's cases in the United States. (2)

Symptoms and Causes

The immediate cause of PD is the degeneration of brain cell in the area known as the substantia nigra, one of the movement control center of the brain. Damage to this area leads to the cluster of symptoms known as parkinsonism. In PD, degenerating brain cells contain Lewy bodies, which identify the disease. The cell damage that leads to parkinsonism may be caused by a number of conditions, including infection, trauma, and poisoning. When no cause of nigral cell degeneration can be found, the disorder is called idiopathic parkinsonism, or Parkinson's disease. The substantia nigra, or black substance, is one of the principal movements control centers in the brain. The body releases a neurotransmitter known as dopamine; it helps to refine movement patterns throughout the body. The dopamine released by nerve cells of the substantia nigra stimulates another brain region, the corpus striatum. If the brain does not have enough dopamine, the corpus straitum cannot control its target muscle control. As a result, the movement patterns of walking, writing, reaching for objects, and other basic programs cannot operate properly, and the symptoms of parkinsonism are the result.

The symptoms of PD include tremors, which usually begin in the hand and on one side of the body and then the other. The classic tremor of PD is called a pill-rolling tremor, because movements resemble the pill rolling between the thumb and forefinger. Slow movements occur, which may involve slowing down or stopping in the middle of familiar tasks such as walking, shaving or eating. After a while the muscle rigidity or stiffness will occur with the jerky movements replacing smooth muscle. There are many other symptoms, a person experiencing these problems should immediately seek medical help. (3) Parkinson's Disease is a neuro-degenerative disorder that is widely assumed to be caused by oxidative stress or damage to the substantial nigra. The symptoms that most show are tremors, bradykinesia, and rigidity. There are also signs of some memory loss and cognitive functioning as well. There are several different proposed mechanisms of Parkinson's but the most prevalent oxidative stress caused by free radicals, either genetic, environmental factors, and even just plain old chronological age. Another mechanism would have to be damage to dopamine or it's turnover caused by the many forms of peroxidation. The brain needs the resources and time to battle the oxidative damage in order to keep the free radicals from harming the precious cerebullar granule cells, dopaminergic cells and neurons, and apoptotic cells to name a few. To make matters even worse, oxidative damage even affects genetic make-up of the bases of DNA. There are other factors that also may play a role in the Parkinson's disorder but they are not as conclusive. The true cause of Parkinson's disease is not yet resolved and the disease is considered incurable and only gets worse as time goes on. It is the second most occurring neurodegenative disorder next to Alzheimer's disease. A lot of the studies going on today are geared to the symptoms of Parkinson's disease in its earlier stages. One of the most known lines of defense against oxidative stress would be antioxidants. Antioxidants are the leading preventive agent in the body to stop free radicals in their tracks. In this review, the main focus will be on how the leading antioxidant in the body, Vitamin E (most commonly in the alpha-tocopherol form) fights off these free radicals and why it is one of the most important agents to fighting the early stages of this dreaded disease, Parkinson's disease (1,5,9)

Vitamin E

Vitamin E or alpha tocopherol is a major free radical chain-breaking antioxidant that plays a huge role in many studies that focus on the oxidative stress that is linked to the early stages of Parkinson's. One of its main functions as an antioxidant is to fight lipid