One of the known mechanisms to destroy neurons is the damage by free radicals or reactive oxygen-molecule species produced by the oxidation of dopamine, a neurotransmitter.
When dopaminergic neurons have been lost in the course of Parkinson's disease, the metabolism of dopamine increases-which, in turn, increases the formation of highly neurotoxic hydroxyl radicals.
The most important free radical collector in the cells of the black substance is the powerful antioxidant brain, the glutathione. Glutathione levels in PD patients are low.
And as we age, the levels of glutathione in the dopaminergic neurons of the substantia nigra decreases. This seems to accelerate cell death and advance the progression of PD.
At least 80 percent of the black substance cells are lost before the symptoms of Parkinson's disease become apparent. This is why it becomes essential to protect or maintain these cells under oxidative stress.
The cells of the black substance use dopamine-a chemical messenger between the nerve cells of the brain or to communicate with cells in another region of the brain called the striated body.
When the cells of the black substance are lost, the levels of dopamine nigral fall, resulting in a decrease of the dopamine in the striatum.
Typical symptoms of PD-deficiencies motor function characterized by muscular stiffness, spasmodic movements and rhythmic tremors at rest-are the result of low levels of dopamine striatal.
Most dopaminergic drugs used to treat Parkinson's disease are aimed at temporarily replenishing or mimicking dopamine. They improve some symptoms but do not restore the normal function of the brain or stop the destruction of brain cells.
Dopaminergic drugs are generally effective at first in reducing many symptoms of PD, but over time they lose their effect.
They also cause serious side effects as they overstimulate nerve cells in other parts of the body and cause confusion, hallucinations, nausea, and fluctuations in limb movement.
Several factors explain why glutathione is so beneficial in Parkinson's disease.
It is a well-known fact that Parkinson's patients are more deficient in their ability to detoxify the chemicals they are exposed to.
The unfortunate few who harbor a hereditary defect in their detoxification pathways have a much greater risk for the harmful effects on the brain of a wide variety of toxins.
Glutathione is one of the most important components of the liver detoxification system. Glutathione therapy is one of the most effective techniques for improving liver and detoxifying brain.
Glutathione treatments considerably improve some of the symptoms of Parkinson's disease, including difficulties with stiffness, walking, coordination of movements and speech. A sharp reduction in the tremor has been observed, as well as a decrease in depression.
Glutathione and N-acetyl-L-cysteine (a precursor of glutathione) have been shown to be very effective in the protection of nerves in the black substance from oxidative stress destruction.
The practical problem in increasing glutathione levels is that taking glutathione itself as a supplement does not increase the cellular levels of glutathione, glutathione as it decomposes into the digestive tract before it reaches the cells.
However, intravenous glutathione therapy and taking glutathione precursors are effective in increasing intracellular levels of glutathione.
Dietary antioxidants and supplements that increase cellular glutathione, such as alpha lipoic acid, NAC, Pycnogenol, silymarin herbs (milk thistle), are effective in restoring normal function.
N-acetyl-cysteine (NAC) and non-denaturing, whey protein from both precursors of intracellular glutathione supply, increase the body's production of glutathione and help the detoxification process.
Other nutritional supplements that help the detoxification process include selenium, vitamins E and C.