What is Alzheimer’s Disease?
Alzheimer’s is the most common form of dementia. It is a disease characterized by a decline in cognitive function and memory loss. Symptoms usually develop slowly and get worse over time, becoming severe enough to interfere with daily tasks. In its early stages, memory loss is mild, but as the disease advances, individuals lose the ability to maintain a conversation and respond to their environment.
Although much progress has been made in AD research, the exact cause is yet to be known. The scientist believes genetics and environmental factors and lifestyle play a significant role in the development of the disease. Researches also believe the formation of amyloid plaques and neurofibrillary tangles contribute to the degradation of the neurons in the brain and the symptoms associated with Alzheimer’s disease.
Amyloid plaques are dense, mostly insoluble protein fragments that the produces normally. In a normal and healthy brain, these protein fragments are degraded and eliminated. People with Alzheimer’s disease have a build up of these plaques in their brain, especially in their hippocampus.
Neurofibrillary tangles are insoluble twisted fibers found inside the brain’s cells. These consist primarily of a protein called tau, which forms an integral part of a microtubule. The microtubule helps to transport nutrients, molecules, and information safely from one neuronal cell to another.
In Alzheimer’s disease, the chemical make-up of tau proteins is altered. The tau becomes tangled and twisted, thereby affecting the structure and integrity of the microtubules, causing them to become unstable and disintegrate. This collapses the entire neuronal transport system.
There’s currently no cure for Alzheimer’s disease, but drugs are available that can help alleviate some of the symptoms.
Two classes of drugs are approved by the Food and Drug Administration for treating Alzheimer’s disease. They include partial glutamate antagonist and cholinesterase inhibitors. These drugs do not reverse the death of brain cells but rather slow the rate of progression of Alzheimer’s and improve some of the symptoms.
Acetylcholinesterase is a chemical substance that prevents the degradation of the brain chemical neurotransmitter called Acetylcholine. Patients with Alzheimer’s disease lack this neurotransmitter. Research has shown that acetylcholine is necessary for the formation of new memories. This class of drugs makes acetylcholine available in the brain by blocking its breakdown in the neuronal synapse. Hence it becomes easier to form new memories. Four drugs in this group have been approved by the FDA; they are donepezil hydrochloride (Aricept), rivastigmine (Exelon), galantamine (Razadyne, previously called Reminyl) and tacrine (Cognex). Only tacrine is not used and recommended by doctors because of the undesirable side effects. Only donepezil is approved for treating all stages of Alzheimer’s disease.
Common side effects of cholinesterase inhibitors involve the gastrointestinal system and include nausea, vomiting, abdominal cramp, and diarrhea. These side effects can be reduced by adjusting the dosage, or by administering the drug with a small amount of food.
Memantine is another drug used in treating Alzheimer’s. It works by partially blocking the effects of glutamate to activate neuronal cells in the brain. Memantine is approved for the treatment of moderate and severe dementia. It is ideal for patients that cannot take or unable to tolerate acetylcholinesterase inhibitors. Side effects include dizziness, constipation, and headaches, but they are only temporary.
Researchers working at the Lewis Katz School of Medicine at Temple University have published research showing that, for the first time, a prescription drug currently on the market to treat asthma may help prevent some characteristic brain lesions that contribute to Alzheimer’s disease. This drug has been shown to reduce the formation of amyloid beta, a peptide in the brain that is implicated in the development of Alzheimer’s disease.
In their study published in Molecular Neurobiology, researchers say the drug zileuton; a leukotriene biosynthesis inhibitor can slow, halt, and potentially reverse the aggressive development of tau proteins, the second-most important lesion in the brain in patients with Alzheimer’s disease. Zileuton is approved by the Food and Drug Administration (FDA) to control symptoms of asthma such as wheezing and shortness of breath
Another common asthma drug which could be the key to slowing, and even stopping dementia is Montelukast. Montelukast is a leukotriene receptor antagonist (LRTA). It is regularly used to prevent shortness of breath and wheezing associated with asthma. It is also used to relieve symptoms of hay fever and allergic rhinitis such as the runny/itchy nose, sneezing. Etc.
Montelukast possesses several properties that could be valuable for the treating Alzheimer’s disease. The experiment shows that it enhances the production of neuronal progenitor cells that generate neurons and supporting cells in the nervous system. It also prevents inflammatory processes that are mediated by leukotrienes. These leukotriene receptors are the same as those implicated in neurodegenerative diseases such as Parkinson’s and Huntington’s disease.
In a research conducted on animal models, it was observed that the leukotriene receptor antagonist Montelukast was able to reverse aging process in rats and highly efficient in restoring cognitive function in them. The drug also improved the integrity of the blood-brain barrier, which prevents infections and unwanted substances from crossing into the brain.
How to Reduce the Risks of Alzheimer’s Disease
Despite no definite way to prevent Alzheimer’s disease, maintain a healthy lifestyle may reduce your risk. This includes
- Avoid smoking.
- Engaging in activities such as cognitive training and exercises aimed to improve problem-solving skills and memory.
- Getting a regular exercise.
- Maintaining a healthy weight
- Eating a healthy and varied diet
- Managing risk of high blood pressure, obesity, diabetes, and cardiovascular diseases.
- Getting plenty of sleep.
AlzheimerÂ’s Disease, Cerebrovascular Disease, and Dementia: A Potentially Preventable and Modifiable Syndrome. (2015). Journal Of Alzheimer’S Disease & Parkinsonism, 05(01). doi: 10.4172/2161-0460.1000184
Richardson, J., & Hunter, J. (2013). Recent advances in the treatment of Alzheimers’: therapeutic strategies. Drug Discovery Today: Therapeutic Strategies, 10(2), e51-e53. doi: 10.1016/j.ddstr.2014.06.001
Veerhuis, R., Boshuizen, R., & Familian, A. (2005). Amyloid Associated Proteins in Alzheimer’s and Prion Diseases. Current Drug Target -CNS & Neurological Disorders, 4(3), 235-248. doi: 10.2174/1568007054038184
Yagami, T. (2006). Cerebral Arachidonate Cascade in Dementia: Alzheimers Disease and Vascular Dementia. Current Neuropharmacology, 4(1), 87-100. doi: 10.2174/157015906775203011