A recent study identified the drug "sildenafil" - whose trade name is "Viagra" - as a candidate for Alzheimer's disease, so what are the details?
The study, conducted by researchers led by the Cleveland Clinic, found that sildenafil is a promising candidate drug to help prevent and treat Alzheimer's disease.
The study was published in the Journal of Scientific Aging, and was reported by EurekAlert and the Guardian newspaper.
According to the Medlineplus database, sildenafil is used to treat erectile dysfunction and is sold under the trade name Viagra, and it is also used under the trade name Revatio to improve the ability to exercise in adults with pulmonary arterial hypertension, which is high blood pressure. Blood in the vessels that carry blood to the lungs, causing shortness of breath, dizziness and fatigue.
The researchers, led by Dr. Feixiong Cheng of the Institute of Genomic Medicine at the Cleveland Clinic, used a computational methodology to screen and validate FDA-approved drugs as potential treatments for Alzheimer's disease.
Sildenafil reduces the incidence of Alzheimer's disease
Through a large-scale analysis of a database of more than 7 million patients, they found that sildenafil was associated with a 69% lower incidence of Alzheimer's disease, indicating the need for follow-up clinical trial testing of the drug's efficacy in patients with the disease.
"Recent studies show that the interaction between amyloid and tau contributes more to Alzheimer's disease than either one alone," Dr. Cheng said. "Therefore, we hypothesized that drugs that target the intersection of the molecular network of amyloid and tau endophenotypes should have the greatest potential for success."
Accumulation of beta-amyloid and tau proteins in the brain leads to amyloid plaques and tau neurofibrillary tangles, two hallmarks of brain changes associated with Alzheimer's disease.
The amount and location of these proteins in the brain may help determine internal patterns.
However, there are currently no FDA-approved small-molecule treatments for Alzheimer's disease, anti-amyloid or anti-tau, as many clinical trials of such treatments have failed in the past decade.
To further explore the effect of sildenafil on Alzheimer's disease, the researchers developed a model of brain cells derived from an Alzheimer's patient using stem cells.
In the model, they found that sildenafil increases brain cell growth and reduces hyperphosphorylation of tau proteins, a hallmark that leads to neurofibrillary tangles.
Dr. Cheng said that because their findings only establish an association between sildenafil use and a reduced incidence of Alzheimer's disease, they are now planning a trial to test causality and confirm the clinical benefits of sildenafil for Alzheimer's patients.
How was Viagra discovered?
Viagra was made by a group of pharmaceutical chemists working for Pfizer in England.
The researchers initially studied the use of this drug to treat high blood pressure and angina pectoris, and the first clinical trials were conducted at Morriston Hospital in Swansea, United Kingdom in the 1990s.
The effectiveness of Viagra for erectile dysfunction was discovered by chance, as researchers were initially studying with the aim of treating cardiovascular problems, as it was supposed to dilate the blood vessels in the heart by blocking a specific protein called "PDE-5" (PDE-5) in the heart. Animal tests.
When tested on animals, sildenafil appeared to work well, as the researchers found evidence that it inhibited BDE-5 and there were no obvious negative side effects in animals.
Experiments
So sildenafil was introduced into human clinical trials in the early 1990s, but initial results showed that the drug had little effect on angina.
But the nurses who were supervising the men participating in the study noticed something strange, as John Lamatina - who was head of research and development at Pfizer during the conduct of this research - said that the nurses noticed that when examining the men, many of them were lying on their stomachs and they were embarrassed because they were feel an erection
It turned out that the dilated blood vessels were not in the heart but in the penis, and because the expansion of blood vessels is an essential part of the process that leads to an erection, the result was amazing, so Pfizer decided to market this drug to treat erectile dysfunction and not for angina pectoris.
The patent was registered in 1996, and it was approved for use in the treatment of erectile dysfunction by the US Food and Drug Administration on March 27, 1998, becoming the first oral treatment for erectile dysfunction in the United States.
What is Alzheimer's?
Alzheimer's is one of the most common types of dementia, usually affecting adults. It is a disease that affects the brain and leads to a decline in a person's ability to carry out his daily activities. It begins slowly and includes the parts of the brain responsible for controlling thoughts, memory and language.
The disease took its name from the German doctor "Alois Alzheimer", who described it in 1906, after he noticed anatomical changes in the brain of a woman who died of an unusual mental illness, and symptoms included memory loss and speech problems.
Alzheimer's disease usually affects people over the age of 60, and begins in the form of mild symptoms such as forgetfulness and problems using language.
But as it develops, the symptoms worsen, as the patient may no longer be able to recognize his family members, or may have difficulties speaking, reading and writing, and may forget how to do simple, routine tasks such as brushing teeth and combing his hair.
mechanism
Changes in the brain begin a decade or more before symptoms begin.
Abnormal clumps of a protein called beta-amyloid and tau fibers start in the brain.
With these abnormal accumulations, the functions of neurons in the brain decline.
Over time, cells lose their ability to connect and function.
Eventually the cells die.
As the dead cells increase, a person's brain shrinks.
risk factors
Age. Most cases of Alzheimer's occur at age 65 or older, and half of those aged 85 or older develop Alzheimer's.
Genes: Some people have rare genetic changes, and they develop Alzheimer's in their forties or fifties, that is, at an early age.
Having a first-degree relative with the disease, such as a father or brother.
Women are more prone to Alzheimer's than men, because they usually live longer.
Suffering from "mild cognitive impairment" may increase the risk of developing dementia and Alzheimer's disease.
Having a head injury or bruising.
idleness.
smoking.
Hypertension.
high cholesterol;
Uncontrolled diabetes mellitus.
Lack of social activities.
Eat a diet low in vegetables and fruits.
Symptoms
Forgetting, which includes appointments, events, or conversations.
Repeating sentences and questions, as the person does not know that he has said this sentence or asked this question before.
Difficulty recognizing the surroundings, which may lead the patient to get lost in places he was familiar with.
Difficulties choosing words to pronounce and write.
Thinking problems, such as the inability to manage and follow up on family financial accounts.
Difficulty doing familiar things such as getting dressed and bathing.
Depression.
Mood swings.
Delusions, such as the patient believing that something has been stolen.
Changes in sleep pattern.