Scientists have identified a chemical compound that may unlock new treatments for autoimmune diseases like multiple sclerosis (MS). In tests on cell cultures and rats, the team found that anacardic acid, which occurs in the shell of cashew nuts, seemed to repair nerve damage and other symptoms of MS.
In patients with MS, the immune system mistakenly attacks myelin, the insulating layer around nerves. As this protective material is eaten away, signals have trouble getting through, leading to issues with coordination, muscles and vision.
A range of possible treatments to slow or even reverse this demyelination are in development, including synthetic peptides and molecules, compounds like indazole chloride, gene therapy, and nanoparticles that “trick” the immune system.
And now, it looks like anacardic acid could be added to that list. In new research from Vanderbilt University, the team found that this compound triggers a chain reaction that appears to promote the repair of myelin.
In previous work, the researchers identified a protein called interleukin 33 (IL-33) that helps myelin form. They also found that an enzyme called histone acetyltransferase (HAT) is linked to IL-33 – basically, inhibiting HAT increases production of IL-33, which in turn could help repair myelin.
Anacardic acid is known to be a HAT inhibitor, so the Vanderbilt team set out to investigate the compound as a potential treatment for MS. And in several tests on cultured cells and in animals, the results were intriguing.
In one experiment, the researchers cultured a type of rat cell called oligodenrocyte precursor cells (OPCs), which play a key role in myelination. When anacardic acid was added, production of IL-33 increased, as did the expression of myelin genes and proteins. They also noticed that levels of myelin basic protein increased as the dose increased.
In other experiments on animals with demyelination, the team found that anacardic acid increased the number of OPCs that expressed IL-33, and reduced the physical effects of paralysis. When the animals were dissected after death, the team observed increases in myelination, in line with the different doses they received.
Of course, these studies are in the very early stages, and there’s no guarantee that the results will carry across to humans. It definitely doesn't mean that eating cashews with the shell still on will cure your MS. But the team says that the findings suggests that further work should be conducted to investigate anacardic acid for these kinds of demyelinating diseases.
The research was published in the journal Proceedings of the National Academy of Sciences.
Source: Vanderbilt University