A pre-clinical study investigating the effects of antioxidants on mitochondrial diseases has shown promising results, reports EurekAlert. Out of the seven antioxidants trialled, at least two (vitamin E and N-acetylcysteine) have produced initial signs of improving the symptoms of mitochondrial disease and should be further evaluated in clinical trials.
Mitochondrial diseases are a group of inherited diseases that affect the functioning of mitochondria in cells, and limit the ability of the mitochondria to produce energy. Since almost any cell, and therefore any body part, can be affected, these diseases produce diverse symptoms that usually differ between individuals. The most common areas of the body to be affected are those that have the largest energy requirements, including the heart, brain, liver, kidneys, and muscles. If you would like to read more about mitochondrial diseases, click here. Although mitochondrial diseases are gaining recognition, there is no known cure at present, and treatment centres on managing the disease through removing metabolic stressors that could worsen disease progression, and medicating symptoms like seizures.
One method used to manage mitochondrial disease symptoms is including high levels of certain antioxidants in the diet, and many people have reported improvements from doing this. However, the effect of antioxidants on mitochondrial diseases has not been well studied, and the effects of different antioxidants are unclear. The lack of research means that it is often unclear which antioxidants are effective, in what doses, and whether there are side effects. Furthermore, supplements and vitamins that contain antioxidants are loosely regulated and vary between providers, making it difficult for people to control their antioxidant intake.
The new study, led by Marni Falk MD, the executive director of the Mitochondrial Medicine Frontier Program at Children’s Hospital of Philadelphia (CHOP), and published in Molecular Genetics and Metabolism, provides important information about the role that antioxidants can play in the treatment of mitochondrial diseases. Three models were used to measure the effects of seven antioxidant compounds. These included two animal models, a species of worm called C. elegans and zebrafish (D. rerio), and cultures of skin cells taken from humans. All models had the same genetic mitochondrial disease, which interrupted the functioning of the respiratory chain and its ability to process nutrients for energy production. This can cause oxidative stress, of which antioxidants are thought to reduce the effects.
Two of the compounds tested, vitamin E and the drug N-acetylcysteine, improved the outcomes across multiple models. In the worms both compounds were found to prolong lifespan, and they also protected the zebrafish from brain damage. N-acetylcysteine was also shown to improve survival in the human cells. In addition to this, these two compounds reduced oxidative stress across the entire cell, not just within the mitochondria. On the basis of these promising results, researchers would like to further evaluate the effects of vitamin E and N-acetylcysteine in clinical trials of mitochondria disease patients, and have speculated that the compounds may improve symptoms through increasing nervous system resilience.
The other compounds tested produced variable effects. Coenzyme Q10 and a variant of it both led to some improvement in worm models, but the effects were limited. The remaining three compounds, vitamin C, orotate, and lipoate, all showed mixed results.