A popular herbal supplement restored hearing in mice. Human ears could be next
While the term “high cholesterol” is usually associated with health issues, there’s at least one possibility that most people would prefer if they had high cholesterol: in the inner ear, so they can continue to have good hearing as they age have. At least that is the premise a Recent study in the journal PLOS Biology, whose authors found that plant-based compounds called phytosterols—which look and act like cholesterol—improved hearing in mice that had become deaf while also losing their inner-ear cholesterol.
“Age triggers a loss of cholesterol from the sensory cells of the inner ear.”
The Argentine scientists hypothesized that there might be a connection between this tendency and the fact that the brain loses cholesterol with age, since hearing loss occurs with age and the outer hair cells (OHCs) in their inner ears lose their elasticity. They also wanted to test whether a common over-the-counter drug could help treat this condition.
To test their hypothesis, the scientists measured an enzyme called CYP46A1 in OHCs in the inner ear of mice, since its presence is inversely correlated with the presence of cholesterol. After noting that older mice had more CYP46A1 in their inner ears than younger mice and therefore had less cholesterol, the researchers used an HIV drug called efavirenz to induce hearing loss in mice. This allowed them to test whether the presence of cholesterol was linked to hearing ability.
They found that in younger mice, overactivation of CYP46A1 led to hearing loss. But when the researchers treated the mice with a plant-based cholesterol-like compound called phytosterols, the anesthetized mice saw an improvement in their hearing.
“Our results are very promising as they provide the first principled evidence that phytosterol supplementation is a possible approach to prevent or treat hearing loss,” the authors wrote, concluding: “Our results point to the importance of cholesterol homeostasis in the brain … towards.” Inner ear as an innovative therapy strategy to prevent and/or delay hearing loss.
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“Our results point to the importance of inner ear cholesterol homeostasis as an innovative therapeutic strategy to prevent and/or delay hearing loss.”
phytosterols, which are readily available in many pharmacies and grocery stores, are currently used to treat cholesterol problems. They work by having a cellular structure that looks and acts like cholesterol and therefore competes with cholesterol in the digestive system. As a result of this competition, the body digests the phytosterols instead of the cholesterol and removes some of that cholesterol as waste. Phytosterols can thereby lower the unhealthy form of cholesterol called low-density lipoprotein cholesterol (LDL), which can clog the heart and arteries and cause serious cardiovascular disease.
That doesn’t mean that phytosterols are harmless. When people have a genetic condition called sitosterolemia, eating cholesterol accumulates in the body, as do phytosterols. There is also a possibility that taking too many phytosterols can lead to atherosclerosis, a disease in which the walls of the arteries develop abnormalities, or lesions. Pregnant women and children should also do this avoid them.
The current study is also significant because, as the authors explain, “the role of cholesterol homeostasis in inner ear physiopathology has not been previously explored.”
Of course, just because this treatment showed promise in mice doesn’t always mean it’s translatable to humans. But it gives scientists a starting point, and in general, phytosterols are well-tolerated supplements. It could one day lead to a treatment for age-related hearing loss.
However, further research on this topic is needed. As the authors point out in their paper, other scientists need to repeat their studies in other strains of mice before doctors can test this in humans. Furthermore: “Although our results show that in aged cochlear tissue there is a reduction in cholesterol levels in inner ear sensory cells – measured by Filipin labeling – and that this reduction correlates with an increase in CYP46A1 immunofluorescence, this will be the case.” be.” be important to test alternative methods for CYP46A1 quantification in specific cell populations.”
