High heritability and clinical heterogeneity describe autism spectrum disorder (ASD). Social communication difficulties are the primary core symptoms. There are no drugs that have been approved for the treatment of these symptoms, and those that are used to treat generalized symptoms have harmful side effects.
A new study asked whether an existing drug provides a new treatment, even if it previously had no association with ASD.
Using a computer model encompassing proteins involved in ASD, scientists identified how different drugs affected proteins in the system. They also identified potential candidates to treat it.
Such networks encompass proteins and the complex interactions between them. It is essential to account for this complexity when studying biological systems, as affecting one protein can often have knock-on effects elsewhere.
By investigating existing drugs and their interaction with proteins in the network, the team identified several candidates that counteract the biological process underlying ASD.
A commonly used antidiarrheal drug called loperamide was a promising candidate. Scientists have an interesting hypothesis about how it may work to treat ASD symptoms.
The opioid receptor protein, often impacted by opioid medications like morphine, is bound to and activated by loperamide. The -opioid receptor affects social behavior in addition to the effects you would often anticipate from opioid treatment, such as pain alleviation.
In previous studies, genetically engineered mice that lack the μ-opioid receptor demonstrated social deficits similar to those seen in ASD. Interestingly, drugs that activate the μ-opioid receptor helped to restore social behaviors.
These findings in mice raise the possibility that loperamide or other medications targeting the -opioid receptor may offer a novel strategy for treating the social symptoms associated with ASD. Still, more research is needed to verify this theory. In any event, the current study represents the importance of assuming that old drugs could indeed pick up new tricks.
- Elise Koch and Ditte Demontis. Drug repurposing candidates to treat core symptoms in autism spectrum disorder. Sec. Neuropharmacology. DOI: 10.3389/fphar.2022.995439