A Review of the Therapeutic Effects of Natural Antioxidant Compounds on the Improvement of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a progressive multifactorial neurological disease. This disease can be diagnosed before the age of 3 with behavioral disorders. Repetitive and stereotyped behaviors, social interaction disorders, and verbal abnormalities are among the prominent diagnostic features of autism. ASD may be caused by disruptions in the synaptic transmission of different parts of the brain, such as the cerebellum, hippocampus, basal ganglia, amygdala, and prefrontal cortex. In an autistic person, the dynamic imbalance between reactive oxygen species and reactive nitrogen species reduces the antioxidant defense. This can be one of the causes of synaptic disorders between neurons in different parts of the brain. The body responds to oxidative stress with its antioxidant defense system. However, reduced defense capacity or disruption of physiological processes may result in inappropriate responses of the immune system. Recent investigations revealed that the administration of natural antioxidant compounds, such as carotenoids, vitamin C, flavonoids, phenols, and selenium, could increase the antioxidant balance and improve behaviors in ASD.

Considering the significant role of oxidative stress in tissue damage and the pathophysiology of ASD, using antioxidant compounds could be a useful approach to promote synaptic plasticity in different brain regions and improve ASD symptoms.