Potential neuroprotective capacity of L-glutamic acid attached to silica nanoparticles on behavioral disturbances, neural oxidative stress,and neural damage induced by hydrogen peroxide in rats

Abstract

Exposure to certain environmental factors and xenobiotic agents can lead to an excess of reactive oxygen species and free radical formation that can damage neuronal cells and affect cognitive function. Silica nanoparticles, as probes for genes or proteins, are already used in nanomedicine as a nanocarrier for several drugs. In the present study, SiO2 NPs were functionalized with glutamate to fight the oxidative-induced stress following chronic exposure to hydrogen peroxide (H2O2). This study aims to investigate whether Glutamate-functionalized Silica Nanoparticles can prevent the neurobehavioral and functional modifications displayed by adult male rats exposed to hydrogen peroxide (H2O2). We observed that subchronic exposure (21 days)to H2O2 induced an anxious state and a decrease in locomotor activity in the animals compared to controls. It the Morris water maze task, rats exposed to H2O2 showed impaired spatial learning and memory abilities. In addition, we observed that compared to controls, H2O2 exposed animals showed an imbalance in the redox status and disturbances of the enzyme’s activities-acetylcholinesterase (AChE) and Monoamine Oxidase (MAO) that were prevented by concomitant SiO2 NPs administration. Furthermore, H2O2 treatment enhanced the occurrence of necrotic and degenerative cell changes in several brain areas (hippocampus, subiculum, caudate-putamen and frontal cortex), that were ameliorated by SiO2 NPs treatment. In summary, the supplementation of L-glutamic acid-functionalized silica Nanoparticles corrected enzymatic activities, reduced behavioral disturbances and diminished histological alterations induced by H2O2. Our results suggest that SiO2 NPs are useful to prevent or ameliorate behavioral impairment, as well as antioxidant enzymatic disturbances and neural damage induced by oxidative stress in the hippocampus and frontal cortex.