Asiatic Acid Prevents Cognitive Deficits by Inhibiting Calpain Activation and Preserving Synaptic and Mitochondrial Function in Rats with Kainic Acid-Induced Seizure

Abstract

Cognitive impairment is not only associated with seizures but also reported as an adverse effect of antiepileptic drugs. Thus, new molecules that can ameliorate seizures and maintain satisfactory cognitive function should be developed. The antiepileptic potential of asiatic acid, a triterpene derived from the medicinal herb Centella asiatica, has already been demonstrated; however, its role in epilepsy-related cognitive deficits is yet to be determined. In this study, we evaluated the effects of asiatic acid on cognitive deficits in rats with kainic acid (KA)-induced seizure and explored the potential mechanisms underlying these effects. Our results revealed that asiatic acid administrated intraperitoneally 30 min prior to KA (15 mg/kg) injection ameliorated seizures and significantly improved KA-induced memory deficits, as demonstrated by the results of the Morris water maze test. In addition, asiatic acid ameliorated neuronal damage, inhibited calpain activation, and increased protein kinase B (AKT) activation in the hippocampus of KA-treated rats. Asiatic acid also increased the levels of synaptic proteins and the number of synaptic vesicles as well as attenuated mitochondrial morphology damage in the hippocampus of KA-treated rats. Furthermore, proteomic and Western blot analyses of hippocampal synaptosomes revealed that asiatic acid reversed KA-induced changes in mitochondria function-associated proteins, including lipoamide dehydrogenase, glutamate dehydrogenase 1 (GLUD1), ATP synthase (ATP5A), and mitochondrial deacetylase sirtuin-3 (SIRT3). Our data suggest that asiatic acid can prevent seizures and improve cognitive impairment in KA-treated rats by reducing hippocampal neuronal damage through the inhibition of calpain activation and the elevation of activated AKT, coupled with an increase in synaptic and mitochondrial function.