Syringic acid alleviates valproic acid induced autism via activation of p38 mitogen-activated protein kinase: Possible molecular approach.

Abstract

Autism spectrum disorder (ASD) is a multifactorial neurodevelopmental disorder characterized by restrictive and repetitive behavior followed by impairment in social, verbal, and non-verbal interaction and communication. Valproic acid (VPA) is a well-known anti-epileptic drug, but its prenatal exposure to animals causes social impairment, neurotransmitters imbalance, and neuroinflammation with ASD-like phenotypes. Syringic acid (SA) is a polyphenolic compound with anti-inflammatory, anti-apoptotic, antioxidant, and neuromodulator activity. The purpose of study was to investigate the protective effect of Syringic acid (SA) in prenatal VPA-treated rats through behavioral, neuroinflammation, oxidative stress, neurotransmitters, neuronal integrity, and apoptotic marker. Single dose of VPA was administered 600 mg/kg, i.p. on a gestational day (GD) 12th and SA was administrated from PnD 26th to 54th at the dose of 25, 50, and 100 mg/kg, p.o. On PnD 56th behavioral parameters (Pain sensitivity, open field test, narrow beam walks test and social impairment test) were performed and all animals were sacrificed, and brain tissue was isolated for oxidative stress (GSH, CAT, and LPO), neuroinflammation (TNF-α and IL-6) and neurotransmitters (GABA and Glutamate), histopathology (H&E, Nissl), immunohistochemistry (p38 MAPK) analysis. Rat treated with SA dose-dependently prevented behavioral alteration, restored antioxidant enzymes, neurotransmitters level, decreased neuroinflammatory markers, and improved neuronal integrity. Furthermore, immunohistochemistry confirmed the reduced p38 MAPK marker expression by SA in VPA induced autistic behavior.