Valproic acid sodium salt (Sodium valproate) is a histone deacetylase (HDAC) inhibitor with an IC50 of approximately 0 4 mM HDACs regulate cellular processes primarily through histone acetylation influencing chromatin remodeling and gene expression Valproic acid sodium salt modulates neuronal cellular responses in vitro by attenuating endoplasmic reticulum stress excitotoxicity and inflammatory injury induced by lipopolysaccharide (LPS) In vivo experiments demonstrate neuroprotective and anti-inflammatory activities following ischemic injury in rodent models reducing infarct volume microglial activation and inflammatory marker levels Clinically investigated in prostate cancer oral administration of Valproic acid sodium salt displays correlation between drug exposure and prostate-specific antigen (PSA) decrease although neurological symptoms and fatigue have been reported