Valproic Acid

Valproic acid acts as an antagonist at T-type voltage-gated Ca2+ channels and voltage-gated Na+ channels; it also inhibits GABA transaminase, potentiating GABA signaling. Valproic acid is used clinically as an antiepileptic/anticonvulsant, although it also exhibits anti-inflammatory, anti-angiogenic, and anticancer chemotherapeutic activities. Valproic acid may also display antihypertensive benefit. In lung tissue, this compound prevents LPS-induced increases in TNF-α, IL-1β, NF-κB, NO, and iNOS. Valproic acid is an inhibitor of class I histone deacetylases (HDACs), primarily active against HDAC1, and downregulates expression of HDAC, VEGF, VEGFR2, and FGF, inhibiting tumor growth and angiogenesis in animal models.