Sulfur – Containing Amino Acids in Seizures: Current State of the Art

Background: Homocysteine and taurine are non-proteinogenic sulfur-containing amino acids with numerous important physiological roles. Homocysteine and taurine are considered to be neurotransmitters and neuromodulators, the first showing clear hyperexcitability role, while the second is known by its inhibitory and neuroprotective properties. Objective: In this article we addressed the role of homocysteine and its related metabolite homocysteine thiolactone in the development of seizures, focusing on its experimental models in vivo, potential mechanisms of proepileptogenic activity via interactions with glutamatergic neurotransmission, sodium pump activity, oxidative stress, cholinergic system and NO-mediated neuronal signaling, as well as the pharmacological and non-pharmacological approaches to modulate its proconvulsive activity. Additionally, herein we will focus on taurine neuroprotective effects linked with its anticonvulsive properties and mediated by taurine interactions with GABA-ergic and glutamatergic system and oxidative stress.