Evaluation of a new benzothiazole derivative with antioxidant activity in the initial phase of acetaminophen toxicity

Increasing evidence indicates that benzothiazoles and thioureas have the ability to inactivate reactive chemical species through their antioxidant activity. In this context, we designed and synthesized two benzothiazole-isothiourea derivatives, (E)-5-((benzo[d]thiazol-2-ylimino)(methylthio)methylamino)-2-hydroxybenzoic acid (compound 1) and (S,E)-2-((benzo[d]thiazol-2-ylimino)(methylthio)methylamino)-3-(4-hydroxyphenyl) propanoic acid (compound 2). The 2,2′-diphenyl-1-picrylhydrazyl radical reduction and Fenton reaction were used to evaluate the free radical scavenging activity of both compounds in vitro. The results indicated that compound 1 exhibited the highest scavenging activity. Hence, it was evaluated ex vivo using the initial phase of the acetaminophen-induced hepatotoxicity model. In particular, we demonstrated that compound 1 increased the reduced glutathione content and decreased the malondialdehyde levels. In addition, it was capable of inhibiting cytochrome P450 and producing a protective effect against the reactive intermediary N-acetyl-p-benzoquinoneimine.