Detoxification of T-2 toxin in human chondrocytes due to its hydroxylation by carboxylesterases and arylacetamide deacetylase in the liver

Abstract

T-2 toxin, a trichothecene mycotoxin produced by Fusarium species, is a global cereal contaminant and an important environmental risk factor for cartilage damage and Kashin–Beck disease (KBD). Although hydrolysis is a major metabolic pathway of T-2 toxin, the human enzymes responsible and their toxicological relevance remain poorly understood. In this study, human liver microsomes, recombinant hydrolases, and selective inhibitors were used to identify the key enzymes mediating T-2 hydrolysis, and LC–MS/MS was applied to quantify T-2 and its major metabolites. Human chondrocytes were further used to evaluate the cytotoxicity of T-2 and its hydrolytic metabolites (HT-2 toxin, neosolaniol, and T-2 tetraol). T-2 toxin was predominantly hydrolyzed to HT-2 toxin, primarily by carboxylesterases (CES1, CES2), with inhibitor-based evidence supporting a potential role for arylacetamide deacetylase (AADAC). The toxicity ranking was T-2 toxin > HT-2 toxin > neosolaniol > T-2 tetraol. T-2 toxin markedly impaired autophagy and extracellular matrix metabolism in chondrocytes, whereas its metabolites showed weaker cytotoxicity. These findings indicate that human CES1 and CES2, together with other hydrolases including AADAC, contributing to the hydrolysis and detoxification of T-2 toxin and may represent potential targets for mitigating T-2–associated cartilage damage and KBD risk.