Trimethylsulfonium: a promising new biomarker for hydrogen sulfide?

Abstract

Hydrogen sulfide is a toxic gas but is naturally produced in human tissues and is referred to as the “third gaseous
signaling molecule”. Little is known about the metabolic pathways of hydrogen sulfide and its endogenous natural
production in humans. Thiosulfate is the currently used biomarker for hydrogen sulfide but its utility has been shown
to be limited to exposure to high levels of inhaled hydrogen sulfide rather than probing low levels of environmental
exposure or as a biomarker for the endogenously produced third gaseous signaling molecule. We recently identified a
new metabolite in human urine, trimethylsulfonium. In the present review, we discuss the little information known
about trimethylsulfonium production in humans, its potential to serve as a biomarker for hydrogen sulfide, and its
utility as a biomarker under various settings