Triclosan is a mitochondrial uncoupler in live zebrafish

Area of Science:

• Biochemistry
• Toxicology
• Developmental Biology

Background:

• Triclosan (TCS) is a widespread antimicrobial agent found in consumer products.
• Previous research identified TCS as a mitochondrial uncoupler in cell cultures.
• Human exposure to TCS is common due to its extensive use.

Purpose of the Study:

• To investigate whether TCS acts as a mitochondrial uncoupler in a living organism.
• To assess the effects of TCS on zebrafish embryo bioenergetics.
• To establish a high-throughput method for identifying mitochondrial uncouplers in vivo.

Main Methods:

• Utilized a Seahorse XF^e 96 Extracellular Flux Analyzer adapted for single zebrafish embryo analysis.
• Measured oxygen consumption rate (OCR) and other bioenergetic parameters in 24-hour post-fertilization zebrafish embryos.
• Employed a 96-well assay format with precise temperature control for high-throughput screening.

Main Results:

• TCS exposure increased basal OCR in zebrafish embryos.
• ATP-linked respiration and spare respiratory capacity were decreased by TCS.
• Proton leak was elevated, confirming mitochondrial uncoupling in vivo without affecting survival or heart rate.

Conclusions:

• Triclosan functions as a mitochondrial uncoupler in living zebrafish embryos.
• These findings necessitate re-evaluation of TCS toxicity and potential pharmaceutical applications.
• The developed Seahorse assay provides a novel high-throughput platform for in vivo mitochondrial uncoupler discovery.