Simultaneous quantification of free curcuminoids and their metabolites in equine plasma by LC-ESI–MS/MS

Abstract The human health benefits attributed to turmeric/curcumin spice has resulted in its wide utilization as a dietary supplement for companion pets and other animals including horses. While the quantification of free curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin) and their phase-2 metabolites (curcumin- O -sulfate, curcumin- O -glucuronide) have been extensively investigated in human and rodent biological samples (primarily plasma and serum), there is lack of similar data for horses. Herein, we report a validated LC-ESI–MS/MS method for the simultaneous quantification of the aforementioned free curcuminoids and their metabolites in equine plasma. The linearity of the aforementioned curcuminoids and curcumin- O -sulfate was in the range of 0.5–1000 ng/mL and 1–1000 ng/mL for curcumin- O -glucuronide with 85–115% accuracy and O -sulfate in equine plasma.