Assessment of cytochrome P450 induction in canine intestinal organoid models

Abstract

Understanding cytochrome P450 (CYP) enzymes in the canine intestine is vital for predicting drug metabolism and developing safer oral medications. This study evaluates canine colonoids as a model to assess the expression and induction of essential intestinal CYP enzymes. Canine colonoids were cultured in expansion medium (EM) with Wnt-3A and in differentiation medium (DM) without Wnt-3A. We assessed the mRNA expression of CYP2B11, CYP2C21, CYP3A12, and CYP3A98 using qPCR and examined the effects of rifampicin and phenobarbital as inducers. Our findings show that DM significantly increased the mRNA expression of CYP3A98 and CYP2B11, but not CYP3A12, compared to EM. CYP2C21, not typically expressed in the intestine, remained unexpressed in colonoids. Rifampicin induced CYP3A98, aligning with pregnane x receptor (PXR) regulation, while phenobarbital did not, suggesting no constitutive androstane receptor (CAR) involvement. CYP2B11 did not respond to either inducer, suggesting alternative regulatory pathways in canine colonoids. This study is a pioneering effort to establish conditions for studying P450 expression in canine colonoids, confirming significant CYP3A98 expression in the canine intestine. It demonstrated colonoids can induce CYP activity post drug treatments. Further research is needed to enhance species-specific drug metabolism understanding and validate this model for broader applications.