Hydrolysis of oleylanilide in the rat

Area of Science:

• Pharmacokinetics and Metabolism
• Toxicology
• Organic Chemistry

Background:

• Understanding the metabolic fate of anilide compounds is crucial for assessing potential toxicological risks.
• Oleylanilide, an anilide derivative, requires investigation into its absorption, distribution, metabolism, and excretion (ADME) profile.

Purpose of the Study:

• To elucidate the metabolic fate and excretion pathways of oleylanilide following oral administration in rats.
• To identify key metabolites and determine the extent of hydrolysis and absorption via different routes.

Main Methods:

• Administration of radiolabeled oleylanilide (oleyl[U-14C]anilide and [9,10(n)-3H]oleyl[U-14C]-anilide) via intragastric gavage to Porton Wistar rats.
• Collection and analysis of excreta (feces, urine) and lymph for radiolabel recovery and metabolite identification using techniques like gas chromatography.
• Hydrolysis of urine samples to identify specific metabolites.

Main Results:

• Approximately 60% of the administered oleylanilide dose was recovered unchanged in feces over 3 days.
• Hydrophilic metabolites were predominantly found in urine.
• p-hydroxyacetanilide, a known aniline metabolite, was detected in hydrolyzed urine samples.
• Absorbed oleylanilide label was primarily recovered in lymph as triglycerides, indicating significant pre-uptake hydrolysis.
• Less than 6% of the dose was identified as intact oleylanilide in lymph.

Conclusions:

• Oleylanilide is largely excreted unmetabolized in feces after oral administration.
• Significant hydrolysis of oleylanilide occurs prior to or during intestinal absorption, with metabolites entering the lymphatic system primarily as triglycerides.
• The study provides insights into the metabolic processing and disposition of oleylanilide in rats.