Excretion, Metabolism, and Tissue Distribution of () in Pigs.

() is a toxic flowering plant in the family Loganiaceae used to treat skin diseases, neuralgia and acute pain. The high toxicity of restricts its development and clinical applications, but in veterinary applications, has been fed to pigs as a feed additive without poisoning. However, until now, the in vivo processes of the multiple components of have not been studied. This study investigates the excretion, metabolism and tissue distribution of the multiple components of after feeding it to pigs in medicated feed. Pigs were fed 2% powder in feed for 45 days. The plasma, urine, bile, feces and tissues (heart, liver, lung, spleen, brain, spinal cord, adrenal gland, testis, thigh muscle, abdominal muscle and back muscle) were collected 6 h after the last feeding and analyzed using high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Five natural products in plasma, twelve natural products and five metabolites in urine, and three natural products in feces were characterized, suggesting that multiple components from were excreted in the urine. However, ten natural products and four metabolites were detected in bile samples, which suggested that is involved in enterohepatic circulation in pigs. A total of seven of these metabolites were characterized, and four metabolites were glucuronidated metabolites. Ten natural products and six metabolites were detected in the tissues, which indicates that is widely distributed in tissues and can cross the blood-brain barrier. Among the characterized compounds, a highly toxic gelsedine-type alkaloid from was the main compound detected in all biological samples. This is the first study of the excretion, metabolism and tissue distribution of multiple components from in pigs. These data can provide an important reference to explain the efficacy and toxicity of . Additionally, the results of the tissue distribution of are of great value for further residue depletion studies and safety evaluations of products of animals fed .