Identification of the metabolites of piperine via hepatocyte incubation and liquid chromatography combined with diode‐array detection and high‐resolution mass spectrometry

Abstract

Rationale Piperine, an alkaloid isolated from Piper nigrum L., has been demonstrated to have many pharmacological effects and several health benefits. The aim of this work was to study the metabolic profiles of piperine in mouse, rat, dog and human hepatocytes. Methods The biotransformation was carried out by incubating piperine with hepatocytes at 37°C. After incubation for 2 h, the samples were pretreated and analyzed using liquid chromatography combined with diode‐array detection and high‐resolution mass spectrometry (LC/DAD‐HRMS). The structures of the metabolites were assigned through a comparison of their accurate masses and product ions with those of the parent compound. Results A total of 20 metabolites were detected, and the structures were proposed. Piperine was metabolized through the following pathways: (a) oxidation to form a catechol derivative, which further underwent methylation, glucuronidation, glutathione (GSH) conjugation, and hydroxylation followed by opening of the piperidine ring; (b) hydroxylation to form a carbinolamine intermediate followed by opening of the piperidine ring and the formation of alcohol and acid derivatives; and (c) hydroxylation to form stable hydroxylated metabolites. In mouse, the formation of the catechol derivative (M12) and hydroxylation (M11) were the major metabolic pathways; in rat, the formation of the catechol derivative (M12) and glucuronidation (M9) were the main pathways; and in dog and human, the formation of the catechol derivative (M12) was the predominant pathway. No human‐specific metabolite was observed. Conclusions This study provided some new information on the metabolic profiles of piperine, which should be of great importance in the study of the pharmacology and toxicity of this compound.

Piperine and Its Metabolite’s Pharmacology in Neurodegenerative and Neurological Diseases

“…Examining PIP-incubated hepatocytes (of rats, dogs, mouse, and human), it was revealed that at least 20 primary and secondary metabolites are formed from PIP [ 28 ]. PIP is fragmented (the basic fragmentation is shown in Figure 2 ) by several steps of reaction to be converted into these metabolites, generally starting with the loss of the piperidine ring followed by the cleavage of the amide bond.…”

“…Oral gavaging of PIP in rats yielded a number of metabolites by oxidation and/or cleavage of the piperidine ring, which were not found in feces, but only in the urine sample ( Figure 2 ). However, it is to be noted that PIP metabolites from rats and human are not the same; thereby, Li et al (2020) have used mouse, human, and rat hepatocyte to identify, characterize, and distinguish PIP metabolites of different species [ 28 ]. Using a thorough screening and analytical techniques containing LC/DAD-HRMS and MS/MS, they have identified 20 metabolites; of them, 5 are primarily from PIP and the remaining 15 are secondary to those 5 primary metabolites (C11, 12, 15, 16, and 18; shown in Figure 2 ).…”

“… Possible biotransformation of PIP metabolites in hepatocyte. Based on Li Y et al [ 28 ], 20 metabolites could be detected from PIP in the liver. Li and colleagues used hepatocytes of four different species (human, rat, mouse, and dog) and found that a few of these 20 metabolites could be detected in all species (C6, C9, C11, C12, C13, C14, C15, C19, and C20), but not all.…”

Safety Aspects of the Use of Isolated Piperine Ingested as a Bolus

“…In rat urine, all three metabolites could be detected [ 38 ]. In an in vitro study comparing the hepatic piperine metabolism in mouse, rat, dog and human hepatocytes, the predominant metabolic pathways included formation of a catechol derivate for all species; however, the metabolic pathways displayed species-specific differences in terms of types and quantities of metabolites [ 47 ].…”

Identification of the metabolite of ophiopogonanone A by liquid chromatography/quadrupole time‐of‐flight mass spectrometry

“…It has been well documented that the methylenedioxyphenyl moiety is ready to undergo cytochrome P450 enzyme–catalyzed metabolism, resulting in the formation of catechol derivative 10 . Such biotransformation may lead to reactive metabolites carbene and ortho ‐quinone intermediates that may bring some unwanted side effects 11–16 . Therefore, it is necessary to identify and profile the metabolites of OPA, especially the identification of reactive metabolites.…”