Development and validation of a sensitive LC–MS/MS assay for the quantification of anserine in human plasma and urine and its application to pharmacokinetic study

Abstract

Carnosine (beta-alanyl-L-histidine) and its methylated analogue anserine are present in relevant concentrations in the omnivore human diet. Several studies reported promising therapeutic potential for carnosine in various rodent models of oxidative stress and inflammation-related chronic diseases.Nevertheless, the poor serum stability of carnosine in humans makes the translation of rodent models hard. Even though anserine and carnosine have similar biochemical properties, anserine has better serum stability. Despite this interesting profile, the research on anserine is scarce.The aim of this study was to explore the bioavailability and stability of synthesized anserine by 1) performing in vitro stability experiments in human plasma and molecular modelling studies and by 2) evaluating the plasma and urinary pharmacokinetic profile in healthy volunteers following different doses of anserine (4-10-20 mg/kg body weight). A bio-analytical method for measuring anserine levels was developed and validated using liquid chromatography-electrospray mass spectrometry.

Important roles of dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline in human nutrition and health

“…Besides using carnosine as a substrate, carnosinase also acts on anserine, but its enzymatic activity is lower for anserine than for carnosine (Boldyrev et al 2013;Yeum et al 2010). Thus, anserine is metabolized in humans and other animals as described previously for carnosine, except that serum carnosinase degrades anserine at a lower rate than carnosine and, therefore, oral administration of anserine or anserinecontaining food (e.g., beef) can transiently increase the concentration of anserine in the human plasma (Everaert et al 2019;Yeum et al et al 2010). Excess anserine, β-alanine and 1-methyl-histidine are excreted from the body via the urine (Sale et al 2010).…”

“…High concentrations of anserine in the mM range are also present in the brains of the non-primate animals. In contrast, anserine is usually absent from the plasma of healthy adult humans without anserine intake (Everaert et al 2019) and is present at 2-10 µM in the plasma of non-primate animals depending on species (Boldyrev et al 2013).…”

“…Excess anserine, β-alanine and 1-methyl-histidine are excreted from the body via the urine (Sale et al 2010). Oral administration of 4, 10 and 20 mg anserine/kg BW to young adults dose-dependently increased its urinary excretion, with peak concentrations of anserine in urine at 90 min after intake (Everaert et al 2019). Even in subjects consuming 20 mg anserine/kg BW, the peak concentration of anserine in the plasma was only 3 µM, indicating extensive catabolism of this peptide by serum carnosinase.…”

“…Anserine has physiological functions similar to those of carnosine, including H + buffering, antioxidation, modulation of muscle contractility (e.g., excitation and contraction through transmembrane potential maintenance and electromechanical coupling), and regulation of metabolism (Boldyrev et al 2013;Everaert et al 2019;Kohen et al 1988). However, as a methylated metabolite of carnosine, anserine has some biochemical properties that are different from those of carnosine.…”

Targeted ultra‐performance liquid chromatography/tandem mass spectrometric quantification of methylated amines and selected amino acids in biofluids

“…Quantification of methylated arginine compounds such as ADMA is established in a clinical context . Dipeptides and methylhistidines were described recently as putative markers of meat intake . However, methods integrating a high number of these compounds into one validated quantitative method are scarce.…”