Urinary pharmacokinetics of Queen Garnet plum anthocyanins in healthy human subjects

A new variety of Prunus salicina, Queen Garnet plum (QGP), was developed as a high anthocyanin, high antioxidant plum, in a Queensland, Australia, Government breeding program. In this manuscript, we are presenting for the first time data about the urinary pharmacokinetics of QGP anthocyanins and derived metabolites in healthy humans. Following consumption of 400 mL QGP juice (QGPJ; 2.49 mmol anthocyanins) by two male subjects, QGP anthocyanins (cyanidin-3-glucoside and cyanidin-3-rutinoside) were excreted mainly as methylated glycosides, glucuronides, and sulfoconjugated metabolites in urine. The cumulative excretion of anthocyanins could be fitted to a one-compartment pharmacokinetic model with instantaneous, parallel excretion of anthocyanin metabolites. The usefulness of this non-linear modeling statistical technique for characterizing the urine excretion-time profiles and estimating relevant PK parameters is demonstrated. Results from this pilot study indicate that methylation and glucuronidation are significant metabolic routes when cyanidin-based anthocyanins are consumed in QGPJ. Future studies investigating the benefits of the consumption of anthocyanin-rich Queen Garnet plums and/or derived products should therefore focus on identifying anthocyanin metabolites and include their putative colonic degradation products. This will assist in evaluating the biological relevance of these compounds to health and disease prevention.