Modelling passive absorption properties of phytochemicals using physicochemical properties


Dietary phytochemicals are associated with reducing risk of chronic diseases in humans. Protective bio-efficacy of phytochemicals depends on absorption in the digestive tract and consequent plasma concentrations of bioactive species, but methods to predict absorption of phytochemicals are lacking. Phytochemicals are structurally heterogeneous and the time to reach their maximum concentration in plasma (Tmax) reflects molecular properties and absorption via either the upper or lower intestine. We have developed two statistical models to predict Tmax of phytochemicals following intestinal passive absorption using selected physicochemical properties. The data used to develop the models was obtained from published reports of pharmacokinetic studies in healthy volunteers for 41 compounds; including 7 phenolics, 17 polyphenolics, 6 carotenoids and 11 vitamins, administered in either liquid, solid or semi-solid forms. Of the 7 physicochemical parameters included in the modelling, it was found that Tmax was significantly dependent on lipophilicity, molecular mass and polar surface area. A predictive model including lipophilicity and molecular mass was applied to characterise the expected absorption properties of a selection of phytochemical extracts. Future studies will test the accuracy of predictions of Tmax for strategic selections of dietary and therapeutic phytochemicals and seek to demonstrate outcomes for biological efficacy.

Publication Title

Acta Horticulturae