Hydroxytyrosol (HT) is one of the most characteristic compound of olive products and
a highly potent compound with proven positive impact to human health [1]. Moreover, HT is also an endogenous metabolite produced from dopamine. The release
of many HT-based products in the market directed the current research efford to the
exploration of HT effect in obesity and investigation of its ADMET properties based
on a human intervation study.
Therefore, HT was administered as a soft capsule to 28 obese/overweight women in different
doses to investigate its anti-obesity effect and the impact on urine metabolome. Towards
this purpose, urine samples were collected in three time points (T=0, T=3 months,
T=6 months) and analyzed via UPLC-Orbitrap MS using untargeted metabolomics aiming
to biomarkers discovery. The three different groups (control, high and low dose) were
discriminated according to the administered capsule and dose and 30 statistically
significant metabolites were uncovered. Among them, hippuric acid (HA) and phenylacetylglutamine
(PAG), two endogenous urine metabolites were distinguished. Additionally, UHPLC-TQ
MS methodology using multipole reaction monitoring (MRM) method was used for HA and
PAG quantitation in urine samples. HT and homovanillic acid, the most common metabolic
derivative of HT, were also quantified. The proposed biomarkers levels verified our
initial findings. HA and PAG were associated for the first time with HT consumption
and could be utilised as biomarkers.
