Oxyresveratrol: A bioavailable dietary polyphenol

To evaluate the potential of oxyresveratrol (OXY), a dietary polyphenol with various health-promoting activities as a nutraceutical/functional food ingredient, its absolute oral bioavailability (F) was examined in Sprague-Dawley rats. Upon single intravenous administration (15 µmol/kg), rapid clearance (Cl) and short mean transit time (MTT) was observed. Dose-escalation to 90 µmol/kg did not alter its Cl and MTT significantly. After single oral administration (100 µmol/kg), although its F was only ~10%, OXY was absorbed rapidly and displayed long residence in systemic circulation. Dose-escalation to 400 µmol/kg brought ~60% and 100% increase in F and dose-normalized maximal plasma concentration (Cmax), respectively. One-week daily dosing (100 µmol/kg) did not cause substantial change in F and Cmax. Although OXY possessed slower Cl, its oral plasma exposure was comparable to RES. As OXY was orally bioavailable, further development of OXY as a nutraceutical/functional food ingredient is warranted.