The degree of absorption of bioflavonoids, a diverse and complex group of plant derived phytonutrients, has been a frequent debate among scientists. Monomeric flavonoid species are known to be absorbed within 2 h. The kinetics of plasma reactive oxygen species, a reflection of bioactivity, of a commercial blend of flavonoids, OPC-3® was investigated. OPC-3® was selected to compare absorption of an isotonic flavonoid solution vs tablet form with the equivalent amount of fluid.
In the case of isotonic OPC-3® the reactive oxygen species of the subject's plasma decreased significantly (p < 0.05), six times greater than OPC-3® tablets by 10 min post-consumption. After 20 min the isotonic formulation was approximately four times more bioavailable and after 40 min twice as bioavailable as the tablet, respectively. At time points 1 h and later, both isotonic and tablet formulations lowered oxidative stress, although the isotonic formulation values remained significantly better throughout the investigation period of 4 h. These findings point to a dramatically accelerated bioavailability of flavonoids delivered in an isotonic formulation. Copyright © 2009 John Wiley & Sons, Ltd.