Liposomes as carriers of resveratrol and vitamin E: Evaluating ameliorative antioxidant effect using chemical and cellular test systems.

Abstract

Resveratrol (RES) in combination with antioxidant vitamins is reported to be more effective in protecting the cells from oxidative stress rather than any of these antioxidants alone. In continuation to our previous work using resveratrol and vitamin C, our main aim was to evaluate the antioxidant restorative effect using chemical and cellular test systems on resveratrol co-encapsulated vitamin E (VE) within liposomes. Z-average size was less than 135nm, polydispersity index<0.3; zeta potential>than±30mV and encapsulation efficiency of RES and VE>90% and 79% respectively. Chemiluminescence measurement indicated that the antioxidative activity of RES could be increased when VE was additionally loaded into liposomes. Inhibition of AAPH induced luminol enhanced chemiluminescence displayed 90% improvement (P<0.001) in comparison to control; on the other hand 70% luminescence inhibition of ROS production in isolated blood leukocytes (P<0.001) was observed. Intracellular oxygen-derived radicals measured by flow cytometry using 2'-7'-dichlorodihydrofluorescein diacetate demonstrated about 1.7 fold (P<0.05) and 1.5 fold (P<0.001) enhancement of radical scavenging activity in buffy coats under basal conditions and human umbilical vein endothelial cells after stimulation by H2O2 respectively. The cellular systems evidenced the ability of liposome loaded antioxidants to scavenge ROS in the extra and intracellular space, confirming enhanced antioxidative effectivity of RES in the presence of VE, which did not occur in combination with vitamin C. Hence it might be possible to improve the antioxidative effectivity of RES by other/additional antioxidants.