Aim: 

Oxidative damages due to lipid peroxidation of biomembranes are involved in the pathogenesis of several major free radical mediated diseases.The flavonoid (quercetin) and stilbene (resveratrol: 3,4',5-trihydroxy-trans-stilbene) highly effective and are used as alternative drugs.The aim of this study is to evaluate both single and synergic protective role of such compound against oxidative damage in normal human RBCs. The experimental approach is based on RBCs exposure to physiological concentrations of each tested polyphenol concentration ranging from 0.5 upto 1.6 mM.

Methods: 

The measurement of the membrane lipids degradation is performed by the determination of complex MDA-TBA derivatives.The morphological changes of erythrocytes are highlighted in optical microscopy. Anion permeability was evaluated by the specific absorption of methemoglobin (CM) at 590 and 635 nm. The osmotic fragility of RBC membrane is evaluated by exposure to hypotonic stress solution. The lipid peroxidation susceptibility is observed after the oxidative stress induced by AAPH.

Results: 

The data in this study show the synergetic action of resveratrol and quercetin to significantly attenuate the oxidative injuries induced at different ionic strengths and AAPH concentrations. The CM evaluation evidences a relevant role in the improvement of membrane function. Furthermore, the antihaemolytic activities of the polyphenols are related to the increase of membrane integrity of the quercetin and resveratrol treated RBC membranes.

Conclusion: 

At physiological concentrations the polyphenols contribute to protect membranes from oxidative stress.