Hippophae rhamnoidesL. Fruits Reduce the Oxidative Stress in Human Blood Platelets and Plasma
Effects of the phenolic fraction fromHippophae rhamnoidesfruits on the production of thiobarbituric acid reactive substances (TBARS, a marker of lipid peroxidation) and the generation of superoxide anion (O2-∙) in human blood platelets (resting platelets and platelets stimulated by a strong physiological agonist, thrombin) were studiedin vitro. We also examined antioxidant properties of this fraction against human plasma lipid peroxidation and protein carbonylation induced by a strong biological oxidant, hydrogen peroxide (H2O2) or H2O2/Fe (a donor of hydroxyl radicals). The tested fraction ofH. rhamnoides(0.5– 50 µg/mL; the incubation time: 15 and 60 min) inhibited lipid peroxidation induced by H2O2or H2O2/Fe. TheH. rhamnoidesphenolic fraction inhibited not only plasma lipid peroxidation, but also plasma protein carbonylation stimulated by H2O2or H2O2/Fe. Moreover, the level ofO2-∙in platelets significantly decreased. In comparative experiments, theH. rhamnoidesfraction was a more effective antioxidant than aronia extract or grape seed extract (at the highest tested concentration, 50 µg/mL). The obtained results suggest thatH. rhamnoidesfruits may be a new, promising source of natural compounds with antioxidant and antiplatelet activity beneficial not only for healthy people, but also for those with oxidative stress-associated diseases.