Effects of Rosa canina fruit extract on neutrophil respiratory burst

Respiratory burst leads polymorphonuclear neutraphils (PMN) to produce reactive oxygen species (ROS) such as superoxide anions (O(2)degrees(-)), hypochlorous acid (HOCI) and hydrogen peroxide (H2O2) which may possess deleterious effects for the organism. Rosa canina fruits are well known to contain a large amount of vitamin C which is antioxidant. This study was focused on the polyphenolics contained in rose hips to evaluate their antioxidative properties. We prepared a rose hip extract deprived of vitamin C. The extract contained mainly phenolics such as proanthocyanidins and flavonoids. We investigated its effects directly against O(2)degrees(-), HOCI and H2O2 and investigated its effects on isolated PMN. For that, in vitro inflammatory conditions were reproduced by stimulating PMN with stimuli having different transductional pathways, in order to determine a possible mechanism of action. The results showed that the extract can inhibit ROS tested in acellular and cellular systems. The IC50 obtained were 5.73 mg/L, 1.33 mg/L and 2.34 mg/L respectively for O(2)degrees(-) , HOCI and H2O2 in acellular experiments. For cellular experiments, the IC50 were quite similar. Thus, the extract did not present an effect on PMN metabolism. Therefore, the antioxidative effects of Rosa canina area due not only to vitamin C but also to polyphenolics. Copyright (C) 2002 John Wiley Sons, Ltd.