No abstract

No abstract

Respiratory burst leads polymorphonuclear neutrophils (PMN) to produce reactive oxygen species (ROS) such as superoxide anions (O(2)(o-)), hypochlorous acid (HOCl) and hydrogen peroxide (H(2)O(2)) 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)(o-)), HOCl and H(2)O(2) 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 IC(50) obtained were 5.73 mg/L, 1.33 mg/L and 2.34 mg/L respectively for (O(2)(o-)), HOCl and H(2)O(2) in acellular experiments. For cellular experiments, the IC(50) were quite similar. Thus, the extract did not present an effect on PMN metabolism. Therefore, the antioxidative effects of Rosa canina are due not only to vitamin C but also to polyphenolics.

No abstract

No abstract

No abstract

No abstract

Plasticizers added to polyvinylchloride used in medical devices can be released into patients’ biological fluids. The substitution of di‐(2‐ethylhexyl)phthalate (DEHP) by alternative plasticizers is essential but their safety must be demonstrated. DEHP, di‐(2‐ethylhexyl)terephthalate (DEHT) and their metabolites were investigated using level 2 Organization for Economic Co‐operation and Development bioassays to screen for in vitro hormonal changes. Differences between the DEHP and DEHT metabolites were observed. Albeit weak, the hormonal activities of DEHT‐derived metabolites, e.g., 5‐OH metabolite of mono‐(ethylhexyl)terephthalate (5‐OH‐MEHT), were detected and the results of docking experiments performed on estrogen receptor alpha and androgen receptor agreed with the biological results. A co‐stimulation of human estrogen receptor alpha and human androgen receptor was also observed. With regard to steroidogenesis, a 16‐fold increase in estrogen synthesis was measured with 5‐OH‐MEHT. Therefore, even if DEHT remains an interesting alternative to DEHP because of its low migration from medical devices, it seems important to verify that multi‐exposed patients in neonatal intensive care units do not have urinary levels of oxidized metabolites, in particular 5‐OH‐MEHT, suggesting a potential endocrine‐disrupting effect.