title: Protective effect of placenta extracts against nitrite-induced oxidative stress in human erythrocytes.
abstract: Aqueous-saline human placenta extract (HPE) is known to possess antioxidant activity due to the high concentration of bioactive substances. This fact allows its application in clinical practice in order to treat oxidation-induced diseases. Extract antioxidant activity is mainly conditioned by proteins. Freezing of extracts has been shown to lead to their antioxidant activity increasing due to protein conformation changes.Different biological models are widely used in order to evaluate efficacy of novel antioxidants and mechanisms of their action. One such model appears to be erythrocytes under nitrite-induced oxidative stress. Nitrite is known to be able to penetrate erythrocyte membrane and to oxidize hemoglobin. In order to investigate whether HPE is able to decrease nitrite-induced oxidative injuries and to evaluate the protein contribution to this process, spectrophotometric and electron spin resonance (ESR) assays were used.Experimental data have revealed that antioxidant activity of extracts and of some of their fractions correlates with methemoglobin concentration lowering. Preliminary erythrocyte incubation with an extract fraction of 12 kDa allows preservation of the structural-dynamic cytosol state the closest to the control.
authors.affiliation: Department of Cryobiophysics, Institute for Problems of Cryobiology and Cryomedicine, NAS of Ukraine, Kharkiv, Ukraine. sv.rosanova@gmail.com
authors.forename: Svitlana
authors.initials: S
authors.lastname: Rozanova
authors.forename: Yana
authors.initials: Y
authors.lastname: Cherkashina
authors.forename: Svitlana
authors.initials: S
authors.lastname: Repina
authors.forename: Katherina
authors.initials: K
authors.lastname: Rozanova
authors.forename: Oleg
authors.initials: O
authors.lastname: Nardid
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D008706:Methemoglobin / Q000378:metabolism; D009573:Nitrites / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects*; D010920:Placenta / Q000737:chemistry / Q000378:metabolism; D011247:Pregnancy; D013053:Spectrophotometry
chemical_list: D009573:Nitrites; D008706:Methemoglobin