The role of the natural antioxidants in the oxihaemoglobin oxidation and the diminution of nitrite concentration [Articol]

Abstract

The paper includes the study of the inhibition of the process of methemoglobinization at oxidation with nitrites in the presence of sodium dihydroxyfumarate (DFH3Na) and resveratrol (3,4’,5-trihydroxystilben). The experimental study was carried out by treatment of the erythrocyte mass by hemolysis and exposure to nitrite. The kinetic investigations were carried out in following conditions: [Resv] = (5.10-5 – 110-3) mol/l, [DFH3Na] = 1.10-6 – 5.10-6 mol/l; [HbO2]=1.10-3mol/l; pH 7,1; t = 370C. The rate of transformation of HbO2 in the presence of resveratrol and DFH3Na was calculated from kinetic curves of consumption of the substrate and formation of MetHb obtained spectrophotometrically (λmax= 540 nm for HbO2 and λmax=630 for MetHb). It has been found out that the introduction of resveratrol and DFH3Na in the system HbO2 – NO2- causes the decrease of the autooxidation factor φDFH3Na approximately by 1.1 – 2.5 times and φresveratrol by 1.1 – 1.7 times. The time of achievement of the maximum rate of oxidation of HbO2 dζ/dτ (where ζ is the rate of transformation of HbO2 in MetHb) increases while the phase of fast oxidation of HbO2 decreases with increase of content of inhibitors. The process of interaction of nitrites with reducers (such as DFH4, DFH3Na, resveratrol and (+)-catechine) was carried out as well. It has been established that degree of diminishing of the ncentration of nitrites in the system RedH2-NO2- decreases as follows: DFH4<DFH3Na<Resv<(+)Catechol.