Previous studies of the biological activity of melanin produced by the Antarctic black yeast Pseudonadsoniela brunnea have shown its antioxidant, stress-adaptogenic, dermatotropic, wound-healing and antibacterial effects. However, the primary physicochemical mechanisms of the system influence of melanins remain insufficiently studied. Therefore, the aim of the study was to determine effects of the intragastral administration of melanin produced by the Antarctic black yeast Pseudonadsoniela brunnea on the optical properties of a protein component and an aqueous phase of rat serum. White nonbread adult male rats weighing 180–200 g were used in the experiments. The intragastric route of administration of melanin by means of soft gastric catheter at a dose of 3 mg/kg was used. Rats of the control group were administered the physiological solution in the same way. After 1 hour the animals were sacrificed by cervical dislocation and blood serum was obtained for further studies. The absorption spectra of blood serum samples were recorded using Shimadzu Biospec-Mini spectrophotometer in the range of 190–1100 nm. Analysis of the absorption spectra of blood serum in a wide range from UV to near IR indicated that one hour after intragastral administration of melanin to rats at the dose of 3 mg/kg the optical properties of protein component were not changed, but the properties of the aqueous phase of the blood serum were changed due to statistically significant decrease of an amount of hydrogen bonds. Authors hypothesized that the appearance of substances that destruct the hydrogen bond network in the blood is one of the reasons for such changes. Changes of properties of water as the solvent and the structure-forming factor can have further systemic consequences due to changes in the hydration of biological polymers and low molecular weight metabolites, their solubility and intermolecular interactions, cell membrane permeability, molecular dynamics and functional activity of biomacromolecules, etc.

The features of the influence of microwave radiation on the optical properties of pure water and water in solutions of hemoglobin in the near infrared range with the aim to characterize the certain structural and dynamic state of water are investigated. The object of the study was the optical properties of distilled water and aqueous solutions of human hemoglobin in the concentration range of 7 and 15 μm and in the temperature range 10–40°C. The optical spectra were recorded by using a BiospecMini spectrophotometer in the wavelength range of 190–1100 nm. In order to increase the accuracy of the analysis of spectral data the spectra were normalized relative to the baseline which was taken as a line that ran parallel to the horizontal axis due to the minimum value of the optical density in the absorption spectrum. The values of the absorption maxima and the optical density were used as the main parameters of the absorption spectra. The B spline function was used to more accurately determine these parameters. Microwave exposures of distilled water and hemoglobin solutions was performed at a wavelength of 7.1 mm with a maximum 100% output power which was calculated to be approximately 24 mW. The dependence of the parameters of the water absorption spectrum in the range of the second overtone of the OH-valence oscillation of the water molecule on temperature is detailed. There were not found statistically significant changes in the distilled water absorption spectrum in the range of the second overtone OH-valence oscillation of the water molecule after one-hour exposure of the microwave EMR. In hemoglobin solutions in this spectral range there is a small but statistically significant increase in absorption. This may indicate on additional EM-induced activation of the libration motions of water molecules and an increase the probability of deformation oscillations that which are manifested in the near IR range in the band of the second overtone of water.

The biological activity of millimeter electromagnetic radiation (MEMR) has long been known that is the basis for its use in medicine. But the primary biophysical mechanisms of this factor at the molecular level remain poorly understood and debated. Because of it the features of the influence of microwave radiation on the optical properties of water solutions of hemoglobin with the aim to characterize the certain structural state of hemoglobin were investigated in this research. The object of the study was the optical properties of aqueous solutions of human hemoglobin in the concentration range of 7 and 15 μM and in the temperature range 10–40°C. The optical spectra were recorded by using a BiospecMini (Shimadzu) spectrophotometer in the wavelength range of 190–1100 nm. In order to increase the accuracy of the analysis of spectral data the spectra were normalized relative to the baseline which was taken as a line that ran parallel to the horizontal axis due to the minimum value of the optical density in the absorption spectrum. The values of the absorption maxima and the optical density were used as the main parameters of the absorption spectra. The B-spline function was used to more accurately determine these parameters. Microwave exposure of hemoglobin solutions was performed at wavelength of 7,1 mm with power that calculated to be approximately 6mW. This power of electromagnetic radiation corresponds to the conditional limit range between thermal and non-thermal action of this factor. The dependence of the optical properties of hemoglobin in the spectral range of heme absorption on temperature was analyzed and effects of microwave radiation on the optical properties of hemoglobin solutions were considered in frame of hypochromic effects induced by temperature. It was revealed that the parameters of the absorption spectrum of an aqueous solution of hemoglobin depend on temperature. The optical density in the Sore band and the spectral bands of the oxygenated form of hemoglobin decreases upon temperature increase. The observed temperature hypochromic effect is associated with increased protein aggregation. The effect of MEMR leads to a small but statistically significant hypochromism in the spectra of hemoglobin absorption that testifies an increase in protein aggregation under the action of this physical factor which cause the changes in the hydration of protein molecules. This effect depends on the protein concentration and is not detected at low concentrations.