N. P. Palmina

Nanoassociate formation in highly diluted water solutions of potassium phenosan with and without permalloy shielding

Abstracts Diluted water solutions of anti-oxidant potassium phenosan, kept before explorations in “usual” conditions and in conditions of “permalloy container”, i.e. shielding of solution from the influence of external low-frequency electromagnetic and/or geomagnetic fields, were studied. It is shown that in solutions kept in shielded conditions in the area of high dilution with a concentration of solutions lower than “threshold”, nanoobjects called “nanoassociates”, are not formed, and anomalous physicochemical and biological properties observed in solutions kept in “usual” conditions, are not found. We conclude that anomalous physicochemical and biological properties of highly diluted water solutions of potassium phenosan made under “usual” conditions are determined by “nanoassociates”, in which an external low-frequency electromagnetic and/or geomagnetic field is a necessary condition of the formation.

Dose dependences of lipid microviscosity of biological membranes induced by synthetic antioxidant potassium phenosan salt

Earlier, we demonstrated for the first time that the natural antioxidant α�tocopherol in a wide concentra� tion range can modify the structure of different lipid regions in the endoplasmic reticulum and plasma membranes of hepatocytes in experiments in vitro (1, 2). Despite the biochemical and functional differences between endoplasmic reticulum and plasma mem� branes, they are characterized by similar polymodal nonlinear dose dependences of the effects of α�toco� pherol on the rigidity of superficial (~8 A) and micro� viscosity of buried (~20 A) lipid bilayer regions. Such patterns are typical for biologically active substances, showing an effect over a wide concentration range, including ultralow doses (1, 2). The polymodality of dose dependences is associated with the statistically significant effects of α�tocopherol in three concentra� tion ranges. It is assumed that three possible mecha� nisms of action may underlie the effect of this com� pound depending on its concentration: insertion into the membrane, interaction with specific binding sites, and the information transfer through the layers of water with special physical and chemical properties (1-3). It is known that the main physicochemical characteristic of antioxidants is their ability to inhibit lipid peroxidation (LPO) both in vitro and in vivo, the regulatory system of which includes the microviscosity of lipids (4). In view of above, a question arises as to what are the common and distinctive features of the effects of nat� ural and synthetic agents at ultralow doses and whether the relationship between the ability of antiox� idants to inhibit LPO and modify the structure of bio� logical membranes is retained when they are used at ultralow doses. To answer this question, we assessed the effect of potassium salt of β�(4 �hydroxy�3,5�diter� tbutylphenyl)�propionic acid (potassium phenosan), a synthetic antioxidant, in a wide concentration range on the lipid microviscosity of EPR and PM of hepato� cytes. The study was performed with 100

Structural and thermodynamic insight into the potentiality of food biopolymers to behave as smart nanovehicles for essential polyunsaturated lipids

Abstract The development of smart (ie, stimuli-sensitive) nanosized natural delivery systems for essential bioactive compounds has attracted particular interest under the functional food formulation. The natural lipids (triacylglycerols and phospholipids), involving the essential ω-3 and ω-6 polyunsaturated fatty acids, are among the most important nutraceuticals. The high susceptibility of such lipids to oxidative degradation during product preparation, transport, and storage, as well as their low solubility in water and, consequently, in body fluids, pose a challenge for their use as food ingredients. This chapter will review the key structural and thermodynamic properties underlying the novel functionality of the complex nanosized particles formed by biopolymers (individual caseins; sodium caseinate and covalent conjugates of sodium caseinate with maltodextrins) and polyunsaturated lipids. This new functionality includes both the protection against oxidation for the lipids, and their controllable release under the action of digestive enzymes in vitro.

Effects of different phases of cigarette smoke on lipid peroxidation and membrane structure in liposomes

This paper discloses for the first time the effects of the gas phase (GP) and the tar of cigarette smoke on lipid peroxidation (LPO) and on the structure of different lipid regions in liposomes. The LPO development was analysed in terms of the total unsaturation of lipids (double-bond, DB, content) and the formation of dienic conjugates (DC), ketodienes (KD), and malonic dialdehyde (MDA). As expected, the exposure of liposomes to either the GP or the tar led to a significant decrease in the DB content. However, the formation of oxidation products revealed different dynamics: MDA generation was inhibited, while the formation of DC and KD increased during the first few hours of the LPO development followed by its inhibition. The smoke constituents exhibited opposite effects on the structure of the lipid bilayer of liposomes: the GP markedly enhanced the microviscosity of liposomal membranes, whereas the tar caused a drastic lowering of microviscosity.

Effect of dilute solutions of biologically active substances on cell membranes

The article presents data on changes in physicochemical properties of different biological membranes (plasmatic, microsomal, synaptosomes) under the action of biologically active substances, which are different in their chemical structure and the mechanism of action (natural and synthetic antioxidants, thyrotropin - releasing hormone, phorbol esters), in the wide range of concentrations (10−22−10−3 M). Dose dependences of the effect of biologically active substances on the activity of membrane-bound enzymes, lipid peroxidation, the structural state of the various regions of the lipid bilayer of membranes have been obtained and analyzed in terms of their formal generality of polymodality, number and position of the maxima, a sign change of the effect. An attempt to explain the mechanism of each of the observed peaks in these curves has been made. The maximum in the range of relatively high “physiological” concentrations (10−3–10−7 M) is associated with introduction of biologically active substances into biomembranes. In this study maxima in the range of ultra-low doses (10−11–10−16 M) and “apparent” concentrations (10−18 M), where the presence of biologically active substance molecule in a reaction volume is probabilistic in nature, are explained by physicochemical properties of diluted biologically active substances solutions. This conclusion is based on our data on the changes in IR spectra of aqueous solutions of biologically active substances and the results obtained by academician A.I. Konovalov et al. concerning the physicochemical properties of dilute solutions of biologically active substances (conductivity, surface tension, charge), due to the formation of so-called “nanoassociates” from biologically active substance molecule and numerous number of water molecules. The nanoassociates formation and biological effect disappear if the low concentration solutions are kept in a special shielded permalloy container protecting its contents from external electromagnetic field. Thus, nanoassociates are the material carriers of the unique ability of the ultra-low doses of biologically active substances to exhibit biological effects.

The Structural State and Form of Free and Biopolymer-Encapsulated Phosphatidylcholine Liposomes in the Absence and Presence of Natural Plant Antioxidants

Electron spin resonance (ESR) and atomic force microscopy (AFM) were used to study liposomes that were prepared from soybean phosphatidylcholine (PC); they incorporated plant antioxidants (ginger, allspice, and black-pepper extracts; clove oil; etc.) that were encapsulated in biopolymers (sodium caseinate or sodium caseinate–maltodextrin covalent conjugates). Plant antioxidants were shown to cause a 15–25% decrease in the microviscosity of deep-lying regions of the liposome lipid bilayer by ESR with a 16-doxylstearic acid spin probe. A ginger extract exerted the greatest effect (24%). Sodium caseinate and its covalent conjugates with maltodextrins (dextrose equivalents (DEs) 2 and 10) increased the microviscosity by 30–35% as compared with free and antioxidant-incorporating liposomes. AFM showed that antioxidants increased the cross-sectional area and volume of liposomes and that the polymers made liposomes denser and their structure more compact.