Study of antioxidant and membrane activity of rosmarinic acid using different model systems

Rosmarinic acid is found in many species of different families of higher plants and its chemical structure is phenol propanoid with various biological activity. In this paper, we conducted a comparative study of antioxidant (radical-scavenging) properties of rosmarinic acid in systems of 2,2tāzo-bis(2-methylpropionamidin)dihydrochloride-luminol and hemoglobin-hydrogen peroxide-luminol, determined its protective potential in preventing peroxidation of linoleic acid, and evaluated the effect on the permeability of planar bilayer lipid membranes. Linoleic acid peroxidation was assessed by iron-thiocyanate method. In these studies, trolox was used as a reference antioxidant, and ascorbic acid, and dihydroquercetin were taken as standards. Rosmarinic acid is significantly superior to trolox, ascorbic acid and dihydroquercetin in the tests for antioxidant activity in the systems studied, as well as in inhibition of linoleic acid peroxidation. According to their activity the investigated substances can be arranged in the following order: rosmarinic acid > dihydroquercetin trolox > ascorbic acid. Rosmarinic acid does not cause significant changes in the permeability of planar bilayer membranes in a dose range of 0.5 to 10 μg/mL. Antioxidant activity of rosmarinic acid is due to the neutralization of reactive oxygen species and/or luminol radicals generated in model systems. The observed features of the antioxidant and membrane activity of rosmarinic acid, which may underlie the previously mentioned pharmacological effects are discussed.     

A Comparative Evaluation of the Actions of Different Secondary Metabolites of Marine Hydrobionts on the Redox Status of Tumor and Immune Cells

Biophysics - Abstract—We performed a comparative analysis of the ability of a number of pharmacologically active natural compounds that are often considered as antioxidants to affect the...     

A study of the antioxidant and membranotropic activities of equinochrome a using different model systems

Echinochrome A (6-ethyl-2,3,5,7,8-pentahydroxy-1,4-naphthoquinone) isolated from the body of sand dollar Scaphechinus mirabilis is an active substance of cardioprotective medication Histochrome and exerts a wide spectrum of anti-inflammatory activities. In the present paper, we conducted a comparative study of the antioxidant (radical-scavengering) properties of echinochrome A in 2,2′-azobis(2-methylpropionamidine) dihydrochloride?luminol and hemoglobin?hydrogen peroxide?luminol systems and assessed its impact on permeability of planar bilayer lipid membranes. Trolox was used as a reference antioxidant and ascorbic acid and dihydroquercetin are taken as standards. Echinochrome A shows moderate antioxidant activity, possessing higher antioxidant capacity than Trolox and ascorbic acid, but exhibiting lower antioxidant potential compared with dihydroquercetin in tests for antioxidant activity in both investigated systems. The test substances can be arranged in the following order according to the effectiveness of the antioxidant effect: dihydroquercetin > echinochrome A > Trolox > ascorbic acid. Echinochrome A does not lead to significant changes in the permeability of planar bilayer membranes in a dose range of 1.5 to 30 μМ. Our data indicate that echinochrome A has a rather high level of radical-scavengering activity without a primary membranotropic effect. It is thought that the high levels of the cardioprotective and anti-inflammatory activities of echinochrome A may be due not only to the ability of this substance to neutralize reactive oxygen species, but also to its capacity to generate physiological concentrations of hydrogen peroxide molecules in biological systems as signaling messengers of various metabolic processes and biochemical pathways. The suspected mechanisms of the biological activity of echinochrome A are discussed.     

Changes in the Composition of Celomic Fluid Metabolites of the Black Sea Urchin Mesocentrotus nudus (Echinoidea) and the Starfish Asterina pectinifera (Asteroidea) under Conditions of Hypoxia Stress

Biology Bulletin - The composition of metabolites in the coelomic fluid of the starfish Asterina pectinifera and sea urchin Mesocentrotus nudus was studied under normal and hypoxic conditions using...     

Pigments in egg cells and epidermis of sand dollar <Emphasis Type="Italic">Scaphechinus mirabilis</Emphasis>

The naphthoquinone pigments of epidermal cells and gametes of clypeasteroid sand dollar Scaphechinus mirabilis isolated enzymatically with subsequent alcohol extraction were studied. It was found that naphthoquinone pigments are present in the pigment cells incorporated into the jelly coat of oocytes but not in the cytoplasm of unfertilized eggs. Laser desorption/ionization mass spectra showed that the pigment cells incorporated into the coats of mature egg cells contain spinochromes E and D, and those found in the epidermis of adult urchins contain echinochrome A and spinochrome D. No spinochromes were found in eggs lacking coats. Fertilization of sea urchins is accompanied by oxidative burst associated with the production of hydrogen peroxide from molecular oxygen by quinone- and naphthoquinone-dependent oxidase Udx1. Since there were no quinones in the egg cells of S. mirabilis, it can be assumed that water-soluble spinochrome E, penetrating by diffusion into the egg cytoplasm from the pigment cells of the coat, is used for hydrogen peroxide stimulation of embryogenesis. Echinochrome A, the dominant echinochrome in epidermal cells of the adult urchin, is insoluble in water and, apparently, immobilized by the ethyl group as a hydrophobic anchor.     

The Antioxidant and Membrane Activities of the Benzotropalone Pigment Purpurogallin

Biophysics - Abstract—The phenolic compound purpurogallin (PPG) is found in oak nutgalls and is a red pigment with a benzotropolone ring structure. PPG shows pronounced cytoprotective and...     

A study of the antioxidant and membranotropic activities of luteolin using different model systems

Luteolin, a water-insoluble 3′,4′,5,7-tetrahydroxyflavon, is one of the best-studied representatives of bioflavonoids. Luteolin is an essential food component for humans and other mammals that possesses a wide spectrum of biological activities by affecting the activities of various metabolic enzymes, target receptors, and signal transduction pathways. In this study, we conducted a comparative study of the antioxidant (free-radical scavenging) properties of luteolin in 2,2′-azobis(2-methylpropionamidine) dihydrochloride–luminol and hemoglobin–hydrogen peroxide–luminol systems and assessed its effect on the permeability of planar lipid bilayer membranes. Trolox was used as a reference antioxidant, while ascorbic acid and dihydroquercetin were taken as standards. Luteolin shows moderate antioxidant activity, exhibiting a higher antioxidant capacity than trolox and ascorbic acid, but it was less effective than dihydroquercetin in tests for antioxidant activity in the studied systems. The studied compounds can be ranked according to the effectiveness of their antioxidant action: dihydroquercetin > luteolin > trolox > ascorbic acid. It should be noted that the antioxidant activity of a water-soluble form of luteolin, luteolin disulfate, is comparable with that of luteolin. Luteolin does not cause significant changes in the permeability of planar bilayer membranes in the dose range from 1.5 to 30 μM. Our findings indicate the presence of a high level of free-radical scavenging activity and the absence of a primary membranotropic effect for luteolin. It can be assumed that the multiple pleiotropic nature of luteolin activity towards a variety of biological systems is associated not only with a neutralizing effect in regard to reactive oxygen species, but also with the ability of luteolin to block and modulate different cell-signaling processes and biochemical pathways. The presumed mechanisms of the biological activity of luteolin and luteolin disulfate are discussed.     

Antitumor and anticoagulant activities of collagen protein from the holothurian <Emphasis Type="Italic">Apostichopus japonicas</Emphasis> modified by proteolytic enzymes

A collagen preparation with antitumor and anticoagulant activity was obtained from the body of the holothurian (sea cucumber) Apostichopus japonicus treated with a complex of proteolytic enzymes. Administration of the collagen preparation inhibited in vivo growth of Ehrlich solid adenocarcinoma 2-fold (P < 0.05) and contributed to the survival of ascitic tumor-bearing mice, increasing their life span by 29.4 ± 3.2% (P < 0.05). With its moderate anticoagulant activity, this preparation is a preferential inhibitor of the initial link of the blood coagulation system. The biomedical properties and the character of the chemical structure of the collagen protein obtained from A. japonicus suggest that the mechanism of its action is similar to that of the collagen-like protein endostatin and sulfated polysaccharides. The obtained protein may be applied as a nontoxic agent of supplementary therapy for oncological and cardiovascular diseases.