ABSTRACT
We analyzed cytotoxicity of water-soluble potassium salts of (+)- and (-) usnic acid (UA) for ciliates P. caudatum. The median lethal concentrations for (+)- and (-) enantiomers did not significantly differ and were 7.5±0.5 and 6.7±0.4, respectively. In a concentration of 8 µM, (+)-UA and (-)-UA salts increased the content of TBA-reactive products, which indicates the formation of oxidative stress under the action of high UA concentrations. In the presence of (+)-UA and (-)-UA salts in a concentration range from 2 to 8 µM, the number of food vacuoles in ciliates decreased, which attested to a decrease in phagocytosis activity. The concentrations of UA enantiomers >0.5 µM affected macronucleus morphology (shape and size). The cytotoxic activity of (+)-UA and (-)-UA salts against P. caudatum did not differ.
Subject(s)
Benzofurans/toxicity , Paramecium caudatum/drug effects , Potassium/toxicity , Animals , Benzofurans/chemistry , Dose-Response Relationship, Drug , Molecular Conformation , Oxidative Stress/drug effects , Paramecium caudatum/physiology , Potassium/chemistry , Salts/chemistry , Salts/toxicity , Structure-Activity Relationship , Toxicity TestsABSTRACT
The effect of usnic acid enantiomers on the genotoxic effects of dioxidine and methyl methanesulfonate was studied in vitro in human peripheral blood lymphocytes by the DNA comet method. We found that usnic acid enantiomers in a concentration range of 0.01-1.00 µM demonstrated pronounced antigenotoxic activity and reduced DNA damage induced by genotoxicants by 37-70%. In the same concentration range, the test enantiomers reduced the level of atypical DNA comets (hedgehogs) induced by genotoxicants by 23-61%. The test compounds did not modulate the effects of genotoxicants in a concentration of 10 µM and potentiated them in a concentration of 100 µM. The modifying activity of usnic acid did not depend on spatial configuration and on the used model genotoxicant.
Subject(s)
Benzofurans/pharmacology , Leukocytes, Mononuclear/drug effects , Lichens/chemistry , Methyl Methanesulfonate/antagonists & inhibitors , Protective Agents/pharmacology , Quinoxalines/antagonists & inhibitors , Benzofurans/chemistry , Benzofurans/isolation & purification , Comet Assay , DNA Fragmentation/drug effects , Hormesis , Humans , Leukocytes, Mononuclear/chemistry , Leukocytes, Mononuclear/cytology , Methyl Methanesulfonate/toxicity , Mutagens/toxicity , Protective Agents/chemistry , Protective Agents/isolation & purification , Quinoxalines/toxicity , StereoisomerismABSTRACT
On the example of the physiological and the cytology-biochemical characteristics variability of an Atriplex patula L. and Artemisia vulgaris L. sprouts which parental plants were generated in various environmental conditions (South Yakutia, the Central Yakutia, Middle Ural), was shown, that radiostability depends not only on set protective antioxidant, on the DNA-reparation systems and on the vulnerability degree of a functioning genome, but also on the phenotypic diversifications of a population which in turn, in the certain degree, are consequence of previous selection of a population to all set of ecological stresses-factors of the environment.
