EFFECT OF COMPOSITE DRUG ETHYLTHIOSULPHONATE WITH SURFACTANT RAMNOLIPID BIOCOMPLEX ON SH-GROUP CONTENT IN DAPHNIA MAGNA

Abstract

One of the main obstacles to the use of thiosulfonates in aquaculture is their insolubility in water. This problem is eliminated by using a composition based on ethylthiosulfanilate (ETS) and surface-active rhamnolipid biocomplex (RBC) of bacteria of the genus Pseudomonas, which provides increased bioavailability of ethylthiosulfanilate and activation of biocidal properties of the drug. However, this may increase the toxic effects of the created composition. Given the possibility of using Daphnia magna Straus in the procedure of bioencapsulation as a vector organism for the delivery of a composite drug, a study of the effect of ETS: RBC in nontoxic concentrations (2.5·10-3 mg / ml and 5·10-3 mg / ml (by ETS) on the content of protein and non-protein thiols in Daphnia magna, as well as the activity of enzymes inhibited by a natural analogue of thiosulfonates - allicin. A decrease in the content of protein and non-protein thiols in the tissues of Daphnia magna was found under the action of both studied concentrations of the drug. A significant reduction in non-protein SH groups compared to protein-bound ones may indicate the active and efficient involvement of glutathione ethylthiosulfanilate, which is the predominant non-protein thiol in the cell and provides protection against oxidation of functional groups of proteins and enzymes. The established inhibition of superoxide dismutase activity may be due to S-thioallylation of ethylthiosulfanilate SH-containing amino acids in the structure of the enzyme. No significant changes in glutathione-S-transferase activity under the action of the study drug were observed. Only when using a higher concentration of the composite drug ETS: RBC begins to show a tendency to decrease activity, most likely due to a decrease in the content of reduced glutathione under these conditions. Given the survival rates of Daphnia magna under the conditions of using the composite drug ETS: RBC at concentrations of 2.·10-3 mg / ml and 5·10-3 mg / ml, it is likely that its effect focuses on reactions involving sulfhydryl groups and does not cause significant changes in the detoxification system of the cell.