Biological Efficacy of Pseudohypericin in Drosophila melanogaster Individuals under Normal Conditions and in Conditions Irradiation

The biological efficacy and radiodromorphine capacity of pseudohypericin isolated from St. John’s wort (Hypericum perforatum L.) were studied in the model organism Drosophila melanogaster. Effective concentrations of the substance (1 and 10 μM) were determined for each genotype. Concentrations exceeding these values had a toxic effect on animals. The highest sensitivity to the preparation was demonstrated by individuals mutant in antioxidant protection and repair. The doses of ionizing radiation at which pseudohypericin changes the radiosensitivity of individuals, decreasing or increasing its level, have been estimated. Radioprotective effects of the substance have been detected at high doses (50–100 Gy) in the wild-type Canton–Sline and doses below 50 Gy in sod-mutants. Such a combined action of agents at given drug concentrations and radiation doses can lead to increased survival and a decrease in the frequency of DNA damage in individuals. The interaction between a substance and a radiation factor is predominantly synergistic or antagonistic character depending on the radiation dose. The obtained results show that the studied parameters and mutant genotypes can be used as test-methods and test-systems for the selection of radioprotectors and their mechanisms of action, as well as the selection of optimal conditions for the use of such drugs in the field of radioprotective technologies.