Search

Background. The expansion of the territory of human habitation leads to inevitable interference in the natural range of distribution of one or another species of animals, some of which may be dangerous for human life. Scorpions—the Arachnida class and order Scorpiones—can be considered as such typical representatives. Scorpions of the Buthidae family pose a particular danger to humans. However, LD50has not yet been defined for many species of this family, in particular, new representatives of the genus Leiurus. Leiurus macroctenusis a newly described species of scorpion distributed in Oman, and the toxicity of its venom is still unknown. Estimating the LD50of the venom is the first and most important step in creating the antivenom and understanding the medical significance of the researched animal species. The purpose of this study was to determine the lethal dose (LD100), the maximum tolerated dose (LD0), and the average lethal dose (LD50) in rats when using Leiurus macroctenusscorpion venom. Methods and Results. 15 sexually mature scorpions were used in the study, which were kept in the same conditions and milked by a common method (electric milking). For the study, 60 male rats were used, which were injected intramuscularly with 0.5?ml of venom solution with a gradual increase in the dose (5 groups, 10 rats in each), and 10 rats were injected intramuscularly with physiological solution as control group. LD calculations were done using probit analysis method in the modification of the method by V.B. Prozorovsky. The LD0of Leiurus macroctenusscorpion venom under the conditions of intramuscular injection was 0.02?mg/kg, LD100was 0.13?mg/kg, and LD50was 0.08?±?0.01?mg/kg. Conclusions. The analysis of scientific publications and other sources of information gives reason to believe that Leiurus macroctenushas one of the highest values of LD50not only among scorpions but also among all arthropods in the world. All these point to the significant clinical importance of this species of scorpion and require further research that will concern the toxic effect of its venom on various organ systems. Determining the LD50 of the venom for new scorpion species is crucial for creating effective antivenoms and understanding the medical implications of envenomation by this species.

Phytotoxic compounds isolated and identified from different plants have the ability to use as plant-based herbicides. Phytotoxic chemicals may be essential to weed management and environmental protection in order to reduce the indiscriminate use of synthetic pesticides. It has been reported that Elaeocarpus floribundusplant possesses phytotoxic compounds. The leaf extracts of this species demonstrated significant growth inhibition against the tested plants (dicot plant lettuce and plant monocot timothy) and inhibition was dose- and species-dependent pattern. Two phytotoxic compounds were separated using different purifications methods and identified as compounds 1and 2. All phytotoxic compounds displayed potent growth limitation against the tested species (cress). The compound concentrations needed for the inhibition of 50% growth (IC50value) of tested species ranged from 1.06 to 8.53?µM (micromolar). Findings of this research suggest that these compounds might be responsible for the phytotoxicity of Elaeocarpus floribundusplant. The results of this study may be helpful for the development of natural herbicide to control weeds.