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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, LD 50 has not yet been defined for many species of this family, in particular, new representatives of the genus Leiurus . Leiurus macroctenus is a newly described species of scorpion distributed in Oman, and the toxicity of its venom is still unknown. Estimating the LD 50 of 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 (LD 100 ), the maximum tolerated dose (LD 0 ), and the average lethal dose (LD 50 ) in rats when using Leiurus macroctenus scorpion 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 LD 0 of Leiurus macroctenus scorpion venom under the conditions of intramuscular injection was 0.02 mg/kg, LD 100 was 0.13 mg/kg, and LD 50 was 0.08 ± 0.01 mg/kg., Conclusions: The analysis of scientific publications and other sources of information gives reason to believe that Leiurus macroctenus has one of the highest values of LD 50 not 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., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2024 Valery Gunas et al.)

Problem of scorpion envenomation becomes more alarming each year. Main effects of scorpion venom are commonly believed to be related to its neurotoxic properties, yet severe symptoms may also be developed due to the uncontrolled enzymatic activity and formation of various bioactive molecules, including middle-mass molecules (MMMs). MMMs are considered as endogenous intoxication markers, their presence may indicate multiple organ failure. Scorpions, belong to the Leiurus macroctenus species, are very dangerous, nevertheless, effects of their venom on protein and peptide composition within the tissues remains unclear. In this work we have focused the attention on changes in protein and MMM levels and peptide composition in various organs during Leiurus macroctenus envenomation. The results revealed a decrease in protein level during envenomation as well as a significant increment of MMM 210 and MMM 254 levels in all assessed organs. Quantitative and qualitative compositions of various protein and peptide factions were continually changing. All of this may suggest that Leiurus macroctenus sting causes considerable destruction of cell microenvironment across all essential organs, providing systemic envenomation. In addition, MMM level increment may indicate endogenous intoxication development. Peptides, formed during envenomation, may possess various bioactive properties, analysis of which constitutes an area of further studies., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Background: Scorpion stings may be life-threatening since their venoms are comprised of a wide range of toxins and other bioactive molecules, such as enzymes. At the same time, scorpion envenomation may increase matrix metalloproteases (MMPs) levels, which enhance proteolytic tissue destruction by venom. However, investigations on the impact of many scorpions' venoms, such as those of Leiurus macroctenus , on tissue proteolytic activity and MMP levels have not yet been conducted., Methods and Results: The present study aimed to examine the total proteolysis levels in various organs after Leiurus macroctenus envenomation and evaluate the metalloproteases and serine proteases' contributions to the total proteolytic activity. Changes in MMPs and TIMP-1 levels were tested as well. Envenomation led to a significant increase in proteolytic activity levels in all assessed organs, mostly in the heart (by 3.34 times) and lungs (by 2.25 times)., Conclusions: Since EDTA presence showed a noticeable decrease in total proteolytic activity level, metalloproteases appeared to play a prominent role in total proteolytic activity. At the same time, MMPs and TIMP-1 levels were increased in all assessed organs, suggesting that Leiurus macroctenus envenomation causes systemic envenomation, which may induce multiple organ abnormalities, mostly because of the uncontrolled metalloprotease activity., Competing Interests: The authors declare that have no conflicts of interest., (Copyright © 2023 Valery Gunas et al.)

Background: One of the pathogenic mechanisms of the progression non-alcoholic liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH) is the accumulation of reactive oxygen species (ROS). So, antioxidant therapy is necessary for successful treatment of the liver injury. We have paid attention to melanin produced by yeast Nadsoniella nigra strain X-1 as novel antioxidant and anti-inflammatory agents with low toxicity. In current study we aimed to investigate the preventive effect of melanin on the monosodium glutamate (MSG) induced NAFLD model in rats., Methods: The study was carried out on 45 Wistar rats that were divided into 3 groups: intact, MSG- and MSG+melanin groups (n=15 in each group). Newborn rats of MSG- and MSG+melanin groups were administered with MSG (4mg/g, 8μl/g, subcutaneously) at 2nd-10th days of life. Since the age of 1 month, rats of MSG-group were treated with water (0.25ml/100g), rats of MSG+melanin groups-with melanin (1mg/kg) dissolved in water (0.25ml/100g)., Introduction: had been performed intermittently (two-week courses alternated with two-week breaks) for 3 months. In 4-month rats anthropometrical parameters and visceral adipose tissue (VAT) mass were estimated. To assess morphological changes in liver we used NAS (NAFLD activity score). The content of pro-inflammatory cytokines (interleukin (IL)-1β, IL-12Bp40, interferon (INF)-γ) and anti-inflammatory cytokines (IL-4, IL-10, tumor growth factor (TGF)-β) were measured by ELISA., Results: We found significantly lower total score (1.0±0.19 vs 3.33±0.36, p<0.001), degree of steatosis (0.73±0.18 vs 1.80±0.17, p<0.001) and manifestation of lobular inflammation (0.27±0.11 vs 1.20±0.17, p<0.001) due to NAFLD activity score in MSG+melanin group compared to MSG-obesity. NASH we confirmed only in 33.3% of rats with MSG-obesity that was significantly higher than after melanin (6.7%) administration (p=0.033). Melanin administration reduce amount of visceral fat on 44.5% (p<0.001) as compared to MSG-obesity group. Melanin reduced the content of IL-1β in rat serum and restored the level of anti-inflammatory cytokines (IL-10, TGF-β) to the control values., Conclusion: Thus, the administration of melanin can prevent development of NAFLD/NASH in rats with MSG-induced obesity and can be considered as possible novel therapeutic agents but further studies to confirm its action needed., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Lichen-forming fungal proteins have been seldom searched due to many difficulties in their extraction. Phenols, quinones, proteases, and other components released during cell disruption have been known to be the greatest challenges related to protein extraction from lichens. To overcome these problems and maintain good electrophoretic resolution and high protein concentration, an extraction buffer containing polyvinylpolypyrrolidone, ascorbic acid, Triton X-100, polyethylene glycol, proteinase, and oxidase inhibitors in sodium phosphate buffer was developed. This extraction buffer showed high efficiency for all lichen species tested in the study.