Comparative study of the in vivo toxicity and pathophysiology of envenomation by three medically important Egyptian snake venoms.

Snakebite envenomation is a serious medical problem in many developing tropical and subtropical countries. Envenomation is registered by the World Health Organization as a neglected tropical disease due to critical shortages in the production of antivenom. Envenomation causes more than 100,000 deaths annually. Snakebites result in several effects to include edema, blistering, hemorrhage, necrosis and respiratory paralysis. Antivenom is the preferred treatment for the systemic effects of snakebite envenomation, though these are often ineffective in neutralizing venom toxin-induced local tissue damage. To effectively treat snakebites, it is important to determine the lethal potency and pathophysiological effects induced by specific snake venoms. In the current study, we compared the lethality, and the hemorrhagic and dermonecrotic activities of venoms from three snakes in Egypt that are the primary causes of local tissue necrosis. Our data show that the intraperitoneal median lethal doses (LD50) for Cerastes cerastes, Echis carinatus and Naja nigricollis venoms are 0.946, 1.744 and 0.341 mg/kg mouse body weight, respectively. These results indicated that N. nigricollis venom is the most toxic and significantly accelerated the time of death compared to the other two venoms. However, no hematoma or associated edema appeared upon sub-plantar injection of N. nigricollis venom into the mice hind paw. Two hours following intradermal injection of C. cerastes and E. carinatus venoms, macroscopic analysis of the inner surface of mouse skin showed severe hemorrhagic lesions, whereas only insignificant hemorrhagic lesion appeared in mice injected with the highest dose of N. nigricollis venom. Furthermore, the minimum necrotic doses (MND) for the same venoms were 43.15, and 70.87 µg/mouse, or not observed in the case of N. nigricollis venom, respectively. These LD50 values and pathophysiological results can be used to guide development of antivenom against bites by these dangerous Egyptian snakes.

Allelic variation of melanocortin-1 receptor locus in Saudi indigenous sheep exhibiting different color coats.

OBJECTIVE: This study was designed to characterize the DNA polymorphisms of the melanocortin-1 receptor (MC1R) gene in indigenous Saudi Arabian sheep breeds exhibiting different color coats, along with individuals of the Sawaknee breed, an exotic sheep imported from Sudan. METHODS: The complete coding region of MC1R gene including parts of 3' and 5' untranslated regions was amplified and sequenced from three the indigenous Saudi sheep; Najdi (generally black, n = 41), Naeimi (generally white with brown faces, n = 36) and Herri (generally white, n = 18), in addition to 13 Sawaknee sheep. RESULTS: Five single nucleotide polymorphisms (SNPs) were detected in the MC1R gene: two led to nonsynonymous mutations (c.218 T>A, p.73 Met>Lys and c.361 G>A, p.121 Asp>Asn) and three led to synonymous mutations (c.429 C>T, p.143 Tyr>Tyr; c.600 T>G, p.200 Leu>Leu, and c.735 C>T, p.245 Ile>Ile). Based on these five SNPs, eight haplotypes representing MC1R Ed and E+ alleles were identified among the studied sheep breeds. The most common haplotype (H3) of the dominant Ed allele was associated with either black or brown coat color in Najdi and Sawaknee sheep, respectively. Two other haplotypes (H6 and H7) of Ed allele, with only the nonsynonymous mutation A218T, were detected for the first time in Saudi indigenous sheep. CONCLUSION: In addition to investigating the MC1R allelic variation in Saudi indigenous sheep populations, the present study supports the assumption that the two independent nonsynonymous Met73Lys and Asp121Asn mutations in MC1R gene are associated with black or red coat colors in sheep breeds.

Entomofaunal Succession Patterns on Burnt and Unburnt Rabbit Carrion.

The influence of burning on the decomposition of rabbit carcasses and on insect succession was investigated in three different habitats (agricultural, desert, and urban) in order to provide data for estimating the postmortem interval (PMI). Each site had six carcasses divided into two groups of three rabbits, with the carcasses in one group being partially burned, while the others were not burned. Carrion reached the dry stage within 5 d in the desert and urban habitats and 13 d in the agricultural habitat. The unburnt and burnt carcasses also decomposed at a similar rate in the three study habitats. Adult dipteran and coleopteran insects were collected daily. A total of 24 species and 2,381 specimens were collected; of these, 732 specimens from 21 species were taken from the partially burnt carcasses and 1,649 specimens from 21 species from the unburnt carcasses. There were significantly distinct insect communities between the agricultural habitat and the desert and urban habitats. There were also significant differences in the insect communities between the decay stage and other stages, with fresh and dry stages recording the lowest number of insects. There were some species which only presented themselves during the decay stage of decomposition, namely, Platypalpus sp., Desmometopa varipalpis Malloch, Atherigona orientalis (Schiner), Atherigona yorki Deeming, Musca sorbens Weidemann, and Onthophagus nitidulus Klug. In addition, there were significant distinctions in the insect communities between unburnt carcasses and burnt carcasses. The presence of these distinctions means that it is possible to estimate the PMI from partially burnt rabbit carcasses.

A preliminary investigation of rabbit carcass decomposition and attracted ants (Hymenoptera: Formicidae) on the seaward coastal beach of Al-Jubail City, Saudi Arabia.

The current study was carried out in the seaward coastal beach environment of Al-Jubail City, Saudi Arabia, to analyze the rabbit carcass decomposition process, the succession pattern of associated ants, and their potential utility in forensic investigation. Experiments were conducted over a 4-season course (from autumn 2018 to summer 2019). A total of 9 species belonging to the 2 subfamilies, Myrmicinae and Formicinae, were recorded. The myrmicine species were Crematogaster aegyptiaca Mayr, 1862; Messor ebeninus Santschi, 1927; Messor foreli Santschi, 1923; and Monomorium abeillei Andre, 1881. The formicine species were Camponotus xerxes Forel, 1904; Cataglyphis albicans (Roger, 1859); Cataglyphis hologerseniCollingwood & Agosti, 1996; Cataglyphis viaticoides (André, 1881); and Nylanderia jaegerskioeldi (Mayr, 1904). M. abeillei was the only species recorded in all 4 seasons, while M. abeillei and C. albicans were the dominant species in summer and C. aegyptiaca and C. albicans in spring. Diversity was lowest in the autumn, with only 4 species recorded. The COI gene sequences of 5 species have been successfully deposited in the GenBank database for the first time. In total, 4 carcass decomposition stages were observed, with the longest duration in winter (13 days), the shortest in summer (11 days), and in between for both autumn and spring. Most ant species were present during both decay and dry stages, while M. abeillei, C. aegyptiaca, M. ebeninus, and C. albicans were observed in all decomposition stages. These data may indicate that ants on this coastal beach showed seasonal and geographical succession patterns that could be taken into consideration in forensic investigations.

Two human cases associated with forensic insects in Riyadh, Saudi Arabia.

In Riyadh, Saudi Arabia, we are reporting two cases of natural death. The two bodies showed different types of habitat, insect colonization and decomposition stage. The first case was about the body of a 65-years-old male, with mummification of the clothed body was found in an outdoor habitat. Different life stages of Dermestes maculatus DeGeer (Coleoptera: Dermestidae were gathered from the cadaver, and due to the advanced degree of decomposition, the PMImin was estimated to be 3 months. The second body belonging to a 40-years-old male, was found in a semi-closed apartment (indoor habitat), and the body was at the end of the bloated decomposition stage. In this case, Musca domestica L. (Diptera: Muscidae) larvae were collected, and the PMImin was estimated to be 4 days. The limited insect activity for the two bodies caused by the advanced decomposition stage in the first case and indoor environment in the second. Average temperatures of (23.3 ± 1.6) °C for the first body and (27.5 ± 1.7) °C2 for the second body. Habitat was the key factor to attract insects to the two cadavers. This study stressed that, for accurate estimates of time since death, knowledge of the impact of different variables on insects found over and around the carrion is essential.

Influence of Clothing on Decomposition and Presence of Insects on Rabbit Carcasses.

The decomposition rate and insects attraction to carcasses are affected by a number of factors such as temperature, body mass, the presence of poisons, humidity, and insect activity. The present study was planned to investigate the influence of clothing on both the decomposition process and the presence of insects on rabbit carcasses. The study was performed in May 2016 and involved the use of 18 live mature rabbits (Oryctolagus cuniculus L.), which were euthanized by chloroform. Rabbit carcasses were divided into three replicates with six rabbits in each replicate. Rabbits in each replicate were further subdivided, so that three rabbits were wrapped with cloth, whereas the remaining three were left unclothed. Both clothed and unclothed carcasses reached the dry stage within 6 d. The results of this study showed that clothes neither affect the decomposition process nor the presence of insects (flies and beetles). The pattern of flies and beetles, however, did vary significantly in the different decomposition stages. In total, 2,849 insects, including 2,459 flies and 390 beetles, were collected and sorted during the decomposition process. Among the dominant species, flies were assigned to the families Calliphoridae and Muscidae, whereas beetles were assigned to the families Dermestidae and Histeridae. Lucilia sericata Meigen, Musca domestica L., Dermestes maculatus DeGeer, and Saprinus moyses Marseul were the most abundant species occurring on both the clothed and unclothed carcasses. In conclusion, this study emphasized that, the clothes have no effect when dealing with decay process and insect attraction to the carrions.

Forensic insects attracted to human cadavers in a vehicular environment in Riyadh, Saudi Arabia.

Insect fauna attracted to cadavers at the crime scene can be identified and used to estimate the post-mortem interval (PMI). In the current study, insects associated with two human cadavers in a vehicular environment were collected and analysed. The first cadaver was found five days' post mortem in a garage. The second cadaver was found in a car ten days after his death. The weather conditions were obtained from the nearest weather station located to the scenes of the death. During the study, six adults, 32 larvae and egg batches were collected from case 1 and identified as Chrysomya albiceps Wiedemann (Diptera: Calliphoridae). From the second case, two larvae of Megaselia scalaris Loew (Diptera: Foridae) and seven larvae of Musca domestica L. (Diptera: Muscidae) were identified. mPMI ranged from five to twelve days. This information expands the knowledge on the insect fauna in the vehicular environment, which could be used to assist estimation of the PMI.

Thymoquinone ameliorates Pachycondyla sennaarensis venom-induced acute toxic shock in male rats.

BACKGROUND: For many decades, the sting of Samsun ant (Pachycondyla sennaarensis) has been a serious clinical challenge for the people living in some of the major Middle East and Asian countries. In the present study, the therapeutic potential of Nigella sativa derived plant extract component, thymoquinone (TQ) has been tested against the Samsun ant venom (SAV) at the toxic dose in the rats. METHODS: The adult male rats were divided into four groups (n = 10): control, SAV treated, SAV + TQ treated and TQ alone treated. It was found that the sub-lethal dose of SAV alters not only many of the kidney and liver function markers but also induces oxidative stress in the animals. Moreover, the SAV also disturbs various immunological parameters including expression of PMNs, CD-80, CD-86, interleukins and other cytokines compromising the affected organism towards mild to severe allergic reactions including life-risking anaphylaxis. RESULTS: The plant extract, TQ, effectively restores many of the biochemical and oxidative stress parameters comparable to the normal concomitant with improving the immunological aspects that might attributive in relieving from SAV-induced toxicity and allergic reactions in the affected organism to a greater extent. CONCLUSION: Hence, TQ has an excellent antidote property against SAV-induced toxicities in vivo. Although the study is a vivid indication of the potential therapeutic potential of TQ against the SAV induced in vivo toxicity, yet the actual mechanism of interaction translating the toxicity amelioration warrants further investigations.

Molecular Identification of the Carrion Beetles (Coleoptera) in Selected Regions of Saudi Arabia.

Geographical regions have a major effect on the arrival times of different insect species on carrion. This means that data generated in one region should not be used to determine time of death in a different region. In the present study, we demonstrate the effect of geographical location on the diversity of carrion beetles in Saudi Arabia, whereas the mitochondrial cytochrome c oxidase subunit I (mtCOI) barcodes were used as a marker for molecular identification of the carrion beetles at a dry stage on sheep carrion. We analyzed 819 adult beetles belonging to nine species originating from Riyadh (609 beetles), Jazan (157 beetles), and Arar (53 beetles). In Riyadh, results showed the presence of six species belonging to three different families. On the other hand, in Jazan five species belonging to four families were collected. From Arar, five species belonging to three families were collected. By comparing between individuals of the same species from different regions, individuals of Necrobia rufipes DeGeer (Coleoptera: Cleridae) showed the highest intraspecific variations 0-20%, while individuals of Saprinus splendens Paykull and Saprinus semistriatus Scriba (Coleoptera: Histeridae) showed the lowest intraspecific variations 0-1%. Interspecific variability was also measured between collected and identified species, with differences revealed to be in the range of 3.8-29.8%. The results are important from an ecological point of view and for Medico-Legal Forensic Entomology.

Biological activity of Xanthium strumarium seed extracts on different cancer cell lines and Aedes caspius, Culex pipiens (Diptera: Culicidae).

Effects of methanol extracts of Xanthium strumarium on different cancer cell lines and on the mortality rates of Aedes caspius, Culex pipiens (Diptera: Culicidae) were investigated. Among the cell lines tested, the Jurkat cell line was the most sensitive to the methanol extract and ethyl acetate fraction, with reported LC50 values of 50.18 and 48.73 µg/ml respectively. Conversely, methanol extracts were not that toxic to the A549 cell line though the toxicity increased on further purification. The percentage of growth inhibition was dose dependent for the methanol extract and ethyl acetate fraction. The ethyl acetate fraction showed higher toxicity to all cell lines tested when compared to the methanol extract. The results showed that methanol extracts of plant seeds caused 100% mortality of mosquito larvae at a concentration of 1000 µg/ml after 24 h of treatment. The LC50 and LC90 values of X. strumarium were found to be 531.07 and 905.95 µg/ml against Ae. caspius and 502.32 and 867.63 µg/ml against Cx. Pipiens, respectively. From the investigations, it was concluded that the crude extract of X. strumarium showed a weak potential for controlling the larval instars of Ae. caspius and Cx. pipiens. However, on further purification the extract lost the larvicidal activity. The ethyl acetate fraction showed higher toxicity to all cell lines tested when compared to the methanol extract. The ethyl acetate fraction investigated in this study appears to have a weak larvicidal activity but a promising cytotoxic activity. Future studies will include purification and investigation in further detail of the action of X. strumarium on Cancer Cell Lines and mosquitoes.