Search

Background: Among venomous elapid snakes, cobras have the highest public awareness, as their venom represents a combination of proteins, peptides, and enzymes that have a range of biochemical and pharmacological roles and are also the main constitutes of biological activity and lethal toxicity. Objectives: The study aimed to evaluate the effect of the venom of Egyptian Spitting Cobra, Naja nubiae, on the vascular permeability based on the extravasation of the azo dye Evans blue (EB) into the tissues of the liver and kidneys of animals envenomed with low (¼ LD50; 0.32 mg/kg) and high (½ LD50; 0.65 mg/ kg) doses at three sampling times (30, 120, 360 min) post-injection of the venom. Methods: Fifty-four adult male Albino rats (8 weeks old and 180±2 0 g body weight) were divided into three main groups (n=6). In the control group, rats were subcutaneously (SC) injected with saline solution. Envenomed groups were SC injected, one group with 0.32 mg/kg and the other group with 0.65 mg/kg body weight of crude venom, respectively. Rats were I.V injected with EB dye 20 minutes before SC injection with saline solution as control animals and with Naja nubiae venom as treatment groups. Results: The results illustrated a high significant rate of EB extravasation to hepatic and renal tissues by the colorimetric determination of EB dye concentration. Conclusion: The venom of Naja nubiae can cause increased hepatic and renal vascular permeability which may explain the inflammatory effect induced by this venom.

Snake bites are considered as one of the serious challenges facing people living in areas near the place of those snakes’ habitat. Antivenin treatment though being the gold standard against expected toxicities, is not always present especially when toxicology centers are out of reach during cases of acute envenomation and injuries. Nubian spitting cobra or Naja nubiae is known to be major threat of hematological and cardiac toxicities in Upper Egypt. Although the main characteristic of its venom is being neurotoxic, cardiotoxicity due to high content of cardiotoxins and generation of reactive oxygen species is profound in cases of toxicity by envenomation. This review highlights the structure of cardiotoxins as the main component of Naja nubiae venom and lists different possible cardiotoxicities associated with it especially myocardial infarction and myocarditis. As well as possible future recommendations for those who are in risk of inhabiting or travelling to where these snakes are found.

Background:In developing countries, there is no doubt that acute kidney injury and chronic liver diseases have a major impact on health. Different venom components are gaining renewed interest as potential sources of new pharmacological compounds relevant for human therapeutics. Aim: The present study was designed to evaluate the therapeutic efficacy of the crude venom extract of the Egyptian spitting cobra (Naja nubiae) venom extract against gentamycin–induced nephrotoxicity and hepatotoxicity in rats. Methods: Eighteen male Wistar rats were divided into three groups, control, gentamycin, and venom extract. The hepatorenal toxicity model was induced by gentamycin (80 mg/kg, intraperitoneal) for 8 days. Results:LD50 of venom extract in rats was 0.2mg/kg. The venom extract group showed a significant decrease in the liver enzymes, urea, uric acid, creatinine, malondialdehyde meanwhile glutathione reduced and catalase levels increased. Histological examination of liver and kidney mild protective efficacy with less extensive degenerative changes in the tissues of venom extract grou Conclusion:The results of the present investigation showed that administration of venom extract proved therapeutic efficacy against gentamycin -induced hepatorenal dysfunction by maintain the normal functional status of the liver and kidney and normalized the antioxidant system.

In Sudan, as in many African countries, no local specific antivenom is manufactured resulting in snake bite victims being treated by antivenoms imported from abroad. In the present work we measured the cytotoxic effect of the recently described spitting cobra (Naja nubiae) and the carpet viper (Echis ocellatus) snake venoms using a cell based assay. We also investigated the efficacy of four antivenoms CSL (Australia), SAIMR (South Africa), snake venom antiserum (India), and EchiTAb-Plus-ICP (Cost Rica) to neutralize the cytotoxic effect of the two venoms. The venoms resulted in a remarkable inhibition of cell viability with N. nubiae being more cytotoxic than E. ocellatus. The four antivenoms studied were effective in neutralizing N. nubiae cytotoxicity. However, only partial efficacy in neutralizing the cytotoxic effect of E. ocellatus was achieved using CSL (Australia) and SVA (India) antivenoms. Based on the cross neutralization by the four antivenoms, the Sudanese N. nubiae venom most likely has homologous epitopes with similar snakes from Australia, South Africa, India, and Cost Rica, while E. ocellatus venom from Sudan shares little homology with similar snakes from other countries.

Embargo por política editorial 2081-01-01 Venomic analysis of the venoms of Naja nigricollis, N. katiensis, N. nubiae, N. mossambica, and N. pallida revealed similar compositional trends. The high content of cytotoxins and PLA2s may account for the extensive tissue necrosis characteristic of the envenomings by these species. The high abundance of a type I α-neurotoxin in N. nubiae may be responsible for the high lethal toxicity of this venom (in rodents). The ability of EchiTAb-Plus-ICP antivenom to immunodeplete and neutralize the venoms of African spitting cobras was assessed by antivenomics and neutralization tests. It partially immunodepleted 3FTx and PLA2s and completely immunodepleted SVMPs and CRISPs in all venoms. The antivenom neutralized the dermonecrotic and PLA2 activities of all African Naja venoms, whereas lethality was eliminated in the venoms of N. nigricollis, N. mossambica, and N. pallida but not in those of N. nubiae and N. katiensis. The lack of neutralization of lethality of N. nubiae venom may be of medical relevance only in relatively populous areas of the Saharan region. The impaired activity of EchiTAb-Plus-ICP against N. katiensis may not represent a major concern. This species is sympatric with N. nigricollis in many regions of Africa, although very few bites have been attributed to it. Universidad de Costa Rica/[741-A9-003]/UCR/Costa Rica /2009CR0021/CRUSA-CSIC/España Ministerio de Innovación y Ciencia/[BFU2007-61563]//España Ministerio de Innovación y Ciencia/[BFU2010-17373]//España UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)

The Yale University Prehistoric Expedition to Nubia collected zoological specimens and archeological artifacts from Egypt and the surrounding region from 1962 to 1965. A total of 2486 herpetological specimens were collected during this time, representing 51 species and 13 families. Among the herpetological specimens is a series of 1232 Chalcides ocellatus and a recently described species of spitting cobra (Naja nubiae). Because most of the collection sites are now under Lake Nasser, most specimens represent extirpated populations. Some specimens are of taxa now considered endangered species in Egypt. Although the primary purpose of the YUPEN expedition was to preserve the rich anthropological history south of Aswan, the herpetological specimens that were preserved provide a valuable temporal snapshot into the historical ecosystems that were present in Lower Egypt.

Objectives: Although many venomous snakes represent a potential human health threat, their venoms provide a rich source of active components, many of which have been recently identified, and used as potential candidates for pharmacological therapeutic purposes. The current study was designed to evaluate the analgesic, antipyretic and antiinflammatory activities of the Egyptian spitting cobra Naja nubiae venom. Methods: The venom of N. nubiae was intraperitoneally injected at two dose levels (1/10 and 1/5 LD50). The peripheral and central analgesic effects were examined using acetic acidinduced abdominal writhing in mice and tail immersion test in rats, respectively. Brewer’s yeast-induced pyrexia in rats was carried out to determine the antipyretic activity of the same doses, whereas the anti-inflammatory activity was tested using carrageenan-induced paw edema in mice. Results: The results showed that N. nubiae venom produced a significant analgesic activity in acetic acid-induced abdominal constriction response in mice and thermal nociception in rat. Moreover, the venom revealed a significant antipyretic effect on yeast-induced pyrexia. In paw edema, venom exhibited a significant activity with a maximum percentage of inhibition reaching 60.1% on both doses after 5 hour treatment, which was more powerful when compared with the standard drug; diclofenac sodium (38.6%). Histologically, the venom induced a moderate inflammatory cells infiltration in the dermis of paw. Conclusion: These results suggest potential analgesic, antipyretic, and anti-inflammatory activities of the Egyptian spitting cobra crude venom.

A new species of spitting cobra Naja nubiae sp. nov. is described from north-eastern Africa. The distinctiveness of the new species is confirmed by multivariate analysis of pattern and scalation data. Phylogenetic analysis of mitochondrial DNA sequences reveals the new species to be the sister taxon of N. pallida, but with considerable levels of sequence divergence relative to that species. The populations concerned had previously been assigned to N. pallida. The new species differs from N. pallida principally in having more than one dark band across the neck and under the throat, as well as a pair of spots under the throat. It occupies a disjunct range across Egypt, the Sudan, Chad, Niger and Eritrea, where it seems to occupy primarily relatively mesic habitats. Naja mossambica is more closely related to N. nigricollis than to N. pallida and the new species. A key to the African species of Naja is presented.

Versión final embargada hasta 2081-11 por política editorial Venoms of several Naja species found in Sub-Saharan Africa, and commonly known as "spitting cobras", induce a predominantly cytotoxic pattern of envenomings that may evolve into tissue necrosis and gangrene. Cytotoxic components of their venoms have been identified as members of the three-finger toxin and phospholipase A2 protein families. In this study, an in vitro assay using the myogenic cell line C2C12, was utilized to compare the cytolytic activities of venoms from five species of spitting cobras: Naja nigricollis, Naja katiensis, Naja pallida, Naja nubiae, and Naja mossambica. These venoms were strongly cytotoxic, causing a 50% effect at ∼1.5 μg/well (15 μg/ml), except for N. katiensis venom, which required nearly twice this amount. Using the cell-based assay, the ability of an equine polyspecific antivenom (EchiTab-Plus-ICP) to neutralize cytotoxicity was assessed. The antivenom completely inhibited the cytotoxic activity of all five venoms, although high antivenom/venom ratios were needed. Neutralization curves displayed the following decreasing order of efficiency: N. nubiae > N. pallida > N. mossambica > N. nigricollis > N. katiensis. Results indicate that neutralizing antibodies toward toxins responsible for this particular effect are present in the antivenom, albeit in low titers. Fucoidan, a natural sulfated polysaccharide known to inhibit the toxic effects of some basic snake venom components, was unable to reduce cytotoxicity of Naja venoms. Results emphasize the need of enhancing the immunogenicity of low molecular mass toxins during antivenom production, as well as to search for useful toxin inhibitors which could complement antivenom therapy. Universidad de Costa Rica/[VI-741-A9-513]/UCR/2011 International Centre for Genetic Engineering and Biotechnology - Collaborative Research Programme/[COS-08-03]/ICGEB-CRP/Italia UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)