Showing papers on "Naja published in 2016"
TL;DR: Investigation of the toxicity and neutralization profile of the venom and toxins from Pakistani spectacled cobra, Naja naja, suggests that optimal neutralization for Pakistani N. naja venom may be achieved by improving the formulation of antivenoms production to enhance antivenom immunoreactivity against long and SNTXs.
Abstract: Geographical variations of snake venoms can result in suboptimal effectiveness of Indian antivenoms that are currently used in most South Asian countries. This study investigated the toxicity and neutralization profile of the venom and toxins from Pakistani spectacled cobra, Naja naja, using VINS polyvalent antivenom (VPAV, India), Naja kaouthia monovalent antivenom (NKMAV, Thailand), and neuro bivalent antivenom (NBAV, Taiwan). Cation-exchange and reverse-phase high-performance liquid chromatography fractionations followed by toxin identification through liquid chromatography-mass spectrometry (MS)/MS indicated that the venom comprised mainly of postsynaptic neurotoxins (NTXs) (long neurotoxins [LNTXs], 28.3%; short neurotoxins [SNTXs], 8%), cytotoxins (CTXs) (31.2%), and acidic phospholipases A2 (12.3%). NKMAV is the most effective in neutralizing the lethal effect of the venom (potency = 1.1 mg venom/mL) and its LNTX (potency = 0.5 mg toxin/mL), consistent with the high content of LNTX in N. kaouthia venom. VPAV was effective in neutralizing the CTX (potency = 0.4 mg toxin/mL), in agreement with the higher CTX abundance in Indian cobra venom. All the three antivenoms were weak in neutralizing the SNTX (potency = 0.03-0.04 mg toxin/mL), including NBAV that was raised from the SNTX-rich Taiwanese cobra venom. In a challenge-rescue experiment, envenomed mice were prevented from death by a maximal dose of VPAV (intravenous 200 μL) but the recovery from paralysis was slow, indicating the need for higher or repeated doses of VPAV. Our results suggest that optimal neutralization for Pakistani N. naja venom may be achieved by improving the formulation of antivenom production to enhance antivenom immunoreactivity against long and SNTXs.
86 citations
TL;DR: The authors conducted face-to-face interviews with snake farmers in Viet Nam and China, with the aim of describing the basic models under which snakes are farmed for meat, synthesized this information to assess the feasibility of farming snakes for human consumption, drawing conclusions about the impact of this industry on the conservation of wild snake populations.
Abstract: Snake farming in Asia has increased over the past decade, and conservationists have expressed concerns that farms may foster overexploitation of wild populations and create legal conduits for illegally harvested wild individuals. We conducted face-to-face interviews with snake farmers in Viet Nam and China, with the aim of describing the basic models under which snakes are farmed for meat. We synthesized this information to assess the feasibility of farming snakes for human consumption, drawing conclusions about the impact of this industry on the conservation of wild snake populations. The most commonly farmed snakes include the monocled cobra Naja kaouthia, the Chinese cobra Naja atra, the oriental rat snake Ptyas mucosus and the king cobra Ophiophagus hannah. These species have life histories that are compatible with the demands of intensive livestock production, including early maturity, rapid growth rates, high reproductive output, efficient food assimilation rates and undemanding space requirements. Snake farmers appear to be capitalizing on the unique energy-efficiency of snakes to produce meat for human consumption. We conclude that the ease and profitability of farming snakes in China and Viet Nam make farming a viable substitute for harvesting wild snakes, with apparently minimal threat to wild populations. Snake farming offers a range of novel agricultural opportunities and has the potential to play a pivotal role in sustainable development.
28 citations
TL;DR: Multiple sequence alignment of 51 kinds of CTX cDNAs and calculations of nonsynonymous and synonymous substitutions indicated that the codons coding the three loops' regions, which may interact with the hydrophobic tails of phospholipids, have undergone an accelerated evolution.
Abstract: The molecular mechanism underlying the hemolytic and cytolytic processes of cobra cytotoxins (CTXs) is not yet fully elucidated. To examine this, we analyzed the amino acid sequences, hemolytic and cytotoxic activities, and affinities to phospholipids of the five major CTXs purified from the venom of Indian cobra, Naja naja. CTX2, CTX7, and CTX8 belonged to S-type, and CTX9 and CTX10 to P-type. Comparisons of CTX7 with CTX8 and CTX9 with CTX10 revealed similar primary structures and hemolytic and cytolytic activities. CTX2, whose primary structure was rather different from the others, showed several times weaker hemolytic and cytolytic biological activities than the others. The comparison of CTX2 with CTX7 suggested the importance of Lys30 in loop II for the strong hemolytic and cytolytic activities of S-type CTXs. Cloning of 12 CTX cDNAs from the Naja naja venom cDNA library revealed that 18 out of 23 substitutions found in CTX cDNAs were nonsynonymous. This clearly indicated the accelerated evolution of CTX genes. Multiple sequence alignment of 51 kinds of CTX cDNAs and calculations of nonsynonymous and synonymous substitutions indicated that the codons coding the three loops' regions, which may interact with the hydrophobic tails of phospholipids, have undergone an accelerated evolution. In contrast, the codons coding for amino acid residues considered to participate in the recognition and binding of the hydrophilic head groups of phospholipids, eight Cys residues, and those likely stabilizing β core structure, were all conserved.
18 citations
TL;DR: The level of exploitation of snakes in Morocco is estimated based on field surveys and questionnaires administered to Aissawas during 2003–2014 and an increase in the market price for snakes, after correction for accumulated inflation, signifying a higher demand for these animals.
Abstract: Traditional activities that potentially threaten biodiversity represent a challenge to conservationists as they try to reconcile the cultural dimensions of such activities. Quantifying the impact of traditional activities on biodiversity is always helpful for decision making in conservation. In the case of snake charming in Morocco, the practice was introduced there 500 years ago by the religious order the Aissawas, and is now an attraction in the country's growing tourism industry. As a consequence wild snake populations may be threatened by overexploitation. The focal species for snake charming, the Egyptian cobra Naja haje, is undergoing both range and population declines. We estimated the level of exploitation of snakes based on field surveys and questionnaires administered to Aissawas during 2003–2014, and compared our results with those of a study conducted 25 years previously. Aissawas use four venomous and four non-venomous species for snake charming and we estimate they harvest a minimum of 4,500 individuals annually, mostly venomous snakes. For exhibition purposes they selectively remove the largest specimens from the wild (i.e. those that could have the highest reproductive output). Compared to the previous data, we detected (1) a reduction in the number of species collected, (2) an increased distance to collecting fields, and (3) an increase in the market price for snakes, after correction for accumulated inflation, signifying a higher demand for these animals.
7 citations
TL;DR: This study is the first to report complete hematologic and blood biochemical ranges for the study species and will be useful in routine health evaluations and aiding in better medical management of the species studied.
Abstract: Aim: To study the hematology and serum biochemistry parameters of Indian spectacled cobra (Naja naja) and Indian rat snake (Ptyas mucosa) and to evaluate the differences in the same between captive and wild populations. Materials and Methods: Animals were categorized into four groups, viz., wild Indian spectacled cobra (n=10), wild Indian rat snakes (n=10), captive Indian spectacled cobra (n=10), and captive Indian rat snake (n=10). The snakes were restrained with restraint tubes, and 2 ml of blood was collected from either heart or ventral coccygeal vein. Hematological examinations were performed manually and serum biochemistry assays were performed on semi-automated clinical chemistry analyzer. Results: The values of total erythrocyte count, packed cell volume, and hemoglobin were slightly low in captive spectacled cobras and captive rat snakes compared to wild ones, whereas total leukocyte count was found to be slightly high in wild spectacled cobras compared to captive ones. All the recorded values of biochemical and electrolyte analytes were found to be well within expected range for snakes except for total protein and chloride levels in both the species which was slightly above the expected range. Conclusion: The hematology and serum biochemistry intervals of the two most common Indian snakes are presented here. The data will be useful in routine health evaluations and aiding in better medical management of the species studied. Since this study is the first to report complete hematologic and blood biochemical ranges for the study species, observations made here can also be used as referral intervals for future use.
4 citations
TL;DR: In this article, a group of freshly-caught central Asiatic cobras, Naja oxiana, were evoked by the proximity of an experimenter, and the cobras responded by hooding and holding 13-22% of their total body length in an elevated or vertical posture.
Abstract: T defensive behaviors of a group of freshly-caught central Asiatic cobras, Naja oxiana, were evoked by the proximity of an experimenter. The cobras responded by hooding and holding 13-22% of their total body length in an elevated or vertical posture. From this vertical posture the cobras would launch defensive sham (closed-mouth) strikes; these strikes were typically associated with a short “burst”-like hiss and were more frequent in the smaller specimens studied. The presence of the experimenter provoked an increase in the cobra’s ventilatory rib movements as well as the tongue flick rates; the latter metric was strongly correlated with the height of vertical posturing, strike frequency and hissing frequency. Most of the observed behaviors’ results from the cobras’ visual perception are interpreted as a visual display intended as a deterrent. This interpretation raises interesting and previously unexplored, questions about intra and interspecific variation of these displays (within both Naja and the Hemibungarini), as well as the relationship between these defensive behaviors and (repeatedly evolved) ability to “spit” venom.
2 citations
TL;DR: Findings suggest a potential antivenom role of Cassia hirsute against Naja naja venom.
Abstract: Snake bite leads to medical emergencies and sometimes death. It is clinically managed by administration of monovalent/polyvalent antisera and it exhibit early or late adverse reactions and sometimes these adverse effects lead to fatalities. Cassia hirsute has been used against snake bite by the traditional healers; however, there is paucity of scientific data in support of this claim. To examine the anti-snake venom activities of ethanolic and aqueous extracts of Cassia hirsute against Indian cobra ( Naja naja ) venom induced toxicity. Anti-snake venom activities of ethanolic and aqueous extracts of Cassia hirsute against Indian cobra ( Naja naja ) venom induced toxicity was studied in mice, rats and sheep by using various models as follows: Phospholipase A 2 induced hemolysis on sheep RBC, Naja naja induced anticoagulation[Coagulation activity], Naja naja induced bleeding, In- vivo Neutralization activity against lethality induced by Naja naja venom (2mg/kg) in rats, Naja naja venom induced odema, liver function of venomized rats. The Minimum lethal dose (MLD) was found as 2mg/kg and both ACH and ECH shown significant neutralization of Naja naja venom induced lethality. Both extracts inhibited phospholipase A2 dependent hemolysis of sheep RBC's and showed a high significant reduction (P<0.001) in the anti-coagulant activity of venom with 80.51% inhibition of anti-coagulation of ECH at 350 ;g and 79.84% of ACH at 300 ;g. ECH and ACH 300, 600 and 900 mg/kg shows significant (P<0.001) decrease in bleeding time also. These findings suggest a potential antivenom role of Cassia hirsute against Naja naja venom.
Journal Article•
Journal Article•
TL;DR: A case of bilateral blindness due to corneal opacification, effects of an attack by a Naja mossambica in a 15 years old woman from Democratic Republic of Congo (DR Congo) is reported.
Abstract: Spitting cobra is the name given to some snakes of the family of Elapidae, belonging to the genus Naja or Hemachatus that have the ability to spitt heir venom (up to 3m) to blind their predators. Naja mossambica is the most answered species in Africa.The precise statistics of attacks due to this snake are available, let alone those related to therate of blindness in relation to its venom.This venom, harmless to the skin,can causecorneal necrosis responsible within hours of blindness in the absence of abundantrinsing of eyes with water. This observation has aimed to report a case of bilateral blindness due to corneal opacification, effects of an attack by a Naja mossambica in a15 years old woman from Democratic Republic of Congo (DR Congo).
TL;DR: There are geographic intra-specific variations of venom composition of the two N. naja venoms and the lower antibody affinity towards the 'heterologous' venom was the likely cause of poor efficacy of the Indian antivenom used to treat NNsl envenoming.