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Pharmacokinetics of Naja sumatrana (Equatorial Spitting Cobra) Venom and Its Major Toxins in Experimentally Envenomed Rabbits  [PDF]
Michelle Khai Khun Yap,Nget Hong Tan ,Si Mui Sim,Shin Yee Fung,Choo Hock Tan
PLOS Neglected Tropical Diseases , 2014, DOI: 10.1371/journal.pntd.0002890
Abstract: Background The optimization of snakebite management and the use of antivenom depend greatly on the knowledge of the venom's composition as well as its pharmacokinetics. To date, however, pharmacokinetic reports on cobra venoms and their toxins are still relatively limited. In the present study, we investigated the pharmacokinetics of Naja sumatrana (Equatorial spitting cobra) venom and its major toxins (phospholipase A2, neurotoxin and cardiotoxin), following intravenous and intramuscular administration into rabbits. Principal findings The serum antigen concentration-time profile of the N. sumatrana venom and its major toxins injected intravenously fitted a two-compartment model of pharmacokinetics. The systemic clearance (91.3 ml/h), terminal phase half-life (13.6 h) and systemic bioavailability (41.9%) of N. sumatrana venom injected intramuscularly were similar to those of N. sputatrix venom determined in an earlier study. The venom neurotoxin and cardiotoxin reached their peak concentrations within 30 min following intramuscular injection, relatively faster than the phospholipase A2 and whole venom (Tmax = 2 h and 1 h, respectively). Rapid absorption of the neurotoxin and cardiotoxin from the injection site into systemic circulation indicates fast onsets of action of these principal toxins that are responsible for the early systemic manifestation of envenoming. The more prominent role of the neurotoxin in N. sumatrana systemic envenoming is further supported by its significantly higher intramuscular bioavailability (Fi.m. = 81.5%) compared to that of the phospholipase A2 (Fi.m. = 68.6%) or cardiotoxin (Fi.m. = 45.6%). The incomplete absorption of the phospholipase A2 and cardiotoxin may infer the toxins' affinities for tissues at the injection site and their pathological roles in local tissue damages through synergistic interactions. Conclusion/Significance Our results suggest that the venom neurotoxin is absorbed very rapidly and has the highest bioavailability following intramuscular injection, supporting its role as the principal toxin in systemic envenoming.
Biochemical and toxinological characterization of Naja sumatrana (Equatorial spitting cobra) venom
Yap, MKK;Tan, NH;Fung, SY;
Journal of Venomous Animals and Toxins including Tropical Diseases , 2011, DOI: 10.1590/S1678-91992011000400012
Abstract: the lethal and enzymatic activities of venom from naja sumatrana (equatorial spitting cobra) were determined and compared to venoms from three other southeast asian cobras (naja sputatrix, naja siamensis and naja kaouthia). all four venoms exhibited the common characteristic enzymatic activities of asiatic cobra venoms: low protease, phosphodiesterase, alkaline phosphomonoesterase and l-amino acid oxidase activities, moderately high acetylcholinesterase and hyaluronidase activities and high phospholipase a2. fractionation of n. sumatrana venom by resource? s cation exchange chromatography (ge healthcare, usa) yielded nine major protein peaks, with all except the acidic protein peak being lethal to mice. most of the protein peaks exhibit enzymatic activities, and l-amino acid oxidase, alkaline phosphomonoesterase, acetylcholinesterase, 5'-nucleotidase and hyaluronidase exist in multiple forms. comparison of the resource? s chromatograms of the four cobra venoms clearly indicates that the protein composition of n. sumatrana venom is distinct from venoms of the other two spitting cobras, n. sputatrix (javan spitting cobra) and n. siamensis (indochinese spitting cobra). the results support the revised systematics of the asiatic cobra based on multivariate analysis of morphological characters. the three spitting cobra venoms exhibit two common features: the presence of basic, potentially pharmacologically active phospholipases a2 and a high content of polypeptide cardiotoxin, suggesting that the pathophysiological actions of the three spitting cobra venoms may be similar.
Hemolitic action of Naja naja atra cardiotoxin on erythrocytes from different animals
Troiano, J. C.;Gould, E. G.;Gould, I.;
Journal of Venomous Animals and Toxins including Tropical Diseases , 2006, DOI: 10.1590/S1678-91992006000100004
Abstract: a comparative study on the sensitivity of erythrocytes from different vertebrate species (avian, mammalian and reptilian) to the hemolytic action caused by cardiotoxin isolated from naja naja atra venom was carried out. cardiotoxin was able to induce direct hemolysis in washed erythrocytes from several animals, except for llama. the ec50 values from hemolysis of the most sensitive (cat) and the most resistant (snake) animal varied approximately tenfold. according to the cell behavior, it was possible to characterize four types of behavior: the first was observed in cat, horse and human cells; the second in rat, rabbit and dog erythrocytes; and the third only in llama erythrocytes, which were resistant to cardiotoxin concentrations up to 300 μg/ml. finally, avian and reptilian erythrocytes were more resistant to cardiotoxin iii-induced hemolysis than those of the mammalian species.
The Professional Medical Journal , 2004,
Abstract: We present the case of a 35-year old male who reported withhistory of cobra snakebite on the nape of his neck. He developed respiratory failure within hours. He wastreated successfully with respiratory support, anti-venom administration and anticholinesterase. Detailed in thisreport is the reversal of envenomation symptoms following the administration of anticholinestrase, neostigminemethyl sulfate.
Gadag J.R,Saroj C.L
International Research Journal of Pharmacy , 2011,
Abstract: A toxin with high in vitro neurotoxicity and Phospholipase A2 activity has been isolated from the venom of the Naja naja (Indian cobra) by column chromatography.
Extended Immunization of Rats using Microencapsulated Cobra Venom  [cached]
H.F. Salem,Aly Fahmy,Ahmed M.A. Ali
British Journal of Pharmacology and Toxicology , 2011,
Abstract: Production of a vaccine with an extended release kinetic and with a high immunization response has an economic value in the third world countries. In this study, production and evaluation of bovine serum albumin microspheres that are incorporating cobra venom were carried out. The microcapsules were prepared using modified emulsification-polymerization technique. They were evaluated for their size using photon correlation spectroscopy and for their morphology using scanning electron microscopy. The release kinetics of the venom from the chosen formula was following Higushi model with r2 >0.97. The average microsphere size of the best formula was 5.6 :m and the encapsulation efficiency approached 82%. The pharmacokinetic parameters of the microencapsulated cobra venom showed a significant difference from the free venom formulations in terms o f prolonged stimulation of in-vivo immune response (production of antibodies). The method of preparation and evaluation of microspheres were characterized by being easy to perform, yielding high entrapment efficiency and maximum induction of immune response, which enables availability of a safe, effective and economic vaccine.
Inhibition of the Nicotinic Acetylcholine Receptors by Cobra Venom α-Neurotoxins: Is There a Perspective in Lung Cancer Treatment?  [PDF]
Angela Alama,Cristina Bruzzo,Zita Cavalieri,Alessandra Forlani,Yuri Utkin,Ida Casciano,Massimo Romani
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0020695
Abstract: Nicotine exerts its oncogenic effects through the binding to nicotinic acetylcholine receptors (nAChRs) and the activation of downstream pathways that block apoptosis and promote neo-angiogenesis. The nAChRs of the α7 subtype are present on a wide variety of cancer cells and their inhibition by cobra venom neurotoxins has been proposed in several articles and reviews as a potential innovative lung cancer therapy. However, since part of the published results was recently retracted, we believe that the antitumoral activity of cobra venom neurotoxins needs to be independently re-evaluated.
Effect of Mucuna pruriens Seed Extract Pretreatment on the Responses of Spontaneously Beating Rat Atria and Aortic Ring to Naja sputatrix (Javan Spitting Cobra) Venom
Shin Yee Fung,Nget Hong Tan,Si Mui Sim,John C. Aguiyi
Evidence-Based Complementary and Alternative Medicine , 2012, DOI: 10.1155/2012/486390
Abstract: Mucuna pruriens Linn. (velvet bean) has been used by native Nigerians as a prophylactic for snakebite. Rats pretreated with M. pruriens seed extract (MPE) have been shown to protect against the lethal and cardiovascular depressant effects of Naja sputatrix (Javan spitting cobra) venoms, and the protective effect involved immunological neutralization of the venom toxins. To investigate further the mechanism of the protective effect of MPE pretreatment against cobra venom toxicity, the actions of Naja sputatrix venom on spontaneously beating rat atria and aortic rings isolated from both MPE pretreated and untreated rats were studied. Our results showed that the MPE pretreatment conferred protection against cobra venom-induced depression of atrial contractility and atrial rate in the isolated atrial preparations, but it had no effect on the venom-induced contractile response of aortic ring preparation. These observations suggested that the protective effect of MPE pretreatment against cobra venom toxicity involves a direct protective action of MPE on the heart function, in addition to the known immunological neutralization mechanism, and that the protective effect does not involve action on blood vessel contraction. The results also suggest that M. pruriens seed may contain novel cardioprotective agent with potential therapeutic value.
Biochemical and morphological analysis of cell death induced by Egyptian cobra (Naja haje) venom on cultured cells
Omran, M. A. A.;Fabb, S. A.;Dickson, G.;
Journal of Venomous Animals and Toxins including Tropical Diseases , 2004, DOI: 10.1590/S1678-91992004000300004
Abstract: we investigated the in vitro process of cell death caused by egyptian cobra venom on primary human embryonic kidney (293t) and mouse myoblast (c2c12) cell lines. the aim of these studies was to provide further information about triggering cell death, and suggest methods for eliminating unwanted cells, such as tumour cells. both cell lines were treated with 10, 20, and 50 m g/ml of egyptian cobra (naja haje) venom in serum free media (sfm) and incubated for 8 hours. total activities of the lactate dehydrogenase (ldh) and creatine kinase (ck) released in the culture during venom incubation were used as an indicator of the venom in vitro cytotoxicity. cell injury was morphologically recognized and apoptosis determined by a fluorescing apoptosis detection system and confirmed by staining nuclear dna with dapi. our data clearly demonstrated marked cytotoxic effects and acute cell injury for both cell lines. release of ldh and ck into the culture media induced by the venom correlates well with the morphological changes and extent of cell death. mostly, these consequences were time and dose-dependent in both cell lines. the results obtained from this study indicated that cobra venom cause cell death by two different mechanisms: necrosis and induction of apoptosis. the apoptotic mechanism, accompanied by cell necrosis, mediated cell destruction of both tested cell lines; however, necrosis was predominant in the c2c12 cell line while apoptosis, in 293t cells. this unusual form of cell death induced by cobra venom may represent a combination of apoptosis and necrosis within the same cell. this is a first-hand investigation showing the apoptotic effects of n. haje venom at the cellular level. however, the contribution of the apoptotic pathway may be dependent on concentration and/or time of exposure to snake venom.
Cross-Reactivity against Naja sumatrana (Black Spitting Cobra) Envenoming from the Haffkine Antivenom in a Mouse Model  [PDF]
Gregory Cham,Francis Lim,Arul Earnest,Ponnampalam Gopalakrishnakone
ISRN Toxicology , 2013, DOI: 10.1155/2013/247645
Abstract: Naja sumatrana is the dominant cobra species in Malaysia, Singapore, Borneo, and Sumatra, and it does not have specific antivenom. The Haffkine antivenom has been advocated instead. This study aims to determine the efficacy of this antivenom against Naja sumatrana envenoming using a mouse model. Methods. Male Swiss albino mice were used. Intravenous LD50 was first determined separately for Naja naja and Naja sumatrana venom. ED50 was determined by preincubating antivenom with each venom at 2.5 LD50 before administering the mixture into the tail vein. Validation was carried out using a challenge test. Each mouse received 111?μg of Naja sumatrana venom intramuscularly followed by intraperitoneal administration of dilute Haffkine antivenom. Survival was recorded 24 hours after envenoming. Results. The LD50 of Naja naja venom was 78.13?μg, standard error (SE) 13.3?μg. The ED50 of the Haffkine antivenom against Naja naja venom was 45.9?mg, SE 7.5?mg. The LD50 and ED50 of Naja sumatrana venom were 55.5?μg, SE 12.0?μg; and 73.9?mg, SE 12.0?mg, respectively. The intra-peritoneal ED50 against 111?μg intramuscular Naja sumatrana venom was 136.95?mg, SE 36.74?mg. Conclusion. The Haffkine polyvalent antivenom exhibited cross-neutralisation against Naja sumatrana venom when used at a higher dose. 1. Introduction 1.1. Background and Importance Naja sumatrana, commonly known as the black spitting cobra or Equatorial spitting cobra, is the dominant cobra species in Peninsular Malaysia, Singapore, Borneo, and Sumatra [1]. It was estimated that the highest burden of snake bites exists in South Asia, Southeast Asia, and sub-Saharan Africa [2]. Cobra bites are common in Peninsular Malaysia and require significant medical intervention [3, 4]. However, snake bites are considered uncommon in largely urban Singapore [5, 6]. Unfortunately specific antivenom therapy against the Naja sumatrana does not exist. The Haffkine antivenom was arbitrarily advocated as an antivenom. It is an equine polyvalent antivenom raised against the Indian binocellate cobra (Naja naja), common krait (Bungarus caeruleus), Russell’s viper (Vipera russelli), and saw-scaled viper (Echis carinatus) [7]. However, these species of snakes are not normally found in Southeast Asia. The antivenom composition of the Haffkine was chosen for the treatment of black spitting cobra snake bites due to the empirical belief that cobras are originated from the Naja naja. These species are, however, considered to be separate now. It is unknown if the Haffkine product has any effective paraspecific activity against the
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