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At least 145 records · Page 8Linked to original sources
PubMed1998

[Use of toxic fraction isolated from Algerian Androctonus australis hector scorpion venom for the assessment of anti-venom serum].

Today, serotherapy is the only specific treatment used against the scorpionique envenomation. This treatment was associated with other drugs as a symptomatic and supportive care. The anti-venom against scorpion stings is still prepared using the conventional manufacturing production. To evaluate the efficacy of the anti-venom, different protocols are used: The immunization of animals (rabbit and horse) with a whole toxic fraction prepared by molecular filtration was the first step to improve the anti-venom. Some observations also show the need for the quality control of this preparation of anti-venom. In this study, we describe the use the toxic fraction isolated from Androctonus australis Hector in the new protocol of anti-venom production. The quality control of the product is evaluated by using a combination of experimental immunological assay systems (ELISA, Hemaglutination, in vivo assessment of the neutralization of the lethal effect of the venom).

Algeria↗
PubMed2002

Capacity of Thai green pit viper antivenom to neutralize the venoms of Thai Trimeresurus snakes and comparison of biological activities of these venoms.

The capacity of Thai green pit viper antivenom raised to Trimeresurus albolabris to neutralize the venoms from six species of Trimeresurus sp. in Thailand has been examined. They were Trimeresurus albolabris, T. macrops, T. popeiorum, T. hageni, T. purpureomaculatus, and T. kanburiensis. The antivenom neutralized lethal and hemorrhagic activities of all these venoms. The capacity of antivenom to neutralize lethal toxicity of the venom was expressed as the amounts (mg) of snake venom neutralized by 1 ml of the antivenom. The largest capacity was found with the homologous venom. Results of immunodiffusion, immunoblotting, and antigen-antibody complex formation experiments supported the results of neutralization experiments. Several biological activities of the Trimeresurus venoms were also examined and compared. They were lethal, hemorrhagic, proteolytic, phospholipase A, arginine ester hydrolyse, and thrombin activities. There was no correlation between the ratios of lethal toxicity and hemorrhagic activity, lethal toxicity and phospholipase A activity, as well as hemorrhagic activity and proteolytic activity.

Animals↗
PubMed2006

Mass spectrometry strategies for venom mapping and peptide sequencing from crude venoms: case applications with single arthropod specimen.

Due to their complexity and diversity, animal venoms represent an extensive source of bioactive compounds such as peptides and proteins. Conventional approaches for their characterization often require large quantities of biological material. Current mass spectrometry (MS) techniques now give access to a wealth of information in a short working time frame with minute amounts of sample. Such MS approaches may now be used for the discovery of novel compounds, and once their structure has been determined they may be synthesized and tested for functional activity. Molecular mass fingerprints of venoms allow the rapid identification of known toxins as well as preliminary structural characterization of new compounds. De novo peptide sequencing by tandem mass spectrometry (MS/MS) offers rapid access to partial or total primary peptide structures. This article, written as a tutorial, also contains new material: molecular mass fingerprint analysis of Orthochirus innesi scorpion venom, and identification of components from bumblebee Bombus lapidarius venom, both collected from one single specimen. The structure of the three major peptides detected in the Bombus venom was fully characterized in one working day by de novo sequencing using an electrospray ionization hybrid quadrupole time-of-flight instrument (ESI-QqTOF) and a matrix-assisted laser desorption ionization time-of-flight instrument (MALDI-LIFT-TOF-TOF). After presenting the MS-based sequence elucidation, perspectives in using MS and MS/MS techniques in toxinology are discussed.

Animals↗
PubMed2007

Snake venomics of Bitis gabonica gabonica. Protein family composition, subunit organization of venom toxins, and characterization of dimeric disintegrins bitisgabonin-1 and bitisgabonin-2.

The protein composition of the venom of the East African Gaboon viper (Bitis gabonica gabonica) was analyzed using RP-HPLC, N-terminal sequencing, MALDI-TOF peptide mass fingerprinting, and CID-MS/MS. In total, 35 proteins of molecular masses in the range of 7-160 kDa and belonging to 12 toxin families were identified. The most abundant proteins were serine proteinases (26.4%), Zn2+-metalloproteinases (22.9%), C-type lectin-like proteins (14.3%), PLA2s (11.4%), and bitiscystatin (9.8%). Other protein classes, that is, bradykinin-potentiating peptides, dimeric disintegrins, Kunitz-type inhibitor, DC-fragments, sv-VEGF, CRISP, and L-amino acid oxidase, comprised between 1.3 and 3.4% of the total venom proteome. Only 11 venom-secreted proteins matched any of the previously reported 22 partial or full-length venom gland transcripts. In addition, venome and transcriptome depart in their relative abundances of different toxin families. The proteomic characterization of purified B. gabonica gabonica proteins run under nonreducing and reducing SDS-PAGE conditions revealed their aggregation state and subunit composition. Multimeric proteins included heterodimeric disintegrins, homodimeric sv-VEGF-A, heterodimeric (alphabeta) and tetrameric (alphabeta)4 C-type lectins, and multimeric PIII Zn2+-metalloproteinases. Determination of the complete primary structure and subunit composition of the two major dimeric disintegrins, bitisgabonin-1 and bitisgabonin-2, showed that each comprised a distinct RGD- and MLD-bearing subunit and a common, N-terminal-blocked, RGD-containing subunit identical to the disintegrin domain of the PII Zn2+-metalloproteinase 4. Cell adhesion inhibition assays showed that bitisgabonin-1 (RGD-RGD) is a potent inhibitor of integrin alpha5beta1, whereas bitisgabonin-2 (MLD-RGD) is a better antagonist of integrins alpha4beta1 and alpha9beta1.

Amino Acid Sequence↗
PubMed1989

Venom production in snake venom gland cells cultured in vitro.

The venom gland cells from a Ghanaian specimen of Bitis gabonica were established in tissue culture for over seven months. During this time the cells maintained their original morphology and divided actively. Tests for the synthesis of venom using an immuno peroxidase technique (on the cells) were strongly positive and tests for the secretion of venom into tissue culture medium using ELISA suggested secreted venom levels of at least 200 ng/ml culture fluid. The B. gabonica specimen used for these studies was designated BG5 and we propose to refer to this venom gland cell culture as BG5.

Animals↗
PubMed1989

The lethal and biochemical properties of Bungarus candidus (Malayan krait) venom and venom fractions.

Bungarus candidus venom exhibited high hyaluronidase, acetylcholinesterase and phospholipase A activities; low proteinase, 5'-nucleotidase, alkaline phosphomonoesterase and phosphodiesterase activities and moderately high L-amino acid oxidase activity. SP-Sephadex C-50 ion exchange chromatographic fractionation of the venom and Sephadex G-50 chromatography of the major lethal venom fractions indicate that the venom contains at least two highly lethal, basic phospholipases A with LD50 (i.v.) values of 0.02 micrograms/g (F6A) and 0.18 micrograms/g (F4A), respectively; as well as two polypeptide toxins with LD50 (i.v.) values of 0.17 micrograms/g and 0.83 micrograms/g, respectively. The major lethal toxin is the basic lethal phospholipase A, F6A, which accounts for approximately 13% of the venom protein and has a mol. wt of 21,000.

Animals↗
PubMed1992

Use of HPLC to demonstrate variation of venom toxin composition in the Thailand cobra venoms Naja naja kaouthia and Naja naja siamensis.

The composition of the venoms of Naja naja kaouthia and Naja naja siamensis from different commercial sources has been investigated using both ion-exchange and reverse-phase high-pressure liquid chromatography (RP-HPLC) in order to investigate variation in toxin contents. The venoms contained identical major toxin components, although in different relative concentrations. The venom collected separately from the left and right glands of individual snakes were virtually the same as judged by RP-HPLC. The cytotoxin CT-II, which was previously only reported to be present in Naja naja siamensis venom, was detected in all the venoms investigated. Two long neurotoxin homologues have also been isolated.

Amino Acids↗
PubMed1994

Studies on venom and venom apparatus of Fea's viper, Azemiops feae.

Enzyme activities tested in the venom gland extract of Azemiops feae snake are similar to those of viperine venoms, except that Azemiops venom has no blood clotting, haemorrhagic or myolytic activities. The venom gland exhibits the characteristic feature of a viperine gland, but the fangs possess a ridge at the tip laterally to the venom orifice and a blade-like structure on the back seen only in some opisthoglyphous and Atractaspidae snakes.

Amino Acid Oxidoreductases↗
PubMed1982

Purification and characterization of anticomplement factor (cobra venom factor) from the Naja naja atra venom.

Anticomplement factor (cobra venom factor) from the venom of Naja naja atra was purified by means of successive chromatography on DEAE-cellulose, Sephadex G-200 and Sepharose CL-6B. The purified anticomplement factor was homogeneous as judged by polyacrylamide discontinuous gel electrophoresis at pH 9.4. The yield from 3.0 g of the crude venom was approx. 28 mg. The molecular weight was estimated to be about 156 000 by SDS-polyacrylamide gel electrophoresis. The isoelectric point was about 5.2. SDS-polyacrylamide gel electrophoresis of the anticomplement factor in the presence of dithiothreitol demonstrated that the molecule possesses three different polypeptide chains cross-linked covalently to one another by disulfide bridge(s). By SDS-polyacrylamide gel electrophoresis, the molecular weight of each subunit was determined to be approx. 77000, 47500 and 29 000, respectively. All subunits were stained with Coomassie brilliant blue G-250 and periodate-Schiff reagent, indicating these subunits to be glycoprotein. Distribution of the anticomplement factor in various snake venoms, which shows cross-reactivity against the anti-Naja naja atra anticomplement factor antiserum, was examined. From the results, all venoms belonging to cobra family in the Elapidae tested so far were found to contain such cross-reactivity.

Amino Acids↗
PubMed2004

Anti-venom potential of butanolic extract of Eclipta prostrata against Malayan pit viper venom.

The butanolic and purified butanolic extracts (PBEs) of Eclipta prostrata were evaluated for their anti-venom potential. Inhibition of lethal, hemorrhagic, proteolytic, and phospholipase A2 activities of Calloselasma rhodostoma (Malayan pit viper (MPV)) venom by these extracts were determined. Demethylwedelolactone was identified as their major constituent. The butanolic extract, at 2.5 mg per mouse, was able to completely neutralize the lethal activity of 2LD50 of MPV venom, but increasing the dose diminished the effect. The PBE, at 1.5-4.5 mg per mouse, was able to neutralize the lethality of the venom at around 50-58%. Both extracts partially inhibited the hemorrhagic activity but displayed very low anti-phospholipase A2 activity and did not inhibit proteolytic activity of MPV venom.

Animals↗
PubMed2001

Novel in vitro assays for assessing the haemorrhagic activity of snake venoms and for demonstration of venom metalloproteinase inhibitors.

Standard methods used for assessing the haemorrhagic toxicity of snake venoms and the effectiveness of antivenoms are laborious, expensive and involve the use of large numbers of laboratory animals. This paper examined the feasibility of using a gelatin degradation ELISA for preliminary screening of snake venom metalloproteinases (MPs). Potent gelatinolytic activity was observed in venoms from snakes of the family Viperidae and, as expected, little or no activity was evident in the venoms of snakes that induce neurotoxic pathology (most elapids). A reverse gelatin zymography assay was used on a variety of venoms to demonstrate a number of inhibitors of MP activity, the first such demonstration of its kind.

Electrophoresis, Polyacrylamide Gel↗
PubMed2004

Heterogeneity of Russell's viper venom affects the sensitivity of the dilute Russell's viper venom time to lupus anticoagulants.

A number of studies have shown that commercial dilute Russell's viper venom time (DRVVT) reagents vary in their sensitivity for lupus anticoagulant (LA) detection. The differences in performance are considered to be predominantly due to antibody heterogeneity and a wide variation in phospholipid content, and also the techniques and clot detection methods employed. The present study compared the LA detection rates of five different Russell's viper venom (RVV) preparations using identical phospholipid reagents to assess the contribution of venom heterogeneity to LA detection by DRVVT. Initial analysis of 300 samples sent for thrombophilia screening identified 48 (16.0%) LAs by DRVVT and confirmatory tests with a single RVV reagent. Subsequent DRVVT analysis of all 300 samples using the other four venom reagents, with confirmatory tests on samples with elevated screen ratios, revealed a further 38 LAs in a variety of combinations of reagents. Only 15 of 86 (17.4%) of LAs were detected with all five RVV reagents. Significant biological variation of RVV exists due to differences between Russell's viper subspecies and a variety of environmental and physiological factors. The clear variations in diagnostic performance between alternative RVV preparations are most probably due to biological venom heterogeneity, and also differences in the manufacturing processes.

False Negative Reactions↗
PubMed1976

Some pharmacological properties of the venom, venom fractions and pure toxin of the yellow-bellied sea snake Pelamis platurus.

The effects of the crude venom, four partially purified venom fractions and pure toxin (Pelamis toxin alpha) from yellow-bellied sea snake, Pelamis platurus, on respiration, blood pressure, heart and skeletal muscle of rabbits have been examined. Results indicated that crude venom, a partially purified toxic fraction and Pelamis toxin alpha caused initial respiratory stimulant effects followed by respiratory paralysis. In most cases, respiratory paralysis occurred before a profound fall in arterial pressure. Depression of the twitch response to nerve stimulation was observed in the tibialis anterior muscle. No significant change in the electrocardiogram was seen. Three partially purified non-toxic fractions of the crude venom induced transient respiratory stimulant effects. It was concluded that the crude venom and Pelamis toxin alpha had an identical mode of action and that they caused respiratory paralysis in rabbits.

Animals↗
PubMed1989

The anticoagulant activity of Malayan cobra (Naja naja sputatrix) venom and venom phospholipase A2 enzymes.

Malayan cobra (Naja naja sputatrix) venom was found to exhibit an in vitro anticoagulant activity that was much stronger than most common cobra (genus Naja) venoms. The most potent anticoagulants of the venom are two lethal phospholipase A2 enzymes with pI's of 6.15 and 6.20, respectively. The anticoagulant activity of the venom is due to the synergistic effect of the venom phospholipase A2 enzymes and polypeptide anticoagulants. Bromophenacylation of the two phospholipase A2 enzymes reduced their enzymatic activity with a concomitant drop in both the lethal and anticoagulant activities.

Animals↗
PubMed1994

The efficacy of compression immobilization technique in retarding spread of radio-labeled Russell's viper venom in rhesus monkeys and 'mock venom' NaI131 in human volunteers.

The efficacy of the modified compression immobilization technique in retarding spread of radio-labeled Russell's viper venom in 3 rhesus monkeys (Macaca mulata) and "mock venom" NaI131 in 14 human volunteers was studied. 0.1 microgram of Russell's viper venom having 10 microCi radioactivity in 0.2 ml normal saline containing 0.5% bovine serum albumin was injected subcutaneously at the lateral aspect of the right hind limb of a rhesus monkey. A hand-tight bandaging of a rubber pad measuring 55 x 28 x 16 mm over the injection site and splinting effectively retard spread of radio-labeled venom for the entire length of time applied, although complete immobilization was not achieved. In human volunteers, application of a pad measuring 60 x 50 x 17 mm over the subcutaneous injection site of 20 microCi or 12 microCi/0.2 ml NaI131 with a hand-tight bandaging (60 +/- 10 mmHg) and immobilization of limb was found to be effective in retarding the movement of radioactive NaI131. These results suggested that the compression pads tried in this study effectively retard the spread of radio-labeled Russell's viper venom (MW ranging from 20,000-90,000) and radioactive NaI131 (MW 150) from the site of injection. Thus, it is highly likely that the present compression pad will be useful as a first-aid measure in Russell's viper bite victims.

Adult↗
PubMed1993

Possible mechanisms of action of cobra snake venom cardiotoxins and bee venom melittin.

Cobra snake venom cardiotoxins and bee venom melittin share a number of pharmacological properties in intact tissues including hemolysis, cytolysis, contractures of muscle, membrane depolarization and activation of tissue phospholipase C and, to a far lesser extent, an arachidonic acid-associated phospholipase A2. The toxins have also been demonstrated to open the Ca2+ release channel (ryanodine receptor) and alter the activity of the Ca(2+)+Mg(2+)-ATPase in isolated sarcoplasmic reticulum preparations derived from cardiac or skeletal muscle. However, a relationship of these actions in isolated organelles to contracture induction has not yet been established. The toxins also bind to and, in some cases, alter the function of a number of other proteins in disrupted tissues. The most difficult tasks in understanding the mechanism of action of these toxins have been dissociating the primary from secondary effects and distinguishing between effects that only occur in disrupted tissues and those that occur in intact tissue. The use of cardiotoxin and melittin fractions contaminated with trace ('undetectable') amounts of venom-derived phospholipases A2 has continued to be common practice, despite the problems associated with the synergism between the toxins and enzymes and the availability of methods to overcome this problem. With adequate precautions taken with regard to methodology and interpretation of results, the cobra venom cardiotoxins and bee venom melittin may prove to be useful probes of a number of cell processes, including lipid metabolism and Ca2+ regulation in skeletal and cardiac muscle.

Animals↗
PubMed1978

Effect of concanavalin A on black widow spider venom activity at the neuromuscular junction: implications for mechanisms of venom action.

Concanavalin A (Con A) inhibits black widow spider venom-induced transmitter release at both tissue-cultured and adult neuromuscular junctions and also inhibits the venom-induced destruction of cultured neurites. This inhibitory action is partially or completely prevented by prior treatment with colchicine. Neither colchicine nor Con A interacts significantly with depolarization-induced transmitter release. These results are analogous to those obtained from experiments on lymphocyte surface receptor capping. They suggest that redistribution of neuronal membrane components may be a crucial step in spider venom action. This membrane redistribution appears to be modulated in neurons, as in other cell types, by microtubule-microfilament array. How such a redistribution causes increased transmitter release cannot as yet be specified. Changes in the ionic permeability of sodium and potassium were examined as likely mechanisms. Increased sodium influx (and seondary release of calcium from intracellular stores) cannot be the basis for spider venom action. Increased potassium efflux remains a possibility, but is not consistent with all of the data. Other possible mechanisms are also suggested.

Animals↗
PubMed1983

Two-dimensional polyacrylamide gel electrophoresis of hymenoptera venom and venom sac extracts.

Hymenoptera venom and venom sac extracts were studied by two-dimensional polyacrylamide gel electrophoresis using non-equilibrium pH gradient electrophoresis in the first dimension and sodium sulfate electrophoresis in the second dimension. Pure Apis mellifera (honeybee) venom collected by electrical stimulation was resolved into five major and more than 20 minor components. Polistes (paper wasp), Vespula (yellow jacket), Dolichovespula (aerial hornet) and Vespa (old world hornet) venom sac extracts contained more than 40 components each. These results illustrate the complexity of the mixtures in current use for immunotherapy for stinging insect hypersensitivity. The degrees of similarity observed between the various aspects of Polistes and Vespula studied correlate with the phylogenetic classification of these species.

Animals↗