Journal of Venom Research最新文献

Although the predominant treatment for snakebite is the antivenom, other treatments are also considered. We studied the effects of single or multiple-doses of anti-inflammatory drugs on local, systemic and laboratory findings of the snakebite victims. In this cross-sectional study, 101 patients (90 male: 89.1%) with snakebite envenomation who were admitted to the Medical Toxicology Center of Khorshid Hospital, Isfahan, Iran, were investigated. One group (35 patients: 34.7%) received a single-dose of anti-inflammatory drugs containing chlorpheniramine (10mg intramuscular injection) with cimetidine (200mg intravenous injection) or ranitidine (50mg intravenous injection) plus hydrocortisone (100mg intravenous injection). The other 55 patients (54.5%) received multiple doses of the same drug combination every 8hr until the symptoms resolved. Local, systemic symptoms and laboratory findings on admission, and during 24hr and 48hr of admission, were recorded. The frequency of the localized signs of inflammation (p=0.03), swelling (p<0.001) and bruising (p<0.001) showed a significant difference between the two treated groups. In addition, the recovery time in the patients who received multiple doses was faster (p<0.001). There was no significant difference in any of the systemic signs, laboratory findings or the outcome between the patients in the various groups during hospitalization. Our data indicate that the administration of multiple doses of anti-inflammatory drugs had a greater effect on reducing local symptoms of snakebite including inflammatory manifestations.

Polistes stigma is a common social wasp found in continental Southeast Asia. Despite its wide distribution and abundance, hitherto, there are no studies on small or medium molecular weight components of the venom. For the first time, this study has described the amino acid sequences and its post-translation modifications (PTM's) of four wasp-mastoparans (Ps 1524, Ps 1540, Ps 1556 and Ps 1630), three chemotactic peptides (Ps1417, Ps1434 and Ps1474) and one more (Ps1549) lysine rich peptide from the venom of P. stigma. There were 27 mass traces obtained from the crude natural venom, in which the complete amino acid sequences of 8 peptides were solved. Further, single disulphide bonded peptides uncommon in wasp venoms were identified. The mastoparan peptides were rich in hydrophobic residues. In addition, the peptides Ps1549, Ps1630, Ps1434 and Ps1417 were found to have unusual PTM's of C-terminal amidation. This preliminary study comprehends the untapped compounds present in wasp venom that are equally valuable to widely studied venoms of snakes, spiders and cone snails.

We document inadequately diagnosed coagulopathy (potential to be life threatening) due to Ovophis monticola bite. Although its bites are common in the hills of Nepal, associated envenomations have not been documented elaborately. Herein, we present the clinical and treatment details of a proven O. monticola bite and areas where it may pose the risk of envenomations (suggesting huge populations in Asia to be vulnerable to its bites). Its envenomation was managed symptomatically with several non-evidence-based interventions. Since no specific pitviper antivenom is available in Nepal yet, managing coagulopathy associated to O. monticola envenomation is still challenging. This case emphasizes the need of developing the standard protocol for the diagnosis and management of pitviper bites and study of effectiveness of the available pitviper antivenoms until specific pitviper antivenom is available. Further, the demonstrated distribution localities of this species may have implications for snakebite prevention and designing and distribution of the effective antivenoms.

Belonging to the Viperidae family, Bothrops moojeni are widely distributed in South America, tropical savanna ecoregion (Cerrado) of Argentina, Bolivia, Brazil, and Paraguay with medical importance in Brazil. Accidents caused by this species have a rapid local action with the development of tissue inflammation, causing erythema, pain, and increased clotting time, which can culminate in gangrene or tissue necrosis. Bothrops moojeni venom has a rich composition that remains underexplored, which is of utmost importance, both for elucidating the envenoming process and the vast library of new bioactive molecules kind of venom can offer. This review aims to analyze which components of the venom have already been characterized towards its structure and biological effect and highlight the pharmacological and biotechnological potential of this venom. Although snake venoms have been studied for their toxic effects for generations, innovative studies address their components as tools for discovering new therapeutic targets and new molecules with pharmacological and biotechnological potential.

Here we describe the processing and development of animal-derived monovalent antibody serum against Macrovipera lebetina obtusa venom by purification and concentration of the immunoglobulins using caprylic acid. We demonstrate that this new viper venom antiserum is pre-clinically effective in neutralizing lethal toxicity and hemorrhagicity of the venom of the Armenian Levantine viper - a significant public health problem in Armenia and a wide region from south-east parts of Europe to south-west Asia. The developed product shows a high capacity to inhibit metalloproteinases and phospholipase activity of venom included in the study in comparison to current specific antivenoms, and following additional experimental approvals, it will be possible to derive the monovalent antivenom satisfying international standards, which will be much cheaper and accessible compared with the current market rivals.

Ticks are unique hematophagous arthropods and possess an astounding array of salivary molecules that ensure their unnoticed and prolonged attachment to the host skin. Furthermore, ticks are very effective vectors of a diverse spectrum of pathogens. In order to feed, tick chelicerae cut the host epidermis and their hypostome penetrates through the layers of the skin. As a result of laceration of the skin and rupturing blood vessels, a pool of blood is formed in the dermis, serving for intermittent blood sucking and secretion of saliva. Cutaneous injury caused by tick mouthparts should normally elicit wound healing, a complex biological process coordinated by interaction among different host cells, numerous signalling pathways and by a variety of soluble factors including growth factors. Growth factors, endogenous signalling proteins involved in various biological events, are key players in all phases of the skin repair process. Maintaining feeding site integrity by overcoming sequential phases of wound healing is particularly important for ixodid ticks and is governed by bioactive molecules in their saliva. Tick saliva is a complex mixture of proteins, peptides, and non-peptide molecules and its composition depends on the feeding phase, tick developmental stage, gender and/or the presence/absence of microbial agents. In addition to already demonstrated anti-haemostatic, anti-cytokine and anti-chemokine activities, anti-growth factors activities were also detected in saliva of some tick species. In consequence of counteracting host defences by ticks, tick-borne pathogens can be transmitted to and disseminated in the host. Elucidation of the complex interplay between ticks - pathogens - host cutaneous immunity could lead to improved vector and pathogens control strategies. Additionally, tick saliva bioactive molecules have a promising therapeutic perspective to cure some human diseases associated with dysregulation of specific cytokines/growth factors and alterations in their signalling pathways.

Ureases are metalloenzymes that hydrolyze urea to ammonia and carbamate. The main urease isoforms present in the seeds of Canavalia ensiformis (jack bean urease - JBU and canatoxin) exert a variety of biological activities. The insecticidal activity of JBU is mediated, at least in part, by jaburetox (Jbtx), a recombinant peptide derived from the JBU amino acid sequence. In this article, we review the neurotoxicity of Jbtx in insects. The insecticidal activity of Jbtx has been investigated in a variety of insect orders and species, including Blattodea (the cockroaches Blatella germânica, Nauphoeta cinerea, Periplaneta americana e Phoetalia pallida), Bruchidae (Callosobruchus maculatus - cowpea weevil), Diptera (Aedes aegypti - mosquito), Hemiptera (Dysdercus peruvianus - cotton stainer bug; Oncopeltus fasciatus - large milkweed bug, and the kissing bugs Rhodnius prolixus and Triatoma infestans), Lepidoptera (Spodoptera frugiperda - fall army worm) and Orthoptera (Locusta migratoria - locust). In N. cinerea, the injection of Jbtx induces marked alteration of locomotor and grooming behavior, whereas in T. infestans Jbtx causes leg paralysis, an extension of the proboscis and abnormal antennal movements. Electromyographical analysis showed that Jbtx causes complete neuromuscular blockade in P. pallida. The same treatment in N. cinerea and L. migratoria causes a decrease in the action potential firing rate. Jbtx forms membrane pore-channels compatible with cations in bilipid membranes. A study using B. germanica voltage-gated sodium (Nav1.1) channels that were heterologously expressed in Xenopus laevis oocytes correlated the entomotoxicity of Jbtx with the activation of these channels. Taken together, these findings demonstrate the potential of this peptide as a natural pesticide.

Philodryas olfersii produces similar local effects to Bothrops jararacussu snakebite, which can induce misidentification and bothropic antivenom administration. Antivenom therapy is effective, but has its limitations regarding local damage. Since plants are used in folk medicine to treat snakebite victims, we evaluated the protective properties of Cordia salicifolia and Lafoensia pacari extracts against Philodryas olfersii and Bothrops jararacussu venoms. Preparations pretreated with both extracts inhibited > 90% the B. jararacussu venom-induced neuromuscular blockade, and 52% to 81% the P. olfersii venom-induced blockade. C. salicifolia inhibited the myonecrosis promoted by both venoms; however, L. pacari prevented only the myofilaments hypercontraction. Regarding haemorrhagic activity, C. salicifolia was more effective against B. jararacussu venom, while L. pacari was more effective against P. olfersii venom. On the other hand, for oedema-forming activity the results were the opposite. Considering that both extracts prevented (to different levels) the main manifestations of both snakebites (local symptoms), we endorse further studies involving these plants as coadjuvant in snakebite therapeutics.

Venoms of viperid snakes affect mostly hemostasis, while C-type lectin-like proteins (CTLPs), one of the main components of viperid venoms, act as anticoagulants, procoagulants, or agonists/antagonists of platelet activation. However, we have shown earlier that CTLPs from the saw-scaled viper Echis multisquamatus, called emunarecins EM1 and EM2, were able to inhibit nicotinic acetylcholine receptors (nAChRs) in neurons of a pond snail (Lymnaea stagnalis). Here we analysed the structure of the emunarecins by mass spectrometry and report that EM1 and EM2 inhibit fluorescent α-bungarotoxin binding to both muscle-type nAChRs from Torpedo californica and human neuronal α7 nAChRs. EM1 at 23µM and EM2 at 9µM almost completely prevented fluorecsent α-bungarotoxin binding to muscle-type nAChRs. Interaction with human neuronal α7 nAChR was weaker; EM1 at the concentration of 23µM blocked the α-bungarotoxin binding only by about 40% and EM2 at 9µM by about 20%. The efficiency of the EM2 interaction with nAChRs was comparable to that of a non-conventional toxin, WTX, from Naja kaouthia cobra venom. Together with the data obtained earlier, these results show that CTLPs may represent new nAChR ligands.