venom toxins
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Toxins ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 11
Author(s):  
Karolina Bodláková ◽  
Jan Černý ◽  
Helena Štěrbová ◽  
Roman Guráň ◽  
Ondřej Zítka ◽  
...  

Bees originally developed their stinging apparatus and venom against members of their own species from other hives or against predatory insects. Nevertheless, the biological and biochemical response of arthropods to bee venom is not well studied. Thus, in this study, the physiological responses of a model insect species (American cockroach, Periplaneta americana) to honeybee venom were investigated. Bee venom toxins elicited severe stress (LD50 = 1.063 uL venom) resulting in a significant increase in adipokinetic hormones (AKHs) in the cockroach central nervous system and haemolymph. Venom treatment induced a large destruction of muscle cell ultrastructure, especially myofibrils and sarcomeres. Interestingly, co-application of venom with cockroach Peram-CAH-II AKH eliminated this effect. Envenomation modulated the levels of carbohydrates, lipids, and proteins in the haemolymph and the activity of digestive amylases, lipases, and proteases in the midgut. Bee venom significantly reduced vitellogenin levels in females. Dopamine and glutathione (GSH and GSSG) insignificantly increased after venom treatment. However, dopamine levels significantly increased after Peram-CAH-II application and after co-application with bee venom, while GSH and GSSG levels immediately increased after co-application. The results suggest a general reaction of the cockroach body to bee venom and at least a partial involvement of AKHs.


2021 ◽  
Vol 01 ◽  
Author(s):  
Soodeh Omidi ◽  
Masoumeh Mehrpouya ◽  
Morteza Oladnabi ◽  
Abbas Azadmehr ◽  
Fatemeh Kazemi-Lomedasht ◽  
...  

: Venom toxins have specific molecular targets that result in envenomated complications such as neurotoxicity. During evolution, the composition of the venom has been evolved synchronously with the evolution of molecular targets. Venom is an important tool for humans from two different perspectives; venom advantages and disadvantages. Meanwhile, clinical and pharmacological applications of venoms due to their specific targeting and modulation of physiological elements or targets are notable in various disorders. The better understanding of venoms and their composition will improve the practical applications of some toxin-based drugs in drugstoresin the future.


2021 ◽  
Author(s):  
Stefanie K. Menzies ◽  
Charlotte A. Dawson ◽  
Edouard Crittenden ◽  
Rebecca Edge ◽  
Steven R. Hall ◽  
...  

Abstract Antivenom is currently the first-choice treatment for snakebite envenoming. However, only a low proportion of antivenom immunoglobulins are specific to venom toxins, resulting in poor dose efficacy and potency. We sought to investigate whether linear venom epitopes displayed on virus like particles can stimulate a robust and focused antibody response capable of recognising venom toxins from diverse medically important species. Bioinformatically-designed epitopes, corresponding to predicted conserved regions of group I phospholipase A2 and three finger toxins, were engineered for display on the surface of hepatitis B core antigen virus like particles and used to immunise female CD1 mice over a 14-weeks. Antibody responses to all venom epitope virus like particles were detectable by ELISA by the end of the immunisation period, although total antibody and epitope specific antibody titres were variable against the different epitope immunogens. Immunoblots using pooled sera demonstrated recognition of various venom components in a diverse panel of six elapid venoms, representing three continents and four genera. Finally, pooled terminal sera was compared to conventional antivenom via quantitative immunoblot, and demonstrated superior recognition of lower-molecular weight elapid venom toxins. This study demonstrates proof-of-principle that virus like particles engineered to display conserved toxin linear epitopes can elicit specific antibody responses in mice which are able to recognise a geographically broad range of elapid venoms.


Author(s):  
SIMRAN SHARMA ◽  
RAVI KANT UPADHYAY!

Present review article explains ant venom components and its allergic and biological effects in man and animals. Red ants or small fire ants secrete and inject venom very swiftly to defend their nest against predators, microbial pathogens, and competitors and to hunt the prey. Ant venom is a mixture of various organic compounds, including peptides, enzymes, and polypeptide toxins. It is highly toxic, allergic, invasive and venomous. It imposes sever paralytic, cytolytic, haemolytic, allergenic, pro-inflammatory, insecticidal, antimicrobial, and pain-producing pharmacologic activities after infliction. Victims show red ring-shaped allergic sign with regional swelling marked with intense pain. Ant venom also contains several hydrolases, oxidoreductases, proteases, Kunitz-like polypeptides, and inhibitor cysteine knot (ICK)-like (knottin) neurotoxins and insect defensins. Ant venom toxins/proteins generate allergic immune responses and employ eosinophils and produce Th2 cytokines, response. These compounds from ant venom could be used as a potential source of new anticonvulsants molecules. Ant venoms contain many small, linear peptides, an untapped source of bioactive peptide toxins. The remarkable insecticidal activity of ant venom could be used as a promising source of additional bio-insecticides and therapeutic agents.


Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 548
Author(s):  
Hong-Yan Zhao ◽  
Yan Sun ◽  
Yu Du ◽  
Jia-Qi Li ◽  
Jin-Geng Lv ◽  
...  

Given that the venom system in sea snakes has a role in enhancing their secondary adaption to the marine environment, it follows that elucidating the diversity and function of venom toxins will help to understand the adaptive radiation of sea snakes. We performed proteomic and de novo NGS analyses to explore the diversity of venom toxins in the annulated sea snake (Hydrophis cyanocinctus) and estimated the adaptive molecular evolution of the toxin-coding unigenes and the toxicity of the major components. We found three-finger toxins (3-FTxs), phospholipase A2 (PLA2) and cysteine-rich secretory protein (CRISP) in the venom proteome and 59 toxin-coding unigenes belonging to 24 protein families in the venom-gland transcriptome; 3-FTx and PLA2 were the most abundant families. Nearly half of the toxin-coding unigenes had undergone positive selection. The short- (i.p. 0.09 μg/g) and long-chain neurotoxin (i.p. 0.14 μg/g) presented fairly high toxicity, whereas both basic and acidic PLA2s expressed low toxicity. The toxicity of H. cyanocinctus venom was largely determined by the 3-FTxs. Our data show the venom is used by H. cyanocinctus as a biochemically simple but genetically complex weapon and venom evolution in H. cyanocinctus is presumably driven by natural selection to deal with fast-moving prey and enemies in the marine environment.


2021 ◽  
Vol 8 ◽  
Author(s):  
Luiza Helena Gremski ◽  
Fernando Hitomi Matsubara ◽  
Nayanne Louise Costacurta Polli ◽  
Bruno Cesar Antunes ◽  
Pedro Henrique de Caires Schluga ◽  
...  

Brown spider (genus Loxosceles) venoms are mainly composed of protein toxins used for predation and defense. Bites of these spiders most commonly produce a local dermonecrotic lesion with gravitational spread, edema and hemorrhage, which together are defined as cutaneous loxoscelism. Systemic loxoscelism, such as hematological abnormalities and renal injury, are less frequent but more lethal. Some Loxosceles venom toxins have already been isolated and extensively studied, such as phospholipases D (PLDs), which have been recombinantly expressed and were proven to reproduce toxic activities associated to the whole venom. PLDs have a notable potential to be engineered and converted in non-toxic antigens to produce a new generation of antivenoms or vaccines. PLDs also can serve as tools to discover inhibitors to be used as therapeutic agents. Other Loxosceles toxins have been identified and functionally characterized, such as hyaluronidases, allergen factor, serpin, TCTP and knottins (ICK peptides). All these toxins were produced as recombinant molecules and are biologically active molecules that can be used as tools for the potential development of chemical candidates to tackle many medical and biological threats, acting, for instance, as antitumoral, insecticides, analgesic, antigens for allergy tests and biochemical reagents for cell studies. In addition, these recombinant toxins may be useful to develop a rational therapy for loxoscelism. This review summarizes the main candidates for the development of drugs and biotechnological inputs that have been described in Brown spider venoms.


Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 302
Author(s):  
Taline D. Kazandjian ◽  
Arif Arrahman ◽  
Kristina B. M. Still ◽  
Govert W. Somsen ◽  
Freek J. Vonk ◽  
...  

Bites from elapid snakes typically result in neurotoxic symptoms in snakebite victims. Neurotoxins are, therefore, often the focus of research relating to understanding the pathogenesis of elapid bites. However, recent evidence suggests that some elapid snake venoms contain anticoagulant toxins which may help neurotoxic components spread more rapidly. This study examines the effects of venom from the West African black-necked spitting cobra (Naja nigricollis) on blood coagulation and identifies potential coagulopathic toxins. An integrated RPLC-MS methodology, coupled with nanofractionation, was first used to separate venom components, followed by MS, proteomics and coagulopathic bioassays. Coagulation assays were performed on both crude and nanofractionated N. nigricollis venom toxins as well as PLA2s and 3FTx purified from the venom. Assays were then repeated with the addition of either the phospholipase A2 inhibitor varespladib or the snake venom metalloproteinase inhibitor marimastat to assess whether either toxin inhibitor is capable of neutralizing coagulopathic venom activity. Subsequent proteomic analysis was performed on nanofractionated bioactive venom toxins using tryptic digestion followed by nanoLC-MS/MS measurements, which were then identified using Swiss-Prot and species-specific database searches. Varespladib, but not marimastat, was found to significantly reduce the anticoagulant activity of N. nigricollis venom and MS and proteomics analyses confirmed that the anticoagulant venom components mostly consisted of PLA2 proteins. We, therefore, conclude that PLA2s are the most likely candidates responsible for anticoagulant effects stimulated by N. nigricollis venom.


Author(s):  
Ana F. Gómez Garay ◽  
Jorge J. Alfonso ◽  
Anderson M. Kayano ◽  
Juliana C. Sobrinho ◽  
Cleopatra A. S. Caldeira ◽  
...  
Keyword(s):  

2021 ◽  
Vol 15 (3) ◽  
pp. e0009242
Author(s):  
Subramanian Senthilkumaran ◽  
Harry F. Williams ◽  
Ketan Patel ◽  
Steven A. Trim ◽  
Ponniah Thirumalaikolundusubramanian ◽  
...  

Following a bite from a juvenile Russell’s viper (Daboia russelii), a priapism (painful erection) developed rapidly in a 16-year-old male and only subsided after administration of antivenom 3 hours later. Potential mechanisms for this snakebite-induced priapism are unclear but likely due to venom toxins causing nitric oxide (NO) release and subsequent vasodilation of endothelium in the corpus cavernosum, although the possible involvement of other mechanisms cannot be ruled out. We strongly believe that this unusual case report may lead to further scientific research in order to improve the clinical understanding of the pathophysiology of envenomation due to Russell’s viper bites. Although it is too early to speculate, further research may also discover the possibilities of developing venom-based candidate molecules to treat sexual dysfunction in males and females.


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