Fraction of C. d. collilineatus venom containing crotapotin protects PC12 cells against MPP + toxicity by activating the NGF-signaling pathway.

Background: Parkinson's disease (PD) is the second most prevalent neurodegenerative disease. There is no effective treatment for neurodegenerative diseases. Snake venoms are a cocktail of proteins and peptides with great therapeutic potential and might be useful in the treatment of neurodegenerative diseases. Crotapotin is the acid chain of crotoxin, the major component of Crotalus durissus collilineatus venom. PD is characterized by low levels of neurotrophins, and synaptic and axonal degeneration; therefore, neurotrophic compounds might delay the progression of PD. The neurotrophic potential of crotapotin has not been studied yet. Methods: We evaluated the neurotrophic potential of crotapotin in untreated PC12 cells, by assessing the induction of neurite outgrowth. The activation of the NGF signaling pathway was investigated through pharmacological inhibition of its main modulators. Additionally, its neuroprotective and neurorestorative effects were evaluated by assessing neurite outgrowth and cell viability in PC12 cells treated with the dopaminergic neurotoxin MPP+ (1-methyl-4-phenylpyridinium), known to induce Parkinsonism in humans and animal models. Results: Crotapotin induced neuritogenesis in PC12 cells through the NGF-signaling pathway, more specifically, by activating the NGF-selective receptor trkA, and the PI3K/Akt and the MAPK/ERK cascades, which are involved in neuronal survival and differentiation. In addition, crotapotin had no cytotoxic effect and protected PC12 cells against the inhibitory effects of MPP+ on cell viability and differentiation. Conclusion: These findings show, for the first time, that crotapotin has neurotrophic/neuroprotective/neurorestorative potential and might be beneficial in Parkinson's disease. Additional studies are necessary to evaluate the toxicity of crotapotin in other cell models.

Understanding the complexity of Tityus serrulatus venom: A focus on high molecular weight components.

Tityus serrulatus scorpion is responsible for a significant number of envenomings in Brazil, ranging from mild to severe, and in some cases, leading to fatalities. While supportive care is the primary treatment modality, moderate and severe cases require antivenom administration despite potential limitations and adverse effects. The remarkable proliferation of T. serrulatus scorpions, attributed to their biology and asexual reproduction, contributes to a high incidence of envenomation. T. serrulatus scorpion venom predominantly consists of short proteins acting as neurotoxins (α and ß), that primarily target ion channels. Nevertheless, high molecular weight compounds, including metalloproteases, serine proteases, phospholipases, and hyaluronidases, are also present in the venom. These compounds play a crucial role in envenomation, influencing the severity of symptoms and the spread of venom. This review endeavors to comprehensively understand the T. serrulatus scorpion venom by elucidating the primary high molecular weight compounds and exploring their potential contributions to envenomation. Understanding these compounds' mechanisms of action can aid in developing more effective treatments and prevention strategies, ultimately mitigating the impact of scorpion envenomation on public health in Brazil.

Sensitivity of different organs and tissues as biomarkers of oxidative stress in juvenile tambaqui (Colossoma macropomum) submitted to fasting.

The present study was conducted to evaluate the effects of fasting on responses of oxidative biomarkers and antioxidant defenses using different organs and tissues of Colossoma macropomum. The fish were divided into two groups: fed (control) and fasting (7 days). After 7 days, the fish were sampled for assessment of oxidative stress biomarkers (MDA-lipid peroxidation and PCO-protein carbonyl) and antioxidant defenses (SOD-superoxide dismutase; CAT-catalase; GPX-glutathione peroxidase; and GST-glutathione-S -transferase) in the liver, intestine, gills, muscle, brain, and plasma. The results showed an increase in MDA, PCO, SOD, and GPX concentrations in the liver and intestine of fasting fish. In contrast, in the branchial tissue, there was a reduction in the activity of SOD and CAT enzymes in fasting fish. There was also a reduction in CAT activity in the muscle of fasting fish, while in the brain, there were no changes in oxidative stress biomarkers. Plasma showed a relatively low antioxidant response. In conclusion, our results confirm that a 7-day fasting period induced tissue-specific antioxidant responses, but the increase in antioxidant responses was only for the SOD and GPX enzymes of the liver and intestine. Additionally, the liver and intestine were the most responsive tissues, whereas the plasma was the least sensitive to oxidative stress.

The complex repertoire of Tityus spp. venoms: Advances on their composition and pharmacological potential of their toxins.

Animal venoms are a rich and complex source of components, including peptides (such as neurotoxins, anionic peptides and hypotensins), lipids, proteins (such as proteases, hyaluronidases and phospholipases) and inorganic compounds, which affect all biological systems of the envenoming victim. Their action may result in a wide range of clinical manifestations, including tachy/bradycardia, hyper/hypotension, disorders in blood coagulation, pain, edema, inflammation, fever, muscle paralysis, coma and even death. Scorpions are one of the most studied venomous animals in the world and interesting bioactive molecules have been isolated and identified from their venoms over the years. Tityus spp. are among the scorpions with high number of accidents reported in the Americas, especially in Brazil. Their venoms have demonstrated interesting results in the search for novel agents with antimicrobial, anti-viral, anti-parasitic, hypotensive, immunomodulation, anti-insect, antitumor and/or antinociceptive activities. Furthermore, other recent activities still under investigation include drug delivery action, design of anti-epileptic drugs, investigation of sodium channel function, treatment of erectile disfunction and priapism, improvement of scorpion antivenom and chelating molecules activity. In this scenario, this paper focuses on reviewing advances on Tityus venom components mainly through the modern omics technologies as well as addressing potential therapeutic agents from their venoms and highlighting this abundant source of pharmacologically active molecules with biotechnological application.

Fraction of C. d. collilineatus venom containing crotapotin protects PC12 cells against MPP + toxicity by activating the NGF-signaling pathway

Abstract Background: Parkinson's disease (PD) is the second most prevalent neurodegenerative disease. There is no effective treatment for neurodegenerative diseases. Snake venoms are a cocktail of proteins and peptides with great therapeutic potential and might be useful in the treatment of neurodegenerative diseases. Crotapotin is the acid chain of crotoxin, the major component of Crotalus durissus collilineatus venom. PD is characterized by low levels of neurotrophins, and synaptic and axonal degeneration; therefore, neurotrophic compounds might delay the progression of PD. The neurotrophic potential of crotapotin has not been studied yet. Methods: We evaluated the neurotrophic potential of crotapotin in untreated PC12 cells, by assessing the induction of neurite outgrowth. The activation of the NGF signaling pathway was investigated through pharmacological inhibition of its main modulators. Additionally, its neuroprotective and neurorestorative effects were evaluated by assessing neurite outgrowth and cell viability in PC12 cells treated with the dopaminergic neurotoxin MPP+ (1-methyl-4-phenylpyridinium), known to induce Parkinsonism in humans and animal models. Results: Crotapotin induced neuritogenesis in PC12 cells through the NGF-signaling pathway, more specifically, by activating the NGF-selective receptor trkA, and the PI3K/Akt and the MAPK/ERK cascades, which are involved in neuronal survival and differentiation. In addition, crotapotin had no cytotoxic effect and protected PC12 cells against the inhibitory effects of MPP+ on cell viability and differentiation. Conclusion: These findings show, for the first time, that crotapotin has neurotrophic/neuroprotective/neurorestorative potential and might be beneficial in Parkinson's disease. Additional studies are necessary to evaluate the toxicity of crotapotin in other cell models.

Understanding the complexity of Tityus serrulatus venom: A focus on high molecular weight components

Tityus serrulatus scorpion is responsible for a significant number of envenomings in Brazil, ranging from mild to severe, and in some cases, leading to fatalities. While supportive care is the primary treatment modality, moderate and severe cases require antivenom administration despite potential limitations and adverse effects. The remarkable proliferation of T. serrulatus scorpions, attributed to their biology and asexual reproduction, contributes to a high incidence of envenomation. T. serrulatus scorpion venom predominantly consists of short proteins acting as neurotoxins (α and ß), that primarily target ion channels. Nevertheless, high molecular weight compounds, including metalloproteases, serine proteases, phospholipases, and hyaluronidases, are also present in the venom. These compounds play a crucial role in envenomation, influencing the severity of symptoms and the spread of venom. This review endeavors to comprehensively understand the T. serrulatus scorpion venom by elucidating the primary high molecular weight compounds and exploring their potential contributions to envenomation. Understanding these compounds' mechanisms of action can aid in developing more effective treatments and prevention strategies, ultimately mitigating the impact of scorpion envenomation on public health in Brazil.

The State-of-the-Art of the Humoral Memory Response to Snakebites: Insights from the Yanomami Population.

Snakebite envenomation (SBE)-induced immunity refers to individuals who have been previously bitten by a snake and developed a protective immune response against subsequent envenomations. The notion stems from observations of individuals, including in the indigenous population, who present only mild signs and symptoms after surviving multiple SBEs. Indeed, these observations have engendered scientific interest and prompted inquiries into the potential development of a protective immunity from exposure to snake toxins. This review explores the evidence of a protective immune response developing following SBE. Studies suggest that natural exposure to snake toxins can trigger protection from the severity of SBEs, mediated by specific antibodies. However, the evaluation of the immune memory response in SBE patients remains challenging. Further research is needed to elucidate the immune response dynamics and identify potential targets for therapeutic interventions. Furthermore, the estimation of the effect of previous exposures on SBE epidemiology in hyperendemic areas, such as in the indigenous villages of the Amazon region (e.g., the Yanomami population) is a matter of debate.

Beyond Angiogenesis: The Multitasking Approach of the First PEGylated Vascular Endothelial Growth Factor (CdtVEGF) from Brazilian Rattlesnake Venom.

A pioneering study regarding the isolation, biochemical evaluation, functional assays and first PEGylation report of a novel vascular endothelial growth factor from Crotalus durissus terrificus venom (CdtVEGF and PEG-CdtVEGF). CdtVEGF was isolated from crude venom using two different chromatographic steps, representing 2% of soluble venom proteins. Its primary sequence was determined using mass spectrometry analysis, and the molecule demonstrated no affinity to heparin. The Brazilian crotalid antivenom recognized CdtVEGF. Both native and PEGylated CdtVEGF were able to induce new vessel formation and migration, and to increase the metabolic activity of human umbilical endothelial vascular cells (HUVEC), resulting in better wound closure (~50% within 12 h) using the native form. CdtVEGF induced leukocyte recruitment to the peritoneal cavity in mice, with a predominance of neutrophil influx followed by lymphocytes, demonstrating the ability to activate the immune system. The molecule also induced a dose-dependent increase in vascular permeability, and PEG-CdtVEGF showed less in vivo inflammatory activity than CdtVEGF. By unraveling the intricate properties of minor components of snake venom like svVEGF, this study illuminates the indispensable significance of exploring these molecular tools to unveil physiological and pathological processes, elucidates the mechanisms of snakebite envenomings, and could possibly be used to design a therapeutic drug.

Effects of Banana (Musa spp.) Bract Flour on Rats Fed High-Calorie Diet.

Research background: The extensive cultivation of bananas (Musa sp.) is related to producing tons of residues, such as leaves, pseudostems and bracts (inflorescences). The banana bract is a commercially interesting residue due to its dietary fibre content and high antioxidant potential. With this in mind, this study evaluates the effects of administering banana bract flour in animal models fed a cafeteria diet. Experimental approach: Thirty-two male rats were divided into 4 groups: (i) control diet, (ii) control diet with 10 % banana bract flour, (iii) hypercaloric diet, and (iv) hypercaloric diet with 10 % bract banana flour. The study was conducted for 12 weeks and included analysis of phenolic compounds, assessment of the antioxidant effect of banana bract flour, determination of serum biochemical parameters (glucose, total cholesterol, triglycerides, aspartate aminotransferase (AST), alanine transaminase (ALT), amylase, albumin, uric acid, creatine, total protein, and oral glucose), determination of faecal fat content, and histomorphological analysis of the liver, pancreas and adipose tissue. In addition, molecular parameters such as IL6, total and phosphorylated JNK, total and phosphorylated IKKß, TNFα, TLR4 and HSP70 were determined. Results and conclusions: The banana bract flour showed a high content of phenolic compounds and an antioxidant effect. The in vivo results suggest that the supplementation of a hypercaloric diet with banana bract flour prevented pathological damage by reducing total cholesterol and glucose amounts, which may imply a hepatoprotective effect of this supplement. Thus, using banana bract flour as a supplement can increase the consumption of fibre, antioxidants and bioactive compounds. Novelty and scientific contribution: The development of flour from banana waste and its inclusion in the diet can prevent and/or help treat obesity. In addition, the use of banana bracts can help protect the environment, as they are considered a source of waste by the food industry.

Harnessing the Power of Venomous Animal-Derived Toxins against COVID-19.

Animal-derived venoms are complex mixtures of toxins triggering important biological effects during envenomings. Although venom-derived toxins are known for their potential of causing harm to victims, toxins can also act as pharmacological agents. During the COVID-19 pandemic, there was observed an increase in in-depth studies on antiviral agents, and since, to date, there has been no completely effective drug against the global disease. This review explores the crosstalk of animal toxins and COVID-19, aiming to map potential therapeutic agents derived from venoms (e.g., bees, snakes, scorpions, etc.) targeting COVID-19.

Incidence of the first diabetic foot ulcer: A systematic review and meta-analysis.

AIM: Investigate the incidence of the first diabetic foot ulcer. METHOD: This is a systematic review with meta-analysis of cohort studies following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and using RevMan software. A systematic search of Medline databases via PubMed, Embase, Lilacs, Scopus databases, and Web of Science was performed until July 2021. In addition to investigating the incidence of the first diabetic foot ulcer, the influence of the variables of the Human Development Index (HDI), glycated hemoglobin, and follow-up time of the participants on the incidence of the first diabetic foot ulcer (DFU) was analyzed through meta-regression. For the meta-analysis of cumulative incidence and possible variable associations, RevMan software was used in the Metaprop data package with 95% confidence interval (CI). RESULTS: A total of 9,772 articles were identified out of which 87 were selected and 12 studies ultimately included in the systematic review and meta-analysis. The meta-analysis of cumulative incidence was 5.65% (95% CI: 4.20; 7.57). By meta-regression, a significant inverse association was identified between DFU incidence and HDI (estimate - 2.38; 95% CI - 4.10--0.67; p = 0.01). CONCLUSION: The study presents the cumulative incidence for the first DFU, an inexistent datum in the national and international literature, and the HDI was inversely associated with the incidence of DFU.

A Promising Biomolecule Able to Degrade Neutrophil Extracellular Traps: CdcPDE, a Rattlesnake Phosphodiesterase.

Neutrophil extracellular traps (NETs) are an important mechanism for defense against pathogens. Their overproduction can be harmful since excessive NET formation promotes inflammation and tissue damage in several diseases. Nucleases are capable to degrade NET on basis of their DNA hydrolysis activity, including the CdcPDE, a nuclease isolated from Crotalus durissus collilineatus snake venom. Here, we report a new finding about CdcPDE activity, demonstrating its efficiency in degrading cell-free DNA from NETs, being a potential candidate to assist in therapies targeting inflammatory diseases.

The nociceptive response induced by different classes of Tityus serrulatus neurotoxins: The important role of Ts5 in venom-induced nociception.

Scorpion sting envenomations (SSE) are feared by the intense pain that they produce in victims. Pain from SSE is triggered mainly by the presence of neurotoxins in the scorpion venom that modulates voltage-gated ion channels. In Brazil, SSE is mostly caused by Tityus serrulatus, popularly known as yellow scorpion. Here, we evaluated experimental spontaneous nociception induced by T. serrulatus venom as well as its isolated neurotoxins Ts1, Ts5, Ts6, Ts8, and Ts19 frag II, evidencing different degrees of pain behavior in mice. In addition, we developed a mice-derived polyclonal antibody targeting Ts5 able to neutralize the effect of this neurotoxin, showing that Ts5 presents epitopes capable of activating the immune response, which decreased considerably the nociception produced by the whole venom. This is the pioneer study to explore nociception using different classes of T. serrulatus neurotoxins on nociception (α-NaTx, ß-NaTx, α-KTx, and ß-KTx), targeting potassium and sodium voltage-gated channels, besides demonstrating that Ts5 plays an important role in the scorpion sting induced-pain.

Evaluation of Alveolar Bone Dimensions and Root Positioning of Anterior Teeth in the Maxilla.

Buccal bone walls present significant resorption after tooth extraction, possibly related to the smaller bone thickness, length, and the sagittal position of the root, as well as the bone morphology. The goal of the present study was to measure the thickness of the cortical bone of the vestibular and palatal walls in the anterior maxilla by means of CBCT images. Measurements were taken from CBCT scans of 300 maxillary anterior teeth from 50 patients (25 women, 25 men) aged 18 to 30 years. The parameters evaluated included the thickness of the buccal and palatal cortical bone in the cervical, apical, and middle thirds of the root, as well as six specific angular measurements from each tooth. The lateral incisors showed a significant difference in thickness between each of the buccal and palatal thirds, and measurements were also significantly smaller than the central and canine incisors. Bone anatomy is tooth-and location-specific, and thus the sagittal root position within the alveolus influences the regional bone morphology and may explain the gingival zenith position in the anterior maxilla. These specific buccal and palatal anatomic parameters should be carefully taken into consideration for surgical planning and intervention in the esthetic area.

Evaluation of teaching low intensity laser in perspective dentist

Search knowledge dentist front surgeon to low intensity laser through a questionnaire. They were selected randomly in the city of Juiz de Fora and region 91 Dental Surgeons of Minas Gerais. These employees were sent during the months from July to October 2013, a standard form printed with questions about laser education assessment of low intensity. Of the 91 participants, 42 (46.2%) were female and 49 (53.8%) were male. Fifty-seven (62.6%) had dental public institution of higher education; 32 (35.2%) attended a private institution and 2 (2.2%) did not report this data. Eighty-nine dentists reported the time of graduation, and this varied with a minimum of 1 year and a maximum of 38 years of training, the average being 11 years and this is the standard deviation of 10.7. The age of these professionals is on average thirty-five years, ranging from twenty-two years to sixty-five years of age and the standard deviation of this is 10.8. The distribution according to academic title was: 35 dentists (38.5%) had a degree in dentistry; 13 (14.3%) were specialists; 14 (15.4%) had master's and 4 (4.4%) doctorate. 25 (27.5%) did not report the academic title. The most relevant mentioned specialties were general practitioner, endodontics and implantology. We can conclude that the Juiz de Fora dentist - MG and region makes little use of laser therapy and this is mainly due to little knowledge acquired at the undergraduate and graduate education.

Urgent care frequency of the assessment carried out in a School Clinic of a Dental College of Minas Gerais

To evaluate the frequency of dental emergencies and specifications, along with the patient's profile attended at the Clinical School of Dentistry, Faculty of Medical Sciences and Juiz de Fora Health (Supreme). We selected 152 medical records of clinical dental school of Juiz de Fora University Hospital - MG were selected and assessed the patient's profile and the classification of emergency cases. It was found that 57.2% of the patients were female and 42.7% male. The age of these patients is on average 44 years and the most frequent causes of visits were: dental prosthesis, endodontic and dental trauma. It can be conclude that some of the diseases found in dental emergencies are likely to be prevented or identified early on. Patients with pain are part of most attending emergency care services. In order to control the emergency care and improve the solvability, preventive actions should be developed, promoting a preventive rather than curative health.

Undetectable proviral DNA and viral RNA levels after raltegravir administration in two cats with natural feline leukemia virus infection.

Feline leukemia virus (FeLV) infection was discovered over 50 years ago; however, the serious clinical changes associated with FeLV infection still have great importance in the diagnosis, prevention, and clinical management of symptomatic patients. Progressive infection with FeLV leads to a reduction in the patient's life expectancy and quality of life. This report describes the use of an antiretroviral integrase inhibitor, raltegravir, in two cats with natural FeLV infection. Raltegravir was administered orally at a dose of 40 mg/cat every 12 h in both cases. In case one, 13 weeks after starting raltegravir, RNA loads were undetectable, while proviral DNA loads were still detectable. In case two, proviral DNA loads were undetectable after 32 weeks of medication, while RNA loads were undetectable throughout the treatment. No adverse effects or laboratory test abnormalities were detected with the use of raltegravir in either patient. The patients are currently clinically healthy, still receiving the drug, and are under close observation. To our knowledge, this is the first report describing the use of raltegravir in naturally infected FeLV-positive cats and its effects on circulating viral load. Moreover, the patients described here were followed-up for a longer period than those in previously reported cases.

A infecção pelo vírus da leucemia felina foi descoberta há mais de 50 anos, mas as graves alterações clínicas associadas à infecção pelo FeLV, ainda denotam grande importância no diagnóstico, nas medidas de prevenção e no manejo clínico de pacientes sintomáticos. A infecção progressiva pelo FeLV acarreta na redução do tempo e qualidade de vida do paciente. Este relato descreve o uso de um antirretroviral inibidor da integrase, o raltegravir, em dois gatos com infecção natural pelo FeLV. O raltegravir foi utilizado na dose de 40 mg/gato por via oral a cada 12 horas em ambos os casos. No primeiro caso após treze semanas do uso do raltegravir, a quantificação de RNA foi indetectável e no segundo caso, após trinta e duas semanas o número de cópias de DNA pró-viral foi indetectável. A carga de RNA nunca foi detectada neste paciente. Nenhum efeito adverso, nem alterações laboratoriais foram detectadas com o uso do raltegravir em ambos os casos. Atualmente, os pacientes encontram-se clinicamente saudáveis, fazem uso do antiretroviral com monitorização contínua. Este é o primeiro relato que descreve o uso do raltegravir em gatos infectados naturalmente pelo FeLV e seus efeitos na carga viral circulante. Além disso, os pacientes descritos aqui foram acompanhados por um período maior que os trabalhos anteriores descritos.

Centro de Convivência Virtual: potencialidades e desafios para a promoção da saúde e redes de afeto em tempos de pandemia / Virtual Coexistence Center: potentialities and challenges for health promotion and networks of affection in times of pandemic / Centro de Convivencia Virtual: potencialidades y desafíos para la promoción de la salud y las redes de afecto en tiempos de pandemia

A pesquisa apresentada neste artigo foi realizada com o objetivo de estudar as potencialidades e os desafios encontrados na convivência virtual para a continuidade do trabalho dos Centros de Convivência e Cultura (CECOs), que são pontos da rede de atenção psicossocial do SUS. O estudo se caracteriza como uma pesquisa-intervenção por meio da qual se investigou como a Agenda ConViver, através das 28 oficinas por ela ofertadas, pôde servir como uma ferramenta para promoção da saúde e o fortalecimento das redes de afeto no período da pandemia de covid-19 estudado. O método usado foi o grupo focal online com gestores, usuários e usuárias, oficineiros e a equipe de comunicação. Os resultados apontaram que a convivência virtual não substitui a convivência presencial, mas que, quando balizados por uma ética afetiva e relacional, é possível reduzir os danos do isolamento social e promover saúde por meio do uso da tecnologia da informação e comunicação (TIC)

The research presented in this article was carried out with the aim of studying the potentialities and challenges encountered in virtual coexistence for the continuity of the work developed by the Centros de Convivência e Cultura (CECOs), which are points of the Unified Health System (SUS) psychosocial care networking. The study is characterized as an intervention-research by means of which it was examined how the ConViver Agenda through the 28 workshops produced by it could serve as a tool for health promotion and strengthening of affection networks during the studied period of the covid-19 pandemic. The method used was the online focus group with managers, users, participants in workshops and the communication team. The results showed that the virtual coexistence cannot replace the face-to-face coexistence but that when it is guided by an affective and relational ethic it is possible to reduce the damage of social isolation and promoting health through the use of information and communication technology (ICT).

La investigación presentada en este artículo ha sido realizada con el objetivo de estudiar las potencialidades y los desafíos encontrados en la convivencia virtual para la continuidad del trabajo de los Centros de Convivência e Cultura (CECOs), que son puntos de la red de atención psicosocial del Sistema Único de Salud (SUS). El estudio se caracteriza como unainvestigación-intervención por medio de la cual se ha examinado como la Agenda ConViver a través de los 28 grupos de actividadesproducidos por ella ha podido servir como herramienta para la promoción de la salud y el fortalecimiento de las redes de afecto durante el periodo de la pandemia de covid-19 estudiado. El método utilizado fue un grupo focal online con gestores, usuarios y usuarias, participantes de los grupos de actividades, y el equipo de comunicación. Los resultados mostraron que la convivencia virtual no puede reemplazar la convivencia presencial, pero que cuando se guía por una ética afectiva y relacional es posible reducir los daños del aislamiento social y promover la salud mediante el uso de las tecnologías de la información y la comunicación (TIC)

State-of-the-art review of snake venom phosphodiesterases (svPDEs).

Phosphodiesterases (PDEs) constitute an enzyme group able to hydrolyze nucleic acids as well as some second messengers. Due to this ability and their expression in several human tissues and organs, PDEs can control a gamut of physiological processes. They are also involved in some pathological conditions, such as Alzheimer's disease and erectile dysfunction. PDEs are also expressed in snake venom glands, being called snake venoms phosphodiesterases, or simply svPDEs. The occurrence of these enzymes has already been reported in crotalid, elapid and viperid venoms, such as Crotalus, Naja and Trimeresurus, respectively, but not all of them have been characterized concerning their structure, activity and function. In this review, we are addressing general characteristics of svPDEs, in addition to their structural, biochemical and functional characteristics, and we also report some potential applications of svPDEs.