Cytoprotective effects of creosote bush (Larrea tridentata) and Southern live oak (Quercus virginiana) extracts against toxicity induced by venom of the black-tailed rattlesnake (Crotalus ornatus).

The venom of Crotalus ornatus (vCo) poses a threat to human health, as it contains a mixture of toxins that can cause cytotoxic, necrotic, and hemolytic effects. The present study assessed methanolic and acetone extracts from leaves and flowers of Larrea tridentata, as well as the bark of Quercus virginiana as potential suppressors of the toxic effects of vCo in vitro. The content of total phenols, flavonoids, and tannins of the plant extracts were quantified for the suppression of vCo cytotoxicity in two cell culture models, human lymphocytes and porcine aortic endothelial (PAE) cells. Extracts from Q. virginiana displayed a greater concentration of total phenols, flavonoids, and tannins. Co-incubation of lymphocytes and PAE cells with fixed concentrations of vCo and plant extracts resulted in decreased vCo-induced cytotoxicity. A 24-hour co-incubation of lymphocytes with vCo (2.36 ± 0.17 µg/mL) and 0.5 µg/mL of methanolic leaf extract from L. tridentata (LLM) significantly suppressed the venom-induced cytotoxicity by 37.33 ± 8.33%. Similarly, the LLM extract (4 µg/mL) caused a significant decrease in vCo cytotoxicity after 24 hours in PAE cells. In contrast, while the acetone extract of Q. virginiana bark (QA) suppressed cytotoxicity by 29.20 ± 3.51% (p < 0.001) in lymphocytes, it failed to protect PAE cells against vCo after 24 hours. In PAE cells, a shorter 4-hour co-incubation showed significant suppression of cytotoxicity with both extracts. Our results collectively suggest that LLM and QA possess cytoprotective properties against the in vitro toxic effects of vCo, and thus establish extracts from these plants as potential therapeutic interventions against Crotalus envenomation.

Transient Receptor Potential Channel Ankyrin 1: A Unique Regulator of Vascular Function.

TRPA1 (transient receptor potential ankyrin 1), the lone member of the mammalian ankyrin TRP subfamily, is a Ca2+-permeable, non-selective cation channel. TRPA1 channels are localized to the plasma membranes of various cells types, including sensory neurons and vascular endothelial cells. The channel is endogenously activated by byproducts of reactive oxygen species, such as 4-hydroxy-2-noneal, as well as aromatic, dietary molecules including allyl isothiocyanate, a derivative of mustard oil. Several studies have implicated TRPA1 as a regulator of vascular tone that acts through distinct mechanisms. First, TRPA1 on adventitial sensory nerve fibers mediates neurogenic vasodilation by stimulating the release of the vasodilator, calcitonin gene-related peptide. Second, TRPA1 is expressed in the endothelium of the cerebral vasculature, but not in other vascular beds, and its activation results in localized Ca2+ signals that drive endothelium-dependent vasodilation. Finally, TRPA1 is functionally present on brain capillary endothelial cells, where its activation orchestrates a unique biphasic propagation mechanism that dilates upstream arterioles. This response is vital for neurovascular coupling and functional hyperemia in the brain. This review provides a brief overview of the biophysical and pharmacological properties of TRPA1 and discusses the importance of the channel in vascular control and pathophysiology.

National Estimates of Noncanine Bite and Sting Injuries Treated in US Hospital Emergency Departments, 2011-2015.

OBJECTIVES: Injuries resulting from contact with animals are a significant public health concern. This study quantifies and updates nonfatal bite and sting injuries by noncanine sources using the most recent data available (2011-2015) from the National Electronic Injury Surveillance System-All Injury Program with the purpose of using these updates to better understand public health consequences and prevention techniques. Increased rates of bites and stings can be expected in this study's time frame, possibly caused by the increasing human population expanding into animal territories, as well as changes in animal geographic distribution and pet ownership. METHODS: The National Electronic Injury Surveillance System-All Injury Program is an ongoing nationally representative surveillance system used to monitor all types and causes of injuries treated in US hospital emergency departments (EDs). Cases were coded by trained hospital coders using information from medical records on animal sources of bite and sting injuries being treated. Data from 2011-2015 were weighted to produce national annualized estimates, percentages, and rates based on the US population. RESULTS: An estimated 1.17 million people visited EDs for noncanine bite and sting injuries annually. This translates to a rate of 371.3/100,000 people. Insects accounted for 71.0% of noncanine bite and sting injuries, followed by arachnids (19.2%) and mammals (7.8%). The estimated annual total lifetime medical and work cost of unintentional noncanine injuries was $5,755,581,000. CONCLUSIONS: Various sources of bite and sting injuries had an outsized effect on injury rates and identify potential areas of focus for education and prevention programs to reduce the burden of these injuries on health and healthcare costs. The study describes the diversity of animal exposures based on a national sample of EDs. Noncanine bite and sting injuries significantly affect public health and healthcare resources. Priorities can be focused on animal sources with the most impact on bite and sting injury rates, healthcare costs, and disease burden.

Defensive behaviors and brain regional activation changes in rats confronting a snake.

In the present study, we examined behavioral and brain regional activation changes of rats). To a nonmammalian predator, a wild rattler snake (Crotalus durissus terrificus). Accordingly, during snake threat, rat subjects showed a striking and highly significant behavioral response of freezing, stretch attend, and, especially, spatial avoidance of this threat. The brain regional activation patterns for these rats were in broad outline similar to those of rats encountering other predator threats, showing Fos activation of sites in the amygdala, hypothalamus, and periaqueductal gray matter. In the amygdala, only the lateral nucleus showed significant activation, although the medial nucleus, highly responsive to olfaction, also showed higher activation. Importantly, the hypothalamus, in particular, was somewhat different, with significant Fos increases in the anterior and central parts of the ventromedial hypothalamic nucleus (VMH), in contrast to patterns of enhanced Fos expression in the dorsomedial VMH to cat predators, and in the ventrolateral VMH to an attacking conspecific. In addition, the juxtodorsalmedial region of the lateral hypothalamus showed enhanced Fos activation, where inputs from the septo-hippocampal system may suggest the potential involvement of hippocampal boundary cells in the very strong spatial avoidance of the snake and the area it occupied. Notably, these two hypothalamic paths appear to merge into the dorsomedial part of the dorsal premammillary nucleus and dorsomedial and lateral parts of the periaqueductal gray, all of which present significant increases in Fos expression and are likely to be critical for the expression of defensive behaviors in responses to the snake threat.

Iron protects porcine plasma coagulation kinetics from degradation by Crotalus atrox venom.

While the administration of antivenom to treat hemotoxic snake bite injury remains the gold standard of therapy, we have demonstrated that modifying human fibrinogen with iron and carbon monoxide renders it resistant to fibrinogenolytic snake venom enzymes. In order to translate these findings into a possible biometal-based therapy complementary to antivenom administration, a preclinical model that possesses fibrinogen that closely mimics the human molecule in response to iron and carbon monoxide needed to be identified. The goal of this investigation was to determine if a swine model could serve in this capacity by assessing the thrombelastographic response of porcine plasma to iron and carbon monoxide exposure, without or with further exposure to the fibrinogenolytic venom of the viper Crotalus atrox. Using plasma obtained from eight swine, it was determined that their plasma responded to iron and carbon monoxide in a manner similar to that of human plasma by displaying enhanced coagulation kinetics. However, in sharp contrast to the response seen with human plasma, only iron significantly protected porcine plasma coagulation kinetics from C. atrox venom degradation. Therefore the pig is an animal beyond humans that could derive benefit from the biometal-focused therapy of iron infusion to protect against venom mediated compromise of coagulation. Thus, future investigation to assess the effects of iron administration to attenuate the effects of fibrinogenolytic envenomation with a pig model is justified.

Effect of a biostimulatory homeopathic complex on venom production in captive rattlesnakes (Crotalus durissus).

The purpose of this study was to evaluate the effect of two administration methods of a biostimulatory homeopathic complex (Convert H®) on the production of fresh and lyophilized venom of rattlesnakes (Crotalus durissus) under intensive captivity conditions. Sixty snakes were subjected to treatment following a randomized block design. The effects of sex and size were controlled for. Thirteen consecutive extractions were performed over 21 months. The first factor considered in the experiment was the origin of mice used as prey: a conventional colony (A1) or the Convert H colony (A2; mice receiving the homeopathic complex in water at 1%). The type of water given to snakes was the second factor: pure (B1) or amended with 5% of Convert H® (B2). The experiment was structured in a factorial 2 × 2 design combining mouse and water types (A1B1, A1B2, A2B1, and A2B2). No consistent treatment effects on fresh venom production (mL) were observed when the experimental groups were compared with controls (A1B1). However, production of lyophilized venom (mg) was significantly higher (p < 0.05) in A2B2 animals than in controls in eight of 13 extractions performed, and also in aggregate. The results revealed that production of lyophilized venom, measured over multiple extractions, can be increased by administering the homeopathic complex simultaneously to rattlesnakes and prey.

HBO2 in snake envenomation (atrox albinus rattlesnake): a case report in a human.

A patient suffered from an envenomation that, at his hospitalization, was judged severe: Grade 3 out of 3, as defined in clinical studies for CroFab™ antidote [Crotalidae Polyvalent Immune Fab (Ovine)]. In addition to the usual antivenom treatment we applied adjunctive hyperbaric oxygen (HBO2) therapy. Our aim was to facilitate better control of the lesions, already presenting as problematic wounds and at high risk of necrotizing soft tissue infection with compartment aspects. The regimen consisted of six treatments, one daily at 2.4 atmospheres absolute at 25 minutes x3 (75 minutes) at FiO2=1, with two five-minute air breaks interposed. The therapy was well tolerated in spite of the patient's declared trait of claustrophobia. Our findings at a long-term follow up suggest that HBO2 therapy may be reasonably and effectively administered at least in the post-acute phase of such occurrences.

Expression of a new serine protease from Crotalus durissus collilineatus venom in Pichia pastoris and functional comparison with the native enzyme.

Snake venom serine proteases (SVSPs) act primarily on plasma proteins related to blood clotting and are considered promising for the treatment of several hemostatic disorders. We report the heterologous expression of a serine protease from Crotalus durissus collilineatus, named collinein-1, in Pichia pastoris, as well as the enzymatic comparative characterization of the toxin in native and recombinant forms. The complementary DNA (cDNA) encoding collinein-1 was amplified from cDNA library of C. d. collilineatus venom gland and cloned into the pPICZαA vector. The recombinant plasmid was used to transform cells of KM71H P. pastoris. Heterologous expression was induced by methanol and yielded 56 mg of recombinant collinein-1 (rCollinein-1) per liter of culture. The native collinein-1 was purified from C. d. collilineatus venom, and its identity was confirmed by amino acid sequencing. The native and recombinant enzymes showed similar effects upon bovine fibrinogen by releasing preferentially fibrinopeptide A. Although both enzymes have induced plasma coagulation, native Colinein-1 has shown higher coagulant activity. The serine proteases were able to hydrolyze the chromogenic substrates S-2222, S-2238, and S2302. Both enzymes showed high stability on different pH and temperature, and their esterase activities were inhibited in the presence of Zn2+ and Cu2+. The serine proteases showed similar k cat/K m values in enzyme kinetics assays, suggesting no significant differences in efficiency of these proteins to hydrolyze the substrate. These results demonstrated that rCollinein-1 was expressed with functional integrity on the evaluated parameters. The success in producing a functionally active recombinant SVSP may generate perspectives to their future therapeutic applications.

Anti-inflammatory potential of zootherapeutics derived from animals used in Brazilian traditional medicine.

CONTEXT: Animals are used for the treatment of diseases caused by inflammatory processes, although few studies evaluate their potential for these purposes. OBJECTIVES: To evaluate the anti-inflammatory potential of zootherapeutic products derived from vertebrates used in Brazilian traditional medicine. MATERIAL AND METHODS: The species analyzed were Tupinambis merianae, Iguana iguana, Crotalus durissus, Boa constrictor, and Euphractus sexcinctus. The methods used in anti-inflammatory assays were ear edema (topical) and paw (systemic). RESULTS: With regard to topical anti-inflammatory activity, the fat from T. merianae, C. durissus, I. iguana, B. constrictor, and E. sexcinctus reduced inflammation, while for systemic anti-inflammatory activity, only the fat and the skin of C. durissus, the skin of I. iguana and the fat from B. constrictor reduced inflammation. CONCLUSIONS: Studies should be conducted to evaluate the mechanisms of action for each product that demonstrated anti-inflammatory activity as well as against other inflammatory processes.

Acute kidney injury caused by Crotalus and Bothrops snake venom: a review of epidemiology, clinical manifestations and treatment.

Ophidic accidents are an important public health problem due to their incidence, morbidity and mortality. An increasing number of cases have been registered in Brazil in the last few years. Several studies point to the importance of knowing the clinical complications and adequate approach in these accidents. However, knowledge about the risk factors is not enough and there are an increasing number of deaths due to these accidents in Brazil. In this context, acute kidney injury (AKI) appears as one of the main causes of death and consequences for these victims, which are mainly young males working in rural areas. Snakes of the Bothrops and Crotalus genera are the main responsible for renal involvement in ophidic accidents in South America. The present study is a literature review of AKI caused by Bothrops and Crotalus snake venom regarding diverse characteristics, emphasizing the most appropriate therapeutic approach for these cases. Recent studies have been carried out searching for complementary therapies for the treatment of ophidic accidents, including the use of lipoic acid, simvastatin and allopurinol. Some plants, such as Apocynaceae, Lamiaceae and Rubiaceae seem to have a beneficial role in the treatment of this type of envenomation. Future studies will certainly find new therapeutic measures for ophidic accidents.

ACUTE KIDNEY INJURY CAUSED BY Crotalus AND Bothrops SNAKE VENOM: A REVIEW OF EPIDEMIOLOGY, CLINICAL MANIFESTATIONS AND TREATMENT / Lesão renal aguda causada pelo veneno das cobras Crotalus e Bothrops: revisão da epidemiologia, das manifestações clínicas e do tratamento

SUMMARY Ophidic accidents are an important public health problem due to their incidence, morbidity and mortality. An increasing number of cases have been registered in Brazil in the last few years. Several studies point to the importance of knowing the clinical complications and adequate approach in these accidents. However, knowledge about the risk factors is not enough and there are an increasing number of deaths due to these accidents in Brazil. In this context, acute kidney injury (AKI) appears as one of the main causes of death and consequences for these victims, which are mainly young males working in rural areas. Snakes of the Bothrops and Crotalus genera are the main responsible for renal involvement in ophidic accidents in South America. The present study is a literature review of AKI caused by Bothrops and Crotalus snake venom regarding diverse characteristics, emphasizing the most appropriate therapeutic approach for these cases. Recent studies have been carried out searching for complementary therapies for the treatment of ophidic accidents, including the use of lipoic acid, simvastatin and allopurinol. Some plants, such as Apocynaceae, Lamiaceae and Rubiaceae seem to have a beneficial role in the treatment of this type of envenomation. Future studies will certainly find new therapeutic measures for ophidic accidents. .

RESUMO Os acidentes ofídicos são importante problema de saúde pública devido à incidência, morbidade e mortalidade. Aumento do número de casos tem sido registrado no Brasil nos últimos anos. Vários estudos apontam para a importância do conhecimento das complicações clínicas e do tratamento adequado desses acidentes. Entretanto o conhecimento dos fatores de risco não é suficiente, e existe número crescente de óbitos devido a esses acidentes no Brasil. Neste contexto, a injúria renal aguda (IRA) aparece como uma das principais causas de óbito e sequela nestas vítimas, que são principalmente homens trabalhadores de zonas rurais. Os gêneros Bothrops e Crotalus são os principais responsáveis pelo envolvimento renal nos acidentes ofídicos na América do Sul. O presente estudo faz uma revisão da literatura sobre a IRA causada pela picada das serpentes dos gêneros Bothrops e Crotalus em suas diversas características, enfatizando a abordagem terapêutica mais adequada para estes casos. Estudos recentes tem sido realizados para a busca de terapias complementares para o tratamento dos acidentes ofídicos, incluindo o uso de ácido lipóico, sinvastatina e alopurinol. Algumas plantas, como a Apocynaceae, Lamiaceae e Rubiaceae parecem ter papel benéfico no tratamento destes envenenamentos. Estudos futuros irão certamente encontrar novas estratégias terapêuticas para os acidentes ofídicos. .

Prairie rattlesnake envenomation in 27 New World camelids.

BACKGROUND: Morbidity and case fatality from rattlesnake envenomation is regionally specific because of variability in relative toxicity of the species of snake encountered. A previous report of rattlesnake envenomation in New World camelids (NWC) from the western coastal United States documented high case fatality rates and guarded prognosis for survival. HYPOTHESIS/OBJECTIVES: To describe clinical findings, treatments, and outcome of NWC with prairie rattlesnake (Crotalus viridis viridis) envenomation in the Rocky Mountain region of the United States. ANIMALS: Twenty-seven NWC admitted to the Colorado State University Veterinary Teaching Hospital for evaluation of acute rattlesnake envenomation between 1992 and 2012. METHODS: Medical records of NWC evaluated for rattlesnake envenomation as coded by the attending clinician and identified by a database search were reviewed retrospectively. Month of admission, signalment, area of bite, clinical and clinicopathologic data, treatments, and outcome were recorded. RESULTS: Twenty-five llamas and 2 alpacas were admitted for envenomation. Llamas were overrepresented compared to hospital caseload. The face was the most common site of envenomation, observed in 96% of recorded cases. Presenting clinical signs included fever, tachypnea, tachycardia, and respiratory distress. Nine animals required a tracheotomy. Median hospitalization time was 3 days and overall survival rate was 69%. CONCLUSIONS AND CLINICAL IMPORTANCE: Case fatality rate for prairie rattlesnake envenomation in NWC was lower than that reported in the Western coastal region of the United States and similar to that reported for prairie rattlesnake envenomation in horses.

Anti-snake venom activities of extracts and fractions from callus cultures of Sapindus saponaria.

CONTEXT: Sapindus saponaria L. (Sapindaceae) bark, root, and fruits are used as sedatives and to treat gastric ulcer and also demonstrate diuretic and expectorant effects. OBJECTIVE: The anti-snake venom properties of callus of S. saponaria are investigated here for the first time. MATERIALS AND METHODS: In vitro cultivated callus of Sapindus saponaria were lyophilized, and the extracts were prepared with different solvents, before submitting to phytochemical studies and evaluation of the anti-ophidian activity. Crude extracts were fractionated by liquid-liquid partition and the fractions were monitored by thin layer chromatography (TLC). Subsequently, anti-ophidian activities were analyzed toward Bothrops jararacussu Lacerda (Viperidae), B. moojeni Hoge (Viperidae), B. alternates Duméril (Viperidea) and Crotalus durissus terrificus Lineu (Viperidae) venoms and isolated myotoxins and phospholipase A(2) (PLA(2)). RESULTS: Fractions A1, A2 and the extract in MeOH:H(2)O (9:1) significantly inhibited the toxic and pharmacological activities induced by snake venoms and toxins, when compared to other extracts and fractions. The lethal, clotting, phospholipase, edema-inducing, hemorrhagic and myotoxic activities were partially inhibited by the different extracts and fractions. TLC profiles of the crude extracts (B and C) and fractions (A1 and A2) showed ß-sitosterol and stigmasterol as their main compounds. Stigmasterol exhibited inhibitory effects on enzymatic and myotoxic activities of PLA(2). DISCUSSION AND CONCLUSION: Sapindus saponaria extracts and fractions presented anti-ophidian activity and could be used as an adjuvant to serum therapy or for its supplementation, and in addition, as a rich source of potential inhibitors of enzymes involved in several pathophysiological human and animal diseases.

Zootherapeutic practices in Aquismón, San Luis Potosí, México.

ETHNOPHARMACOLOGICAL IMPORTANCE: Animal derived products have been a source of medicinal compounds since ancient times. This work documents the use of animal species in traditional medicine in the municipality of Aquismón, San Luis Potosí, México. MATERIALS AND METHODS: Direct interviews were performed with inhabitants from Aquismón. The interviews were analyzed with two quantitative tools: (a) the informant consensus (ICF) that estimates the level of agreement about which animals may be used for each category and (b) the relative importance (RI) that determines the extent of potential utilization of each species. RESULTS: A total of 24 animal species used for medicinal purposes, belonging to 22 families and 4 taxonomic categories, were reported by interviewees. Nine medicinal species had not been reported in scientific literature. The results of the IFC showed that diseases of the respiratory systems had the greatest agreement. The most versatile species according to their RI are Crotalus atrox and Mephitis macroura. CONCLUSION: Further studies with medicinal fauna from Aquismón are required for the experimental validation of their traditional uses, especially with Mephitis macroura and Crotalus atrox.

Cytoplasmic ankyrin repeats of transient receptor potential A1 (TRPA1) dictate sensitivity to thermal and chemical stimuli.

Transient receptor potential (TRP) channels are polymodal signal detectors that respond to a wide array of physical and chemical stimuli, making them important components of sensory systems in both vertebrate and invertebrate organisms. Mammalian TRPA1 channels are activated by chemically reactive irritants, whereas snake and Drosophila TRPA1 orthologs are preferentially activated by heat. By comparing human and rattlesnake TRPA1 channels, we have identified two portable heat-sensitive modules within the ankyrin repeat-rich aminoterminal cytoplasmic domain of the snake ortholog. Chimeric channel studies further demonstrate that sensitivity to chemical stimuli and modulation by intracellular calcium also localize to the N-terminal ankyrin repeat-rich domain, identifying this region as an integrator of diverse physiological signals that regulate sensory neuron excitability. These findings provide a framework for understanding how restricted changes in TRPA1 sequence account for evolution of physiologically diverse channels, also identifying portable modules that specify thermosensitivity.

Hypotensive effects of the Crotalus durissus cascavella venom: involvement of NO.

Crotalus durissus cascavella is a snake native of northeastern Brazil. The aim of the study was to investigate the effects of C. d. cascavella venom on rat mean arterial pressure and vascular reactivity in the mesenteric vascular bed. The venom evoked a dose-dependent decrease in mean arterial pressure, cardiac and respiratory frequency with increased plasma nitrite levels. L-NAME (10 mg/kg) blunted both the hypotension and increased nitrite production observed after the venom administration. To investigate the effects of C. d. cascavella in resistance vessels, the vascular mesenteric bed was studied, and the results suggested that the hypotensive effect of the venom is not dependent on a direct vasodilatory activity. In conclusion, C. d. cascavella venom presented indirect hypotensive effects with the involvement of nitric oxide.

Folk medicinal use of fauna in Mapimi, Durango, México.

AIM OF THE STUDY: To document the use of animal species in traditional medicine from the municipality of Mapimi, Durango, México. MATERIALS AND METHODS: Direct interviews were performed in several short visits with inhabitants from the municipality of Mapimi, Durango. The interviews were analyzed with two quantitative tools. The informant consensus factor that estimates the level of agreement between interviewees over which animals to use for each category and the fidelity level which indicates the percentage of informants claiming the use of a certain animal species for the same medicinal purpose. RESULTS: A total of 18 animal species, belonging to 17 families and four taxonomic categories, were reported by interviewees as used for medicinal purposes. Thirteen medicinal species were identified not previously reported. The results of the informant consensus factor showed that the dermatological, diabetes and reproductive categories had the greatest agreement. The most important species according to their fidelity level are: Mephitis macroura and Crotalus atrox. CONCLUSION: This study demonstrates that many animal species play an important role in healing practices among inhabitants from Mapimi, Durango. Further experiments with medicinal fauna from Mapimi are needed to be carried out to obtain experimental information about their traditional uses, especially with C. atrox.

In vitro antiophidian properties of Dipteryx alata Vogel bark extracts.

Extracts from Dipteryx alata bark obtained with different solvents (hexane, dichloromethane, ethyl acetate and methanol) were mixed in vitro with Bothrops jararacussu (Bjssu, 40 µg/mL) and Crotalus durissus terrificus (Cdt, 15 µg/mL) snake venoms, and applied to a mouse phrenic nerve-diaphragm preparation to evaluate the possible neutralization of venom effects. Cdt venom neurotoxic effect was not inhibited by any of the extracts, while the neurotoxic and myotoxic actions of Bjssu venom were decreased by the methanolic extract. This inhibition appears to be augmented by tannins. Dichloromethane bark extract inhibited ~40% of Bjssu venom effects and delayed blockade induced by Cdt. The methodology used to determine which extract was active allows inferring that: (i) phenolic acids and flavonoids contained in the methanolic extract plus tannins were responsible mostly for neutralization of Bjssu effects; (ii) terpenoids from the dichloromethane extract may participate in the anti-Cdt and anti-Bjssu venom effects; (iii) a given extract could not inhibit venoms from different species even if those belong to the same family, so it is improper to generalize a certain plant as antiophidian; (iv) different polarity extracts do not present the same inhibitory capability, thus demonstrating the need for characterizing both venom pharmacology and the phytochemistry of medicinal plant compounds.

K+(ATP) channels-independent analgesic action of Crotalus durissus cumanensis venom.

The effect was investigated of the K+ channel blocker, glibenclamide, on the ability of Crotalus durissus cumanensis venom (CDCM) to promote peripheral antinociception. This was measured by formalin-induced nociception in male Swiss mice. CDCM (200 and 300 microg/kg) produced an antinociceptive effect during phase 2 in the formalin test. The effect of CDCM (200 microg/kg) was unaffected by the ATP-sensitive K+ channel blocker glibenclamide (2 mg/kg). These results suggest that CDCM is effective against acute pain. However, the ATP-sensitive K+ channels pathway is not contributable to the antinociceptive mechanism of CDCM.

New nanostructured silica adjuvant (SBA-15) employed to produce antivenom in young sheep using Crotalus durissus terrificus and Apis mellifera venoms detoxified by cobalt-60.

Equine antivenom is considered the only treatment for animal-generated envenomations, but it is costly. The study aimed to produce Apis mellifera (Africanized honeybee) and Crotalus durissus terrificus (C.d.t.) antivenoms using nanostructured silica (SBA-15) as adjuvant and cobalt-60 ((60)Co)-detoxified venoms utilizing young sheep. Natural and (60)Co-irradiated venoms were employed in four different hyperimmunization protocols. Thus, 8 groups of 60- to 90-d-old sheep were hyperimmunized, enzyme-linked immunosorbent assay (ELISA) serum titers collected every 14 d were assessed clinically daily, and individual weight were measured, until d 84. Incomplete Freund's (IFA) and nanostructured silica (SBA15) adjuvants were compared. The lethal dose (LD(50)) for both venoms was determined following intraperitoneal (ip) administration to mice. High-performance liquid chromatography on reversed phase (HPLC-RP) was used also to measure the (60)Co irradiation effects on Apis venom. At the end of the study, sheep were killed in a slaughterhouse. Kidneys were histologically analyzed. LD(50) was 5.97 mg/kg Apis and 0.07 mg/kg C.d.t. for native compared to 13.44 mg/kg Apis and 0.35 mg/kg C.d.t. for irradiated venoms. HPLC revealed significant differences in chromatographic profiles between native and irradiated Apis venoms. Native venom plus IFA compared with SBA-15 showed significantly higher antibody titers for both venoms. Apis-irradiated venom plus IFA or SBA-15 displayed similar antibody titers but were significantly lower when compared with native venom plus IFA. Weight gain did not differ significantly among all groups. (60)Co irradiation decreased toxicity and maintained venom immunogenic capacity, while IFA produced higher antibody titers. SBA-15 was able to act as an adjuvant without producing adverse effects. Hyperimmunization did not affect sheep weight gain, which would considerably reduce the cost of antiserum production, as these sheep were still approved for human consumption even after being subjected to hyperimmunization.