Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
Add more filters










Publication year range
1.
Environ Monit Assess ; 195(2): 261, 2023 Jan 04.
Article in English | MEDLINE | ID: mdl-36598707

ABSTRACT

Coastal zones support the most productive marine ecosystems, yet they are increasingly threatened by anthropogenic stressors such as dredging. In this study, we investigated how seasonal variation and dredging activities conducted during the construction of a harbor and submarine base (Sepetiba Bay, RJ, Brazil) affected the phytoplankton and zooplankton assemblages. The observed temporal variability at five different sites over 10 years revealed that dredging exceeds the expected influence of dry and rainy seasons on plankton abundance and diversity. In general, the abundance of both groups increased during dredging due to the resuspension of nutrients and benthic organisms. This increase was particularly evident in the dinoflagellate Scrippsiellaa cuminata, the diatoms Thalassiosira rotula and Nitzschia longissima, and the herbivorous zooplankton Acartia clausii and Pseudevadne tergestina. Moreover, season and dredging activities synergistically influenced plankton assemblages, resulting in larger seasonal variations during dredging activities. After the end of the harbor construction, plankton abundance decreased and remained low until the end of the monitoring, which may indicate persistent changes in the biodiversity and ecosystem functioning of impacted areas.


Subject(s)
Diatoms , Plankton , Animals , Seasons , Ecosystem , Environmental Monitoring , Phytoplankton , Zooplankton
2.
Int J Clin Pharm ; 44(1): 118-126, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34498216

ABSTRACT

Background Clinical activities provided by pharmacists are increasing worldwide, including in Europe. However, an overview of clinical pharmacy education and practice is needed. Aim To map clinical pharmacy (CP) education and practice among European countries. Method A cross-sectional web-based survey led by the Education Committee of the European Society of Clinical Pharmacy (ESCP) was conducted. The survey comprised three domains focusing on: undergraduate education, postgraduate education, and practice. A multi-phased validation process was undertaken, attributing levels of evidence according to the number of information sources for each country. Triangulation was used to seek within country consensus. Main outcome measures included the number of hours of education in CP; existence of a specialization in CP and activities delivered in practice. Results Data from 40 European countries were included (response rate 95.2%). Most respondents (86.8%) agreed with the ESCP definition of CP. Almost every country (94.9%) reported CP topics at the undergraduate level [median number = 65 h/semester (IQR: 2.0-5.6)], including practical teaching [median = 30.0% (IQR: 17.0-42.0)]. At postgraduate level, 92.5% of countries reported PhD programmes including CP and 65.0% mentioned the existence of specific CP master/diploma degrees. Continuous professional development (CPD) courses were also reported by 63.9% of respondents. More than half the countries (52.5%; n = 21) recognized CP as an area of specialization, which for 60.0% of participants was applied solely in the hospital setting. Conclusion Although CP is embedded in education and practice in European countries, there is wide variability in education and practice patterns.


Subject(s)
Education, Pharmacy , Pharmacy Service, Hospital , Cross-Sectional Studies , Europe , Humans , Pharmacists , Surveys and Questionnaires
3.
Antibiotics (Basel) ; 10(11)2021 Nov 01.
Article in English | MEDLINE | ID: mdl-34827270

ABSTRACT

The present study aimed to characterize the extended-spectrum ß-lactamases and plasmid-mediated AmpC ß-lactamases (ESBL/PMAß) among Escherichia coli producers isolated from beef, pork, and poultry meat collected at retail, in Portugal. A total of 638 meat samples were collected and inoculated on selective medium for the search of E. coli resistant to 3rd generation cephalosporins. Isolates were characterized by antimicrobial susceptibility testing, molecular assays targeting ESBL/AmpC, plasmid-mediated quinolone resistance (PMQR), and plasmid-mediated colistin resistance (PMCR) encoding genes. The highest frequency of E. coli non-wild type to 3rd generation cephalosporins and fluoroquinolones was observed in broiler meat (30.3% and 93.3%, respectively). Overall, a diversity of acquired resistance mechanisms, were detected: blaESBL [blaCTX-M-1 (n = 19), blaCTX-M-15 (n = 4), blaCTX-M-32 (n = 12), blaCTX-M-55 (n = 8), blaCTX-M-65 (n = 4), blaCTX-M-27 (n = 2), blaCTX-M-9 (n = 1), blaCTX-M-14 (n = 11), blaSHV-12 (n = 27), blaTEM-52 (n = 1)], blaPMAß [blaCMY-2 (n = 8)], PMQR [qnrB (n = 27), qnrS (n = 21) and aac(6')-Ib-type (n = 4)] and PMCR [mcr-1 (n = 8)]. Our study highlights that consumers may be exposed through the food chain to multidrug-resistant E. coli carrying diverse plasmid-mediated antimicrobial resistance genes, posing a great hazard to food safety and a public health risk.

4.
Front Microbiol ; 12: 653595, 2021.
Article in English | MEDLINE | ID: mdl-34354678

ABSTRACT

The emergence and dissemination of resistance to third- and fourth-generation cephalosporins among Enterobacteriaceae from different sources impose a global public health threat. Here, we characterized by whole-genome sequencing four Escherichia coli strains harboring the bla CTX-M-65 gene identified among 49 isolates from beef and pork collected at retail. The genomic content was determined using the Center for Genomic Epidemiology web tools. Additionally, the prediction and reconstruction of plasmids were conducted, the genetic platform of the bla CTX-M-65 genes was investigated, and phylogenetic analysis was carried out using 17 other genomes with the same sequence type and harboring the bla CTX-M-65 gene. All strains harbored bla CTX-M-65, bla OXA-1, and bla TEM-1B, and one also carried the bla SHV-12 gene. Other resistance genes, namely, qnrS2, aac(6')-Ib-c, dfrA14, sul2, tetA, and mphA, were present in all the genomes; the mcr-1.1 gene was identified in the colistin-resistant strains. They belong to sequence type 2179, phylogenetic group B1, and serotype O9:H9 and carried plasmids IncI, IncFIC(FII), and IncFIB. All strains share an identical genetic environment with IS903 and ISEcp1 flanking the bla CTX-M-65 gene. It seems likely that the bla CTX-M-65 gene is located in the chromosome in all isolates based on deep in silico analysis. Our findings showed that the strains are clonally related and belong to two sub-lineages. This study reports the emergence of CTX-M-65-producing E. coli in Portugal in food products of animal origin. The chromosomal location of the bla CTX-M-65 gene may ensure a stable spread of resistance in the absence of selective pressure.

5.
J Sport Rehabil ; 29(6): 851-854, 2020 Aug 01.
Article in English | MEDLINE | ID: mdl-32028258

ABSTRACT

Trunk-flexor muscle strength plays a fundamental role in athletic performance, but objective measurements are usually obtained using expensive and nonportable equipment, such as isokinetic dynamometers. The aim of this study was to assess the concurrent validity of a portable, one-dimensional, trunk-flexor muscle strength measurement system (Measurement System) that uses calibrated barbells and the reliability of the measurements obtained using the Measurement System, by conducting test-retests. As a complementary assessment, the measurements obtained during a maximum contraction test performed by a group of 15 subjects were also recorded. Four conditions were assessed: repeatability, time reproducibility, position reproducibility, and subject reproducibility. The results demonstrate that both the concurrent validity and the measured reliability (intraclass correlation coefficient > .98) of the Measurement System are acceptable. The Measurement System provides valid and reliable measures of trunk-flexor muscle strength.


Subject(s)
Abdominal Muscles/physiology , Equipment Design , Muscle Strength Dynamometer/standards , Muscle Strength/physiology , Torso/physiology , Humans , Reproducibility of Results
6.
Article in English | MEDLINE | ID: mdl-30181737

ABSTRACT

BACKGROUND: Cnidarians produce toxins, which are composed of different polypeptides that induce pharmacological effects of biotechnological interest, such as antitumor, antiophidic and anti-clotting activities. This study aimed to evaluate toxicological activities and potential as antitumor and antiophidic agents contained in total extracts from five cnidarians: Millepora alcicornis, Stichodactyla helianthus, Plexaura homomalla, Bartholomea annulata and Condylactis gigantea (total and body wall). METHODS: The cnidarian extracts were evaluated by electrophoresis and for their phospholipase, proteolytic, hemorrhagic, coagulant, fibrinogenolytic, neuromuscular blocking, muscle-damaging, edema-inducing and cytotoxic activities. RESULTS: All cnidarian extracts showed indirect hemolytic activity, but only S. helianthus induced direct hemolysis and neurotoxic effect. However, the hydrolysis of NBD-PC, a PLA2 substrate, was presented only by the C. gigantea (body wall) and S. helianthus. The extracts from P. homomalla and S. helianthus induced edema, while only C. gigantea and S. helianthus showed intensified myotoxic activity. The proteolytic activity upon casein and fibrinogen was presented mainly by B. annulata extract and all were unable to induce hemorrhage or fibrinogen coagulation. Cnidarian extracts were able to neutralize clotting induced by Bothrops jararacussu snake venom, except M. alcicornis. All cnidarian extracts were able to inhibit hemorrhagic activity induced by Bothrops moojeni venom. Only the C. gigantea (body wall) inhibited thrombin-induced coagulation. All cnidarian extracts showed antitumor effect against Jurkat cells, of which C. gigantea (body wall) and S. helianthus were the most active; however, only C. gigantea (body wall) and M. alcicornis were active against B16F10 cells. CONCLUSION: The cnidarian extracts analyzed showed relevant in vitro inhibitory potential over the activities induced by Bothrops venoms; these results may contribute to elucidate the possible mechanisms of interaction between cnidarian extracts and snake venoms.

7.
Int J Biol Macromol ; 107(Pt A): 1014-1022, 2018 Feb.
Article in English | MEDLINE | ID: mdl-28951306

ABSTRACT

Phospholipases A2 (PLA2s) are important enzymes present in snake venoms and are related to a wide spectrum of pharmacological effects, however the toxic potential and therapeutic effects of acidic isoforms have not been fully explored and understood. Due to this, the present study describes the isolation and biochemical characterization of two new acidic Asp49-PLA2s from Bothrops brazili snake venom, named Braziliase-I and Braziliase-II. The venom was fractionated in three chromatographic steps: ion exchange, hydrophobic interaction and reversed phase. The isoelectric point (pI) of the isolated PLA2s was determined by two-dimensional electrophoresis, and 5.2 and 5.3 pIs for Braziliase-I and II were observed, respectively. The molecular mass was determined with values ​​of 13,894 and 13,869Da for Braziliase-I and II, respectively. Amino acid sequence by Edman degradation and mass spectrometry completed 87% and 74% of the sequences, respectively for Braziliase-I and II. Molecular modeling of isolated PLA2s using acid PLA2BthA-I-PLA2 from B. jararacussu template showed high quality. Both acidic PLA2s showed no significant myotoxic activity, however they induced significant oedematogenic activity. Braziliase-I and II (100µg/mL) showed 31.5% and 33.2% of cytotoxicity on Trypanosoma cruzi and 26.2% and 19.2% on Leishmania infantum, respectively. Braziliase-I and II (10µg) inhibited 96.98% and 87.98% of platelet aggregation induced by ADP and 66.94% and 49% induced by collagen, respectively. The acidic PLA2s biochemical and structural characterization can lead to a better understanding of its pharmacological effects and functional roles in snakebites pathophysiology, as well as its possible biotechnological applications as research probes and drug leads.


Subject(s)
Phospholipases A2/chemistry , Platelet Aggregation Inhibitors/chemistry , Platelet Aggregation/drug effects , Snake Venoms/chemistry , Amino Acid Sequence/genetics , Animals , Bothrops/genetics , Leishmania infantum/drug effects , Leishmania infantum/pathogenicity , Models, Molecular , Phospholipases A2/genetics , Phospholipases A2/isolation & purification , Phospholipases A2/pharmacology , Platelet Aggregation Inhibitors/isolation & purification , Platelet Aggregation Inhibitors/pharmacology , Sequence Homology, Amino Acid , Trypanosoma cruzi/drug effects , Trypanosoma cruzi/pathogenicity
8.
J. venom. anim. toxins incl. trop. dis ; 24: 22, 2018. ilus, graf
Article in English | LILACS | ID: biblio-954854

ABSTRACT

Cnidarians produce toxins, which are composed of different polypeptides that induce pharmacological effects of biotechnological interest, such as antitumor, antiophidic and anti-clotting activities. This study aimed to evaluate toxicological activities and potential as antitumor and antiophidic agents contained in total extracts from five cnidarians: Millepora alcicornis, Stichodactyla helianthus, Plexaura homomalla, Bartholomea annulata and Condylactis gigantea (total and body wall). Methods: The cnidarian extracts were evaluated by electrophoresis and for their phospholipase, proteolytic, hemorrhagic, coagulant, fibrinogenolytic, neuromuscular blocking, muscle-damaging, edema-inducing and cytotoxic activities. Results: All cnidarian extracts showed indirect hemolytic activity, but only S. helianthus induced direct hemolysis and neurotoxic effect. However, the hydrolysis of NBD-PC, a PLA2 substrate, was presented only by the C gigantea (body wall) and S. helianthus. The extracts from P. homomalla and S. helianthus induced edema, while only C gigantea and S. helianthus showed intensified myotoxic activity. The proteolytic activity upon casein and fibrinogen was presented mainly by B. annulata extract and all were unable to induce hemorrhage or fibrinogen coagulation. Cnidarian extracts were able to neutralize clotting induced by Bothrops jararacussu snake venom, except M. alcicornis. All cnidarian extracts were able to inhibit hemorrhagic activity induced by Bothrops moojeni venom. Only the C. gigantea (body wall) inhibited thrombin-induced coagulation. All cnidarian extracts showed antitumor effect against Jurkat cells, of which C. gigantea (body wall) and S. helianthus were the most active; however, only C. gigantea (body wall) and M. alcicornis were active against B16F10 cells. Conclusion: The cnidarian extracts analyzed showed relevant in vitro inhibitory potential over the activities induced by Bothrops venoms; these results may contribute to elucidate the possible mechanisms of interaction between cnidarian extracts and snake venoms.(AU)


Subject(s)
Animals , Male , Rats , Antivenins/toxicity , Cnidarian Venoms/pharmacology , Crotalid Venoms/immunology , Bothrops , Neoplasms/immunology
9.
J. venom. anim. toxins incl. trop. dis ; 24: 1-11, 2018. ilus, tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1484757

ABSTRACT

Background: Cnidarians produce toxins, which are composed of different polypeptides that induce pharmacological effects of biotechnological interest, such as antitumor, antiophidic and anti-clotting activities. This study aimed to evaluate toxicological activities and potential as antitumor and antiophidic agents contained in total extracts from five cnidarians: Millepora alcicornis, Stichodactyla helianthus, Plexaura homomalla, Bartholomea annulata and Condylactis gigantea (total and body wall). Methods: The cnidarian extracts were evaluated by electrophoresis and for their phospholipase, proteolytic, hemorrhagic, coagulant, fibrinogenolytic, neuromuscular blocking, muscle-damaging, edema-inducing and cytotoxic activities. Results: All cnidarian extracts showed indirect hemolytic activity, but only S. helianthus induced direct hemolysis and neurotoxic effect. However, the hydrolysis of NBD-PC, a PLA2 substrate, was presented only by the C gigantea (body wall) and S. helianthus. The extracts from P. homomalla and S. helianthus induced edema, while only C gigantea and S. helianthus showed intensified myotoxic activity. The proteolytic activity upon casein and fibrinogen was presented mainly by B. annulata extract and all were unable to induce hemorrhage or fibrinogen coagulation. Cnidarian extracts were able to neutralize clotting induced by Bothrops jararacussu snake venom, except M. alcicornis. All cnidarian extracts were able to inhibit hemorrhagic activity induced by Bothrops moojeni venom. Only the C. gigantea (body wall) inhibited thrombin-induced coagulation. All cnidarian extracts showed antitumor effect against Jurkat cells, of which C. gigantea (body wall) and S. helianthus were the most active; however, only C. gigantea (body wall) and M. alcicornis were active against B16F10 cells...


Subject(s)
Animals , Bioprospecting , Drug Screening Assays, Antitumor , Cnidarian Venoms/pharmacology , Cnidaria , Caribbean Region
10.
Med Chem ; 12(8): 733-741, 2016.
Article in English | MEDLINE | ID: mdl-27140186

ABSTRACT

Cardiovascular diseases, such as thrombosis and stroke, represent the major cause of disability and death worldwide; and dysfunctions in platelet aggregation and blood coagulation processes are involved. The regular antithrombotic drugs have unsatisfactory results and may produce side effects. Therefore, alternative therapies have been extensively investigated. OBJECTIVE: The anticoagulant and antiplatelet aggregation potential of a series of six synthetic 1,2,3-triazole derivatives were investigated through in vitro models. METHODS: Coagulation tests included the prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) assays, and were performed on a multichannel coagulometer, using human plasma. The platelet aggregation assays were carried out using human platelet-rich-plasma (PRP). Aggregation was initiated by adding ADP or collagen and monitored turbidimetrically on a Whole Blood Aggregometer. Toxicity of derivatives was evaluated on platelets and red blood cells, by measuring the release of lactate dehydrogenase and hemoglobin, respectively. Moreover, theoretical toxicity of derivatives was calculated using the software Osiris® Property Explorer. RESULTS: All the six derivatives tested inhibited, but with different potencies, the plasma coagulation assessed by the PT and TT assays, and also inhibited platelet aggregation of PRP induced by collagen or ADP. The derivatives did not interfere in the aPTT assay and did not affect the viability of platelets or red blood cells. Theoretical studies also revealed that all derivatives will likely to have low toxicity, great pharmacological and oral bioavailability profiles, and a Druglikeness and Drug score similar to some commercial anticoagulant and antiplatelet drugs. CONCLUSION: 1,2,3-triazoles are potential candidates for molecular modeling of new antithrombotic drugs.


Subject(s)
Anticoagulants/pharmacology , Platelet Aggregation Inhibitors/pharmacology , Triazoles/pharmacology , Anticoagulants/chemical synthesis , Anticoagulants/toxicity , Blood Platelets/cytology , Blood Platelets/drug effects , Cell Survival/drug effects , Computer Simulation , Erythrocytes/cytology , Erythrocytes/drug effects , Humans , Partial Thromboplastin Time , Platelet Aggregation Inhibitors/chemical synthesis , Platelet Aggregation Inhibitors/toxicity , Prothrombin Time , Triazoles/chemical synthesis , Triazoles/toxicity
11.
Article in English | MEDLINE | ID: mdl-26827743

ABSTRACT

Snake venom toxins are related not only in detention, death and the promotion of initial digestion of prey but also due to their different biochemical, structural and pharmacological effects they can result in new drugs. Among these toxins snake venom serine proteases (SVSPs) should be highlighted because they are responsible for inducing changes in physiological functions such as blood coagulation, fibrinolysis, and platelet aggregation. This article presents the first serine protease (SP) isolated from Bothrops brazili: BbrzSP-32. The new SP showed 36 kDa of relative molecular mass and its absolute mass was confirmed by mass spectrometry as 32,520 Da. It presents 79.48% identity when compared to other SVSPs and was able to degrade the α-chain of fibrinogen, in in vitro models, because of this it is considered a SVTLE-A. It showed dose-dependent activity in the process of degradation of fibrin networks demonstrating greater specificity for this activity when compared to its thrombolytic action. BbrzSP-32 demonstrated proteolytic activity on gelatin and chromogenic substrates for serine proteases and thrombin-like enzymes (S-2288 and S-2238 respectively), besides having coagulant activity on human plasma. After pre-incubation with PMSF and benzamidine the coagulant and proteolytic activities on the S-2288 and S-2238 substrates were reduced. BbrzSP-32 shows stability against pH and temperature variations, demonstrating optimum activity between 30 and 40 °C and in the pH range 7.5 to 8.5. A new SP with potential biotechnological application was isolated.


Subject(s)
Crotalid Venoms/chemistry , Serine Proteases/isolation & purification , Amino Acid Sequence , Animals , Bothrops , Molecular Sequence Data , Sequence Homology, Amino Acid , Serine Proteases/chemistry
12.
Mar Drugs ; 12(5): 2471-84, 2014 Apr 30.
Article in English | MEDLINE | ID: mdl-24796305

ABSTRACT

Cardiovascular diseases represent a major cause of disability and death worldwide. Therapeutics are available, but they often have unsatisfactory results and may produce side effects. Alternative treatments based on the use of natural products have been extensively investigated, because of their low toxicity and side effects. Marine organisms are prime candidates for such products, as they are sources of numerous and complex substances with ecological and pharmacological effects. In this work, we investigated, through in vitro experiments, the effects of three diterpenes (pachydictyol A, isopachydictyol A and dichotomanol) from the Brazilian marine alga, Dictyota menstrualis, on platelet aggregation and plasma coagulation. Results showed that dichotomanol inhibited ADP- or collagen-induced aggregation of platelet-rich plasma (PRP), but failed to inhibit washed platelets (WP). In contrast, pachydictyol A and isopachydictyol A failed to inhibit the aggregation of PRP, but inhibited WP aggregation induced by collagen or thrombin. These diterpenes also inhibited coagulation analyzed by the prothrombin time and activated partial thromboplastin time and on commercial fibrinogen. Moreover, diterpenes inhibited the catalytic activity of thrombin. Theoretical studies using the Osiris Property Explorer software showed that diterpenes have low theoretical toxicity profiles and a drug-score similar to commercial anticoagulant drugs. In conclusion, these diterpenes are promising candidates for use in anticoagulant therapy, and this study also highlights the biotechnological potential of oceans and the importance of bioprospecting to develop medicines.


Subject(s)
Anticoagulants/pharmacology , Diterpenes/pharmacology , Phaeophyceae/chemistry , Platelet Aggregation Inhibitors/pharmacology , Anticoagulants/isolation & purification , Blood Coagulation/drug effects , Collagen/pharmacology , Diterpenes/chemistry , Diterpenes/isolation & purification , Humans , Hydrolysis , In Vitro Techniques , Platelet Aggregation/drug effects , Platelet Aggregation Inhibitors/isolation & purification , Thrombin/pharmacology
13.
Biomed Res Int ; 2014: 195356, 2014.
Article in English | MEDLINE | ID: mdl-24724078

ABSTRACT

Bothrops mattogrossensis snake is widely distributed throughout eastern South America and is responsible for snakebites in this region. This paper reports the purification and biochemical characterization of three new phospholipases A2 (PLA2s), one of which is presumably an enzymatically active Asp49 and two are very likely enzymatically inactive Lys49 PLA2 homologues. The purification was obtained after two chromatographic steps on ion exchange and reverse phase column. The 2D SDS-PAGE analysis revealed that the proteins have pI values around 10, are each made of a single chain, and have molecular masses near 13 kDa, which was confirmed by MALDI-TOF mass spectrometry. The N-terminal similarity analysis of the sequences showed that the proteins are highly homologous with other Lys49 and Asp49 PLA2s from Bothrops species. The PLA2s isolated were named BmatTX-I (Lys49 PLA2-like), BmatTX-II (Lys49 PLA2-like), and BmatTX-III (Asp49 PLA2). The PLA2s induced cytokine release from mouse neutrophils and showed cytotoxicity towards JURKAT (leukemia T) and SK-BR-3 (breast adenocarcinoma) cell lines and promastigote forms of Leishmania amazonensis. The structural and functional elucidation of snake venoms components may contribute to a better understanding of the mechanism of action of these proteins during envenomation and their potential pharmacological and therapeutic applications.


Subject(s)
Bothrops/metabolism , Leishmania/drug effects , Mycotoxins/chemistry , Mycotoxins/pharmacology , Neoplasms, Experimental/drug therapy , Snake Venoms/chemistry , Snake Venoms/pharmacology , Animals , Cell Line, Tumor , Cell Survival/drug effects , Male , Mice , Mycotoxins/isolation & purification , Neoplasms, Experimental/pathology , Snake Venoms/isolation & purification , Survival Rate , Treatment Outcome
14.
Biomed Res Int ; 2013: 294289, 2013.
Article in English | MEDLINE | ID: mdl-23710441

ABSTRACT

Snake venoms are complex mixtures of proteins of both enzymes and nonenzymes, which are responsible for producing several biological effects. Human envenomation by snake bites particularly those of the viperid family induces a complex pathophysiological picture characterized by spectacular changes in hemostasis and frequently hemorrhage is also seen. The present work reports the ability of six of a series of 1,2,3-triazole derivatives to inhibit some pharmacological effects caused by the venoms of Bothrops jararaca and Lachesis muta. In vitro assays showed that these compounds were impaired in a concentration-dependent manner, the fibrinogen or plasma clotting, hemolysis, and proteolysis produced by both venoms. Moreover, these compounds inhibited biological effects in vivo as well. Mice treated with these compounds were fully protected from hemorrhagic lesions caused by such venoms. But, only the B. jararaca edema-inducing activity was neutralized by the triazoles. So the inhibitory effect of triazoles derivatives against some in vitro and in vivo biological assays of snake venoms points to promising aspects that may indicate them as molecular models to improve the production of effective antivenom or to complement antivenom neutralization, especially the local pathological effects, which are partially neutralized by antivenoms.


Subject(s)
Bothrops , Snake Venoms/antagonists & inhibitors , Triazoles/administration & dosage , Viperidae , Animals , Antivenins/administration & dosage , Antivenins/chemistry , Blood Coagulation/drug effects , Humans , Mice , Snake Bites/drug therapy , Triazoles/chemistry
15.
Biochimie ; 94(12): 2545-58, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22819993

ABSTRACT

This study reports the isolation and biochemical characterization of two different serine proteases from Bothrops pirajai snake venom, thus providing a comparative analysis of the enzymes. The isolation process consisted of three consecutive chromatographic steps (Sephacryl S-200, Benzamidine Sepharose and C2/C18), resulting in two serine proteases, named BpirSP27 and BpirSP41 after their molecular masses by mass spectrometry (27,121 and 40,639 Da, respectively). Estimation by SDS-PAGE under denaturing conditions showed that, when deglycosylated with PNGase F, BpirSP27 and BpirSP41 had their molecular masses reduced by approximately 15 and 42%, respectively. Both are acidic enzymes, with pI of approximately 4.7 for BpirSP27 and 3.7 for BpirSP41, and their N-terminal amino acid sequences showed 57% identity to each other, with high similarity to the sequences of other snake venom serine proteases (SVSPs). The enzymes showed different actions on bovine fibrinogen, with BpirSP27 acting preferentially on the Bß chain and BpirSP41 on both Aα and Bß chains. The two serine proteases were also able to degrade fibrin and blood clots in vitro depending on the doses and incubation periods, with higher results for BpirSP41. Both enzymes coagulated the human plasma in a dose-dependent manner, and BpirSP41 showed a higher coagulant potential, with minimum coagulant dose (MCD) of ∼3.5 µg versus 20 µg for BpirSP27. The enzymes were capable of hydrolyzing different chromogenic substrates, including S-2238 for thrombin-like enzymes, but only BpirSP27 acted on the substrate S-2251 for plasmin. They also showed high stability against variations of temperature and pH, but their activities were significantly reduced after preincubation with Cu(2+) ion and specific serine protease inhibitors. In addition, BpirSP27 induced aggregation of washed platelets to a greater extent than BpirSP41. The results showed significant structural and functional differences between B. pirajai serine proteases, providing interesting insights into the structure-function relationship of SVSPs.


Subject(s)
Bothrops/metabolism , Isoenzymes/metabolism , Serine Proteases/metabolism , Snake Venoms/enzymology , Adult , Amino Acid Sequence , Animals , Biocatalysis , Blood Coagulation/drug effects , Bothrops/genetics , Cattle , Dipeptides/metabolism , Electrophoresis, Polyacrylamide Gel , Enzyme Stability , Female , Fibrinolysis/drug effects , Humans , Isoelectric Focusing , Isoenzymes/chemistry , Isoenzymes/genetics , Male , Molecular Sequence Data , Molecular Weight , Platelet Aggregation/drug effects , Sequence Homology, Amino Acid , Serine Proteases/chemistry , Serine Proteases/genetics , Snake Venoms/pharmacology , Substrate Specificity , Temperature , Young Adult
16.
Mar Drugs ; 9(8): 1346-1358, 2011.
Article in English | MEDLINE | ID: mdl-21892349

ABSTRACT

The ischemic disorders, in which platelet aggregation and blood coagulation are involved, represent a major cause of disability and death worldwide. The antithrombotic therapy has unsatisfactory performance and may produce side effects. So, there is a need to seek molecules with antithrombotic properties. Marine organisms produce substances with different well defined ecological functions. Moreover, some of these molecules also exhibit pharmacological properties such as antiviral, anticancer, antiophidic and anticoagulant properties. The aim of this study was to evaluate, through in vitro tests, the effect of two extracts of brown algae and ten marine sponges from Brazil on platelet aggregation and blood coagulation. Our results revealed that most of the extracts were capable of inhibiting platelet aggregation and clotting measured by plasma recalcification tests, prothrombin time, activated partial thromboplastin time, and fibrinogenolytic activity. On the other hand, five of ten species of sponges induced platelet aggregation. Thus, the marine organisms studied here may have molecules with antithrombotic properties, presenting biotechnological potential to antithrombotic therapy. Further chemical investigation should be conducted on the active species to discover useful molecules for the development of new drugs to treat clotting disorders.


Subject(s)
Anticoagulants/chemistry , Anticoagulants/pharmacology , Phaeophyceae/chemistry , Platelet Aggregation Inhibitors/chemistry , Platelet Aggregation Inhibitors/pharmacology , Porifera/chemistry , Animals , Blood Coagulation/drug effects , Brazil , Fibrinolytic Agents/chemistry , Fibrinolytic Agents/pharmacology , Humans , Platelet Aggregation/drug effects , Prothrombin Time
17.
J Thromb Thrombolysis ; 31(2): 235-40, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21210185

ABSTRACT

Marine brown algae of the family Dictyotaceae are rich sources of monocyclic, bicyclic, and tricyclic diterpenes. These molecules are responsible for a wide range of pharmacological and ecological functions, as antitumor and antiviral. Here, we analyzed the effect of the dolastane diterpene (4R, 9S, 14S)-4α-Acetoxy-9ß,14α-dihydroxydolast-1(15),7-diene, isolated from the marine brown alga, Canistrocarpus cervicornis on blood clotting and platelet aggregation. The dolastane diterpene was able to inhibit either plasma or fibrinogen coagulation induced by thrombin as well as delayed coagulation in the recalcification test. The dolastane diterpene impaired, in a concentration-dependent manner platelet aggregation induced by collagen or adenosine diphosphate with no lysis on such cells. Thus, the dolastane diterpene maybe a promising source of natural inhibitors for hemostatic disturbs (clotting and platelet aggregation) leading to the discovery of drugs of potential use as antithrombotic and antiplatelet. In addition, the dolastane diterpene may be used as a molecular model for development of new antithrombotic agents giving new approaches to the management to the treatment of thrombotic disturbs.


Subject(s)
Anticoagulants , Blood Coagulation/drug effects , Diterpenes , Phaeophyceae/chemistry , Platelet Aggregation Inhibitors , Platelet Aggregation/drug effects , Anticoagulants/chemistry , Anticoagulants/pharmacology , Diterpenes/chemistry , Diterpenes/pharmacology , Humans , Platelet Aggregation Inhibitors/chemistry , Platelet Aggregation Inhibitors/pharmacology
18.
Biomed Pharmacother ; 2010 Oct 23.
Article in English | MEDLINE | ID: mdl-21131161

ABSTRACT

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.bionut.2011.06.021. The duplicate article has therefore been withdrawn.

19.
Bioorg Med Chem ; 17(21): 7429-34, 2009 Nov 01.
Article in English | MEDLINE | ID: mdl-19815419

ABSTRACT

The current treatment used against envenomation by Lachesis muta venom still presents several side effects. This paper describes the synthesis, pharmacological and theoretical evaluations of new 1-arylsulfonylamino-5-methyl-1H-[1,2,3]-triazole-4-carboxylic acid ethyl esters (8a-f) tested against the hemolytic profile of the L. muta snake venom. Their structures were elucidated by one- and two-dimensional NMR techniques ((1)H, APT, HETCOR (1)J(CH) and (n)J(CH), n=2, 3) and high-resolution electrospray ionization mass spectrometry. The series of triazole derivatives significantly neutralized the hemolysis induced by L. muta crude venom presenting a dose-dependent inhibitory profile (IC(50)=30-83 microM) with 1-(4'-chlorophenylsulfonylamino)-5-methyl-1H-[1,2,3]-triazole-4-carboxylic acid ethyl ester (8e) being the most potent compound. The theoretical evaluation revealed the correlation of the antiophidian profile with the coefficient distribution and density map of the Highest Occupied Molecular Orbitals (HOMO) of these molecules. The elucidation of this new series may help on designing new and more efficient antiophidian molecules.


Subject(s)
Crotalid Venoms/toxicity , Triazoles/chemical synthesis , Viperidae/metabolism , Animals , Esters/chemistry , Hemolysis , Humans , Magnetic Resonance Spectroscopy , Rabbits , Spectrometry, Mass, Electrospray Ionization , Structure-Activity Relationship , Thermodynamics , Triazoles/chemistry , Triazoles/pharmacology
20.
Nat Prod Commun ; 4(8): 1075-8, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19768986

ABSTRACT

The aim of this work was to investigate the hemolysis and blood clotting activity of Lomonia obliqua venom and the ability of some Brazilian marine algal extracts (Canistrocarpus cervicornis, Stypopodium zonale and Dictyota pfaffi) to antagonize such biological activities. L. obliqua caterpillars are dangerous to human beings and envenomation symptoms are characterized by hemorrhagic, hemolytic and blood clotting disorders, and acute renal failure, which sometimes lead to the death of the victims. Through in vitro experiments we have shown that L. obliqua venom is able to clot human plasma and hemolize human erythrocytes and that the coagulation activity of the venom is inhibited by the extracts of C. cervicornis, S. zonale and D. pfaffi. In contrast, C. cervicornis and S. zonale extracts did not inhibit the hemolytic activity of L. oblqua, as did the extract of D. pfaffi. These finding indicate that marine algae may be used as antivenoms or may contribute to the development of compounds with antilonomic effects.


Subject(s)
Phaeophyceae/chemistry , Seaweed/chemistry , Venoms/toxicity , Acute Kidney Injury/chemically induced , Animals , Blood Coagulation Disorders/chemically induced , Brazil , Erythrocytes/drug effects , Hemolysis/drug effects , Humans , Larva , Moths/chemistry , Moths/growth & development , Venoms/isolation & purification
SELECTION OF CITATIONS
SEARCH DETAIL
...