Pharmacological screening of mucus produced by the pacamã fish, Lophiosilurus alexandri / Triagem farmacológica de muco produzido pelo pacamã, Lophiosilurus alexandri

Recently, fish byproducts have been appraised as a source of structurally diverse bioactive compounds. In this context, fish mucus has revealed a myriad of pharmacological activities. This study describes a new bioactive molecule release system composed of protein nanoparticles from pacamã (Lophiosilurus alexandri) mucus, an endemic fish to the São Francisco River (Brazil). The process of obtaining and applying these nanoparticles, composed of proteins present in the pacamã mucus, as biocompatible carriers of bioactive molecules is also addressed herein. Therefore, the external mucus of the fish was collected, lyophilized and hydrated in deionized water containing the template molecule. After pH adjustment to 7.5, followed by sonication and centrifugation, the formed nanoparticles were collected in the supernatant. Additionally, the mucus and the particles were characterized, and pharmacological effects were evaluated regarding their antifungal, antibacterial, anticancer, anti or pro-inflammatory and antinociceptive proprieties. NP-Mucus did not exhibit antibacterial activity against Pseudomonas aeruginosa or Staphylococcus aureus. However, it showed potential effects against Candida albicans with a minimum inhibitory concentration (MIC) of 1 µg/mL, and significant pro-inflammatory role, reflected by cellular recruitment activity and healing effects. Therefore, future studies are now needed in order to identify specific compounds in NP-mucus responsible for the observed effects in order to provide new pharmacological and therapeutic strategies.(AU)

Recentemente, os subprodutos de peixes foram avaliados como uma fonte de compostos bioativos estruturalmente diversos. Nesse contexto, o muco dos peixes revelou uma miríade de atividades farmacológicas. Este estudo descreve um novo sistema de liberação de moléculas bioativas compostas por nanopartículas de proteínas do muco do pacamã (Lophiosilurus alexandri), um peixe do Rio São Francisco (Brasil). O processo de obtenção e aplicação dessas nanopartículas, compostas por proteínas presentes no muco do pacamã, como carreadores biocompatíveis de moléculas bioativas também são abordados neste artigo. Para tanto, o muco externo dos peixes foi coletado, liofilizado e hidratado em água deionizada contendo a molécula template. Após ajuste do pH para 7,5, seguido de sonicação e centrifugação, as nanopartículas formadas foram coletadas no sobrenadante. Adicionalmente, foram caracterizados o muco e as partículas, sendo avaliados os efeitos farmacológicos quanto às propriedades antifúngicas, antibacterianas, anticancerígenas, anti ou pró-inflamatórias e antinociceptivas. NP-Mucus não exibiu atividade antibacteriana contra Pseudomonas aeruginosa ou Staphylococcus aureus. No entanto, apresentou efeitos potenciais contra Candida albicans com concentração inibitória mínima (MIC) de 1 µg/mL, além de importante papel próinflamatório, refletido pela atividade de recrutamento celular e efeitos cicatrizantes. Portanto, estudos são necessários para identificar compostos no NP-muco responsáveis pelos efeitos observados, a fim de fornecer novas estratégias farmacológicas e terapêuticas.(AU)

Pharmacological screening of mucus produced by the pacamã fish, Lophiosilurus alexandri / Triagem farmacológica de muco produzido pelo pacamã, Lophiosilurus alexandri

Recently, fish byproducts have been appraised as a source of structurally diverse bioactive compounds. In this context, fish mucus has revealed a myriad of pharmacological activities. This study describes a new bioactive molecule release system composed of protein nanoparticles from pacamã (Lophiosilurus alexandri) mucus, an endemic fish to the São Francisco River (Brazil). The process of obtaining and applying these nanoparticles, composed of proteins present in the pacamã mucus, as biocompatible carriers of bioactive molecules is also addressed herein. Therefore, the external mucus of the fish was collected, lyophilized and hydrated in deionized water containing the template molecule. After pH adjustment to 7.5, followed by sonication and centrifugation, the formed nanoparticles were collected in the supernatant. Additionally, the mucus and the particles were characterized, and pharmacological effects were evaluated regarding their antifungal, antibacterial, anticancer, anti or pro-inflammatory and antinociceptive proprieties. NP-Mucus did not exhibit antibacterial activity against Pseudomonas aeruginosa or Staphylococcus aureus. However, it showed potential effects against Candida albicans with a minimum inhibitory concentration (MIC) of 1 µg/mL, and significant pro-inflammatory role, reflected by cellular recruitment activity and healing effects. Therefore, future studies are now needed in order to identify specific compounds in NP-mucus responsible for the observed effects in order to provide new pharmacological and therapeutic strategies.

Recentemente, os subprodutos de peixes foram avaliados como uma fonte de compostos bioativos estruturalmente diversos. Nesse contexto, o muco dos peixes revelou uma miríade de atividades farmacológicas. Este estudo descreve um novo sistema de liberação de moléculas bioativas compostas por nanopartículas de proteínas do muco do pacamã (Lophiosilurus alexandri), um peixe do Rio São Francisco (Brasil). O processo de obtenção e aplicação dessas nanopartículas, compostas por proteínas presentes no muco do pacamã, como carreadores biocompatíveis de moléculas bioativas também são abordados neste artigo. Para tanto, o muco externo dos peixes foi coletado, liofilizado e hidratado em água deionizada contendo a molécula template. Após ajuste do pH para 7,5, seguido de sonicação e centrifugação, as nanopartículas formadas foram coletadas no sobrenadante. Adicionalmente, foram caracterizados o muco e as partículas, sendo avaliados os efeitos farmacológicos quanto às propriedades antifúngicas, antibacterianas, anticancerígenas, anti ou pró-inflamatórias e antinociceptivas. NP-Mucus não exibiu atividade antibacteriana contra Pseudomonas aeruginosa ou Staphylococcus aureus. No entanto, apresentou efeitos potenciais contra Candida albicans com concentração inibitória mínima (MIC) de 1 µg/mL, além de importante papel próinflamatório, refletido pela atividade de recrutamento celular e efeitos cicatrizantes. Portanto, estudos são necessários para identificar compostos no NP-muco responsáveis pelos efeitos observados, a fim de fornecer novas estratégias farmacológicas e terapêuticas.

PHARMACOLOGICAL SCREENING OF MUCUS PRODUCED BY THE PACAMÃ FISH, Lophiosilurus alexandri

Recently, fish byproducts have been appraised as a source of structurally diverse bioactive compounds. In this context, fish mucus has revealed a myriad of pharmacological activities. This study describes a new bioactive molecule release system composed of protein nanoparticles from pacamã (Lophiosilurus alexandri) mucus, an endemic fish to the São Francisco River (Brazil). The process of obtaining and applying these nanoparticles, composed of proteins present in the pacamã mucus, as biocompatible carriers of bioactive molecules is also addressed herein. Therefore, the external mucus of the fish was collected, lyophilized and hydrated in deionized water containing the template molecule. After pH adjustment to 7.5, followed by sonication and centrifugation, the formed nanoparticles were collected in the supernatant. Additionally, the mucus and the particles were characterized, and pharmacological effects were evaluated regarding their antifungal, antibacterial, anticancer, anti or pro-inflammatory and antinociceptive proprieties. NP-Mucus did not exhibit antibacterial activity against Pseudomonas aeruginosa or Staphylococcus aureus. However, it showed potential effects against Candida albicans with a minimum inhibitory concentration (MIC) of 1 µg/mL, and significant pro-inflammatory role, reflected by cellular recruitment activity and healing effects. Therefore, future studies a

Antinociception induced by artemisinin nanocapsule in a model of postoperative pain via spinal TLR4 inhibition.

Artemisinin (ART) was initially described for the control of inflammation and pain. However, the mechanisms involved with its antinociceptive effect are still poorly understood. Thus, this present study aimed to investigate the effect of ART in both free and nanocapsulated form on postoperative pain, as well as the participation of the spinal Toll-like receptor 4 (TLR4) in this process. Postoperative pain was induced using the skin/muscle incision retraction (SMIR) model in male Swiss mice. After 3 and 28 days of SMIR, the animals received an intrathecal injection of free or nanocapsulated ART, and the nociceptive threshold was evaluated by von Frey filament test. To evaluate the involvement of the microglia, astrocytes, and TLR4, minocycline (a microglia inhibitor), fluorocitrate (an astrocyte inhibitor), and Lipopolysaccharide Rhodobacter sphaeroides (LPS-RS), a TLR4 antagonist, were intrathecally injected on the third day of SMIR. The levels of spinal TLR4 protein and proinflammatory cytokines tumor necrosis factor-alpha (TNF-α), and interleukin-1-beta (IL-1ß) were quantified by western blot and enzyme-linked immunosorbent assay, respectively. The results showed that free ART reduced postoperative pain (P < 0.001, F5,30 = 7.49, 16.66% for 1000 ng dose; and P < 0.01, F5,30 = 7.49, 14.58% for 500 ng dose) on the 3rd day of SMIR; while the ART nanocapsule had this effect on both the third (P < 0.001; F5,30 = 4.94; 43.75, 39.58 and 72.91% for the 250, 500 and 1000 ng doses, respectively) and 28th (P < 0.05; F5,30 = 7.71; 29.16 and 33.33% for the 500 and 1000 ng doses, respectively) day. The ART nanocapsule had a more potent and longer antinociceptive effect than free ART or morphine. Postoperative pain was also reduced by minocycline and LPS-RS. The ART nanocapsule also reduced the increased levels of TLR4, TNF-α, and IL-1ß induced by SMIR. These data suggest that the ART nanocapsule has a potent analgesic effect on postoperative pain at the spinal level, and this response involves the inhibition of TLR4 and the proinflammatory cytokines TNF-α and IL-1ß.

Preparação e caracterização inicial de complexo de inclusão entre nitrofurazona e 2-hidroxipropil-Beta-ciclodextrina / Preparation and initial characterization of inclusion complex between nitrofurazone and 2-hydroxypropyl-Beta-cyclodextrin

Nitrofurazona(NF), 5-nitro-2-furaldeído semicarbazona, é um antibiótico de amplo espectro, que apresenta diversos efeitos tóxicos e baixa solubilidade aquosa. A complexação da NF com ciclodextrinas é de grande interesse para o desenvolvimento de uma formulação para este antibiótico que seja mais segura e eficiente. Neste trabalho foi realizada a preparação e caracterização inicial do complexo de inclusão entre NF e hidroxipropil-Beta-ciclodextrina (HP-Beta-CD) através de experimentos para determinação da cinética de complexação, medidas de fotoestabilidade, medidas de constante de afinidade fármaco: ciclodextrina, ensaios de liberação in vitro, estequiometria de formação do complexo e morfologia do complexo por microscopia eletrônica de varredura. Os ensaios de cinética de complexação mostram que para o complexo atingir o equilíbrio são necessárias 17,3h. As isotermas de solubilidade determinadas para a NF em função da temperatura mostraram perfis do tipo A e B indicando que a temperatura é um fator importante na complexação da NF com ciclodextrina. Os experimentos de fotoestabilidade indicam que a inserção da molécula de NF na cavidade interna da ciclodextrina protege o fármaco da fotodecomposição. A cinética de liberação mostra que o perfil de liberação do fármaco é modificado pela presença da ciclodextrina no meio. A estequiometria de complexação entre NF e HP-Beta-CD determinada foi de 1:1 NF:HP-Beta-CD. Os resultados demicroscopia eletrônica de varredura indicam alterações na estrutura cristalina da NF em presença deciclodextrina. Este estudo está baseado na caracterização físico-química da complexação entre NF e HP-Beta-CD podendo ser uma nova potencial opção para utilização terapêutica do NF.

Nitrofurazone (NF), 5-nitro-2-furaldehyde semicarbazone, a broad-spectrum antibiotic, has reported toxic effects and low solubility in water. It would be of great interest to form inclusion complexes between NF and a cyclodextrin, to develop more effective and safer antibiotic formulations. This paper focuses on the preparation of inclusion complexes of NF with 2- hydroxypropyl- -cyclodextrin (HP- -CD) and their initial characterization by evaluating rates of complex formation, photostability, solubility isotherms, release rate profiles, stoichiometry of the complexes and their morphology, as revealed by scanning electron microscopy. The kinetic tests of complex formation revealed that 17,3 h is enough for stabilization of the NFcyclodextrin complex. The solubility isotherm studies showed that the isotherm changes from type A to type B, as a function of temperature. The photostability experiments showed that the insertion of the NF in the HP- -CD cavity protects the drug from photodecomposition. The release kinetic tests showed that the profile of NF release from the complex is altered by the presence of HP- -CD in the medium. A Job's plot indicated that the stoichiometry of the complex was 1:1 NF:HP- -CD. The scanning electron micrographs showed changes in the crystal structure of NF in the complex. This study focused on the physicochemical properties of drug-delivery formulations that could potentially be developed into a novel type of therapy with NF.

Interação de anestésicos locais com lipossomos determinada por espectroscopia de infravermelho / Interaction between local anesthetic and liposomes determined by infrared spectroscopy

Neste trabalho foram investigados os efeitos de dois anestésicos locais, lidocaína e benzocaína, sobre as propriedades estruturais e dinâmicas de vesículas unilamelares de fosfatidilcolina de ovo em pH 7,4 e 10,5 para determinar a localização preferencial destes anestésicos no interior da bicamada.Mudanças na organização de vesículas unilamelares pequenas foram determinadas através de espectroscopia de infravermelho com transformada de Fourier.Os experimentos de infravermelho mostraram que os anestésicos locais alteram as ligações de hidrogênio das moléculas de água monitoradas através das regiões da cadeia acila, grupamento fosfato e carbonilas da região do glicerol dos fosfolipídios.Os efeitos do aumento da concentração dos anestésicos locais nestas regiões mostraram que a lidocaína ionizada torna maior o acesso de moléculas de água nas regiões do grupamento de fosfato e carbonilas da região do glicerol.Para a lidocaína neutra (pH 10,5) o principal efeito observado foi na região do glicerol.Já para o anestésico local benzocaína foi observada uma diminuição do acesso de moléculas de água na região das carbonilas do glicerol.Um modelo proposto indica que a lidocaína ionizada e a neutra ligam-se aos lipídios próximos ao grupamento fosfato e região do glicerol.Para a benzocaína a localização preferencial proposta foi a região do glicerol e os primeiros carbonos da cadeia acila.A posição preferencial dos anestésicos nas membranas fosfolipídicas modelo pode modular o acesso destas moléculas em seus sítios de ligação na proteína canal de sódio voltagem-dependente.

Inclusion complex of S(-) bupivacaine and 2-hydroxypropyl-beta-cyclodextrin: study of morphology and cytotoxicity

Local anesthetics (LA) belong to a class of pharmacological compounds that attenuate or eliminate pain by binding to the sodium channel of excitable membranes, blocking the influx of sodium ions and the propagation of the nerve impulse. S (-) bupivacaine (S(-)bvc) is a local anesthetic of amino-amide type, widely used in surgery and obstetrics for sustained peripheraland central nerve blockade. This article focuses on the characterization of an inclusion complex of S(-) bvc in2-hydroxypropyl- beta-cyclodextrin (HP-beta -CD). Differential scanning calorimetry, scanning electron microscopy andX-Ray diffraction analysis showed structural changes inthe complex. In preliminary toxicity studies, the cellviability tests revealed that the inclusion complex decreased the toxic effect (p smaller that 0.001) produced by S(-) bvc.These results suggest that the S(-) bvc:HP- beta-CD inclusion complex represents a promising agent for the treatment of regional pain.

Interaction of benzocaine with model membranes.

We measured the absorption properties, water solubility and partition coefficients (P) between n-octanol, egg phosphatidylcholine (EPC) liposomes and erythrocyte ghosts/water for benzocaine (BZC), an ester-type always uncharged local anesthetic. The interaction of BZC with EPC liposomes was followed using Electron Paramagnetic Resonance, with spin labels at different positions in the acyl chain (5, 7, 12, 16-doxylstearic acid methyl ester). Changes in lipid organization upon BZC addition allowed the determination of P values, without phase separation. The effect of BZC in decreasing membrane organization (maximum of 11.6% at approx. 0.8:1 BZC:EPC) was compared to those caused by the local anesthetics tetracaine and lidocaine. Hemolytic tests revealed a biphasic (protective/inductive) concentration-dependent hemolytic effect for BZC upon rat erythrocytes, with an effective BZC:lipid molar ratio in the membrane for protection (RePROT), onset of hemolysis (ReSAT) and 100% membrane solubilization (ReSOL) of 1.0:1, 1.1:1 and 1.3:1, respectively. The results presented here reinforce the importance of considering hydrophobic interactions in the interpretation of the effects of anesthetics on membranes.