Atividade in vitro de extratos e frações de Copernicia prunifera (Arecaceae) contra bactérias de importância clínica em saúde pública / In vitro activity of extracts and fractions of Copernicia prunifera (Arecaceae) against bacteria of clinical importance in public health / Actividad in vitro de extractos y fracciones de Copernicia prunifera (Arecaceae) frente a bacterias de importancia clínica en salud pública

Introdução: O aumento contínuo da resistência bacteriana aos antibióticos convencionais é um problema de importância global. Encontrar produtos como alternativas terapêuticas naturais é essencial. As plantas medicinais possuem uma composição química muito rica, que podem ser estruturalmente otimizadas e processadas em novos antimicrobianos. Objetivo: Avaliar o potencial antibacteriano frente a microrganismos humanos potencialmente patogênicos do extrato etanólico e frações de Copernicia prunifera. Metodologia: A triagem fitoquímica de plantas foi realizada usando métodos de precipitação e coloração e a atividade antibacteriana utilizando o método de difusão em disco e microdiluição em caldo contra cepas padronizadas de Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa e Staphylococcus aureus. Resultados: A triagem fitoquímica revela a presença de taninos, flavonoides, esteroides, triterpernóides, saponinas e alcaloides. Os extratos etanólico e frações da casca do caule e folhas tiveram atividade inibitória contra S. aureus e K. pneumonie com zona de inibição que variou de 7,0±1,73 a 9,33±0,58 mm pelo método de difusão em disco. Pelo método de microdiluição em caldo os extratos foram satisfatórios somente contra K. pneumoniae (CIM = 125 a 1000 µg/mL) S. aureus, P. aeruginosa e E. coli se mostraram resistentes aos testes (CIM > 1000 µg/mL). Conclusão: Esses resultados fornecem uma base para futuras investigações em modelos in vivo, para que os compostos de C. prunifera possam ser aplicados no desenvolvimento de novos agentes antimicrobianos contra K. pneumoniae.

Introduction: The continuous increase in bacterial resistance to conventional antibiotics is a problem of global importance. Finding products as natural therapeutic alternatives is essential. Medicinal plants have a very rich chemical composition, which can be structurally optimized and processed into novel antimicrobials. Objective: To evaluate the antibacterial potential against potentially pathogenic human microorganisms of the ethanolic extract and fractions of Copernicia prunifera. Methodology: Phytochemical screening of plants was performed using precipitation and staining methods and antibacterial activity using the disk diffusion and broth microdilution method against standardized strains of Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Results: Phytochemical screening reveals the presence of tannins, flavonoids, steroids, triterpernoids, saponins and alkaloids. The ethanolic extracts and fractions of stem bark and leaves had inhibitory activity against S. aureus and K. pneumonie with zone of inhibition ranging from 7.0±1.73 to 9.33±0.58 mm by disc diffusion method. By broth microdilution method the extracts were satisfactory only against K. pneumoniae (MIC = 125 to 1000 µg/mL) S. aureus, P. aeruginosa and E. coli were resistant to the tests (MIC > 1000 µg/mL). Conclusion: These results provide a basis for further investigation in in vivo models, so that compounds from C. prunifera can be applied in the development of new antimicrobial agents against K. pneumoniae.

Introducción: El continuo aumento de la resistencia bacteriana a los antibióticos convencionales es un problema de importancia mundial. Es esencial encontrar productos como alternativas terapéuticas naturales. Las plantas medicinales tienen una composición química muy rica, que puede optimizarse estructuralmente y transformarse en nuevos antimicrobianos. Objetivo: Evaluar el potencial antibacteriano frente a microorganismos humanos potencialmente patógenos del extracto etanólico y fracciones de Copernicia prunifera. Metodología: Se realizó el cribado fitoquímico de las plantas mediante los métodos de precipitación y tinción y la actividad antibacteriana mediante el método de difusión en disco y microdilución en caldo frente a cepas estandarizadas de Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa y Staphylococcus aureus. Resultados: El cribado fitoquímico revela la presencia de taninos, flavonoides, esteroides, triterpernoides, saponinas y alcaloides. Los extractos etanólicos y las fracciones de la corteza del tallo y las hojas presentaron actividad inhibitoria contra S. aureus y K. pneumonie con una zona de inhibición que osciló entre 7,0±1,73 y 9,33±0,58 mm por el método de difusión en disco. Por el método de microdilución en caldo, los extractos sólo fueron satisfactorios frente a K. pneumoniae (CMI = 125 a 1000 µg/mL). S. aureus, P. aeruginosa y E. coli fueron resistentes a las pruebas (CMI > 1000 µg/mL). Conclusiones: Estos resultados proporcionan una base para futuras investigaciones en modelos in vivo, de modo que los compuestos de C. prunifera puedan aplicarse en el desarrollo de nuevos agentes antimicrobianos contra K. pneumoniae.

Microemulsions Improve Topical Protoporphyrin IX (PpIX) Delivery for Photodynamic Therapy of Skin Cancer

Abstract We report here microemulsions (MEs) for topical delivery of protoporphyrin IX (PpIX) for Photodynamic Therapy (PDT) of skin cancers. Selected MEs consisting of Oil/Water (O/W) bicontinuous (BC) and Water/Oil (W/O) preparations were characterized as to pH, nanometric size, zeta potential, drug content, and viscosity. Sustained in vitro PpIX release was achieved from MEs 2A (O/W), 10B (BC) and 16B (W/O) through an artificial membrane for up to 24 h, characterizing MEs as drug delivery systems. None of these MEs showed permeation through the skin, demonstrating the required topical effect. After 4 h, in vitro retention of PpIX in the stratum corneum (SC) was higher from both ME 10B and control (PpIX at 60 µg/mL in PEG 300). However, in the Epidermis + Dermis ([Ep + D]), retention from ME 10B and ME 16B was ~40 times higher compared to control. Confocal Laser Scanning Microscopy (CLSM) showed higher fluorescence intensity in the SC for both control and ME 10B, whereas ME 10B fluorescence was higher in [Ep+D]. The results indicate that ME 10B is suitable for PpIX encapsulation, showing good characteristics and a localized effect for a potential delivery system for PDT-associated treatments of skin cancers.

Chromatographic profile of xanthones and flavonoids in the anti-dengue extracts of Fridericia samydoides (Cham. ) L. G. Lohmann (Bignoniaceae)

Abstract The flavonoids and xanthones present in the ethanol extracts of leaves and stems of Fridericia samydoides showed that anti-dengue activities in vitro were investigated qualitatively by liquid chromatography-ultraviolet-mass spectrometry in series. Nineteen flavones and fifteen xanthones were detected and characterized on the basis of their fragmentation pattern in the positive and negative ion mode tandem mass spectrometry spectra and ultraviolet bands. Acacetin, chrysin, vitexin, isovitexin, orientin, isoorientin, mangiferin, 2'-O-trans-caffeoylmangiferin, 2'-O-trans-coumaroylmangiferin and 2'-O-trans-cinnamoylmangiferin were identified by comparison with authentic samples. The other compounds detected were tentatively assigned by analysis of the spectral data and by comparison with literature reports. In addition, it performed the fractionation of the leaves extract leading to the isolation of mangiferin, isovitexin and isoorientin. All extracts and isolated compounds inhibited the Dengue virus replication cycle with EC50 less than 25.0 µg/mL for extracts and 272.5, 85.6 and 79.3 µg/mL for mangiferin, isovitexin and isoorientin, respectively.

In vitro susceptibility of Sporothrix spp. to complexes coordinated with Co(II) and cobalt chloride hexahydrate

Abstract Sporothrix spp. are the major dimorphic fungus associated with a type of subcutaneous mycosis, sporotrichosis. The limitation of antifungal availability and the past reports of in vitro resistance of Sporothrix spp. clinical isolates makes it important to search for new compounds with antifungal activities. In this study, we therefore evaluate the in vitro activities of complexes coordinated with Co(II) and cobalt chloride hexahydrate against clinical isolates of Sporothrix spp. Broth microdilution test was performed as per M38-A2 from CLSI (2008) in duplicate for 31 clinical isolates of Sporothrix spp. (27 S. brasiliensis e 04 S. schenckii stricto sensu). The antifungal activities of the complexes coordinated with Co(II) and cobalt chloride hexahydrate were detected at a concentration range of 32-128 µg/mL for all isolates. None of the compounds demonstrated any cytotoxicity (to macrophage cells) at the concentration of 200 µg/mL. The activity against Sporothrix spp. recorded in this study instigate the continuity of experimental studies with Co(II) to search for the mechanisms of antifungal action as well as to evaluate its interaction with the commercial antifungal drugs.

Desenvolvimento e caracterização de lipossomas peguilados para veiculação de L-asparaginase / Development and characterization of peg-grafted liposomes for lasparaginase encapsulation

A Leucemia Linfoide Aguda (LLA) é um câncer de maior incidência em crianças, e tem a Lasparaginase (ASNase) como fármaco amplamente utilizado no tratamento dos afetados. A ASNase catalisa a hidrólise do aminoácido L-asparagina (Asn), presente na corrente sanguínea, a ausência do aminoácido no meio extracelular leva à morte células leucêmicas, que necessitam deste aminoácido para as funções celulares. Fatores envolvendo a eficiência do tratamento com ASNase como reações adversas e curta meia-vida, principalmente devido ao reconhecimento pelo sistema imune e degradação por proteases, limitam a sua eficácia. A encapsulação da enzima em lipossomas pode conferir proteção à degradação, melhorar seu perfil farmacocinético e diminuir os efeitos adversos, de forma a melhorar o tratamento da LLA sendo este o objetivo desse trabalho. Lipossomas de DOPC (1,2-dioleoil-sn-glicero-3-fosfocolina) e DMPC (1,2-dimiristoil-snglicero-3-fosfocolina) foram desenvolvidos empregando-se o método de hidratação do filme lipídico e diferentes protocolos de preparo contendo ou não diferentes concentrações de 18:0 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polietilenogicol)-2000] (DSPE-PEG). Os lipossomas produzidos foram utilizados para encapsular a ASNase e os sistemas contendo ou não ASNase encapsulada foram caracterizados por espalhamento de luz dinâmico (DLS), potencial zeta, microscopia eletrônica de transmissão (MET) e criomicroscopia de transmissão. Adicionalmente, foram avaliados a taxa de encapsulação e o perfil de permeabilidade das vesículas à L-asparagina. As análises de DLS mostraram que as nanoestruturas formadas empregando-se agitação magnética a partir de sistemas contendo 10% e 20% de DSPE-PEG possuem diâmetro hidrodinâmico menor (~ 25 nm a 60 nm) que os mesmos sistemas sem o fosfolipídio peguilado (~190 nm a 222 nm), demonstrando a relação entre a diminuição do tamanho e o aumento da quantidade de fosfolipídio peguilado e possível formação de estruturas micelares ou bicelares. O emprego de agitação em vórtex para hidratação do filme lipídico, adição do antioxidante -tocoferol e redução da concentração de DSPE-PEG (5% e 10%) levou à formação de sistemas com diâmetro hidrodinâmico maior, sendo esse protocolo e concentrações de PEG definidos como padrão. As análises de MET comprovaram a formação de lipossomas com diâmetro hidrodinâmico semelhante ao observado por DLS; com a utilização da criomicroscopia foi possível observar os lipossomas sem deformações. Os lipossomas de DMPC/DSPE-PEG 10% apresentaram maior permeabilidade à L-asparagina ao longo do tempo e, portanto, poderiam funcionar como nanoreatores, depletando o aminoácido da circulação. Estudos in vitro com células tumorais devem ser realizados e em seguida estudos in vivo, para confirmar este potencial

L-asparaginase (ASNase) is a first-choice drug, combined with other drugs, in therapeutic schemes to treat Acute Lymphoblastic Leukemia (ALL) in children and adolescents. ASNase catalyzes the hydrolysis of L-asparagine (Asn) in the bloodstream; since ALL cells cannot synthesize this amino acid, protein synthesis is impaired leading to leukemic cells death by apoptosis. In spite of its therapeutic importance, treatment with ASNase is associated to side effects, mainly hypersensitivity and immunogenicity. Another drawback refers to degradation by plasma proteases that altogether with immunogenicity shortens the enzyme half-life. Encapsulation of ASNase in liposomes, vesicular nanostructures formed by the self-aggregation of phospholipids, is an attractive alternative that possibly will protect the enzyme from plasma proteases, resulting on better pharmacokinetics profile. In this work, we prepared by thin film hydration liposomal formulations of the phospholipid 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or 1,2-dimyristoyl-sn-glycero-3- phosphocholine (DMPC) containing or not different concentrations of 18:0 1,2-distearoyl-snglycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG), and encapsulated ASNase by electroporation. The systems containing or not ASNase were analyzed by Dynamic Light Scattering, zeta potential and Electron Microscopy. The encapsulation efficiency and vesicles permeability were also evaluated. According to the DLS analysis, the nanostructures formed by film hydration under magnetic stirring employing 10% or 20% DSPE-PEG presented smaller hydrodynamic diameter (~ 25 nm to 60 nm) than the same systems without the pegylated phospholipid (~ 190 nm to 222 nm), demonstrating the relation between size and the amount of pegylated phospholipid that results in formation of micellar or bicellar structures. The protocol was stabilize by hydration of the lipid film under vortex agitation, addition of the antioxidant - tocopherol and reduction of the concentration of DSPE-PEG (5% and 10%), what altogether led to the formation of nanostructures of higher hydrodynamic diameter and monodisperse systems. TEM analyzes confirmed the formation of liposomes with hydrodynamic diameter similar to that observed by DLS; with the use of cryomicroscopy it was possible to observe the liposomes without deformations. Liposomes of DMPC/DSPE-PEG 10% showed permeability to L-asparagine over time and, therefore, could function as nanoreactors, depleting the circulating amino acid

Nanocristais de besifloxacino para o tratamento de conjuntivite bacteriana: preparação, caracterização físico-química e toxicidade / Besifloxacin nanocrystals for treating bacterial conjunctivitis: preparation, physicochemical characterization, and toxicity

A conjuntivite bacteriana tem significante impacto na Saúde Pública. Essa infecção representa mais de um terço das doenças oculares relatadas em âmbito global. É uma doença altamente contagiosa causada por variedade de bactérias aeróbias e anaeróbias. Diferentes antibióticos empregados no tratamento dessa doença têm apresentado elevada incidência de resistência bacteriana. Dentre os antibióticos de última geração, destaca-se o besifloxacino, antibiótico de quarta geração da classe das fluoroquinolonas, indicado exclusivamente para uso oftálmico tópico. Entretanto, esse fármaco possui baixa solubilidade em água, diminuindo sua biodisponibilidade. Tendo em vista superar esse desafio, foi proposta abordagem nanotecnológica para o desenvolvimento de nanocristais desse fármaco. A preparação de nanocristais de besifloxacino empregando moagem via úmida em escala reduzida foi promissora empregando tensoativo Povacoat®. O Diâmetro hidrodinâmico médio (DHM) da partícula foi de aproximadamente 550 nm, com índice de polidispersão (IP) menor que 0,2. Esse resultado permitiu aumentar a solubilidade de saturação em aproximadamente duas vezes em relação a matéria-prima, possibilitando aumentar a velocidade de dissolução desse fármaco e melhorar sua biodisponibilidade e segurança. Além disso, foi validado o método para quantificação do besifloxacino por CLAE, apresentando especificidade, linearidade no intervalo de 20 a 80µg/mL (r= 0,9996), precisão por repetibilidade (DPR= 1,20%, 0,84% e 0,39%), precisão intermediária (DPR= 0,94%) e exatidão 99,03%. Estudo de estabilidade acelerado (90 dias) na condição 40°C±2°C/75%UR±5%UR e estudo de estabilidade de acompanhamento (150 dias) na condição: 25°C ± 2°C / 60% UR ± 5% UR evidenciaram a estabilidade do teor no período avaliado. Ainda, a nanossuspensão de besifloxacino 0,6% m/m (nanocristais) na dose máxima (500 mg/kg) e o estabilizante Povacoat® (750 mg/kg) não apresentaram toxicidade em larvas de G. mellonella. A concentração inibitória mínima (CIM) para a formulação inovadora foi de 0,0960 µg/mL e 1,60 µg/mL frente a Staphylococcus aureus e Pseudomonas aeruginosa, respectivamente, confirmando eficácia in vitro

Bacterial conjunctivitis greatly impacts the population's health, presenting more than a third of eye diseases reported worldwide. It is an infection caused by various aerobic and anaerobic bacteria and is highly contagious. Therefore, it presents a high incidence of bacterial resistance to the antibiotics commonly used for treatment. Among the most recent antibiotics, besifloxacin is a fourth-generation fluoroquinolone antibiotic indicated exclusively for topical ophthalmic use. Due to its importance in treating bacterial conjunctivitis and its low solubility in the water, a nanotechnological approach was proposed to develop besifloxacin nanocrystals. The preparation of besifloxacin nanocrystals using small-scale wet milling was promising using Povacoat® surfactant. The particle's average hydrodynamic diameter (DHM) was approximately 550 nm, with a polydispersity index (IP) of less than 0.2. This result increased the saturation solubility approximately two times concerning the raw material, making it possible to increase the dissolution rate of this drug and improve its bioavailability and safety. In addition, the method for quantification of besifloxacin by HPLC was validated, presenting specificity, linearity in the range of 20 to 80µg/mL (r= 0.9996), precision by repeatability (DPR= 1.20%, 0.84% and 0.39%), intermediate precision (DPR= 0.94%) and accuracy 99.03%. Accelerated stability study (90 days) at 40°C±2°C/75%RH±5%RH condition and follow-up stability study (150 days) at 25°C ± 2°C / 60% RH ± condition 5% RH showed the stability of content in the evaluated period. Furthermore, the 0.6% besifloxacin nanosuspension (nanocrystals) at the maximum dose (500 mg/kg) and the Povacoat® stabilizer (750 mg/kg) did not show toxicity in G. mellonella larvae. The minimum inhibitory concentration (MIC) to innovative formulation was 0.0960 µg/mL and e 1.60 µg/mL against Staphylococcus aureus and Pseudomonas aeruginosa, respectively, confirming in vitro efficacy

Formulation, Optimization, in vitro and in-vivo evaluation of levofloxacin hemihydrate Floating Tablets

Abstract The objective of the present investigation was to design, optimize and characterize the gastro retentive floating levofloxacin tablets and perform in-vivo evaluation using radiographic imaging. The floating tablets were prepared by using polymers i.e hydroxy propyl methyl cellulose (HPMC-K4M) and carbopol-940 individually and in combination by nonaquous granulation method. All the Formulations were evaluated for swelling index (S.I), floating behavior and in-vitro drug release kinetics. The compatibility study of levofloxacin with other polymers was investigated by FTIR, DSC, TGA and XRD. Results from FTIR and DSC revealed no chemical interaction amongst the formulation components. The optimized formulation (F11) showed floating lag time (FLT), total floating time (TFT) swelling index (S.I) of 60 sec, >16h and approximately 75 %, respectively. Moreover, F11 showed zero order levofloxacin release in simulated gastric fluid over the period of 6 h. X-ray studies showed that total buoyancy time was able to delay the gastric emptying of levofloxacin floating tablets in rabbits for more than 4 hours. In conclusion the optimized formulation (F11) can be used for the sustained delivery of levofloxacin for the treatment of peptic ulcer.

Formulation of stomach-specific floating microparticles of nizatidine and their radiographic evaluation

Nizatidine is an anti-secretogogue and a gastroprotective drug with a half-life of 1-2 h and is well absorbed in the stomach. This study aimed to optimize the process and develop floating microparticles of nizatidine that are based on low methoxyl pectin. Oil-in-oil dispersion method and Taguchi orthogonal array design were employed, and the prolonged residence time of the microparticles in the stomach was demonstrated. The constraints for independent variables, viz. A-polymer, B-internal solvent volume, C-surfactant, D-stirring rate and E-stirring time were set to generate the experimental runs. Particle size, percentage yield, micromeritic properties, entrapment efficiency, in vitro buoyancy and in vitro release were characterized. Surface morphology, zeta potential, in vitro release kinetics and in vivo floating performance of the optimized formulation was examined. The microparticles were free-flowing, irregular in shape and had a mean particle size distribution of 73-187 µ. Low methoxyl pectin played a predominant role in achieving buoyancy and optimum gastric retention for the modified release of the drug, suggesting Korsmeyer-Peppas model as the possible release mechanism. In vivo radiographic study in rabbits revealed that the drug was retained in the stomach for a period of 6 h. These results indicate that nizatidine floating microparticulate system provides modified drug release for the effective treatment of gastric ulcer

Use of biorelevant dissolution media in dissolution tests as a predictive method of oral bioavailability

Abstract Dissolution is a key step in the uptake of oral drugs. In order to compare the behaviour of the dissolution of two formulations, the dissolution profile test was used. This assay must be discriminative and should mimic in vivo conditions. Many dissolution media described in pharmacopoeias are not predictive of bioavailability. Due to this, biorelevant media are used as an alternative to solve this problem. The objective of this work is to evaluate the relevance of biorelevant dissolution media to predict in vivo drug dissolution. For this, a bibliographic search was carried out in scientific databases. The search was first performed for articles verifying the physicochemical properties of human gastrointestinal fluids. Subsequently, a comparison was made between the properties of gastrointestinal fluids and those of biorelevant and pharmacopoeial media. Finally, the results of bioequivalence studies and dissolution profile tests in biorelevant media described in the literature were compared. The results revealed that there are a few publications that have analysed some physicochemical properties of gastrointestinal fluids. In addition, high variability was observed for some properties. Regarding the comparison of these properties with pharmacopoeial media and biorelevant media, the analysis showed that the biorelevant media are more similar to gastrointestinal fluids than the pharmacopoeial media. Finally, the in vitro dissolution profile results were similar to the results obtained in vivo. Thus, biorelevant media may be useful for analysing dissolution profiles.

In vitro cytotoxicity assay of Fucoidan extracted from Turbinaria conoides against cancer cell lines MCF7, A549, and normal cell line L929

Abstract The main aim of the study is to quantify the cytotoxic property of the Fucoidan extracted from the Turbinaria conoides using the MTT assay with the standard fucose. Fucoidan was extracted using the soaked water method and it was determined using the HPLC procedure the obtained Test sample Fucoidan extracted from the Turbinaria conoides and standard fucose was subjected to the cytotoxicity assay against the MCF7 Human breast cancer cell line, A549 lung cancer cell line, and L929 normal mouse fibroblast cell line. From the results it was found that the Test sample showed good IC50 value for MCF7 cell line then A549 with an increasing concentration 24 hours incubation at 37°C The IC50 for MCF7 was 115.21 µg/ml and A549 396.46µg/ml and the Fucoidan extract was checked for its cytotoxicity against the normal mouse fibroblast cell line L929, Fucoidan was found non-lethal to the L929 mouse fibroblast normal cell line. Standard fucose also gave a significant result towards MCF7 and against the L929. This indicates that the Fucoidan extracted from Tubinaria conoides shows better anticancer potential in it. Hence its application can be further extended in the pharmacological fields.

Formulation and Optimization of Diclofenac Sodium Loaded Ethylcellulose Nanoparticles

Abstract Design of experiment (DoE) is a useful time and cost-effective tool for analyzing the effect of independent variables on the formulation characteristics. The aim of this study is to evaluate the effect of the process variables on the characteristics involved in the preparation of Diclofenac Sodium (DC) loaded ethylcellulose (EC) nanoparticles (NP) using Central Composite Design (CCD). NP were prepared by W/O/W emulsion solvent evaporation method. Three factors were investigated (DC/EC mass ratio, PVA concentration, homogenization speed) in order to optimize the entrapment efficiency (EE) and the particle size of NP. The optimal formulation was characterized by Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), and in vitro release. Optimized formulation showed an EE of 49.09 % and an average particle size of 226.83 nm with a polydispersity index of 0.271. No drug-polymer interaction was observed in FTIR and DSC analysis. SEM images showed that the particles are spherical and uniform. The in vitro release study showed a sustained release nature, 53.98 % of the encapsulated drug has been released over 24hours period. This study demonstrated that statistical experimental design methodology can optimize the formulation and the process variables to achieve favorable responses.

Antibacterial and Cytotoxic Effects of Cyclodextrin-Triazole-Titanium Based Nanocomposite

Abstract In this paper, the antibacterial activity of triazole functionalized cyclodextrin (CD.Click) and cyclodextrin-triazole-titanium based nanocomposite (CD.COM) was evaluated. The results indicated that CD.Click and CD.COM perform a wide range of antibacterial activity against both gram positive (Staphylococcus aureus and Bacillus subtilis) and gram negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The cytotoxic effect of CD.COM was investigated in vitro on cancerous cell lines (cervical cancer, breast carcinoma and sarcoma osteogenic) and fibroblast cells by MTT assay. The cell viability evaluation confirmed that the growth of cancerous cells is inhibited in a dose and time dependent way without any significant effect on the normal fibroblast cells.

Nanostructured lipid carrier containing hydroxymethylnitrofurazone: preparation, characterization and in vitro and in vivo evaluation of leishmanicidal activity / Carreador lipídico nanoestruturado contendo hidroximetilnitrofural: preparação, caracterização físico-química e avaliação in vitro e in vivo da atividade leishmanicida

Leishmaniasis, a neglected tropical disease (NTD), is a set of diseases caused by obligatory parasitic protozoa of the genus Leishmania. And it has cutaneous and visceral eishmaniasis as its main forms. Treatment includes pentavalent antimonials. These drugs have several disadvantages, such as the need for parenteral administration, use of high dosages, long duration of treatment, severe toxicity, resistance and variable efficacy. The candidate for hydroxymethylnitrofural drug (NFOH), a prodrug derived from nitrofural, showed high activity in cell cultures infected with Trypanosoma cruzi and less toxicity when compared to nitrofural. Due to its low solubility in water and reduced bioavailability, NFOH has failed the in vivo efficacy tests. Nanostructured drug delivery systems have the potential to overcome these challenges due to their evident advantages: greater therapeutic efficacy, less toxicity, modified drug release and increased gastrointestinal absorption of drugs with low water solubility. The objective of this project will be the preparation and evaluation of the physicochemical characteristics of a nanostructured lipid carrier containing hydroxymethylnitrofural (NLC-NFOH). The NFOH showed the highest solubility in Miglyol® 840 among the tested liquid lipids. For solid lipids, Gelucire® 50/13 and Precirol® ATO5 proved to be more suitable for the solubilization of NFOH. The optimized NLC-NFOH consisted of these three lipids. These lipids were selected using a quick Technobis Crystal 16TM methodology, microscopy and DSC. Different lipid selection tools provided scientific knowledge relevant to the development of NLC. The NLC-NFOH had an average z of 198.6 ± 5.4 nm, a PDI of 0.11 ± 0.01 and a zeta potential of -13.7 ± 0.7 mV. This study allowed a design space development approach of the first NLC-NFOH with the potential to treat leishmaniasis orally. The development of a sensitive bioanalytical method using HPLC and evaluation of some analytical figures of merit for the validation allowed the quantification of NFOH and NF. The bioanalytical method for analysis of NFOH and NF use Zorbax SB-C18, 5µm, (4.6x250mm) HPLC column. The mobile phase was consisted of acetonitrile:water (20:80 v/v) with flow rate of 1.2 ml/min, at UV detection of 370 nm. The linearity of NFOH and NF was found in the range 0.0253.0 µg/ml with a correlation coefficient of r > 0.98. The precision was 2.44 to 13.77% for NFOH and 2.61 to 18.42%; the accuracy was 2.66 to 14.28% for NFOH and 2.09 to 19.06% for NF. The method showed to be suitable for effectively evaluation of NFOH is serum. NLC-NFOH (2.8 mg/kg) was administered to animals by gavage, and the blocking flow of the chylomicrons model was performed with an intraperitoneal injection of cycloheximide. The presence of NFOH in serum was evaluated with and without cycloheximide. The cytotoxicity assay of NLC-NFOH and blank-NLC showed more than 90% viable cells at the maximum concentration used (2560 µM). NFOH and NF were detected at 1h after the gavage of DMSO-NFOH or NLC-NFOH, without the pretreatment with cycloheximide. The concentration found for DMSO-NFOH and NLC-NFOH were 0.0316 and 0.0291 µg/mL, respectively. The NLC presented the NFOH absorption by the lymphatic system, demonstrated by blocking chylomicrons flow

A leishmaniose, uma doença tropical negligenciada (DTN), é um conjunto de doenças causadas por protozoários parasitas obrigatórios do gênero Leishmania. E tem como formas principais a leishmaniose cutânea e visceral. O tratamento inclui antimoniais pentavalentes. Esses fármacos apresentam várias desvantagens, como necessidade de administração parenteral, uso de altas dosagens, longa duração do tratamento, toxicidade grave, resistência e eficácia variável. O candidato ao fármaco hidroximetilnitrofural (NFOH), um pró-fármaco derivado do nitrofural, apresentou alta atividade em culturas de células infectadas pelo Trypanosoma cruzi e menor toxicidade quando comparado ao nitrofural. Devido à sua baixa solubilidade em água e biodisponibilidade reduzida, o NFOH falhou nos testes de eficácia in vivo. Os sistemas nanoestruturados de liberação de fármacos têm potencial para superar esses desafios devido às suas vantagens evidentes: maior eficácia terapêutica, menor toxicidade, liberação modificada do fármaco e aumento da absorção gastrointestinal de fármacos com baixa solubilidade em água. O objetivo deste projeto será a preparação e avaliação das características físico-químicas de um carreador lipídico nanoestruturado contendo hidroximetilnitrofural (NLC-NFOH). O NFOH apresentou a maior solubilidade no Miglyol® 840 entre os lipídios líquidos testados. Para lipídios sólidos, Gelucire® 50/13 e Precirol® ATO5 se mostraram mais adequados para a solubilização de NFOH. O NLC-NFOH otimizado consistiu desses três lipídios. Esses lipídios foram selecionados usando Technobis Crystal 16TM, microscopia e DSC. Diferentes ferramentas de seleção de lipídios forneceram conhecimento científico relevante para o desenvolvimento de NLC. O NLC-NFOH teve z-average de 198,6 ± 5,4 nm, PDI de 0,11 ± 0,01 e potencial zeta de -13,7 ± 0,7 mV. Este estudo permitiu o desenvolvimento por abordagem de Design Space do primeiro NLC-NFOH com potencial para tratar a leishmaniose por via oral. O desenvolvimento de um VIII método bioanalítico sensível utilizando HPLC e a avaliação de algumas figuras analíticas de mérito para a validação permitiram a quantificação de NFOH e NF em soro. O método bioanalítico para análise de NFOH e NF usou coluna de HPLC Zorbax SB-C18, 5 µm, (4,6 x 250 mm). A fase móvel foi constituída por acetonitrila: água (20:80 v / v) com vazão de 1,2 ml / min, com detecção no UV de 370 nm. A linearidade de NFOH e NF foi encontrada na faixa de 0,0253,0 µg / ml com um coeficiente de correlação de r> 0,98. A precisão foi de 2,44 a 13,77% para NFOH e 2,61 a 18,42%; a precisão foi de 2,66 a 14,28% para NFOH e 2,09 a 19,06% para NF. O método mostrou-se adequado para avaliação efetiva do NFOH no soro. NLC-NFOH (2,8 mg / kg) foi administrado aos animais por gavagem, e o modelo de bloqueio do fluxo de quilomícrons foi realizado com injeção intraperitoneal de cicloheximida. A presença de NFOH no soro foi avaliada com e sem cicloheximida. O ensaio de citotoxicidade de NLC-NFOH e brancoNLC mostrou mais de 90% de células viáveis na concentração máxima utilizada (2560 µM). NFOH e NF foram detectados 1h após a gavagem de DMSO-NFOH ou NLC-NFOH, sem o pré-tratamento com cicloheximida. As concentrações encontradas para DMSO-NFOH e NLC-NFOH foram 0,0316 e 0,0291 µg / mL, respectivamente. O NLC apresentou a absorção do NFOH pelo sistema linfático, demonstrada pelo bloqueio do fluxo dos quilomícrons

Ocotea daphnifolia: phytochemical investigation, in vitro dual cholinesterase inhibition, and molecular docking studies

This study aimed to evaluate the anticholinesterase activities of extracts and fractions of Ocotea daphnifolia in vitro and characterize its constituents. The effects of hexane, ethyl acetate, and ethanolic extracts on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity were determined with a spectrophotometry assay. All extracts inhibited cholinesterase activity, and the ethanolic extract (2 mg/mL) exhibited the highest inhibition of both enzymes (99.7% for BuChE and 82.4% for AChE). The ethanolic extract was fractionated by column chromatography resulting in 14 fractions that were also screened for their anticholinesterase effects. Fraction 9 (2 mg/mL) showed the highest activity, inhibiting AChE and BuChE by 71.8% and 90.2%, respectively. This fraction was analyzed by high-performance liquid chromatography high-resolution mass spectrometry which allowed the characterization of seven glycosylated flavonoids (containing kaempferol and quercetin nucleus) and one alkaloid (reticuline). In order to better understand the enzyme-inhibitor interaction of the reticuline toward cholinesterase, molecular modeling studies were performed. Reticuline targeted the catalytic activity site of the enzymes. Ocotea daphnifolia exhibits a dual cholinesterase inhibitory activity and displays the same pattern of intermolecular interactions as described in the literature. The alkaloid reticuline can be considered as an important bioactive constituent of this plant.

Quinolinotriazole antiplasmodials via click chemistry: synthesis and in vitro studies of 7-Chloroquinoline-based compounds

Malaria is nowadays one of the most serious health concerns in a global scale and, although there is an evident increase in research studies in this area, pointed by the vast number of hits and leads, it still appears as a recurrent topic every year due to the drug resistance shown by the parasite exposing the urgent need to develop new antimalarial medications. In this work, 38 molecules were synthesized via copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) or "click" chemistry, following different routes to produce 2 different organic azides, obtained from a 4,7 dicholoquinoline, reacted with 19 different commercially available terminal alkynes. All those new compounds were evaluated for their in vitro activity against the chloroquine resistant malaria parasite Plasmodium falciparum (W2). The cytotoxicity evaluation was accomplished using Hep G2 cells and SI index was calculated for every molecule. Some of the quinoline derivatives have shown high antimalarial activity, with IC50 values in the range of 1.72-8.66 µM, low cytotoxicity, with CC50>1000 µM and selectivity index (SI) in the range of 20-100, with some compounds showing SI>800. Therefore, the quinolinotriazole hybrids could be considered a very important step on the development of new antimalarial drugs

Expression analysis of drug-resistant gene (blaOXA-51) in carbapenemases producing Acinetobacter baumannii treated with imipenem/sulbactam combination

Drug-resistant Acinetobacter baumannii is a frightening reality. The aim of this study is to examine the expression profiles of blaOXA-51 gene in carbapenemases producing A. baumannii treated with imipenem/sulbactam combination. Carbapenemases producing A. baumannii was identified among clinical isolates of A. baumannii obtained from patients at Shahid Rajaee hospital, Gachsaran, Iran, from January to June 2018. Synergism testing of imipenem/sulbactam on carbapenemases producing A. baumannii was carried out by broth microdilution method. Eventually, the expression of blaOXA-51 gene was carried out to investigate the inhibitory properties of imipenem/sulbactam combination against carbapenemases producing A. baumannii using quantitative real time RT-PCR. Among A. baumannii isolates, 24% were carbapenemases producing A. baumannii. Imipenem/sulbactam combination revealed synergistic and partial synergistic effect for all tested isolates (FIC= 0.313-0.75). Finally, imipenem/sulbactam combination displayed significant down-regulation of blaOXA-51 gene in carbapenemases producing A. baumannii. Imipenem synergizes with sulbactam against carbapenemases producing A. baumannii by targeting of the blaOXA-51 gene.

Avaliação in vitro e in vivo do potencial imunomodulador de frações polissacarídicas extraídas do chuchu / In vitro and in vivo evaluation of the immunomodulatory potential of polysaccharide fractions extracted from chayote

Os polissacarídeos não amido constituem importante parcela das fibras dietéticas, e podem ser considerados modificadores de resposta biológica (MRBs), uma vez que são capazes de interagir com o sistema imune, e suas características estruturais estão atreladas aos efeitos biológicos gerados. O potencial imunomodulador dos polissacarídeos do chuchu já foi demonstrado, entretanto, informações sobre suas características estruturais e sua relação com o perfil imunológico são limitadas a ensaios in vitro, não havendo, até o momento, estudos in vivo. Assim, o objetivo do estudo foi avaliar, in vitro e in vivo, o perfil imunomodulador de frações isoladas do polissacarídeo do chuchu. Por meio da filtração tangencial foram obtidas as frações de estudo, SeRI<50 e SeSE<50, respectivamente as frações isoladas do polissacarídeo do chuchu extraídas do resíduo insolúvel e do sobrenadante pós-tratamento enzimático para retirada do amido com peso molecular menor que 50 kDa. A caracterização por meio da determinação da composição monossacarídica e da análise de ligação apontou que ambas as frações são formadas por galacturonanos, arabinanos, arabinogalactanos e glicomananos. A SeRI<50 é menos ramificada e, provavelmente, composta por galactanos, enquanto SeSE<50 é mais ramificada e, provavelmente, composta por galactuglucomananos. Essas frações foram capazes de estimular os macrófagos murinos RAW 264.7 e as células mononucleares do baço, do sangue e do intestino delgado de camundongos Balb/c, sugerindo um perfil de ação mais pró-inflamatório, com base nos efeitos produzidos pelas espécies reativas de oxigênio, citocinas e pelos marcadores de ativação de linfócitos. Ambas as amostras, SeRI<50 e SeSE<50, mostraram ser eficientes em ativar a cascata imunológica, não sendo citotóxicas mesmo com a maior concentração testada no ensaio in vitro

Non-starch polysaccharides are important components of dietary fibers, and they may be considered biological response modifiers (MRBs), as they may interact with the immune system, depending on their structural characteristics. The immunomodulatory potential of chayote polysaccharides has already been demonstrated, however, information on their structural characteristics and their relationship with the immunological profile are limited to in vitro assays, with no reports on in vivo studies. Thus, the objective of the study was to evaluate, in vitro and in vivo, the immunomodulatory profile of polysaccharide from chayote. Through tangential filtration two fractions, SeRI <50 and SeSE <50, were obtained, respectively the fraction isolated from the chayote polysaccharide extracted from the insoluble residue and the fraction from the enzymatic post-treatment supernatant to remove starch, both under molecular weight 50 kDa. The monosaccharide composition and linkage analysis showed that both fractions are formed by galacturonans, arabinans, arabinogalactans and glycomanans. SeRI <50 is less branched and probably composed of galactans, while SeSE <50 is more branched and probably composed of galactuglucomannans. These fractions were able to stimulate murine macrophages RAW 264.7 and mononuclear cells of the spleen, blood and small intestine of Balb / c mice, suggesting a more proinflammatory action profile, based on the reactive oxygen species production, cytokines and lymphocyte activation markers. Both samples, SeRI <50 and SeSE <50, were able to efficiently activate the immunological cascade, not being cytotoxic even at the highest concentration tested in the in vitro assay

New flavonoid with antidiabetic and antioxidant potential from Tetrastigma angustifolia (Roxb. ) Deb leaves

Ethnomedicinal survey documents the traditional practices of Tetrastigma angustifolia leaves in the management of diabetes in the North-eastern region of India. The present study was aimed at isolation of possible antidiabetic principle(s) from T. angustifolia leaves and evaluation of antidiabetic efficacy of isolated compound(s) in experimental animal model. The methanolic extract of T. angustifolia leaves was obtained by Soxhlet extraction method and subjected to silica gel column chromatography (100-200 mesh). Fraction 18-176 chloroform:methanol (70:30) yielded a pale yellow colored compound. The structure of pure compound was elucidated with the help of UV, IR, NMR and Mass spectrometric/techniques. The antioxidant activity of the isolated compound was evaluated in vitro by various radical scavenfing assay methods.. Oral acute toxicity study was carried out according to OECD guideline 423 in Wistar rats. The antidiabetic efficacy of the isolated compound was evaluated in STZ-induced diabetic rats at the dose of 5 mg/kg b.w. for duration of 21 days. The present study reports a new flavocnoid compound isolated from the methanolic extract of T. angustifolia leaves and identified as 8-hydroxyapigenin 7-O-D-glucopyranoside. The flavonoid compound exhibited potent antidiabetic (hypoglicemic) activity in STZ-induced diabetic rats with promising antioxidant (radical scavenging activity) potential in vitro.

Paclitaxel and spirulina co-loaded polymeric nanoparticles: in-vitro and in-vivo anticancer study

Paclitaxel spirulina nanoparticles were said to have promising anticancer activity against gastric cancer. Nanoparticles of paclitaxel-spirulina were prepared for treating gastric cancer using precipitation technique. The synergistic anticancer efficiency againstMKN45 cells retains when the paclitaxel and spirulina were encapsulated into nanoparticles. To increase the site specific delivery, intra-tumoral administration was carried in the in vivo evaluation. There was an increase in overall survival in an MKN45-transplanted mice model and notable improvement in anti-tumour efficacy when paclitaxel-spirulina nanoparticles were delivered through intra-tumoral administration. The further investigation of overall anticancer mechanism of these nanoparticles is made as a major part in this research. Hence, the conjecture of this research is that, the paclitaxel-spirulina encapsulated nanoparticles could be an effective chemotherapeutic formulation for gastric cancer.

Preparation and in vitro characterization of monoclonal antibody ranibizumab conjugated magnetic nanoparticles for ocular drug delivery

Gold coated magnetite nanoparticles were prepared and coated with ranibizumab as an ocular drug delivery system. The surface morphologies of the nanoparticles were determined by Scanning Electron Microscopy (SEM). The size and surface charge were determined by using the dynamic light scattering (DLS) technique. Crystallographic properties of the gold coated Fe3O4 nanoparticles were recorded on X-ray diffractometer (XRD) the XRD pattern of nanoparticlees were shown to have uniqe Fe3O4 and gold peaks. Conjugation of ranibizumab onto nanoparticles was achieved using the physical adsorption method. The amount of ranibizumab on the surface of the nanoparticles was determined by thermogravimetric analysis (TGA). In the in vitro release studies performed using UV spectroscopy; it was found that almost 60% of antibodies were released within the first 30 minutes. Antibody activity after release studies was also proved with ELISA. Non-toxicity of gold coated Fe3O4 particles were proved with MTT. Results of the studies, showed that the antibody conjugated magnetic nanoparticle system could be a potential treatment system for ocular diseases.