A limited number of studies with application of the Arrhenius equation have been reported to drugs and biopharmaceuticals in biological fluids at frozen temperatures. This paper describes stability ...studies of ampicillin and cephalexin in aqueous solution and human plasma applying the Arrhenius law for determination of adequate temperature and time of storage of these drugs using appropriate statistical analysis. Stability studies of the beta-lactams in human plasma were conducted at temperatures of 20°C, 2°C, −20°C and also during four cycles of freeze-thawing. Chromatographic separation was achieved using a Shimpak C18 column, acetonitrile as organic modifier and detection at 215nm. LC-UV–MS/MS was used to demonstrate the conversion of ampicillin into two diastereomeric forms of ampicilloic acid. Stability studies demonstrated degradation greater than 10% for ampicillin in human plasma at 20°C, 2°C and −20°C after 15h, 2.7days, 11days and for cephalexin at the same temperatures after 14h, 3.4days and 19days, respectively, and after the fourth cycle of freezing–thawing. The Arrhenius plot showed good prediction for the ideal temperature and time of storage for ampicillin (52days) and cephalexin (151days) at a temperature of −40°C, but statistical analysis (least squares method) must be applied to avoid incorrect extrapolations and estimated values out uncertainty limits.
Pest mites that survive the exposure of acaricides can suffer from sublethal effects. The objective of this work was to evaluate the sublethal toxicity of the ovicidal, repellent, and residual ...effects as well as instantaneous population growth rate (r
i
), of A. squamosa hexane extract and microencapsulation of A. squamosa seeds to Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae). The microencapsulation in LC
99
had the lowest egg viability at 7.50 ± 2.70%. The repellent effect was observed from LC
95
and LC
50
for extract and microencapsulation, respectively. The instantaneous rate of population growth for both products decreased with increasing concentrations. Efficient residual effect was observed for LC
99
up to 8 and 15 days after spraying (DAS), for the microencapsulation and extract, respectively, in greenhouse. For the field experiments 1 and 2, the microencapsulation at LC
99
was efficient up to 6 and 9 DAS, respectively, and the hexane extract until 7 and 10 DAS. Thus, A. squamosa hexane extract and the microencapsulation extract cause sublethal effects to T. urticae and can be used to manage this pest.
This study investigated the chemical composition, flavonoids, phenolic compounds, antioxidant activity and antibacterial activity of commercial propolis extracts produced in the Sergipe and Alagoas ...States of Brazil as potential bioproducts for the food and pharmaceutical industries. Four samples were analyzed, three brown propolis extracts and one red propolis extract, and were characterized through phytochemical screening, chemical, chromatographic profile and antibacterial activity. Phytochemical analysis detected the presence of triterpenoids and phenolic compound in propolis extracts. Propolis extracts showed total phenolic content between 9 and 15% and total flavonoids >2%. Propolis extracts showed excellent antioxidant activity with inhibition of the Free radical DPPH˙ between 97 and 60%, which confirm the results obtained in total phenolics, total flavonoids content and antibacterial activity. The chromatographic profile showed differences for brown propolis samples and quite different from the red propolis extract, which present flavonoids as isoflavonoids, pterocarpans, chalcones and guttiferones. Commercial propolis extract (propolis extract C and propolis extract D) showed excellent activity for Staphylococcus aureus ATCC 25923 and moderate activity for Pseudomonas aeruginosa ATCC 27853. The chemical characterization of propolis extracts is fundamental in the process of standardization and monitoring of the chemical composition susceptible to geographic and seasonal variation. These results point to new possibilities of use as bio-preservative of processed foods as well as in the development of pharmaceuticals and nutraceuticals products from propolis extract C and D in its formulation actuate on the inhibition of some pathogenic microorganisms strains.
The aim of the present study was to compare two nanoparticle composition loaded with Brazilian red propolis extract regarding its physicochemical characteristics and its antioxidant and ...antileishmanial activities. The red propolis nanoparticles in an aqueous medium and in solid-state presented particle size in a nanometric scale with an apparent size of 100-288 nm for the NEPE and 175-380 nm for the NPPE. ATR-FTIR and thermal analysis revealed an encapsulation of flavonoids from the red propolis extract in polymeric matrices for the multidrug delivery system. UPLC-DAD identified red propolis markers (flavonoids) in EPE, NEPE and NPPE. The efficiency of encapsulation (28.0-55.0% for NEPE and 61.2-81.0% for NPPE) were determined and calculated using UPLC-DAD. DPPH method showed the antioxidant activity of both EPE and nanoparticle compositions of red propolis. These polymeric matrices systems were able to encapsulate flavonoids from red propolis extract with specific characteristics of solubility and polarity. EPE and nanoparticles loaded with red propolis extract in the multi-constituent co-delivery system presented leishmanicidal activity and a good correlation was established between IC
50
and efficiency of encapsulation. Red propolis nanoparticles exhibited leishmanicidal activity but NEPE presented a lower leishmanicidal effect in relation to NPPE, which showed similar activity compared to EPE. The nanopolymeric matrices choice should be established in propolis nanoparticle compositions to avoid lack of efficacy of bioproducts. Red propolis nanoparticles were shown to be a potential final bulk product for the preparation of various pharmaceutical and cosmetics compositions in therapy against diseases such as leishmaniasis.
Scanning Electron Microscopy of red propolis nanoparticles (NEPE 30) (A). ATR-FTIR spectra of NPPE 30 and NPPE placebo (B). Chromatogram of the NPPE 30 (C). Determination of IC using leishmanicidal assay against Leishmania braziliensis for EPE, NEPE and NPPE (D).
The aim of this study was to evaluate the bioactivity of microencapsulated extract from the soursop seeds, Annona muricata L. ( Annonaceae ), on diamondback moth, Plutella xylostela L. (Lepidoptera: ...Plutellidae ). Microencapsulation was performed in a Mini Spray Dryer model B-290 using 50mL of ethanolic and hexanic extracts plus 150mL of ethanol and 150mL of ultrapure water, mixed with aerosil (first polymer) or arabic gum (second polymer). It was possible to microencapsulate the ethanolic extract of soursop seeds only by using the polymer arabic gum at 20%. The microencapsulated extract caused significant acute toxicity (LC50=258mg L-1) and chronic effects, especially reduction of larval viability and increased larval stage. We concluded that the microencapsulation of the ethanolic extract of soursop seeds can be a viable alternative for controlling diamondback moth with possible gains for the environment.
RESUMO: O objetivo deste estudo foi avaliar a bioatividade do extrato microencapsulado das sementes de graviola, Annona muricata L. ( Annonaceae ), sobre a traça-das-crucíferas, Plutella xylostella L. (Lepidoptera: Plutellidae ). A microencapsulação foi realizada em um Mini Spray Dryer modelo B-290 utilizando-se 50mL dos extratos etanólico e hexânico mais 150mL de álcool etílico e 150mL de água ultrapurificada, misturado com aerosil (primeiro polímero) ou com goma arábica (segundo polímero). Só foi possível microencapsular o extrato etanólico de sementes de graviola com a utilização do polímero goma arábica a 20%. O extrato microencapsulado causou significativa toxicidade aguda (CL50=258mg L-1) e efeitos crônicos, especialmente redução da viabilidade larval e aumento da duração do estágio larval. Conclui-se que a microencapsulação do extrato etanólico da semente de graviola pode ser uma alternativa viável no controle da traça com possíveis ganhos para o meio ambiente.
Abstract This study aims to develop a nano-sized fluoridated layered double hydroxide (LDH)-based release system via hydrothermal treatment for the controlled delivery of fluoride (F-) ions in the ...oral environment. The synthesis of conventional LDH-type (C-LDH) precursor nanomaterials was conducted using a co-precipitation method at constant pH, and the nanoparticulate-LDH (N-LDH) was synthesized by a hydrothermal procedure. Fluoride LDH (F-LDH) products were obtained through indirect synthesis using the precursor ion-exchange technique by varying the agitation time (2 and 24 h) and temperature (25 and 40 °C) to produce 12 material samples. The materials were characterized by energy dispersive x-ray, hexamethyldisilazane, digital radiography x-ray, Fourier-transform infrared, thermogravimetric analysis, and scanning electron microscopy. Additionally, the F-release kinetic profile was evaluated for 21 d in neutral and acid media with mathematical model analysis. Products with varying F-quantities were obtained, revealing specific release profiles. In general, there was a higher F-release in the acid medium, with emphasis on F-LDH-8. Fluoride-LDH and controlled fluoride delivery was successfully obtained, proving the potential of these nanomaterials as alternative anti-caries agents.
The implementation of new public healthcare models that stimulate the use of natural products from traditional medicine, as a so-called integrated medicine, refers to an approach that use best of ...both conventional medicine and traditional medicine. Propolis is a widely used natural product by different ancient cultures and known to exhibit biological activities beneficial for health. The large number of studies conducted with propolis had shown that its chemical composition differs as a function of the climate, plant diversity and bee species and plays an important role on its therapeutic properties. The aim of this study was to analyse the phytochemical profile of the ethanolic extract of red propolis (EEP) and its fractionation, antioxidant action of EEP and its fractions hexane, cloroform and ethyl acetate and cytotoxic activity of EEP on human tumour cell lines SF-295 (glioblastoma), OVCAR-8 (ovary) and HCT-116 (colon).
EEP was obtained by maceration with absolute ethanol, then it was concentrated in rotaevaporator up to complete evaporation of the solvent. The crude extract was fractionated with hexane, ethyl acetate, chloroform and methanol and they were subjected to phytochemical screening and total phenolic compounds. Antioxidant activity of EEP and fractions was done by means of the 2,2-diphenyl-1-picryhydrazyl (DPPH) method. Biomarkers of red propolis were identified by LC-Orbitrap-FTMS. To assess cytotoxic activity of the extract, cells were exposed to EEP over 72 h. Cell viability was assessed by means of MTT assay. The percentage of cell growth inhibition (IC50) was analysed by means of non-linear regression, and the absorbance values of the various investigated concentrations were subjected to one-factor analysis of variance (ANOVA) followed by Tukey's or Tamhane's tests (α = 0.05).
The results obtained using phytochemical screening and LC-Orbitrap-FTMS indicated the presence of phlobaphene tannins, catechins, chalcones, aurones, flavonones, flavonols, xanthones, pentacyclic triterpenoids and guttiferones in Brazilian red propolis. EEP and its hexane, chloroform and ethyl acetate fractions obtained by liquid-liquid partitioning exhibited satisfactory antioxidant percentages. EEP (IC50 < 34.27 μg/mL) exhibited high levels of cytotoxicity on all human tumour cell lines tested when compared to negative control.
C-Orbitrap-FTMS was useful to establish the chemical profile of the red propolis. Brazilian red propolis has antioxidant properties and decreases substantially the percentage of cell survival of human tumour cells; thus, it has potential to serve as an anticancer drug.
O iogurte é o leite fermentado mais consumido no mundo, mas sua vida útil é relativamente curta se comparado a outros derivados lácteos. Assim, o objetivo deste trabalho foi desenvolver um iogurte em ...barra, pronto para consumo, sem necessidade de refrigeração, desde o transporte até consumidor final. Inicialmente foi desenvolvido o iogurte natural, após produção foi preparado 4 formulações: F1: Apenas os ingredientes provenientes da fermentação do iogurte; F2: ingredientes de F1, acrescida de 10% de maltodextrina; F3: ingredientes de F1, acrescida de 0,2% de lecitina e F4: ingredientes de F1, acrescida de 10% de maltodextrina e 0,2% de lecitina. Foi realizada a secagem de todas as formulações em liofilizador de bandeja por 48 horas. Em seguida, foram trituradas e moldadas em forma de barra. Foram realizadas as análises de rendimento, umidade, acidez titulável, pH, solubilidade e contagem de bactérias lácticas totais. Os resultados obtidos foram avaliados por análise de variância (ANOVA) e as médias comparadas pelo teste de Tukey a 5 % de probabilidade, utilizando o software Sisvar. Houve diferença significativa (p<0,05) para todos os parâmetros avaliados, com exceção do pH. A adição de maltodextrina e lecitina nas formulações melhorou a solubilidade, mostrando efeito positivo na sua adição. Todas as formulações apresentaram contagem de bactérias lácticas superior a 107 UFC/g, podendo serem classificadas como iogurte. Assim, devido ao maior rendimento e melhor solubilidade, as formulações 2 e 4 são as mais indicadas para trabalhos futuros e produção em larga escala.
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