RESUMO
Global food production faces challenges concerning access to nutritious and sustainably produced food. Pleurotus djamor, however, is an edible mushroom that can be cultivated on agricultural waste. Considering that nutritional and functional potential of mushrooms can change based on cultivation conditions, we examined the influence of substrates with different compositions of banana leaf and sugarcane bagasse on the nutritional, mycochemical, and antioxidant properties of P. djamor. The mushrooms were grown for 120 days and dried in a circulating air oven at 45 °C for three days. We conducted bromatological analyses and mycochemical characterization (1H-NMR, total phenolics, and flavonoids) of the mushrooms and assayed the antioxidant activity of extracts from the dried mushrooms using an ethanol/water solution (70:30 v/v). In general, the substrates produced mushrooms with high protein (18.77 ± 0.24% to 17.80 ± 0.34%) and dietary fiber content (18.02 ± 0.05% to 19.32 ± 0.39%), and with low lipid (0.28 + 0.08% to 0.4 + 0.6%), and caloric content (maximum value: 258.42 + 8.49), with no significant differences between the groups (p ≥ 0.05). The mushrooms also exhibited high levels of total phenolics and flavonoids. The mushrooms cultivated on sugarcane bagasse substrates presented the highest values (p < 0.05). Analysis of the 1H-NMR spectra indicates an abundant presence of heteropolysaccharides, ß-glucans, α-glucans, and oligosaccharides, and all the mushroom extracts exhibited high antioxidant activity. In conclusion, our study demonstrates that agricultural residues permit sustainable production of edible mushrooms while maintaining nutritional and functional properties.
Assuntos
Antioxidantes , Celulose , Musa , Folhas de Planta , Pleurotus , Saccharum , Pleurotus/metabolismo , Pleurotus/química , Pleurotus/crescimento & desenvolvimento , Saccharum/química , Saccharum/metabolismo , Antioxidantes/metabolismo , Antioxidantes/química , Musa/química , Folhas de Planta/química , Celulose/metabolismo , Valor Nutritivo , Flavonoides/metabolismo , Flavonoides/análise , Fenóis/metabolismo , Agricultura/métodosRESUMO
Infections of fungal origin are mainly caused by Candida spp. Some species, such as C. albicans, C. glabrata, C. parapsilosis, and C. tropicalis, stand out as promoters of diseases in humans. This study evaluated the synthesis and antifungal effects of (E)-3-(furan-2-yl)acrylic acid. The synthesis of the compound showed a yield of 88%, considered high. The minimum inhibitory concentration of the synthetic compound, amphotericin B, and fluconazole isolated against four Candida species ranged from 64 to 512 µg/mL, 1 to 2 µg/mL, and 32 to 256 µg/mL, respectively. The synergistic effect of the test compound was observed when associated with amphotericin B against C. albicans and C. tropicalis, with no antagonism between the substances against any of the strains tested. The potential drug promoted morphological changes in C. albicans, decreasing the amount of resistance and virulence, and reproduction structures, such as the formation of pseudohyphae, blastoconidia, and chlamydospores. Furthermore, it was also possible to identify the fungistatic profile of the test substance by studying the growth kinetics of C. albicans. Finally, it was observed that the test compound stimulated ergosterol biosynthesis by the yeast, probably by activating microbial resistance responses.
Assuntos
Antifúngicos , Candida , Humanos , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Anfotericina B/farmacologia , Acrilatos/farmacologia , Fluconazol/farmacologia , Candida albicans , Candida parapsilosis , Testes de Sensibilidade Microbiana , Candida glabrata , Farmacorresistência FúngicaRESUMO
Abstract The genus Candida represents the main cause of infections of fungal origin. Some species stand out as disease promoters in humans, such as C. albicans, C. glabrata, C. parapsilosis, and C. tropicalis. This study evaluated the antifungal effects of propyl (E)-3-(furan-2-yl) acrylate. The minimum inhibitory concentration of the synthetic compound, amphotericin B and fluconazole alone against four species of Candida ranged from 64 to 512 µg/mL, 1 to 2 µg/mL, and 32 to 256 µg/mL, respectively. The synergistic effect of the test substance was observed when associated with fluconazole against C. glabrata, there was no antagonism between the substances against any of the tested strains. The potential drug promoted morphological changes in C. albicans, decreasing the amount of resistance, virulence, and reproduction structures, such as the formation of pseudohyphae, blastoconidia, and chlamydospores, ensuring the antifungal potential of this substance. It was also possible to identify the fungicidal profile of the test substance through the study of the growth kinetics of C. albicans. Finally, it was observed that the test compound inhibited the ergosterol biosynthesis by yeast
Assuntos
Candida albicans/efeitos dos fármacos , Ergosterol/agonistas , Antifúngicos/análise , Candida/classificação , Preparações Farmacêuticas/análise , Testes de Sensibilidade Microbiana/instrumentaçãoRESUMO
Resumo A saúde planetária vem se consolidando como área transdisciplinar do conhecimento, fundamentada na caracterização e mitigação dos impactos antropogênicos sobre a saúde do ser humano e dos sistemas terrestres. O estilo de vida em sociedades capitalistas impulsiona a degradação ambiental e suas consequências (como emergência climática e perda de biodiversidade), relacionando-se também à alta prevalência de doenças crônicas não transmissíveis. No entanto, essas questões não costumam receber a atenção necessária no processo de ensino e aprendizagem dos profissionais de saúde. Assim, este ensaio objetiva contribuir para sistematização das informações que correlacionam os fatores ambientais e a saúde humana na perspectiva do pensamento sistêmico, destacando a importância de se pensar a saúde sistêmica no âmbito das profissões da saúde. Observa-se que o profissional de saúde, sendo ponte entre o conhecimento científico e a sociedade, pode desempenhar os papéis de mediador do cuidado integral e curador do conhecimento. Além disso, é preciso incentivar o pensamento sistêmico no processo formativo em saúde para que esses papéis sejam alcançados, tanto em atitudes individuais quanto coletivas.
Abstract Planetary Health has been consolidated as a transdisciplinary area of knowledge grounded in characterizing and mitigating anthropogenic impacts on the health of human beings and earth systems. The capitalist lifestyle drives environmental degradation and its consequences (such as climate emergency and biodiversity loss), and is related to the high prevalence of chronic non- communicable diseases. This information, however, usually lacks the necessary emphasis in health teaching and learning process. Thus, this essay aims to systematize information that correlates environmental factors and human health from a systemic thinking perspective, highlighting the importance of reflecting on systemic health within health professions. As the bridge between scientific knowledge and society, health professionals can play the role of integral care agent and knowledge curator. Moreover, we must encourage systemic thinking in health education to achieve these roles, both in individual and collective attitudes.
Assuntos
Saúde AmbientalRESUMO
The Caatinga is an exclusively Brazilian biome where semiarid climatic conditions promote singularities in adaptive biodiversity. Many aromatic species are found in this region possessing antifungal properties, which are attributed to their essential oils. Thus, we questioned whether essential plant oils found in the Caatinga present anti-dermatophytic potential. Dermatophytes are keratinophilic fungi that cause one of the most prevalent mycoses globally, skin infections known as dermatophytoses (tineas). Here, we provide a comprehensive report of the available published information, analyzing the methods used to evaluate the antifungal activity, verifying the quality of the evidence and possible clinical applications, and discussing research trends in this area. The plants studied concentrated in the genera Croton (Euphorbiaceae), Lippia (Verbenaceae), Piper (Piperaceae), and Mentha (Lamiaceae). All of the studies used in vitro tests to analyze antifungal potential, and little evidence was ascertained concerning the mechanism of antifungal action. In addition, the essential oils also evidenced drug modifying activity of conventional antifungal drugs (Ketoconazole and Terbinafine). We believe that the anti-dermatophyte potential of plant essential oils occurring within the Caatinga is underestimated and that this review will encourage future chemical-pharmacological investigations into the plants within this biome.Key points⢠The essential oils from plants occurring in the Caatinga Biome present unknown anti-dermatophyte potential.⢠The studies against dermatophyte fungi concentrate on the families Lamiaceae and Verbenaceae.⢠In vitro assays were used to assess the anti-dermatophyte potential of the essential oils.
Assuntos
Óleos Voláteis , Tinha , Antifúngicos/farmacologia , Ecossistema , Humanos , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Óleos de PlantasRESUMO
Spondias mombin L. (Anacardiaceae) has a worldwide distribution and is present in all regions of Brazil. Its leaves, flowers and bark are used as teas in folk medicine to treat diseases of the digestive system. This study aimed to evaluate the acute non-clinical toxicity, gastroprotective activity, and the related mechanisms of action of nebulized extract and tablets based on dried Spondias mombin (SmNE). SmNE screening showed the presence of flavonoids (0.65%), polyphenols (25.50%), where the major compound is gallic acid. In the acute oral toxicity assay, a dose of 2000 mg/kg of SmNE administered orally in Swiss mice did not induce any behavioral changes. SmNE (250 or 500 mg/kg p.o) significantly reduced the ulcerative lesion area when compared to the control group in ethanol and non-steroidal anti-inflammatory drug (NSAIDs) models. Results showed that treatment with SmNE (250 mg/kg) reduced acid secretion and gastric content, accompanied with an increase in pH. Previous administration of indomethacin and glibenclamide reversed the protection provided by SmNE, confirming the participation of prostaglandins (PGs) and ATP-sensitive potassium channels (KATP) in its gastroprotective effect. The SmNE tablets met the pharmacopeial quality requirements with gastroprotective activity and similar protection in comparison to the isolated extract administrated. In conclusion, SmNe has a gastroprotective activity related to cytoprotective mechanisms, such as the participation of endogenous prostaglandins and KATP channels, having an anti-secretory effect with systemic action. The formulation obtained presented gastroprotective effects similar to the administration of the extract, the tablets showed favorable compression characteristics by the direct route and met the pharmacopeial quality requirements.
Assuntos
Anacardiaceae/química , Antiulcerosos/administração & dosagem , Fitoterapia , Úlcera Gástrica/prevenção & controle , Animais , Anti-Inflamatórios não Esteroides/toxicidade , Antiulcerosos/química , Antiulcerosos/toxicidade , Modelos Animais de Doenças , Composição de Medicamentos , Etanol/toxicidade , Feminino , Ácido Gástrico/metabolismo , Canais KATP/metabolismo , Masculino , Camundongos , Nebulizadores e Vaporizadores , Compostos Fitoquímicos/administração & dosagem , Compostos Fitoquímicos/química , Compostos Fitoquímicos/toxicidade , Piroxicam/toxicidade , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Plantas Medicinais/química , Prostaglandinas/metabolismo , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/metabolismo , ComprimidosRESUMO
Dental caries and periodontal disease are the most prevalent of the biofilm-dependent diseases. With numerous side effects on the use of chlorhexidine, the search for new safe therapeutic alternatives for microorganisms involved with these diseases increases every day. This study aimed to evaluate the antimicrobial activity and cytotoxicity of extracts made from the bark of Schinopsis brasiliensis Engl. against five oral microorganisms and analyze their phytochemical and thermal degradation profile. The liquid-liquid partition was performed with hexane, chloroform and ethyl acetate. The identification and quantification of the chemical marker was done. Antimicrobial activity was evaluated based on the minimum inhibitory concentration. The cytotoxicity was analyzed based on the hemolysing potential of the samples. The thermal degradation profile was performed by two different methods. Gallic acid was identified as the main compound of the samples and showed the highest amount in the chloroform fraction. All samples were able to inhibit the growth of the microorganisms tested and showed no cytotoxicity. The ethanol extract absorbs less heat than the fractions. All samples exhibited exothermic peak consistent with degradation of gallic acid. Based on the results, the samples used are potential candidates for use in dental formulations for biofilm control.
Assuntos
Anacardiaceae , Cárie Dentária , Biofilmes , Humanos , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos , Extratos Vegetais/farmacologiaRESUMO
Enterococcus faecalis infections represent a health concern, mainly in oral diseases, in which treatments with chlorhexidine solution (0.2%) are often used; however, it presents high toxicity degree and several side effects. Based on this, the use of natural products as an alternative to treatment has been explored. Nonetheless, plant extracts have poor organoleptic characteristics that impair theirs in natura use. Therefore, this work aimed to evaluate the analytical profile, biological activity, and cytotoxicity in vitro of S. brasiliensis-loaded chitosan microparticles (CMSb) produced using different aspersion flow rates. The analytical fingerprint was obtained by FTIR and NIR spectra. Principal components analysis (PCA) was used to verify the similarity between the samples. The crystallinity degree was evaluated by X-ray diffraction (XRD). Phytochemical screening (PS) was performed to quantify phytocompounds. Antimicrobial activity was evaluated by minimum inhibitory concentration (MIC). Antibiofilm activity and bactericidal kinetics against E. faecalis (ATCC 29212 and MB 146-clinical isolated) were also assessed. The hemolytic potential was performed to evaluate the cytotoxicity. Data provided by FTIR, NIR, and PCA analyses revealed chemical similarity between all CMSb. Furthermore, the results from XRD analysis showed that the obtained CMSb present amorphous characteristic. Tannins and polyphenols were accurately quantified by the PS, but methodology limitations did not allow the flavonoid quantification. The low hemolytic potential assay indicates that all samples are safe. Antimicrobial assays revealed that CMSb were able to inhibit not only the E. faecalis ATCC growth but also the biofilm formation. Only one CMSb sample was able to inhibit the clinical strain. These results highlighted the CMSb antimicrobial potential and revealed this system as a promising product to treat infections caused by E. faecalis.
Assuntos
Anacardiaceae , Anti-Infecciosos/administração & dosagem , Quitosana/administração & dosagem , Enterococcus faecalis/efeitos dos fármacos , Microesferas , Extratos Vegetais/administração & dosagem , Administração Oral , Anti-Infecciosos/isolamento & purificação , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Enterococcus faecalis/fisiologia , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Humanos , Testes de Sensibilidade Microbiana/métodos , Tamanho da Partícula , Casca de Planta , Extratos Vegetais/isolamento & purificaçãoRESUMO
Dental caries and periodontal disease are the most prevalent of the biofilm-dependent diseases. With numerous side effects on the use of chlorhexidine, the search for new safe therapeutic alternatives for microorganisms involved with these diseases increases every day. This study aimed to evaluate the antimicrobial activity and cytotoxicity of extracts made from the bark of Schinopsis brasiliensis Engl. against five oral microorganisms and analyze their phytochemical and thermal degradation profile. The liquid-liquid partition was performed with hexane, chloroform and ethyl acetate. The identification and quantification of the chemical marker was done. Antimicrobial activity was evaluated based on the minimum inhibitory concentration. The cytotoxicity was analyzed based on the hemolysing potential of the samples. The thermal degradation profile was performed by two different methods. Gallic acid was identified as the main compound of the samples and showed the highest amount in the chloroform fraction. All samples were able to inhibit the growth of the microorganisms tested and showed no cytotoxicity. The ethanol extract absorbs less heat than the fractions. All samples exhibited exothermic peak consistent with degradation of gallic acid. Based on the results, the samples used are potential candidates for use in dental formulations for biofilm control.
RESUMO
In this study, the chemical composition, genotoxic, cytotoxic and antibacterial-modulating activities of the P. pyramidalis (NPpE) extract was evaluated. The fingerprint chromatogram was determined using HPLC-DAD. The NPpE Minimal Inhibitory Concentration (MIC), as well as that of antimicrobial drugs in the presence and absence of the extract, were evaluated using the microdilution method against Gram positive bacteria. In vivo assays with mice were used for the determination of the extract's genotoxicity and cytotoxicity. The presence of the polyphenol catechin was confirmed in the extract. The extract showed significant antimicrobial activity (MIC ≤ 1000 µg mL-1) against Staphylococcus aureus, Streptococcus oralis and S. mutans. When the NPpE was associated with several antimicrobials, the MIC of most of these were significantly reduced (P < 0.001) demonstrating good prospective usage in antimicrobial therapy. The extract has mutagenic and cytotoxic potential, however, further studies should be performed to confirm their toxicity.
Assuntos
Antibacterianos/farmacologia , Fabaceae/química , Compostos Fitoquímicos/farmacologia , Animais , Antibacterianos/química , Catequina/farmacologia , Cromatografia Líquida de Alta Pressão , Avaliação Pré-Clínica de Medicamentos , Camundongos , Testes de Sensibilidade Microbiana , Testes de Mutagenicidade , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/química , Compostos Fitoquímicos/toxicidade , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polifenóis/análise , Staphylococcus aureus/efeitos dos fármacos , Streptococcus oralis/efeitos dos fármacosRESUMO
Herbal medicines currently represent an important part of the world pharmaceutical market, which shows growing interest in the use of herbal medicines. However, the production of such medicines involves a complex series of steps, which determine the production viability and the quality of the final product. Ximenia americana L. is a plant occurring in several regions of the world, with well-known and applied medicinal properties. Thus, the aim of this work was to develop and evaluate the physical and physical-chemical quality of tablets produced with X. americana L. extract. The extract was spray-dried from a hydroethanolic extractive solution and characterized as to its phytochemical composition. The chemical marker was determined and quantified using validated chromatographic methods. These methods indicated the presence of gallic acid at a concentration of 1.61 mg g(-1). Formulations were proposed and analyzed for their flow and compaction properties. The best formulation was used to obtain a batch of tablets, which was evaluated for its quality characteristics and showed to be within the pharmacopoeial specifications for average weight, hardness, friability, and disintegration time. The dissolution profile of the tablets produced was obtained, showing the release of about 70% of the vegetable extract content within 30 minutes. Results showed that it was possible to obtain herbal tablets containing a high content of vegetal extract by direct compression, developing a rapid process of formulation and production and guaranteeing the quality characteristics of the final product.
Assuntos
Olacaceae , Extratos Vegetais/análise , Comprimidos/análise , Liberação Controlada de Fármacos , Excipientes/análise , Dureza , Compostos Fitoquímicos/análise , Pós/análise , Solubilidade , Comprimidos/normasRESUMO
Poincianella pyramidalis (Tul.) LP Queiroz (Fabaceae) is an endemic tree of northeastern Brazil, occurring mainly in the Caatinga. Its medicinal use is widespread and is an important therapeutic option against diarrhea, dysentery, and respiratory and urinary infections, among other diseases. In this study we determined the chemical marker and evaluated the interaction between P. pyramidalis extract and a commercial antimicrobial through the use of biological and analytical models. To obtain the extract, an ethanol-water mixture (50:50 v/v) was used as solvent. It was nebulized in a spray dryer using colloidal silicon dioxide as a drying adjuvant. The extract (ENPp) was subjected to HPLC analysis to verify the presence of certain secondary metabolites. The Minimum Inhibitory Concentration (MIC) of the extract against Gram-negative bacteria was determined by broth microdilution and the MIC of synthetic antimicrobial drugs in the presence and absence of the extract. The antioxidant activity of ENPp was evaluated by the DPPH method. The compatibility between the antimicrobial and the extract was evaluated by thermal analysis (TG/DTA). The acute toxicity of the extract was evaluated in vivo in rodents. The results indicate significant additive action of the extract on synthetic antibiotics, considerable antioxidant activity and absence of toxicity. This extract shows high potential for the development of formulations for antimicrobial therapy when used with a vegetable-active ingredient.
Assuntos
Anti-Infecciosos/farmacologia , Caesalpinia/química , Extratos Vegetais/farmacologia , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Cromatografia , Interações Medicamentosas , Feminino , Flavonoides/química , Flavonoides/farmacologia , Masculino , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Polifenóis/química , Polifenóis/farmacologia , Ratos , Termodinâmica , Termogravimetria , Testes de Toxicidade AgudaRESUMO
AbstractThe aim of this work was to develop and validate an analytical method for the identification of the chemical marker of Schinopsis brasiliensis Engl., Anacardiaceae. It would determine the total polyphenols and flavonoid content by spectrophotometric methodology in the dried extract of plant. The chromatographic profiles of S. brasiliensis were determined using HPLC-UV. The liquid chromatography method was conducted on a Phenomenex Gemini NX C18 column (250 × 4.6 mm, 5 μm). The mobile phase consisted of 0.05% orthophosphoric acid: methanol. The flow rate was 1 ml/min and effluents were monitored at 271 nm. The retention time for gallic acid was 8.5 min. The described method has the advantage of being both rapid and easy. Hence it can be applied for routine quality control analysis of herbal preparation containing S. brasiliensis.
RESUMO
A Agência Nacional de Vigilância Sanitária (ANVISA) não exige a realização de ensaios de bioequivalência utilizando métodos enantiosseletivos de quantificação de fármacos para o registro de medicamentos genéricos ou similares contendo fármacos racêmicos. Porém, existe a possibilidade das diferenças de concentrações plasmáticas dos enantiômeros entre o medicamento referência e os genéricos e/ou similares comercializados no Brasil serem maiores que as estabelecidas pelos limites de bioequivalência. Esse estudo teve a finalidade de investigar a influência da velocidade de liberação do fármaco metoprolol, a partir da forma farmacêutica, sobre o processo de absorção do fármaco total e de seus enantiômeros por meio da avaliação das concentrações plasmáticas de metoprolol total, (S)-metoprolol e (R)-metoprolol, e da relação entre as concentrações dos enantiômeros (S/R) após a administração oral de medicamentos contendo mistura racêmica deste fármaco. Para isso, foi realizado ensaio de biodisponibilidade in vivo, em um grupo de 20 voluntários saudáveis, de acordo com procedimentos éticos estabelecidos internacionalmente. Foram empregados três esquemas de administração do metoprolol, com a finalidade de simular diferentes velocidades de liberação do fármaco a partir da forma farmacêutica, na Fase 1 foi administrado uma dose única de 100 mg de metoprolol em solução, na Fase 2 e Fase 3 essa mesma dose foi particionada em duas e cinco administrações, respectivamente, com intervalo de 30 minutos entre elas. Foram coletadas amostras de sangue, e estas foram analisadas utilizando método convencional e método quiral para quantificação do metoprolol total e seus enantiômeros, respectivamente, utilizando cromatografia líquida de alta eficiência, com detector de fluorescência. Os parâmetros farmacocinéticos de ASC0-t, Cmáx e Tmáx foram utilizados para comparação entre as três velocidades de liberação do fármaco a partir da forma farmacêutica. A análise farmacocinética para o fámaco (R,S) metoprolol e seus enantiômeros e a comparação entre seus parâmetros farmacocinéticos obtidos após administração oral do metoprolol, indicam uma cinética enantioseletiva para o metoprolol, que pode ter ocorrido devido a uma biotransformação pré-sistêmica dose-dependente, ou a uma inibição do metabolismo do (S)-metoprolol pela forma (R)-metoprolol
ANVISA, brazilian regulatory agency for drug products, does not require the use of enantioselective bioanalytical methods in bioequivalence assays of generic and similar drug products containing racemic drugs. Therefore, it is possible that two formulations are bioequivalent based on plasmatic concentration of total drug, but are not bioequivalent on the basis of the comparison of the data of the stereoisomers. The objective of this study was to investigate the influence of the release rate of metoprolol from the dosage form on its absorption process and on its enantiomers' absorption process by measuring plasmatic concentrations of total metoprolol, (S)-metoprolol and (R)-metoprolol after oral administration of drug products containing racemic metoprolol. An in vivo bioavailability study was conducted in a group of 20 healthy volunteers, according to national and international guidelines for biomedical research, in which the administration rate of metoprolol was varied. In Phase 1 a single dose of 100 mg metoprolol was administered in solution, in Phase 2 and Phase 3 the same dose was partitioned into two and five administrations, respectively, with an interval of 30 minutes between them. Blood samples were collected, and these were analyzed using the conventional method and chiral method for quantification of (R,S)-metoprolol and for its enantiomers, using high performance liquid chromatography with fluorescence detection. The pharmacokinetic parameters AUC0-t, Cmax and Tmax were used for comparisons between three different drug release rates. Pharmacokinetic analysis for (R, S) metoprolol and its enantiomers and comparison of their pharmacokinetic parameters obtained after oral administration of metoprolol, to indicate an enantioselective kinetic, which may be due to a biotransformation pre-systemic dose dependent or the inhibition of metabolism of the (S)-form for metoprolol (R)-metoprolol
Assuntos
Humanos , Masculino , Feminino , Absorção , Metoprolol/administração & dosagem , Farmacocinética , Disponibilidade Biológica , Cromatografia LíquidaRESUMO
We describe the validation data of a simple but selective chromatographic method for determination of ampicillin in human plasma using liquid chromatography-diode array detector. Blank plasma free of drugs was transferred to eppendorf's tubes and spiked with ampicillin stock solution to obtain quality control samples at 1.00, 2.50, 5.00, and 10.00 microg/mL. Extraction of ampicillin and cephalexin (internal standard) from plasma samples (250 microL) was investigated using three different methods: precipitation with perchloric acid, ultra-filtration and solid-phase extraction. Chromatographic separation was achieved using a Shimpak C(18) column (300 mm x 4.6 mm i.d.; 5 microm), and detection was done at 215 nm with a diode array UV-Vis detector. The mobile phase consisted of dihydrogen phosphate (pH 3.5)-acetonitrile (87.5:12.5, v/v) delivered at a flow rate of 1.00 mL/min. Selectivity was evaluated with different pools of human plasma. Perchloric acid precipitation showed an excellent selectivity for normal plasma. The precipitation method presented recoveries above 84.0 +/- 3.3% and 82.0 +/- 1.6%, (n = 3) for ampicillin and cephalexin, respectively. The method has a limit of detection of 0.15 microg/mL and is linear in the range of 0.30 to 100.00 microg/mL. Standardized residue analysis demonstrated normality and homocedasticity. Inter-day precision was 4.5%, and accuracy was 11.1% (n = 9). Stability studies demonstrated instability of b-lactamics in human plasma at 20 and 2 degrees C after 6 and 360 h of storage, respectively.
Assuntos
Ampicilina/sangue , Cromatografia Líquida/métodos , Cromatografia Líquida/instrumentação , Humanos , Sensibilidade e Especificidade , Espectrofotometria UltravioletaRESUMO
A method for the quantification of aflatoxins B1, G1, B2 and G2 in the medicinal herb Maytenus ilicifolia was developed and validated. The method used immunoaffinity columns for sample clean-up and HPLC with fluorescence detection without any derivatisation step. The method showed good inter-day accuracy (bias values in the range 4.5-10.7%) and precision (5-16% RSD) when applied to the determination of levels of aflatoxins ranging from 7 to 20 ppb in the plant material. The detection limits for samples of the plant material spiked with aflatoxins were 3.5 ng/g for B1 and G1 and 0.1 ng/g for B2 and G2. The method was successfully applied to commercial samples of Maytenus ilicifolia for the screening of aflatoxin contaminants.