RESUMO
A healthy skin provides a protective barrier against pathogenic micro-organisms. Recent studies have shown that probiotics, as those of Bifidobacterium genus, could act beneficially in dermatology, both when ingested and by topical use. In the present study, we evaluated by in vitro antagonism assays and using two skin cell lines the potential of four strains of Bifidobacterium spp. Among the four bifidobacteria, Bifidobacterium longum 51A was the only one able to inhibit the growth of the eight pathogenic indicators tested. Production of some cytokines and extracellular matrix proteins was determined when ccc or inactivated cells of the bifidobacteria were incubated with keratinocyte and/or fibroblast cell cultures. Significant results were observed only for IL-6, IL-8 and IL-18 production, and inactivated Bifidobacterium pseudolongum 1191A was the only one which significantly stimulated collagen production, whereas lumican was stimulated by treatments with live Bifidobacterium bifidum 1622A , B. longum 51A and B. pseudolongum 1191A . Highest adhesion and internalization capabilities were observed with B. bifidum 1622A and Bifidobacterium breve 1101A . Concluding, B. longum 51A was highlighted for its antagonistic capacity and B. bifidum 1622A and B. pseudolongum 1191A for stimulating the production of cytokines and proteins of the extracellular matrix. SIGNIFICANCE AND IMPACT OF THE STUDY: The skin is the first line of defence against invasive micro-organisms, and its local microbiota provides additional protective functions based on antagonism against pathogenic micro-organisms and immunomodulation. Based on in vitro assays using Bifidobacterium spp. we demonstrated the antagonistic potential, as well as capacity in stimulating the production of cytokines and proteins of the extracellular matrix that these bacteria may exert on skin cells. This positive influence suggests the use of a consortium of these bifidobacteria in a topical product for dermatological treatments.
Assuntos
Antibiose/fisiologia , Bifidobacterium/metabolismo , Citocinas/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Probióticos/metabolismo , Pele/microbiologia , Bifidobacterium/classificação , Candida albicans/crescimento & desenvolvimento , Linhagem Celular , Humanos , Malassezia/crescimento & desenvolvimento , Propionibacterium acnes/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus epidermidis/crescimento & desenvolvimentoRESUMO
BACKGROUND: Investigations in the field of pharmaceutical analysis and quality control of medicines require analytical procedures that achieve suitable performance. An analytical curve is one of the most important steps in the chemical analysis presenting a direct relationship to features such as linearity. OBJECTIVE: This study has the aim of developing a new methodology, the stationary cuvette, to derive analytical curves by spectroscopy for drug analysis. METHODOLOGY: The method consists basically of the use of a cuvette with a path length of 10 cm, containing a constant volume of solvent in which increasing amounts of a stock solution of the sample are added, droplet by droplet. After each addition, the cuvette is stirred and the absorbance is measured. This procedure was compared with the currently used methodology, which requires a labour-intensive dilution process, and possible sources of variation between them were evaluated. RESULTS: The results demonstrated that the proposed technique presented high sensitivity and similar reproducibility compared with the conventional methodology. In addition, a number of advantages were observed, such as user-friendliness, cost-effectiveness, accuracy, precision and robustness. CONCLUSION: The stationary cuvette approach may be considered to be an appropriate alternative to derive analytical curves for analysing drug content in raw materials and medicines through UV-VIS spectrophotometry.
Assuntos
Hidrocortisona/química , Ibuprofeno/química , Kalanchoe/química , Penicilina G Benzatina/química , Extratos Vegetais/química , Espectrofotometria/métodos , Reprodutibilidade dos TestesRESUMO
The aim of this work was to investigate the influence of a lipophilic drug, Ibuprofen, on the stability of o/w emulsions. Five formulations were prepared by the phase inversion temperature (PIT) method, and Ibuprofen was incorporated into their oil phase. Emulsion stability was evaluated by short- and long-term studies. Concerning the former, stability under centrifugation showed an improved profile for Ibuprofen-loaded emulsions. The latter confirmed such findings. In conclusion, a rather resistant interfacial film may take place when Ibuprofen was incorporated into the emulsions. Therefore, the critical hydrophilic-lipophilic-balance (HLB) of o/w emulsions can be affected by a lipophilic drug into their oil phase. Such approach is of great importance on the development of lipid carriers for therapeutic drug targeting.
Assuntos
Anti-Inflamatórios não Esteroides/química , Portadores de Fármacos/química , Emulsões/química , Ibuprofeno/química , Anti-Inflamatórios não Esteroides/administração & dosagem , Estabilidade de Medicamentos , Emulsificantes/química , Concentração de Íons de Hidrogênio , Ibuprofeno/administração & dosagem , Óleo Mineral/química , Reologia , Água/químicaRESUMO
Suboptimal disposition behavior of drugs requires innovative delivery approaches. Magnetic drug targeting seems to be a promising one. Magnetic particles develop magnetic polarization and magnetophoretic mobility, and because of such unique properties, these carriers may be eligible candidates for delivering drugs to specific locations within the body. Their special properties also allow other uses, such as those in magnetic separation, hyperthermia, and magnetic resonance imaging. This review focuses on a brief discussion of magnetic drug targeting, the properties and fate of magnetic carriers, the methods used to produce and characterize them, and their other uses in biotechnology.
Assuntos
Portadores de Fármacos/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Biotecnologia/métodos , Biotecnologia/tendências , Sistemas de Liberação de Medicamentos/tendências , Humanos , MagnetismoRESUMO
Turnera ulmifolia L. is used in Brazilian folk medicine as an anti-inflammatory. Since this activity may be correlated with the presence of antioxidant compounds, a leaf extract was evaluated for its radical scavenging capacity (RSC). The in vitro RSC of a 50% hydroethanolic (HE) extract was evaluated by beta-carotene/linoleic acid coupled oxidation system for the inhibition of oxidation and the lipid peroxidation inhibition in rat brain homogenates, using thiobarbituric acid reactive substances (TBARS) and chemiluminescence (CL). Results indicated, through peroxidation suppression, that this extract exhibited greater antioxidative activity (77.4% +/- 10%) than alpha-tocopherol (58.4% +/- 3.7%). TBARS and CL inhibition was concentration-dependent and Q(1/2) values were 8.2 and 6.0 microg/mL for TBARS and CL, respectively. For alpha-tocopherol these values were 7.1 microg/mL (TBARS) and 9.8 microg/mL (CL). Phenolic compounds may be responsible for this antioxidant capacity.
Assuntos
Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Turnera/metabolismo , Animais , Antioxidantes/metabolismo , Biotecnologia/métodos , Encéfalo/metabolismo , Desenho de Fármacos , Radicais Livres , Peroxidação de Lipídeos , Folhas de Planta , Ratos , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico , beta Caroteno/metabolismoRESUMO
O objetivo desse trabalho foi o de desenvolver e avaliar do ponto de vista físico-químico um sistema micelar de penicilina G benzatina (BPG) em desoxicolato de sódio (NaDC).Foram estudadas as características físicoquímicas da BPG quanto à solubilidade em água e em soluções tampões com diferentes pHs, além do coeficiente de partição octanol-água.Foram avaliadas as propriedades da concentração micelar crítica (CMC) das soluções micelares de Desoxicolato de sódio (NaDC) em baixa e alta força iônica provocada pela presença de cloreto de sódio.O estudo da incorporação da BPG em soluções micelares de NaDC usando várias concentrações de NaDC também foi realizado.O aumento da solubilidade da BPG provocada pela presença de micelas de NaDC foi analisada quantitativamente pelo formalismo do modelo de pseudo-fase.Houve indicação da aplicabilidade do sistema micelar estudado quanto à incorporação de penicilina e aumento se sua solubilidade aparente, com taxa de incorporação de até 90 por cento.Espera-se que a formulação micellar de BPG apresente melhor estabilidade, considerando-se que o antibiótico incorporado na região hidrofóbica das micelas está protegido do meio aquoso externo.
Assuntos
Penicilina G Benzatina/administração & dosagem , Penicilina G Benzatina/farmacologia , Ácido Desoxicólico , Estabilidade de Medicamentos , Micelas , SolubilidadeRESUMO
Laryngectomy for treatment of laryngeal-pharyngeal carcinomas may impair the sensation in the larynx and epiglottis, with consequent impairment of esophageal motility. Our aim in the present study was to investigate the esophageal motility of laryngectomized patients. Esophageal manometry was performed on 17 patients submitted to laryngectomy 2 to 71 months (median 29 months) before the examination. Eleven were rehabilitated with esophageal voice and six could not speak. Ten swallows of a 5 ml bolus of water were recorded at the lower esophageal sphincter and at 5, 10 and 15 cm above it. The lower esophageal sphincter pressure was measured by the rapid pull-through method and the upper esophageal sphincter pressure by the station pull-through method. The results were compared with those obtained for a control group of 40 healthy volunteers. The amplitude of contractions was lower and the number of nonperistaltic contractions was higher in laryngectomized patients than in volunteers (P < 0.05). The duration of lower esophageal sphincter relaxation (7.4 +/- 1.5 s) was shorter in laryngectomized patients than in volunteers (8.8 +/- 1.6 s, P < 0.05). The upper esophageal sphincter pressure was lower (34.9 +/- 29.1 mm Hg) in laryngectomized patients than in volunteers (61.2 +/- 20.8 mm Hg, P < 0.05). There was no difference between groups in contraction duration or velocity, in the numbers of multipeaked or failed contractions, lower esophageal sphincter pressure or in the number of swallows followed by complete lower esophageal sphincter relaxation. In conclusion, laryngectomy causes esophageal motility impairment characterized by low contraction amplitude, nonperistaltic contraction and shorter lower esophageal sphincter relaxation duration.