Comparison of extraction methods for chemical composition, antibacterial, depigmenting and antioxidant activities of Eryngium maritimum.

OBJECTIVE: The objective is to develop a natural cosmetic ingredient from Eryngium maritimum regarding the high interest of consumer in these ingredients for cosmetic use. METHODS: Five eco-friendly techniques of extraction were applied to Eryngium maritimum aerial parts among conventional reflux extraction (with green solvent) and alternative techniques (supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and ultrasound combined with microwave extraction (UAE + MAE)). Several criteria were evaluated to allow the optimal choice for an industrialized ingredient: yield of extraction, chemical composition and biological activities such as antimicrobial, antioxidant, anti-collagenase and anti-tyrosinase activities. The extracts were analysed by liquid chromatography mass spectrometry (LC-HRMS), and the hierarchical Pearson classification (HCA) allowed to highlight the group of metabolites preferably extracted depending on the technique of extraction used. RESULTS: The biological results highlight that SFE and 80% ethanol reflux extracts have the best responses to biological activities such as antimicrobial, depigmenting and antioxidant activities, followed by water reflux extraction. Their activities might be due to the presence of different groups of metabolites favourably extracted by these techniques. CONCLUSION: Among these extractions, water reflux extraction provided the optimal results considering the compromise between extraction yield and biological activities for the development of a cosmetic ingredient.

OBJECTIF: L'objectif est d'évaluer différentes méthodes d'extraction permettant l'obtention d'un ingrédient cosmétique naturel, à partir d'Eryngium maritimum, efficace biologiquement, et respectant les principes du développement durable et de la beauté éthique et responsable. MÉTHODES: Cinq techniques d'extraction respectueuses de l'environnement ont été appliquées à des parties aériennes d'Eryngium maritimum tels que le reflux conventionnel (avec des solvants agrosourcés) et des techniques alternatives (extraction au fluide supercritique (SFE), extraction assistée par micro-ondes (MAE), extraction assistée par ultrasons (UAE) et ultrasons combinés aux micro-ondes (UAE + MAE)). Plusieurs critères ont été évalués pour permettre le choix optimal d'un ingrédient cosmétique efficace, naturel et industrialisable : rendement d'extraction, composition chimique (sureté) et efficacités biologiques (antibactérien, antioxydant, anti-âge et dépigmentant). Les extraits ont été analysés par chromatographie liquide spectrométrie de masse (LC-HRMS), et la classification par hiérarchie de Pearson (HCA) a permis de mettre relier les groupes de métabolites extraits de préférence par technique d'extraction testée. RÉSULTATS: Les résultats biologiques mettent en évidence que les extractions par SFE et à reflux par éthanol 80% permettaient les meilleures réponses (les plus importantes) pour des activités antimicrobiennes, éclaircissantes et antioxydantes, devant l'extraction à reflux par l'eau. Leurs activités pourraient être dues à la présence préférentielle de certains groupes de métabolites extraits plus favorablement par ces techniques. CONCLUSION: Parmi les extractions testées, l'extraction par reflux à l'eau (procédé respectueux de l'environnement) d'Eryngium maritimum, fournit le meilleur compromis en termes d'efficacités biologiques plurielles, de rendement d'extraction et de productivité/consommation énergétique, pour le développement d'un ingrédient cosmétique 'ecofriendly'.

Inhibitory impact of bifidobacteria on the transfer of beta-lactam resistance among Enterobacteriaceae in the gnotobiotic mouse digestive tract.

While looking for new means to limit the dissemination of antibiotic resistance, we evaluated the role of potentially probiotic bifidobacteria on the transfer of resistance genes between enterobacteria. Transfers of bla genes encoding extended-spectrum beta-lactamases (SHV-5 and CTX-M-15) were studied in the absence or presence of bifidobacteria. In vitro, transfer frequencies of these bla genes decreased significantly in the presence of three of five tested strains, i.e., Bifidobacterium longum CUETM-89-215, Bifidobacterium bifidum CIP-56.7T, and Bifidobacterium pseudocatenulatum CIP-104168T. Four transfer experiments were conducted in the digestive tract of gnotobiotic mice, the first three observing the effect of B. longum CUETM-89-215, B. bifidum CIP-56.7T, and B. pseudocatenulatum CIP-104168T on blaSHV-5 transfer and the fourth experiment studying the effect of B. bifidum CIP-56.7T on blaCTX-M-15 transfer. These experiments revealed significant decreases in the transconjugant levels (up to 3 logs) in mice having received B. bifidum CIP-56.7T or B. pseudocatenulatum CIP-104168T compared to control mice. Bifidobacteria appear to have an inhibitory impact on the transfer of antibiotic resistance genes. The inhibitory effect is associated to specific bifidobacterial strains and may be related to the production of thermostable metabolites by these strains.

Evaluation of bronchoscopic techniques for the diagnosis of nosocomial pneumonia.

To compare the usefulness of specimens obtained by bronchoalveolar lavage (BAL) and using a protected specimen brush (PSB) in the diagnosis of nosocomial pneumonia, both procedures were performed via fiberoptic bronchoscopy just after death in a series of 20 ventilated patients who had not developed pneumonia before the terminal phase of their disease and who had no recent changes in antimicrobial therapy. These results were compared with both histologic and microbiologic postmortem lung features in the same area. The total number of bacteria obtained by culture of lung segments and the latters' histologic grade were closely correlated (rho = 0.79, p < 0.0001). PSB and BAL quantitative culture results were strongly correlated with lung tissue values (rho = 0.67 and 0.75, respectively; p < 0.0001). Using discriminative values of > or = 10(3) and > or = 10(4) bacteria/ml to define positive PSB and BAL cultures, respectively, these techniques identified lung segments yielding > or = 10(4) bacteria/g tissue with sensitivities of 82 and 91% and specificities of 89 and 78%, respectively. Moreover, upon direct observation, the percentage of BAL cells containing intracellular bacteria was closely correlated with the total number of bacteria obtained from corresponding lung samples (p < 0.001). These findings indicate that bronchoscopic PSB and BAL samples very reliably identify both qualitatively and quantitatively microorganisms present in lung segments with bacterial pneumonia, even when the infection develops as a superinfection in a patient already receiving antimicrobial treatment for several days.

Follow-up protected specimen brushes to assess treatment in nosocomial pneumonia.

To prospectively determine the bacteriologic and clinical efficacy of antimicrobial therapy for nosocomial bacterial pneumonia selected based upon information provided by cultures of protected specimen brush (PSB) samples obtained during bronchoscopy, 76 consecutive patients with ventilator-associated pneumonia were studied using follow-up quantitative PSB cultures obtained after 3 days of treatment. Of the 173 microorganisms initially present in the PSB samples, only 11 (6%) were not eradicated by antimicrobial therapy, including three recovered at high (> or = 10(3) cfu/ml) concentrations. Thirty-two emerging pathogens, including nine at high concentrations, were also detected; 26 of them (81%) were resistant to the initial antibiotics administered. Of the 76 patients included in the study, cultures of follow-up PSB samples identified 51 in whom the infection site in the lung was completely sterilized, 16 with low-grade infection, and only nine with persistent high-grade infection. Analysis of clinical outcome within the 15 days after the initiation of antimicrobial therapy demonstrated clinical improvement in 62 of 67 (93%) patients in whom the site of infection was contained by treatment as compared with four of 9 (44%) patients with persistent high-grade infection (p < 0.01). These data suggest that appropriate antimicrobial therapy for ventilator-associated pneumonia results in the control of the initial infection in 88% of the patients. However, an early superinfection caused by multiresistant pathogens can occur in a small subset of these patients. When follow-up PSB cultures were negative, an improved outcome was noted.