Chemical composition and evaluation of modulatory of the antibiotic activity from extract and essential oil of Myracrodruon urundeuva

Context: The combination of antibiotics with natural products has demonstrated promising synergistic effects in several therapeutic studies.

Objective: The aim of this study was to determine the effect of a combination of an ethanol extract of Myracrodruon urundeuva Fr. All. (Anacardiaceae) (aroeira plant) and its essential oil with six antimicrobial drugs against multiresistant strains of Staphylococcus aureus and Escherichia coli from clinical isolates.

Materials and methods: After identification of the chemical components by GC-MS, the antibacterial activity of the natural products and antibiotics was assessed by determining the minimal inhibitory concentration (MIC) using the microdilution method and concentrations ranging 8–512?μg/mL and 0.0012–2.5?mg/mL, respectively. Assays were performed to test for a possible synergistic action between the plant products and the antimicrobials, using the extract and the oil at a sub-inhibitory concentration (128?μg/mL) and antibiotic at concentrations varying between 8 and 512?μg/mL.

Results: The GC-MS analysis identified the main compound as δ-carene (80.41%). The MIC of the natural products was >1024?μg/mL, except against S. aureus ATCC25923. Only the combinations of the natural products with gentamicin, amikacin and clindamycin were effective against S. aureus 358, enhancing the antibiotic activity by reducing the MIC.

Conclusions: The extract from aroeira showed a higher antibacterial activity and the oil was more effective in potentiating the activity of conventional antibiotics.     

A new nanoemulsion formulation improves antileishmanial activity and reduces toxicity of amphotericin B

This work aimed to optimise a new nanoemulsion (NE) formulation loaded with Amphotericin B (AmB) and to evaluate its in vivo antileishmanial activity and in vitro haemolytic toxicity. The influence of gradual increases in pressure, using a high-pressure homogeniser, was evaluated. The NE was characterised for droplet size, polydispersity index, zeta potential and encapsulation efficiency (EE). For antileishmanial activity studies, AmB-NE was administered intravenously in mice infected by Leishmania infantum chagasi, which causes Visceral Leishmaniasis (VL). When the NE was submitted to gradual increases in pressure, the PI values and droplet size decreased. The droplet size (～145?nm) was lower than that obtained in previous studies. The zeta potential was negative and the EE was almost 100%. The haemolytic toxicity, evaluated on human red blood cells, for AmB-loaded NE was lower than that observed for the conventional AmB (C-AmB). C-AmB at 2?mg/kg was very toxic. In contrast, administration of the AmB-loaded NE, at same dose, did not result in any sign of acute toxicity, promoting a significant reduction in parasite burden as compared to the C-AmB. These findings suggest that this new AmB-loaded NE constitutes an attractive alternative for the treatment of VL due to improved efficacy and lower toxicity.     

Low fecal calprotectin predicts clinical remission in Crohn's disease patients: the simple answer to a challenging question

Background and aim: Fecal calprotectin (FC) is a noninvasive marker of intestinal inflammation. Predicting relapses in Crohn’s disease (CD) patients can allow earlier changes in therapy. The aim of this study was to evaluate the role of FC in predicting relapse in CD patients in clinical remission within six months follow-up.

Methods: Patients with CD who were in clinical remission at least ≥3 months were included in this study. The first FC sample during the remission period was evaluated and was used as the baseline value. Relapse was defined as an unexpected escalation in therapy, hospitalization or need for surgery for active CD. The accuracy and optimal cutoff FC values for predicting clinical relapse at six months were assessed by the area under the ROC curve (AUC).

Results: One hundred and forty-four patients were evaluated, with mean age of 38.4 years. Of these, 13 (9%) had a relapse during the follow-up period. The mean FC value was significantly lower for non-relapsers (203.2?μg/g) than for relapsers (871.3?μg/g), p?<?.001. The AUC for predicting relapse by using FC values was 0.924. The optimal cutoff FC value to predict relapse was 327?μg/g; with values of sensitivity, specificity, negative predictive value and positive predictive value were 92.3%, 82.4%, 99.1% and 34.3%, respectively.

Conclusions: FC is more useful in predicting remission maintenance than relapse in patients with CD in clinical remission. Values of FC ≤327?μg/g can exclude relapse at least at six months follow-up period.     

Myofibroblasts and their relationship with oral squamous cell carcinoma

Myofibroblasts are hybrid-phenotype differentiated cells in between fibroblasts and smooth muscle cells. Due to their contractile features and ability to synthesize extracellular matrix components, cytokines, proteases, and proangiogenic factors, myofibroblasts have been implicated in the pathogenesis of fibrocontractive diseases and in the progression of many tumors, including oral squamous cell carcinoma (SCC).ObjectiveTo perform a literature review on the origin of myofibroblasts, their main morpho-physiological and immunohistochemical aspects, and to discuss the correlations with oral SCC.MethodA search was made on the PUBMED database to select the main papers in the literature in English related to the subject, published between January 1991 and December 2011.ConclusionMyofibroblasts are an important component of the stroma of oral SCCs, although they are not present in all tumors. Abundant presence of myofibroblasts may be associated with local disease recurrence and decreased patient survival. However, given the relatively limited number of studies on the subject, further research is needed to clarify the molecular mechanisms by which myofibroblasts influence the biological behavior of oral SCC.     

Phthalimido-thiazole as privileged scaffold: activity against immature and adult worms of Schistosoma mansoni

Parasitology Research - Phthalimide, 1,3-thiazole, and thiazolidinone cores are considered privileged scaffolds and represent an attractive starting point to design new bioactive compounds for...