Ursolic acid-rich extract presents trypanocidal action in vitro but worsens mice under experimental acute Chagas disease.

Chagas disease is a neglected tropical disease with only two drugs available for treatment and the plant Cecropia pachystachya has several compounds with antimicrobial and anti-inflammatory activities. This study aimed to evaluate a supercritical extract from C. pachystachya leaves in vitro and in vivo against Trypanosoma cruzi. A supercritical CO2 extraction was used to obtain the extract (CPE). Cytotoxicity and immunostimulation ability were evaluated in macrophages, and the in vitro trypanocidal activity was evaluated against epimastigotes and trypomastigotes forms. In vivo tests were done by infecting BALB/c mice with blood trypomastigotes forms and treating animals orally with CPE for 10 days. The parasitemia, survival rate, weight, cytokines and nitric oxide dosage were evaluated. CPE demonstrated an effect on the epi and trypomastigotes forms of the parasite (IC50 17.90 ± 1.2 µg/mL; LC50 26.73 ± 1.2 µg/mL) and no changes in macrophages viability, resulting in a selectivity index similar to the reference drug. CPE-treated animals had a worsening compared to non-treated, demonstrated by higher parasitemia and lower survival rate. This result was attributed to the anti-inflammatory effect of CPE, demonstrated by the higher IL-10 and IL-4 values observed in the treated mice compared to the control ones. CPE demonstrated a trypanocidal effect in vitro and a worsening in the in vivo infection due to its anti-inflammatory activity.

Influence of Ozonated Water as an Irrigant and Dentin-cleaning Solution on the Bond Strength of Fiberglass Pins.

AIM AND OBJECTIVE: This study aimed to evaluate the effect of ozonated water used as an irrigant and dentin-cleaning solution on the bond strength of fiberglass pins in vitro, comparing it with the commonly used solutions. MATERIAL AND METHODS: Seventy-seven bovine roots were randomly divided into seven groups according to the irrigant and dentin-cleaning solution to be used: HP/HP, 2.5% sodium hypochlorite; DA/DA, distilled water; CHX/CHX, 2% chlorhexidine; OA/OA, 4 ppm ozonated water; HP/DA; HP/CHX; and HP/OA. In each group, the root canals were endodontically prepared by using the corresponding irrigant and stored in DA; after 7 days, they were cleared and cleaned with the corresponding cleaning solution. The fiberglass pins were cemented by using self-adhesive cement. After 7 days, the roots were sectioned (six discs each) and submitted to the push-out test. The type of fracture was analyzed with a 4.5x stereoscopic magnifying glass. The data were analyzed by the analysis of variance and the Tukey test at a 5% significance level. RESULTS: The OA/OA (11.67), HP/HP (11.21), and HP/OA (9.71) groups showed the highest mean push-out bond strength (MPa) in the cervical third. The same trend was maintained in the middle and apical thirds. CONCLUSION: Ozonated water and 2.5% sodium hypochlorite are the most relevant solutions for root dentin treatment. CLINICAL RELEVANCE: Teeth treated with ozonated water, sodium hypochlorite, and a combination of the two showed greater bond strength than those treated with other solutions.

Antibiotic Activity of Wickerhamomyces anomalus Mycocins on Multidrug-Resistant Acinetobacter baumannii.

To evaluate the susceptibility of multidrug-resistant Acinetobacter baumannii to mycocins produced by Wickerhamomyces anomalus and to verify the cytotoxicity of these compounds. Three culture supernatants of W. anomalus (WA40, WA45, and WA92), containing mycocins (WA40M1, WA45M2, and WA92M3), were tested on A. baumannii using broth microdilution methods, solid medium tests, and cytotoxicity tests in human erythrocytes and in Artemia saline Leach. W. anomalus was able to produce high antimicrobial mycocins, as even at high dilutions, they inhibited A. baumannii. In a solid medium, it was possible to observe the inhibition of A. baumannii, caused by the diffusion of mycocins between agar. Finally, the three supernatants were not cytotoxic when tested on human erythrocytes and Artemia salina. According to the evidence in this study, the mycocins of W. anomalus have been effective and could be used in the development of new antimicrobial substances.

Leishmanicidal, Trypanocidal and Antioxidant Activity of Amyrin-Rich Extracts from Eugenia pyriformis Cambess.

AIMS: This study aimed to characterize and evaluate leishmanicidal and trypanocidal action as well as cytotoxicity on macrophages and antioxidant ability of extracts, obtained by supercritical CO2 and ultrasound-assisted extractions of Uvaia (Eugenia pyriformis) leaves. METHODS: Leaves from E. pyriformis were submitted to supercritical CO2 (E1) and ultrasound-assisted (E2) extractions. The characterization of extracts was done using GC-MS and HPLC. L. amazonensis (promastigotes) and T. cruzi (epimastigotes and trypomastigotes) were treated with crescent concentrations of E1 and E2. After this, parasites were counted and the percentage of inhibition and IC50/LC50 was calculated. Murine macrophages were treated with both extracts for 48 h and after that, the cellular viability was determined and CC50 was calculated. DPPH method was used to determine the antioxidant capacity of both extracts. RESULTS: The results of identification showed a great amount of α and ß-amyrin in E1 and E2. Both extracts showed growth inhibition of L. amazonensis with an IC50 of 5.98 and 9.38 µg/mL to E1 and E2, showing a selectivity index > 30. In trypanocidal tests, an LC50 of 16.69 and 7.80 µg/mL (trypomastigotes) and IC50 of 5.56 and 34.34 µg/mL (epimastigotes) was reached by E1 and E2. Both extracts showed no toxicity to macrophages and an antioxidant capacity similar to the positive control (tocopherol). CONCLUSIONS: This is the first study demonstrating the activity of an amyrin rich-extract against microorganisms that cause Chagas disease and leishmaniasis, as well as its antioxidant capacity, justifying further studies for future in - vivo tests.

Exopolysaccharides from Aspergillus terreus: Production, chemical elucidation and immunoactivity.

Aspergillus terreus, a fungus commonly used in pharmaceutical industry to produce lovastatin and other secondary metabolites, has been reported to have beneficial biological properties. In this study the exopolysaccharides (AT-EPS) produced by A. terreus were evaluated as potential modulators of certain functions of macrophages. The production parameters for EPS obtained from the liquid culture broth of the studied fungus were optimized using response surface methodology (RSM) and indicated good correlation between the experimental and predicted values. The optimum conditions for AT-EPS extraction included fermentation at 28 °C, pH 8.79, under 98 rpm of agitation, using 2.39% glucose (carbon source) and 0.957% ammonium nitrate (nitrogen source). Under these optimized conditions, AT-EPS production was 1.34 g/L medium. The chemical analyses showed that AT-EPS was composed by mannose (Man; 40.5 mol%), galactose (Gal; 35.2 mol%), and glucose (Glc; 24.3 mol%), and the spectroscopic (FTIR; NMR) and methylation analyses indicated the presence of galactomannans, ß-1,3-glucans, and glycogen-like glucans. AT-EPS was tested on murine macrophages to verify its immunoactivity and the treated cells were able to produce nitric oxide, superoxide anion, TNF-α and interleukin 6 similarly to the positive control cells. Furthermore, the macrophages treated with AT-EPS showed activated-like morphological alterations.

ß-(1→6)-D-glucan secreted during the optimised production of exopolysaccharides by Paecilomyces variotii has immunostimulatory activity.

Paecilomyces variotii is a filamentous fungus that occurs worldwide in soil and decaying vegetation. Optimization of the fermentation process for exopolysaccharide (EPS) production from the fungus P. variotii, structure determination and immuno-stimulating activity of EPS were performed. Response surface methodology (RSM) coupled with central composite design (CCD) was used to optimize the physical and chemical factors required to produce EPS in submerged fermentation. Preliminary investigations to choose the three factors for the present work were made using a factorial experimental design. Glucose, ammonium nitrate (NH4NO3) and pH were used as variables for which, with constant temperature of 28 °C and agitation of 90 rpm, the optimal process parameters were determined as glucose values of 0.96%, NH4NO3 0.26% and pH 8.0. The three parameters presented significant effects. In this condition of culture, the main composition of the isolated EPS was a linear ß-(1 â†’ 6)-linked-D-glucan, as determined by Nuclear Magnetic Resonance (NMR) and methylation analysis. This polysaccharide is a very unusual as an EPS from fungi, especially a filamentous fungus such as P. variotii. Murine peritoneal macrophages cultivated with ß-glucan for 6 and 48 h showed an increase in TNF-α, IL-6 and nitric oxide release with increased polysaccharide concentrations. Therefore, we conclude that the ß-(1 â†’ 6)-linked-D-glucan produced in optimised conditions of P. variotii cultivation has an immune-stimulatory activity on murine macrophages.