Cayane Genro Santos

Anti biofilm effect of dihydromyricetin-loaded nanocapsules on urinary catheter infected by Pseudomonas aeruginosa

Nosocomial infections associated with biofilm formation on urinary catheters are among the leading causes of complications due to biofilm characteristics and high antimicrobial resistance. An interesting alternative are natural products, such as Dihydromyricetin (DMY), a flavonoid which presents several pharmacological properties, including strong antimicrobial activity against various microorganisms. However, DMY, has low aqueous solubility and consequently low bioavailability. Nanoencapsulation can contribute to the improvement of characteristics of some drugs, by increasing the apparent solubility and sustained release has been reported among other advantages. The aim of this study was to evaluate, for the first time, the feasibility of DMY nanoencapsulation, and to look at its influence on nanoencapsulation of DMY as well as verify its influence on antimicrobial and antibiofilm activity on urinary catheters infected by Pseudomonas aeruginosa. The physicochemical characterization showed an average diameter less than 170nm, low polydispersity index, positive zeta potential (between +11 and +14mV), slightly acidic pH. The values of the stability study results showed that the best condition for suspension storage without losing physical and chemical characteristics was under refrigeration (4±2°C). The antibiofilm activity of the formulations resulted in the eradication of biofilms both in free DMY formulations and in nanocapsules of DMY during those periods. However, within 96h the results of the inhibition of biofilm by DMY nanocapsules were more effective compared with free DMY. Thus, the nanocapsule formulation containing DMY can potentially be used as an innovative approach to urinary catheter biofilm treatment or prevention.

Feed addition of curcumin to laying hens showed anticoccidial effect, and improved egg quality and animal health

The aim of this study was to evaluate whether the addition of curcumin in the diet of commercial laying hens could have an anticoccidial action and improve egg quality. For this, 60 laying hens were divided into three groups: T0 (the control group); T30 and T50 (30 and 50 mg/kg of curcumin in the feed, respectively). Eggs recently laid were collected on days 14 and 21 of the experiment, and stored for 21 days. It was observed increased specific gravity and yolk index in stored eggs of the groups T30 and T50 compared to T0. The yolk color reduced in the eggs stored from groups T30 and T50 compared to T0. Moreover, TBARS levels were lower in fresh and stored eggs from groups T30 and T50. It was observed increased TAC levels in fresh eggs from groups T30 and T50 and in stored eggs from the group T50. The presence of curcumin was not detected by HPLC in the yolk and albumen. Seric levels of albumin and uric acid did not differ between groups, while seric levels of total proteins increased on day 21 on groups T30 and T50. Finally, it was observed a significant reduction on the number of oocysts in fecal samples on days 14 and 21 of T30 and T50 compared to T0. Based on these evidences, it is possible to conclude that the addition of curcumin in the diet of laying hens has an anticoccidial effect and improves egg quality.

Ecotoxicology of Glycerol Monolaurate nanocapsules

Glycerol Monolaurate (GML) is a compound with known antimicrobial potential, however it is not much used due to its low solubility in water and high melting point. The nanoencapsulation of some drugs offers several advantages such as improved stability and solubility in water. The present study aimed to produce, characterize, and evaluate the ecotoxicity of GML nanocapsules. The nanocapsules were produced and presented a mean diameter of 210nm, polydispersity index of 0.044, and zeta potential of -23.4mV. The electron microscopy images showed the nanometric size and spherical shape. The assay in soil showed that GML has a high toxicity while the GML nanocapsules showed decreased toxic effects. Nanostructuration also protected the Rhamdia quelen against the toxic effects of GML. Concluding, the formulation shows positive results and is useful to predict the success of development besides not damaging the soil.