Antimicrobial activity and safety applications of meso-tetra(4-pyridyl)platinum(II) porphyrin.

Tetra-platinated(II) porphyrin hexafluorophosphate compound (4-PtTPyPor) was synthetized and along 5,10,15,20-tetrakis(4-pyridyl)porphyrin (4-TPyPor), evaluated about the antimicrobial activity and safety. The effect was evaluated with and without light exposition. The antimicrobial activity was analyzed by microdilution and growth curve method. The assays showed an increase of antimicrobial potential caused by porphyrins with light exposition comparing the treatment without light irradiation. The biocompatibility was tested by MTT, ROS production, dsDNA on culture medium and hemolysis. All platinum porphyrin concentrations showed hemolytic activity under light exposition. The ROS measurement doesn't showed statistic difference between treatments and control. The picogreen assay demonstrates a reduction of dsDNA on culture medium with cells treated with porphyrins under light irradiation. The study demonstrated that the platinated porphyrins might be promising microbial photodynamic inactivation with potential applications in wastewater treatment, biofilm control and bioremediation.

Anti-biofilm activity of A22 ((S-3,4-dichlorobenzyl) isothiourea hydrochloride) against Pseudomonas aeruginosa: Influence on biofilm formation, motility and bioadhesion.

Bacterial biofilms are involved in various medical infections and for this reason it is of great importance understanding adhesion mechanisms of involved microorganisms is essential to develop new strategies of prevention and control. Different approaches have been used for preventing biofilm related infections in health care settings, such as use of surface coatings agents in medical implants. In this context, is necessary to explore new compounds with anti-biofilm activity. Thus, this study evaluated for the first time the action of A22 against biofilms of Pseudomonas aeruginosa PAO1 strain and multi-resistant clinical isolates on biotic and abiotic surfaces. A22 acts as inhibitor of the MreB protein of the bacterial cell wall, causing the rods to change shape to the coccoid form. In this work, A22 at subinhibitory concentrations was able to prevent biofilm formation, and atomic force microscopy images showed that A22 was highly effective in inhibiting adhesion on polyethylene surfaces. Pseudomonas aeruginosa PAO1 exhibited a strong ability to adhere to HeLa cells, and A22 inhibited the aggregation after 4 h of exposure. Swarming and twitching motilities were significantly altered by A22 at subinhibitory concentrations. Thus, by changing the shape of the bacterial cell, many properties can be affected, such as motility, surface adhesion and biofilm formation. This work presents A22 as a promising novel antibacterial or surface coating agent of medical materials.

Development, characterisation, stability study and antileukemic evaluation of nanoemulsions containing Astrocaryum aculeatum extract.

The objective of this work was to produce and characterise nanoemulsions containing tucumã extract and to evaluate the performance of the nanostructure and the free compound regarding antitumor activity, cytotoxicity, and oxidative metabolism in NB4/APL cells. The nanoemulsions showed adequate physicochemical characteristics (average size approx. 200 nm, polydispersity index less than 0.3, negative zeta potential and acid pH) maintained stable up to 90 days of storage in refrigeration condition. The nanoformulations did not present protein corona formation. Blank nanoemulsion treatments showed moderate toxicity. Furthermore, the nanoemulsion loaded with extract showed better antileukemic results than the free extract. However, nanoemulsions can be promising carriers of natural compounds, emphasising their biological properties and constituting alternatives in treating diseases.

Randia ferox (Cham & Schltdl) DC.: phytochemical composition, in vitro cyto- and genotoxicity analyses.

Randia ferox is a Brazilian native species used in folk medicine. Scientific information regarding the toxicology and phytochemistry of this plant remains unclear. We aimed to produce a R. ferox extract, identify its chemical matrix, and evaluate its safety profile. The extract chemical composition was accessed through UHPLC-MS/MS. Mononuclear cells, erythrocytes, fibroblasts, macrophages, and kidney cells were subjected to extract concentration-response curve testing. The cellular viability, proliferation, dsDNA release, reactive oxygen species (ROS), nitric oxide (NO), hemolysis, and DNA damage were determined. Ten molecules were found in the extract matrix. Most of the tested concentrations can be considered safe. Cellular viability, proliferation, dsDNA release, and NO remained at similar levels to the control. The extract increased ROS in macrophages. None of the tested concentrations induced DNA damage or hemolysis. The data suggest R. ferox extract contains several bioactive molecules and has a safety profile in vitro.

Evaluation of the in vivo safety of tucumã oil nanocapsules in an experimental model of silver catfish Rhamdia quelen.

The aim of this study was to evaluate the toxicity of tucumã oil nanocapsules from the Amazon region in silver catfish, Rhamdia quelen. Fish were exposed to water treated with different concentrations of tucumã nanocapsules, white, solubilized oil and surfactant vehicles. After three days of exposure, fish were euthanized and liver, gills and brain removed for analysis of the dichlorofluorescein, nitric oxide and PicoGreen® assays. Plasma was collected for assay of hepatic transaminases. The nanocapsules had a diameter of 221 ± 1.27 nm, confirmed by atomic force microscopy. The oil nanocapsules were not toxic to this species of fish, but white nanocapsules and surfactant increased the levels of reactive oxygen species. Thus, nanocapsules are promising for the transport of tucumã oil. In view of the anti-inflammatory properties of this oil, it is possible to envisage its application in skin diseases for example, since they present essentially inflammatory conditions.HighlightsThe most abundant carotenoid in tucumã oil was all-trans-beta-carotene.Nanocapsules are good carriers for tucumã oil.Tucumã oil nanocapsules does nothas toxicity effect in catfish.

Açaí (Euterpe oleracea Mart.) as a Potential Anti-neuroinflammatory Agent: NLRP3 Priming and Activating Signal Pathway Modulation.

Neurological disorders have been demonstrated to be associated with mitochondrial dysfunction. This impairment may lead to oxidative stress and neuroinflammation, specifically promoted by NLRP3 expression. Açaí (Euterpe oleracea Mart.) has been studied in this field, since it presents important biological activities. We investigated açaí extract's anti-neuroinflammatory capacity, through NLRP3 inflammasome modulation. Microglia (EOC 13.31) were exposed to LPS and nigericin, as agents of inflammatory induction, and treated with açaí extract. Additionally, we used lithium (Li) as an anti-inflammatory control. Three different experiment models were conducted: (1) isolated NLRP3 priming and activation signals; (2) combined NLRP3 priming and activation signals followed by açaí extract as a therapeutic agent; and (3) combined NLRP3 priming and activation signals with açaí extract as a preventive agent. Cells exposed to 0.1 µg/mL of LPS presented high proliferation and increased levels of NO, and ROS, while 0.1 µg/mL of açaí extract was capable to reduce cellular proliferation and recover levels of NO and ROS. Primed and activated cells presented increased levels of NLRP3, caspase-1, and IL-1ß, while açaí, Li, and orientin treatments reversed this impairment. We found that açaí, Li, and orientin were effective prophylactic treatments. Preventative treatment with Li and orientin was unable to avoid overexpression of IL-1ß compared to the positive control. However, orientin downregulated NLRP3 and caspase-1. Lastly, primed and activated cells impaired ATP production, which was prevented by pre-treatment with açaí, Li, and orientin. In conclusion, we suggest that açaí could be a potential agent to treat or prevent neuropsychiatric diseases related to neuroinflammation.