Arginine Gemini-Based Surfactants for Antimicrobial and Antibiofilm Applications: Molecular Interactions, Skin-Related Anti-Enzymatic Activity and Cytotoxicity.

The antimicrobial and antibiofilm properties of arginine-based surfactants have been evaluated. These two biological properties depend on both the alkyl chain length and the spacer chain nature. These gemini surfactants exhibit good activity against a wide range of bacteria, including some problematic resistant microorganisms such us methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Moreover, surfactants with a C10 alkyl chain and C3 spacer inhibit the (MRSA) and Pseudomonas aeruginosa biofilm formation at concentrations as low as 8 µg/mL and are able to eradicate established biofilms of these two bacteria at 32 µg/mL. The inhibitory activities of the surfactants over key enzymes enrolled in the skin repairing processes (collagenase, elastase and hyaluronidase) were evaluated. They exhibited moderate anti-collagenase activity while the activity of hyaluronidase was boosted by the presence of these surfactants. These biological properties render these gemini arginine-based surfactants as perfect promising candidates for pharmaceutical and biological properties.

Metabolomic Profile and Its Correlation with the Plasmatic Levels of Losartan, EXP3174 and Blood Pressure Control in Hypertensive and Chronic Kidney Disease Patients.

Systemic arterial hypertension (SAH) is one of the most prevalent chronic diseases worldwide and, when dysregulated, may cause serious complications. Losartan (LOS) blocks relevant physiological aspects of hypertension, acting mainly on the reduction of peripheral vascular resistance. Complications of hypertension include nephropathy, in which diagnosis is based on the observation of functional or structural renal dysfunction. Therefore, blood pressure control is essential to attenuate the progression of chronic kidney disease (CKD). In this study, 1H NMR metabolomics were used to differentiate hypertensive and chronic renal patients. Plasmatic levels of LOS and EXP3174, obtained by liquid chromatography coupled with mass-mass spectroscopy, were correlated with blood pressure control, biochemical markers and the metabolomic fingerprint of the groups. Some biomarkers have been correlated with key aspects of hypertension and CKD progression. For instance, higher levels of trigonelline, urea and fumaric acid were found as characteristic markers of kidney failure. In the hypertensive group, the urea levels found could indicate the onset of kidney damage when associated with uncontrolled blood pressure. In this sense, the results point to a new approach to identify CKD in early stages and may contribute to improving pharmacotherapy and reducing morbidity and mortality associated with hypertension and CKD.

Copaiba essential oil loaded-nanocapsules film as a potential candidate for treating skin disorders: preparation, characterization, and antibacterial properties.

Infections have emerged as a novel target in managing skin and mucosa diseases. Bacterial resistance to antimicrobials and biofilm elimination from surfaces remains a challenge. Because polymeric nanocapsules (NC) can increase antimicrobial activity, this study aimed to produce and characterize NC into chitosan films (CSF). Copaiba essential oil (CO) presents antimicrobial activity and was chosen to load NC. In addition, the antibacterial activity was evaluated to obtain a new biodegradable polymeric platform system with the potential to treat topical diseases associated with bacterial infections. The CO-NC produced by nanoprecipitation presented particle size lower than 250 nm, negative charge, and encapsulation efficiency higher than 70 %. Direct incorporation of CO into CSF (CO-CSF) by casting method worsened the film's characteristics. However, incorporating CO-NC into CSF (CO-NC-CSF) avoided these drawbacks demonstrating improved physical, mechanical, morphological, and topographical properties. FTIR results demonstrated possible intermolecular interactions among the polymers and CO. The CO-NC-CSF and CO-CSF presented antibacterial properties against Staphylococcus aureus, and Pseudomonas aeruginosa, especially the formulation containing 1 % of CO. These results indicated that CO-NC-CSF is a promising candidate for treating skin disorders.

Zein Nanoparticles Containing Arginine-Phenylalanine-Based Surfactants: Stability, Antimicrobial and Hemolytic Activity.

Although cationic surfactants have a remarkable antimicrobial activity, they present an intrinsic toxicity that discourages their usage. In this work novel zein nanoparticles loaded with arginine-phenylalanine-based surfactants are presented. The nanoparticles were loaded with two single polar head (LAM and PNHC12) and two with double amino acid polar head surfactants, arginine-phenylalanine (C12PAM, PANHC12). The formulations were characterized and their stability checked up to 365 days. Furthermore, the antimicrobial and hemolytic activities were investigated. Finally, NMR and molecular docking studies were carried out to elucidate the possible interaction mechanisms of surfactant-zein. The nanoparticles were obtained with satisfactory size, zeta potential and dispersibility. The surfactants containing arginine-phenylalanine residues were found to be more stable. The nanoencapsulation maintained the antimicrobial activities unaltered in comparison to the surfactants' solutions. These results are in agreement with the NMR and docking findings, suggesting that zein interacts with the surfactants by the aromatic rings of phenylalanine. As a result, the cationic charges and part of the aliphatic chains are freely available to attack the bacteria and fungi, while not available to disrupt the cellular membranes. This approach opens new possibilities for using cationic surfactants and benefits from their extraordinary antimicrobial responses for several applications.

Toxicological and genotoxic evaluation of anacardic acid loaded-zein nanoparticles in mice.

Anacardic acid extracted from cashew nut shells of Anacardium occidentale L has demonstrated important biological activities, such as antibacterial activity against the cariogenic specie Streptococcus mutans. Zein nanoparticles containing anacardic acid (9.375 µg/mL) were evaluated in terms of toxicity and genotoxicity in vivo. The subacute toxicity assay was used to evaluate the cumulative effects of the oral administration of nanoencapsulated anacardic acid at 2.25 and 112.5 µg/kg for 7 days in mice, simulating a mouth rinse short-term clinical course treatment. Blank zein nanoparticles and saline solution 0.9 % were used as negative controls. Peripheral blood samples were collected to evaluate the genotoxicity in polychromatic erythrocytes using the micronucleus test. The animals were anesthetized, euthanized and the target organs collected, weighed and submitted to histopathological analysis. Liver, kidney and spleen relative weights did not change. Nevertheless, stomach, lung and heart increased the relative weights in the group receiving the highest dose, in which occasional histopathological findings were also identified. Both doses maintained the micronucleus frequency within the normal range and the animals treated with the highest dose presented a discrete weight lost, which could explain the organs' relative weight reductions. Blank and anacardic acid loaded zein nanoparticles were nontoxic when administered repeatedly for 7 days, as no relevant histopathological changes neither genotoxicity were observed. These preparations demonstrated limited toxicity under the conditions used in this study and could become an antibacterial alternative for preventing/treating oral infections in short-term treatments.

Percepción asociada a la automedicación con antimicrobianos en farmacias de Fortaleza, Brasil / Perception of self-medication with antibiotics in pharmacies of Fortaleza, Brazil

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