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.

Zein Nanoparticles Containing Arginine-Based Surfactants: Physicochemical Characterization and Effect on the Biological Properties.

Cationic surfactants carry antimicrobial activity, based on their interaction and disruption of cell membranes. Nonetheless, their intrinsic toxicity limits their applicability. To overcome this issue, a feasible strategy consists of using solid nanoparticles to improve their delivery. The zein nanoparticles were loaded with four cationic arginine-based surfactants: one single chain Nα-lauroyl-arginine (LAM) and three Gemini surfactants Nα Nω-Bis (Nα-lauroyl-arginine) α, ω-diamide) (C3(LA)2, C6(LA)2 and C9(LA)2). Blank and loaded zein nanoparticles were characterized in terms of size, polydispersity and zeta potential. Furthermore, the antimicrobial activity against bacteria and yeasts and the hemolytic activity were investigated and compared to the surfactants in a solution. Nanoparticles were found to be monodisperse, presenting a size of between 180-341 nm, a pdI of <0.2 and a positive zeta potential of between +13 and +53 mV, remaining stable over 365 days. The nanoencapsulation maintained the antimicrobial activity as unaltered, while the extensive hemolytic activity found for the surfactants in a solution was reduced drastically. Nuclear Magnetic Ressonance (NMR), molecular docking and monolayer findings indicated that zein entraps the surfactants, interfering in the surfactant-membrane interactions. Accordingly, the nanoepcasulation of arginine surfactants improved their selectivity, while the cationic charges were free to attack and destroy bacteria and fungi; the aliphatic chains were not available to disrupt the cellular membranes.

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.

Antimicrobial effect of anacardic acid-loaded zein nanoparticles loaded on Streptococcus mutans biofilms.

Bacterial biofilms play a key role in the pathogenesis of major oral diseases. Nanoparticles open new paths for drug delivery in complex structures such as biofilms. This study evaluated the antimicrobial effect of zein nanoparticles containing anacardic acid (AA) extracted from cashew shells of Anacardium occidentale on in vitro Streptococcus mutans biofilm formation and mature biofilms. The minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC), and antibiofilm assays were performed. Streptococcus mutans UA159 biofilms were formed on saliva-coated hydroxyapatite disk for 5 days. To evaluate the preventive effect on biofilm formation, before contact with the inoculum, the disks were immersed once for 2 min in (1) hydroethanolic solution; (2) blank zein nanoparticles; (3) zein nanoparticles containing AA; and (4) 0.12% chlorhexidine gluconate. To determine the effect against mature biofilms, the disks containing 5-day preformed biofilms were further treated using the same procedure. The bacterial viability and dry weight were determined for both assays and used to compare the groups using ANOVA followed by Tukey's test (p < 0.05). Both MIC and MBC for AA-loaded zein nanoparticles were 0.36 µg/mL. Groups 3 and 4 were very effective in inhibiting S. mutans biofilm formation, as no colony-forming units were detected. In contrast, for mature biofilms, no difference in bacterial viability (p = 0.28) or dry weight (p = 0.09) was found between the treatments. Therefore, the AA-based nanoformulation presented very high inhibitory and bactericidal activities against planktonic S. mutans, and the results indicate a strong antiplaque effect. However, the formulation showed no antimicrobial effect on the established biofilm.

Microbial contamination in herbal medicines: a serious health hazard to elderly consumers.

INTRODUCTION: The use of herbal medicine is on the rise worldwide, and safety issues associated with herbal medicines may have an exacerbated impact in elderly because this population has an increased susceptibility and sensitivity to health complications due to the aging process. METHODS: This cross-sectional study was carried out at a primary health care unit in the city of Macapa, Brazil. The herbal medicines used and the sociodemographic characteristics of 123 voluntarily consenting participants were collected using a structured questionnaire. A total of 132 herbal medicines with oral or topical administration were donated by the elderly for microbial analysis before consumption, and 18 water samples used in the preparation of homemade herbal medicines were collected. Bacterial and fungal counts and identification of bacterial pathogens (Escherichia coli, Salmonella spp., Pseudomonas aeruginosa and Staphylococcus aureus) were performed according to the regulations of the Brazilian Pharmacopoeia and World Health Organization. Water analysis for the detection of coliforms and E. coli was carried out using Colilert® according to the manufacturer's instructions and the techniques established by Standard Methods. RESULTS: Of the study participants, 78.8% were women. Bacterial growth was observed in samples from 51.5% of study and 35.6% had fungal growth. A total of 31.8% of the herbal medicine samples exceeded the safety limits (CFU/g ≤ 105), including 16.7% of the homemade herbal medicines and 15.1% of the commercial herbal medicines. It was also found that 31.0% of the samples exceeded the safety limit for fungal growth. The microorganisms most commonly isolated from the herbal medicines were S. aureus (49.2%), followed by Salmonella spp. (34.8%), E. coli (25.8%), and P. aeruginosa (14.4%). Of water samples analyzed, 77.8% were positive for total coliforms (1 ml) and in 66.7% water samples E. coli was detected (1 ml), making them unfit for consumption. CONCLUSIONS: The use of homemade and commercial herbal medicines is a major risk to the health of elderly who use these therapies due to the lack of microbial quality standards. We observed levels of viable bacteria and fungi that were above safety limits; in addition, we were able to isolate pathogenic bacteria from these herbal medicines.

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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Chemical profiling of Curatella americana Linn leaves by UPLC-HRMS and its wound healing activity in mice.

Based on ethnopharmacological studies, a lot of plants, as well as its compounds, have been investigated for the potential use as wound healing agents. In Brazil, Curatella americana is traditionally used by local people to treat wounds, ulcers and inflammations. However, to the best of our knowledge, its traditional use in the treatment of wounds has not been validated by a scientific study. Here, some compounds, many of them flavonoids, were identified in the hydroethanolic extract from the leaves of C. americana (HECA) by LC-HRMS and LC-MS/MS. Besides that, solutions containing different concentrations of HECA and a gel produced with this extract were evaluated for its antimicrobial, coagulant and wound healing activities on an excision mouse wound model as well as its acute dermal safety. A total of thirteen compounds were identified in HECA, mainly quercetin, kaempferol and glucoside derivatives of both, besides catechin and epicatechin known as wound healing agents. The group treated with 1% of HECA exhibited highest wound healing activity and best rate of wound contraction confirmed by histopathology results. The present study provides scientific evidence of, this extract (HECA) possess remarkable wound healing activity, thereby, supporting the traditional use.

Phytopharmacovigilance in the Elderly: Highlights from the Brazilian Amazon.

Practices described as traditional medicine may coexist with formalized, science-based medicine. In this context, the present study aimed to verify the profile of the elderly who consumed herbal medicines concomitantly with medications and to identify suspected adverse drug reactions (ADRs) in the Brazilian Amazon (Macapá, Amapá). The study was carried out in two steps: a cross-sectional study (structured questionnaire) and a clinical study (pharmacotherapeutic follow-up). Out of 208 participants, 78.8% were female with age between 60 and 69 years (58.7%), 59.1% used herbal medicines concurrently with medications, and 40.9% did not report use of herbal medicine. Losartan was the most used medication, and Lippia alba (Mill.) N.E. Br was the most common herbal medicine used. The total prevalence of suspected ADRs, among the elderly who answered the structured questionnaire, was 41.3%, with 27.4% being in the elderly who used herbal medicines and medications, and 13.9% being in the elderly who used only medications. Meanwhile, the total prevalence of suspected ADRs was 71.0% among the elderly patients who underwent pharmacotherapeutic follow-up, 60.5% in elderly who used herbal medicines and medications, and 10.5% in elderly who used only medications. The most reported ADR symptoms were related to disorders that affect the nervous system (38.4%) in the structured questionnaire and related to digestive disorders (36.4%) in the pharmacotherapeutic follow-up. The probability associated with the occurrence of a given ADR in the face of a set of demographic, socioeconomic, and clinical variables was estimated; the results showed that, in the studied population, only sex (p = 0.030) had an influence on the occurrence of ADR. The prevalence of ADRs with probable causality was high in this study population, but it was only sex-related, although more prevalent in the elderly who consume herbal medicines.

Nanotechnology in dentistry: drug delivery systems for the control of biofilm-dependent oral diseases.

Dental disorders, such as caries, periodontal and endodontic diseases are major public health issues worldwide. In common, they are biofilm-dependent oral diseases, and the specific conditions of oral cavity may develop infectious foci that could affect other physiological systems. Efforts have been made to develop new treatment routes for the treatment of oral diseases, and therefore, for the prevention of some systemic illnesses. New drugs and materials have been challenged to prevent and treat these conditions, especially by means of bacteria elimination. "Recent progresses in understanding the etiology, epidemiology and microbiology of the microbial flora in those circumstances have given insight and motivated the innovation on new therapeutic approaches for the management of the oral diseases progression". Some of the greatest advances in the medical field have been based in nanosized systems, ranging from the drug release with designed nanoparticles to tissue scaffolds based on nanotechnology. These systems offer new possibilities for specific and efficient therapies, been assayed successfully in preventive/curative therapies to the oral cavity, opening new challenges and opportunities to overcome common diseases based on bacterial biofilm development. The aim of this review is to summarize the recent nanotechnological developments in the drug delivery field related to the prevention and treatment of the major biofilm-dependent oral diseases and to identify those systems, which may have higher potential for clinical use.