Fernanda Cramer Flores

Nanostructured systems containing an essential oil: protection against volatilization

The goal of this study was to evaluate the feasibility of preparing nanocapsules and nanoemulsions using tea tree oil as oily phase aiming to protect its volatilization. The nanostructures presented nanometric mean size (160-220 nm) with a polydispersity index below 0.25 and negative zeta potential. The pH values were 6.43 ± 0.37 and 5.98 ± 0.00 for nanoemulsions and nanocapsules, respectively. The oil content after preparation was 96%. The inclusion of tea tree oil in nanocapsules showed higher protection against volatilization. The analysis of mean size and polydispersity index of formulations presented no significant alteration during the storage time.

Genotoxic effects of Campomanesia xanthocarpa extracts on Allium cepa vegetal system.

Abstract Context. Campomanesia xanthocarpa Berg. (Myrtaceae), popularly known in Brazil as guabiroba, is a plant used as antidiarrheic, anti-inflammatory and antirheumatic agents, and in stomach and hepatic disorders. Objective: The antiproliferative and genotoxic effects of aqueous extracts and essential oil of C. xanthocarpa were evaluated. Materials and methods: Cytotoxicity and genotoxicity of the aqueous extracts (6 and 30 mg/mL) and essential oil (0.25%, v/v) obtained from leaves of C. xanthocarpa were evaluated using the Allium cepa L. (Amaryllidaceae) assay. Mitotic index was calculated as the percentage of dividing cells of total cells observed; chromosome abnormalities were observed and counted during cell division. Additionally, the composition of the essential oil and the quantification of the main compounds of the extracts were determined by gas chromatography/mass spectrometry and high performance liquid chromatography coupled with diode array detector, respectively. Results and discussion: Aqueous extracts (6 and 30 mg/mL) led to a reduction of 67.7% and 34.1% of the mitotic index, respectively, whereas the treatment with essential oil caused a 48.2% reduction in the mitotic index, when compared with negative control. Chromosomal mutations were observed and included anaphase bridges, delay chromosome, break chromosome, as well as metaphase with disorganized chromosomal and binuclear cells. The main compounds of the essential oil were β-caryophyllene (8.87%), viridiflorol (6.40%), spathulenol (5.16%), δ-cadinene (4.92%), linalool (4.46%) and α-cadinol (4.25%). Gallic acid (3.19%), chlorogenic acid (1.04%), quercetin (2.97%) and rutin (4.82%) were identified in an aqueous extract (30 mg/mL). Conclusion: Our results demonstrated that genotoxic and antiproliferative activities are present in C. xanthocarpa infusions using the in vivo onion root-tip cell test.

Essential Oils for Treatment for Onychomycosis: A Mini-Review.

Onychomycosis are fungal infections affecting finger and toenails mainly caused by dermatophyte fungi and some Candida species. Low cure rates and frequent recurrence, development of a fungal resistance front to various antimicrobial agents topical and systemic, and an ineffective topical treatment make onychomycosis difficult to treat. Essential oils are excellent candidates for the topical treatment for onychomycosis because the development of resistance by fungi is rare, and the presence of side effects is low. They are composed of a complex variety of compounds, mainly terpenes, with low molecular weight, which may easily penetrate into the nail plate, finding the fungi elements. The complex mixture confers a broad antifungal spectrum of action, through interaction with biological membranes, interference in radical and enzymatic reaction of fungi cells. Essential oils may become the source of new therapeutic molecules, and the use of an essential oil incorporated into a topical formulation is an interesting, safe, and effective alternative for the treatment for onychomycosis. However, studies are needed to evaluate the efficacy of essential oils in the treatment for onychomycosis in vivo. This mini-review aims to present the potential use of essential oils for the treatment for onychomycosis, focusing on the last decade.

Spray-dried powders improve the controlled release of antifungal tioconazole-loaded polymeric nanocapsules compared to with lyophilized products

This work aimed to obtain solid formulations from polymeric nanocapsules and nanoemulsions containing tioconazole, a broad spectrum antifungal drug. Two dehydration methods were used: spray-drying and freeze drying, using lactose as adjuvant (10%, w/v). The liquid formulations had a mean particle size around 206 nm and 182 nm for nanocapsules and nanoemulsions, respectively, and an adequate polydispersity index. Tioconazole content was close to the theoretical amount (1.0 mg/mL). After drying, the content ranged between 98 and 102%with a mean nanometric size of the dried products after redispersion. Scanning electron microscopy showed that the particles are rounded, sphere-shaped for the dried products obtained by spray-drying, and shapeless and irregular shapes for those obtained by freeze-drying. In the microbiological evaluation, all dried products remained active against the yeast Candida albicans when compared to the original systems. The dried products obtained by spray-drying from nanocapsules presented better control of the tioconazole release when compared to the freeze-drying products.

Atividade de nanoformulações de Melaleuca alternifolia e terpinen-4-ol em isolados de Rhodococcus equi

Rhodococcus equi causes rodococose in horses, characterized by bronchopneumonia in foals. Due to reports of antimicrobial resistance, it is important to develop studies involving alternative therapies and new technologies, including the use of medicinal plants and nanotechnology. In this work, the plant Melaleuca alternifolia in oil free formulations, nanocapsule, nanoemulsion and the combination of free and nanocapsule oil nanoemulsion, besides its major compound, terpinen-4-ol, were used in order to verify antimicrobial activity against isolates of R. equi. The broth microdilution method was employed to determine the minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations of different formulations against 24 isolates. There was low antibacterial activity of M. alternifolia in oil free formulation; however, it was observed that the activity was enhanced when incorporated as essential oil the nanoformulations. The major compound, terpinen-4-ol, showed bactericidal and bacteriostatic activity when used alone. It is suggested that M. alternifolia, in association with nanocarriers systems, as well as terpinen -4-ol, presents potential for future studies concerning the equine rodococosis therapy.

Detecção de fatores de virulência de Escherichia coli e análise de Salmonella spp. em psitacídeos

The enteric flora of psittacines is mainly composed of Gram positive bacteria. Gram negative bacteria, like Escherichia coli and Salmonella spp., have a high pathogenic potential and can be considerate as an indicative of management problems that may culminate in disease manifestation due to stress factors, poor diets and overcrowding, in combination with a high bacterial load on the environment. The objective of this study was evaluated the presence of Salmonella spp., Escherichia coli and the virulence genes iss and iutA from E. coli isolates. Forty-four samples were analyzed from psittacines living in captivity, which fifteen samples were from organs fragments of necropsied birds, and twenty-nine were from cloacal and crop swabs of red-spectacled parrots (Amazona pretrei) keeping in captivity. No samples were positive for Salmonella spp. In the samples in which E. coli was detected, both virulence factors (genes iss and iutA) were present.

An innovative polysaccharide nanobased nail formulation for improvement of onychomycosis treatment

&NA; Tioconazole‐loaded nanocapsule suspensions and its coating with a cationic polymer were developed for nail drug delivery. The colloidal systems presented a nanometric size around 155 nm for uncoated nanoparticles and 162 nm for those with the cationic coating, with negative and positive zeta potential values, respectively. Both nanosuspensions showed drug content close to theoretical values (1 mg mL− 1), association efficiency close to 100% (HPLC) and were able to control tioconazol release. The developed formulations showed in vitro antifungal activity (agar diffusion method) against C. albicans. The cationic nanocapsules were considered bioadhesive, showed higher viscosity and were chosen to be incorporated into an ungueal formulation. Pullulan nanobased nail formulation showed adequate viscosity for nail application and drug content close to the theoretical values. It was equivalent to the commercial formulation Trosid® in preventing nail infection by T. rubrum in an in vitro onychomycosis model. The nanocapsule suspensions and Pullulan nanobased nail formulation showed lower irritant potential than the commercial formulation and than free drug in an in vitro evaluation. Pullulan nanobased nail formulation is promising for the treatment of onychomycosis. Graphical abstract Figure. No caption available.

Mutagenic and antimutagenic effects of Eugenia uniflora L. by the Allium cepa L. test

Eugenia uniflora (Surinam cherry tree) is an important species in traditional medicine and is used to decrease blood pressure and prevent heartburn, bronchitis, colic and stomachaches. The tealeaves have antirheumatic, anti-dysenteric, and febrifuge properties and are used to treat diabetes. This study aimed to assess the antiproliferative, mutagenic and antimutagenic effects of the leaves and fruits of E. uniflora through the Allium cepa test. The infusions were prepared using dried leaves (6.l−1 and 24 gl−1) and the oil extraction was undertaken using hydrolyzation (0.25%, in ethanol). For juice preparation, fruit pulp with and without seeds was used. Allium cepa root tips were used for slide preparation following the squashing technique. Analysis of 500 cells for each bulb was undertaken, 250 of each root, summing 2500 cells per treatment, a total of 17,500 and 10,000 cells in the first and second experiments, respectively. The mitotic index was calculated and statistical analyses were performed. We found that the aqueous extract and oil of E. uniflora has mutagenic activity at low concentrations and the extract at a higher than average concentration can be considered antimutagenic. Furthermore, both juice extracts with and without seeds have anti-proliferative capacity.

Avaliação da resistência do cascudinho (Alphitobius diaperinus) (Panzer) (Coleoptera: Tenebrionidae) a diferentes temperaturas

Alphitobius diaperinus, known as the lesser mealworm, is abundantly found in poultry houses, and causes losses in poultry worldwide. The ways to control this beetle are based exclusively on the use of insecticides, concerning which there are already several reports of resistant populations, thus forcing the use of alternative methods such as biological control, interfering in the life cycle of the insect. The present study evaluated, under laboratory conditions, the mortality of larvae and adults of A. diaperinus at different temperatures of heating (45o, 50o, 55o and 60o C) and cooling (-10o, -13o and -18o C) in the presence (PM) and absence of wood shavings (AM) by way of the lethal time of 100% of insects (TL100) in minutes at each temperature. The TL100 for larvae and adults at 45o C were 36 and 38 AM and 42 and 57 PM, at 50o C they were 15 and 11 AM and 19 and 16 PM, at 55o C they were 8 and 9 AM and 12 PM, and at 60o C they were 5 and 6 AM and 11 and 9 PM. At -10o C they were 57 and 60 AM and 70 and 75 PM, at -13o C they were 52 and 55 AM and 60 and 64 PM, and at -18o C they were 42 and 43 AM and 51 and 52 PM. At all temperatures, the mortality of the insects was quick; therefore methods of control by way of temperature should consider these points for reference.

Comportamento de células do sistema imune frente ao desafio com Salmonella Enteritidis em aves tratadas e não tratadas com ácidos orgânicos

Salmonellosis is an important zoonosis, considered the leading cause of bacterial infections, and is associated with the consumption of poultry products. As alternative control, organic acids have been widely used. However, little is known about the immune status of poultry production, and an evaluation of this status is necessary to protect against disease and to ensure the safe application of therapeutic agents or prophylactic vaccination. This study aimed to verify the behavior of the immune system of birds previously infected with Salmonella Enteritidis (SE) treated with a compound of organic acids in different concentrations administered via water and food, compared with the infected birds and untreated. One hundred and twenty broilers were orally inoculated with 1ml of SE at a concentration of 1.0x108 CFU/mL, at 1 and 2-days-old and divided into six treatments with two repetitions of 200, 400, 500 and 1000ppm organic acid. From 35-days-old birds of all groups were collected aliquots of 3mL of blood into a tube containing EDTA for the evaluation of immune cells by flow cytometry. We then analyzed the percentages of circulating CD4+, CD8β+, MHC I+ MHC II+, TCRVβ1+, CD28+ + and TCRVβ2. For microbiological analysis were collected caecal tonsils of these birds. We found that organic acids in dosages 1000ppm 500ppm in water and in feed for 2 to 7 days before slaughter, respectively, were effective in reducing SE infection in broilers, proven by microbiological method and demonstrated through the behavior of immune cells. The infected birds showed a lower proportion of circulating T helper cells compared with infected poultry, but treated with AO or with the uninfected group. The same trend can be observed for CD28+ cells, and MHC IIbright+ TCRVβ 1+, and with lower resolution, for CD8β+.