Francine Souza Alves da Fonseca

Background and Aim: Antimicrobial resistance (AMR) is a major One Health concern, especially in dairy production systems where multidrug-resistant (MDR) Staphylococcus aureus limits mastitis control. Essential oils (EOs), such as Syzygium aromaticum EO, possess strong antimicrobial properties, but their volatility restricts stability. Microencapsulation enhances EO stability and functional performance. This study aimed to evaluate the antimicrobial effect of microencapsulated S. aromaticum EO (OESAM) combined with β-lactam antibiotics against MDR S. aureus. Additionally, bioinformatic analysis was used to explore the potential role of whey protein isolate (WPI) used in the microcapsule wall material in modulating antimicrobial action. Materials and Methods: OESAM was prepared via complex coacervation using WPI and gum arabic as wall materials. Ten MDR S. aureus isolates from bovine mastitis were tested for minimum inhibitory concentrations (MICs) of OESAM, oxacillin, and meropenem using broth microdilution. Synergy was evaluated using the Checkerboard method and interpreted through the fractional inhibitory concentration index (FICI). A protein–protein interaction network was generated in STRING database to investigate molecular pathways potentially affected by amino acids in WPI. Results: Microencapsulation produced stable microcapsules with a yield of 39.11%. The addition of OESAM significantly reduced the MICs of oxacillin and meropenem (p < 0.05), resulting in antimicrobial dose reductions of up to 2.7-fold. Synergistic and additive effects predominated among the isolates. These outcomes were further supported by their FICI values, which confirmed potentiation between OESAM and β-lactams. Bioinformatic analysis identified three major functional clusters: tryptophan biosynthesis, siderophore biosynthesis, and phosphorelay signal transduction, suggesting that amino acids present in WPI may interfere with metabolic and regulatory pathways of S. aureus, enhancing antimicrobial effectiveness. Conclusion: OESAM substantially enhances β-lactam efficacy against MDR S. aureus, offering a promising strategy for reducing antimicrobial doses and combating resistance in veterinary practice. Microencapsulation improves EO stability and enables controlled-release, thereby enhancing antimicrobial activity. Further in vivo validation, toxicity assessment, and formulation development are recommended to facilitate practical applications in mastitis control and broader AMR mitigation. Keywords: antimicrobial resistance, Staphylococcus aureus, fractional inhibitory concentration index, mastitis, microencapsulation, One Health, Synergy, Syzygium aromaticum, whey protein isolate.

BIOPROSPECTING OF ESSENTIAL OILS WITH POTENTIAL FOR PHARMACEUTICAL FORMULATIONS. Essential oils derived from aromatic plants have garnered significant attention for their therapeutic and medicinal properties. Among these, α-thujone and β-thujone stand out due to their notable biological effects. This study aimed to assess native and exotic aromatic plants as potential sources of these bioactive compounds. Based on the literature, five plant species were selected: Artemisia absinthium (Asteraceae), Hyptis marrubioides (Lamiaceae), Salvia officinalis (Lamiaceae), Tanacetum vulgare (Asteraceae), and Thuja occidentalis (Cupressaceae), resulting in the analysis of 19 samples. The plant leaves were dried, and their essential oils were extracted and evaluated for yield and chemical composition. The oil yields ranged from 0.15 to 1.57%. Gas chromatographymass spectrometry (GC-MS) analysis identified 82 major volatile constituents, with particular emphasis on α-thujone and β-thujone. Among the species studied, H. marrubioides (62.7%) and T. occidentalis (76.4%) exhibited the highest relative concentrations of α-thujone, while A. absinthium was especially rich in β-thujone (63.91%). Overall, α-thujone and β-thujone were detected in four samples from three species, underscoring their potential as valuable sources of these bioactive compounds. Notably, the native species H. marrubioides demonstrated an essential oil composition comparable to that of T. occidentalis in terms of thujone content, further supporting its viability for industrial and pharmacological applications.

Fagopyrum esculentum é um pseudoceral que tem elevado valor no mercado e produção de baixo custo. O Brasil é um país exportador e consumidor de grãos e rutina dessa planta. No entanto, há carência de estudos visando a produção da espécie em muitas das regiões do País. Assim, o objetivo desse trabalho foi avaliar a produção de flavonoides e atributos agronômicos de cultivares de F. esculentum em função da época de colheita. O experimento foi conduzido no Instituto de Ciências Agrárias da Universidade Federal de Minas Gerais, em vasos na casa de vegetação, no delineamento inteiramente casualizado, com quatro repetições. Os tratamentos foram oito épocas de colheita (15, 30, 45, 60, 75, 90, 105 e 120 dias após a emergência) e duas cultivares (‘IPR 92’ e ‘IPR 91’) em esquema fatorial (8 x 2). Os dados foram submetidos às análises de variância e de regressão. O ideal é colher F. esculentum entre 71 e 86 dias após a emergência, visando a produção de grãos e de rutina. A ‘IPR 91’ é a cultivar mais precoce, possui menor teor de flavonoides totais (8,75 mg g-1), produção de rutina (32,86 mg) e de matéria seca (3,54 g) que a ‘IPR 92’ (12,58 mg g-1, 42,68 mg, e 3,72 g, respectivamente).

The present study was carried out with the objective of assessing the acute toxicity of four essential plant oils against the brine shrimp lethality bioassay. The essential oils were dissolved in dimethyl sulfoxide (DMSO) at 1 % and concentrations at 0.01; 0.05; 0.25; 1.25; 6.25 and 31.25 µg/ml were prepared which were added in microcells of 96 dishes containing from 10 to 15 nauplii of Artemia salina in saline solution with a total volume of 150 µL. Each concentration was replicated 8 times. Two controls were used, one with saline water solution containing 38 g of coarse salt/l and the other with DMSO 1 % solvent dissolved in the saline solution. Samples were maintained with light and at environmental temperature. Larvae death on exposing them to contact for 24 h was counted. The Lethal Concentration 50 (LC50) was determined by the Probit method using the statistical package SPSS, version 22. All essential oils tested manifested a high acute toxicity at low dosages. These showed high lethality and its results followed by order of toxicity were: Cymbopogon citratus (LC50= 1.212 µg/ml) >Lippia rotundifolia (LC50= 1.256 µg/ml) >Lippia origanoides (LC50= 1.267 µg/ml) >Cymbopogon citratus Lemon-Grass© (LC50= 1.284 µg/ml). It is concluded that given the lethality exhibited by the essential oils of Cympogogon citratus Lemon-Grass©, C.citratus, Lippia origanoides and Lippia rotundifolia against the Artemia salina micro-crustaceous can be considered promissory essential oils for its use for the control of harmful organisms. Other more specific studies are recommended for demonstrating its biological activity.

This study aimed to verify the action of bioactive compounds from Brazilian plants on the leader genes involved in the SARS-CoV-2 pathway. The main human genes involved were identified in GeneCards and UNIPROT platforms, and an interaction network between leader genes was established in the STRING database. To design chemo-biology interactome networks and elucidate the interplay between genes related to the disease and bioactive plant compounds, the metasearch engine STITCH 3.1 was used. The analysis revealed that SMAD3 and CASP3 genes are leader genes, suggesting that the mechanism of action of the virus on host cells is associated with the molecular effects of these genes. Furthermore, the bioactive plant compounds, such as ascorbate, benzoquinone, ellagic acid, and resveratrol was identified as a promising adjuvant for the treatment inhibiting CASP3-mediated apoptosis. Bioactive plant compounds were verified as the main pathways enriched with KEGG and related to viral infection, assessments/immune/infections, and cell proliferation, which are potentially used for respiratory viral infections. The best-ranked molecule docked in the CASP3 binding site was rutin, while the SMAD3 binding site was resveratrol. In conclusion, this work identified several bioactive compounds from Brazilian plants showing potential antiviral functions that can directly or indirectly inhibit the new coronavirus.

Varronia curassavica is a medicinal species native to Brazil; its anti-inflammatory properties are attributed to α-humulene and β-caryophyllene. This study to investigated the population variability of V. curassavica. Leaves were collected from 40 individuals of a natural population and transferred to glass flasks (2 mL). The volatiles were extracted and analyzed using static headspace gas chromatography coupled with mass spectrometry (HS-GC-MS). A total of 17 compounds were detected: monoterpenes (1.6% - 68%) and sesquiterpenes (25.7% - 79.0%), including α-humulene and β-caryophyllene. Multivariate analysis was performed to estimate the dissimilarity of individuals separated the compounds into four groups. Group I was characterized by the content of α-pinene, groups II and IV by β-caryophyllene, and group III by β-pinene. The abundance of α-humulene showed small variations; while β-caryophyllene showed larger variations that contributed to the population variability. This is the first report on the chemical composition analysis of volatile compounds in V. curassavica using the HS-GC-MS technique.

Objetivou-se descrever e relacionar compostos de plantas do Cerrado com ação inibitória para microrganismos patogênicos para humanos e animais. Para tanto, realizou-se uma busca preliminar nos Descritores em Ciências da Saúde (DeCS) para definir as palavras a serem utilizadas no levantamento da literatura. Definiu como palavras chaves, “Antimicrobiano ou Bactericida ou Fungicida” e “Planta ou Vegetal” e “Cerrado ou Bioma Cerrado”. Por meio da ferramenta Medical Subject Headings (MeSH), selecionou estudos em que a combinação de palavras chaves foram identificadas nos títulos e ou resumos dos estudos. A busca pelos artigos foi realizada nas bases de dados Science Direct,Web of Science e PubMed. Foram revelados inicialmente 48 estudos, após leitura na integra foram incluídos para análise, 10 artigos publicados nos entre os anos (2017-2021). Após avaliação dos estudos, identificou-se 13 espécies vegetais pertencentes a 8 famílias botânicas com potencial antimicrobiano, sendo Fabaceae a família com maior número de espécies. Para extração dos compostos, a folha das plantas foi o órgão mais usado e o etanol, como solvente. Os compostos vegetais bioativos majoritários foram terpenos e compostos fenólicos. Os metabólitos secundários detectados nos extratos das plantas apresentaram diferentes formas de ação para inibição microbiana, sob diferentes concentrações. Os compostos vegetais do Cerrado são promissores como alternativas aos antimicrobianos convencionais, sendo importantes para produção de novos fármacos. Os estudos analisados demonstraram que existem espécies vegetais nativas do Cerrado já estudadas com notório potencial antimicrobiano.

Varronia curassavica has anti-inflammatory properties because of the terpenes, α-humulene and β-caryophyllene, present in the essential oil. The objective of this study was to evaluate the influence of seasonality on the essential oil of V. curassavica accessions. Leaves from six accessions were collected from the Germplasm Bank of the Federal University of Minas Gerais over 12 months. Correlations between the essential oil content and meteorological factors were determined. Gas chromatography analysis coupled with mass spectrometry was conducted to determine the chemical composition of the essential oil. The content and chemical composition of the oil varied throughout the year. Relative humidity was correlated with accessions ICA-VC2 (-0.64) and ICA-VC4 (0.68). β-bourbonene, β-elemene, spathulenol, germacrene, caryophyllene oxide, α-humulene, and β-caryophyllene occurred in all accessions. Accession ICA-VC3 exhibited lower variation (22.17%), higher average (0.97%) essential oil, and maintained an average abundance of α-humulene greater than 2.6%, which is the amount necessary for phytotherapeutics.

Background and Aim: Broiler meat is susceptible to lipid oxidation due to its high content of unsaturated fatty acids, especially when stored for a long time. Concerning with that problem, we can add natural compounds to the animal feed, as the plant essential oils, which have antioxidant, antimicrobial, and antifungal activities. The objective of this study was to evaluate the antioxidant activity, fatty acid profile, and chemical composition of the meat of broilers fed with diets containing different essential oil, including lemongrass (Cymbopogon flexuosus) and pedestrian tea (Lippia aff. rotundifolia). Materials and Methods: The experimental design used was a 4×4 factorial scheme (storage time×diets), and each treatment was repeated thrice. The treatments were applied as negative control (without antimicrobial); positive control (ration supplemented with 10 ppm of enramycin and 42 ppm of salinomycin), lemongrass (ration with 120 mg of essential oil of lemongrass for each kilogram of live weight of the animals), and pedestrian tea (ration with 120 mg of essential oil of pedestrian tea for each kilogram of live weight of the animals). Storage was performed after slaughter and evaluated monthly for 4 months. Results: The inclusion of lemongrass oil and pedestrian tea in the broiler diet did not change the ether extract content of the meat sample obtained from thigh and drumstick. The storage time promotes an increase in the moisture loss of the meat from the 2nd month in all treatments. There was an interaction between the additive and storage time for moisture loss. In the 2nd month of storage, the meat from broilers fed the antibiotic-containing feed had a lower moisture loss than those from broilers in the other treatment groups. The fatty acid profile did not differ statistically between the different treatment groups. The inclusion of additives in the food dropped the lipid oxidation at the 2nd month of storage. From the 3rd month, however, only the essential oils showed antioxidant effect. Conclusion: Antioxidant activity was positive for treatments that included essential oils. The lemongrass oil and pedestrian tea can be used as antioxidant additives in broiler diets to improve the oxidative stability of thigh-drumstick meat during storage. The results of the study suggest a good prospective for further research with profitability of usage essentials oils examined, for their economical application as feed components in broiler nutrition.