Phytochemical characterization and inhibition of Candida sp. by the essential oil of Baccharis trimera (Less.) DC.

This study aimed to investigate the chemical composition and antifungal potential of the essential oil of Baccharis trimera (Less.) DC. against Candida strains. The half maximal inhibitory concentration (IC50) was assessed by the microdilution method using the essential oil at a concentration range of 8192 to 8 µg/mL. The minimum fungicide concentration (MFC) was determined by subculture in solid medium. The ability of the essential oil to modulate the activity of antifungals was determined in wells treated simultaneously with the oil at a subinhibitory concentration (MFC/16) and fluconazole (FCZ). The fungal morphology was analyzed by microscopy. Gas chromatography coupled with mass spectrometry (GC/MS) was used to identify the chemical composition. The essential oil presented an CI50 of 11.24 and 1.45 µg/mL, which was found to potentiate the effect of FCZ against Candida albicans. On the other hand, this combined treatment resulted in antagonism against Candida tropicalis and no evident modulation against Candida krusei was observed. The essential oil significantly inhibited hyphae growth. However, with a MFC ≥ 16,384 µg/mL, it is assumed that it has a fungistatic action. The antifungal properties demonstrated in this study might be related to the presence of sesquiterpenes and monoterpenes, and the interaction between them. In conclusion, Baccharis trimera showed promising anti-Candida effects, in addition to potentiating the activity of FCZ against Candida albicans, affecting its morphological transition. Therefore, this species constitutes a source of chemical compounds with the potential to be used in the combat of fungal infections.

UPLC-MS-ESI-QTOF Analysis and Antifungal Activity of the Spondias tuberosa Arruda Leaf and Root Hydroalcoholic Extracts.

The aim of this study was to identify and evaluate the chemical compositions and effects of the S. tuberosa leaf and root hydroalcoholic extracts (HELST and HERST) against different strains of Candida. Chemical analysis was performed by Ultra-Performance Liquid Chromatography Coupled to Quadrupole/Time of Flight System (UPLC-MS-ESI-QTOF). The Inhibitory Concentration of 50% of the growth (IC50) as well as the intrinsic and combined action of the extracts with the antifungal fluconazole (FCZ) were determined by the microdilution method while the minimum fungicidal concentrations (MFCs) and the effect on fungal morphological transitions were analyzed by subculture and in humid chambers, respectively. From the preliminary phytochemical analysis, the phenols and flavonoids were the most abundant. The intrinsic IC50 values for HELST ranged from 5716.3 to 7805.8 µg/mL and from 6175.4 to 51070.9 µg/mL for the HERST, whereas the combination of the extracts with fluconazole presented IC50 values from 2.65 to 278.41 µg/mL. The MFC of the extracts, individually, for all the tested strains was ≥16384 µg/mL. When fluconazole was combined with each extract, the MFC against CA URM 5974 was reduced (HELST: 2048 and HERST: 4096 µg/mL). Synergism was observed against standard C. albicans (CA) and C. tropicalis (CT) strains and with the root extract against the CT isolate. The leaf extract inhibited the morphological transition of all strains while the root extract inhibited only CT strains.

Piper diospyrifolium Kunth.: Chemical analysis and antimicrobial (intrinsic and combined) activities.

The secular use of plants in popular medicine has emerged as a source for the discovery of new compounds capable of curing infections. Among microbial resistance to commercial drugs, species such as Piper diospyrifolium Kunth, which are used in popular therapy, are targets for pharmacological studies. With this in mind, antimicrobial experiments with the essential oil from the P. diospyrifolium (PDEO) species were performed and its constituents were elucidated. The oil compounds were identified by gas chromatography coupled to mass spectrometry (GC/MS). The broth microdilution method with colorimetric readings for bacterial tests (Escherichia coli and Staphylococcus aureus) and spectrophotometric readings for fungal tests (Candida albicans and Candida tropicalis), whose data were used to create a cell viability curve and calculate its IC50 against fungal cells, were used to determine the minimum inhibitory concentration of the oil and its combined action with commercial drugs. The oil's minimal fungicidal concentration and its action over fungal morphological transition were analyzed by subculture and microculture, respectively. Chemical analysis revealed Z-Carpacin, Pogostol and E-Caryophyllene as the most abundant compounds. Results from the intrinsic analysis were considered clinically irrelevant, however the oil presented a synergistic effect against multiresistant E. coli and S. aureus strains when associated with gentamicin, and against the standard and isolated C. tropicalis strains with fluconazole. A fungicidal effect was observed against the C. albicans isolate. Candida spp. hyphae inhibition was verified for all strains at the highest tested concentrations. The P. diospyrifolium essential oil presented a promising effect when associated with commercial drugs and against a fungal virulence factor. Thus, the oil presented active compounds which may help the development of new drugs, however, new studies are needed in order to clarify the oil's mechanism of action, as well as to identify its active constituents.

Chemical identification and antimicrobial potential of essential oil of Piper rivinoides kunth (BETIS-WHITE).

The family Piperaceae is known for presenting in its species flavoring, healing and antimicrobial properties among others. The objective of the present study was: to study the chemical profile of the essential oil of Piper rivinoides (EOPR); to analyze its anti-bacterial and antifungal potential, as well as to evaluate the antifungal and antibiotic-modifying capacity. The chemical constituents were identified by gas chromatography with flame ionization detector (GC-FID), allowing the identification of 7 constituents of a total of 86.99%. E-Isoelemicin was identified as the main constituent of petroleum (40.81%). Clinically relevant MIC results were obtained against fungi in which the inhibitory concentration remained <256 µg/mL, as for Candida albicans 4127 (217.6 µg/mL). The association of EOPR with an antifungal showed a high synergistic affinity against the strains of C. tropicalis 40042 and 4262. We concluded that no intrinsic EOPR activity was observed at any concentrations tested against bacteria. However, EOPR associated with Gentamicin acted synergistically against S. aureus 10 and Escherichia coli 06, but with Erythromycin there was a synergistic effect against Escherichia coli 06, and antagonism with norfloxacin.

GC-MS analysis of the fixed oil from Sus scrofa domesticus Linneaus (1758) and antimicrobial activity against bacteria with veterinary interest.

The bioprospection of zootherapeutic products can be a source of new drugs and to the creation of new strategies of natural resources conservation and management of endangered species. This fact is supported by ethnobiological studies indicating that the usage of zootherapeutic products can be replaced by the use of natural products isolated from plants and domestic animals. The emergence of antibiotic-resistant bacteria has increased the need for research for new active principles. Ethnoveterinary studies in Brazil have shown that Sus scrofa domesticus fat is used for diseases associated with bacterial pathogens. The objective of this study was to identify the chemical composition and to evaluate the antibacterial activity of the fixed oil of Sus scrofa domesticus (OFSC) when used alone or associated with antibiotics. In the analysis of the oil composition, there were 4 constituents identified, with oleic acid being the major constituent. The OFSC did not present antibacterial activity when tested alone; however, it showed synergism in the modulating activity when associated with antibiotics Amikacin and Amoxicillin.

Chemical composition, antifungal activity and potential anti-virulence evaluation of the Eugenia uniflora essential oil against Candida spp.

The development of fungal resistance to antifungal drugs has been worsening over the years and as a result research on new antifungal agents derived from plants has intensified. Eugenia uniflora L. (pitanga) has been studied for its various biological actions. In this study the chemical composition and antifungal effects of the E. uniflora essential oil (EULEO) were investigated against Candida albicans (CA), Candida krusei (CK) and Candida tropicalis (CT) standard strains. The essential oil obtained through hydro-distillation was analyzed by gas chromatography coupled to mass spectrometry (GC-MS). To determine the IC50 of the oil, the cellular viability curve and the inhibitory effects were measured by means of the oil's association with Fluconazole in a broth microdilution assay with spectrophotometric readings. The Minimum Fungicidal Concentration (MFC) was determined by solid medium subculture with the aid of a guide plate while the assays used to verify morphological changes emerging from the action of the fractions were performed in microculture chambers at concentrations based on the microdilution. Two major oil constituents stand out from the chemical analysis: selina-1,3,7(11)-trien-8-one (36.37%) and selina-1,3,7(11)-trien-8-one epoxide (27.32%). The concentration that reduced microorganismal growth was ≥8,192 µg/mL while the IC50 varied, this being between 1892.47 and 12491.80 µg/mL (oil), 10.07 - 80.78 µg/mL (fluconazole) and 18.53 - 295.60 µg/mL (fluconazole + oil). The combined activity (fluconazole + oil) resulted in indifference and antagonism. A MFC of the oil in association with fluconazole was recorded at the concentration of 8,192 µg/mL against CA and CK. The oil caused the inhibition of CA and CT morphological transition. In view of the results obtained, additional research is needed to elucidate the activity of the E. uniflora oil over genetic and biochemical processes regarding its effect on Candida spp. virulence.