Chemical composition and antimicrobial potential of Acrocomia aculeata (Jacq.) Lodd. ex Mart. and Syagrus cearensis Noblick (Arecaceae).

This study aimed to evaluate the antibiotic effects of the fixed oils of Acrocomia aculeata (FOAA) and Syagrus cearenses (FOSC) against the bacterial strains and the fungi strains of the genus Candida spp. The method of serial microdilution using different concentrations was used for measuring the individual biological activity of the fixed oils. The fixed oil of A. aculeata showed the presence of oleic acid (24.36%), while the oil of S. cearensis displayed the content of myristic acid (18.29%), compounds detected in high concentration. The combination FOAA + Norfloxacin, and FOSC + Norfloxacin showed antibacterial activity against E. coli and S. aureus strains, demonstrating possible synergism and potentiation of the antibiotic action against multidrug-resistant strains. The combination FOAA + Fluconazole displayed a significant effect against Candida albicans (IC50 = 15.54), C. krusei (IC50 = 78.58), and C. tropicalis (IC50 = 1588 µg/mL). Regarding FOSC + Fluconazole, it was also observed their combined effect against the strains of C. albicans (IC50 = 3385 µg/mL), C. krusei (IC50 = 26.67 µg/mL), and C. tropicalis (IC50 = 1164 µg/mL). The findings of this study showed a significant synergism for both fixed oils tested when combined with the antibiotic.

Phytochemical Analysis, Antibacterial Activity and Modulating Effect of Essential Oil from Syzygium cumini (L.) Skeels.

One of the main global problems that affect human health is the development of bacterial resistance to different drugs. As a result, the growing number of multidrug-resistant pathogens has contributed to an increase in resistant infections and represents a public health problem. The present work seeks to investigate the chemical composition and antibacterial activity of the essential oil of Syzygium cumini leaves. To identify its chemical composition, gas chromatography coupled to mass spectrometry was used. The antibacterial activity test was performed with the standard strains Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 25853 and Staphylococcus aureus ATCC 25923 and multidrug-resistant clinical isolates E. coli 06, P. aeruginosa 24 and S. aureus 10. The minimum inhibitory concentration (MIC) was determined by serial microdilution as well as the verification of the modulating effect of the antibiotic effect. In this test, the oil was used in a subinhibitory concentration. The test reading was performed after 24 h of incubation at 37 °C. The results show that the major chemical constituent is α-pinene (53.21%). The oil showed moderate activity against E. coli ATCC 25922, with the MIC of 512 µg/mL; there was no activity against the other strains. The oil potentiated the effect of antibiotics demonstrating possible synergism when associated with gentamicin, erythromycin and norfloxacin against E. coli 06 and S. aureus 10.

UPLC-MS-ESI-QTOF Analysis and Antifungal Activity of Aqueous Extracts of Spondias tuberosa.

This study aimed to identify the chemical composition of the Spondias tuberosa aqueous leaf and root extracts (EALST and EARST) and to evaluate their effect, comparatively, against opportunistic pathogenic fungi. Ultra-Performance Liquid Chromatography Coupled to a Quadrupole/Time of Flight System (UPLC-MS-ESI-QTOF) was employed for chemical analysis. Candida albicans and C. tropicalis standard strains and clinical isolates were used (CA INCQS 40006, CT INCQS 40042, CA URM 5974, and CT URM 4262). The 50% Inhibitory Concentration for the fungal population (IC50) was determined for both the intrinsic action of the extracts and the extract/fluconazole (FCZ) associations. The determination of the Minimum Fungicidal Concentration (MFC) and the verification of effects over fungal morphological transitions were performed by subculture in Petri dishes and humid chambers, respectively, both based on micro-dilution. UPLC-MS-ESI-QTOF analysis revealed the presence of phenolic and flavonoid compounds. The association of the extracts with fluconazole, resulted in IC50 values from 2.62 µg/mL to 308.96 µg/mL. The MFC of the extracts was ≥16,384 µg/mL for all tested strains, while fluconazole obtained an MFC of 8192 µg/mL against C. albicans strains. A reduction in MFC against CA URM 5974 (EALST: 2048 µg/mL and EARST: 1024 µg/mL) occurred in the extract/fluconazole association.

Antibacterial, modulatory activity of antibiotics and toxicity from Rhinella jimi (Stevaux, 2002) (Anura: Bufonidae) glandular secretions.

The increase in microorganisms with resistance to medications has caused a strong preoccupation within the medical and scientific community. Animal toxins studies, such as parotoid glandular secretions from amphibians, possesses a great potential in the development of drugs, such as antimicrobials, as these possess bioactive compounds. It was evaluated Rhinella jimi (Stevaux, 2002) glandular secretions against standard and multi-resistant bacterial strains; the effect of secretions combined with drugs; and determined the toxicity using two biologic in vivo models, and a in vitro model with mice livers. Standard strains were used for the determination of the Minimum Inhibitory Concentration (MIC), while for the modulatory activity of antibiotics, the clinical isolates Escherichia coli 06, Pseudomonas aeruginosa 03 and Staphylococcus aureus 10 were used. Modulatory activity was evaluated by the broth microdilution method with aminoglycosides and ß-lactams as target antibiotics. The secretions in association with the antibiotics have a significant reduction in MIC, both the aminoglycosides and ß-lactams. The toxicity and cytotoxicity results were lower than the values used in the modulation. R. jimi glandular secretions demonstrated clinically relevant results regarding the modulation of the tested antimicrobials.