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Malassezia furfur is a yeast known as the etiological agent of seborrheic dermatitis. We evaluated the action of five different antimicrobials (amphotericin B, chloramphenicol, ketoconazole, fluconazole, and nystatin) on inhibiting biofilm formation and removing biofilm already formed by M. furfur. The assays were carried out using the microdilution method, and scanning electron microscopy images were used to analyze the biofilm structure. According to the results obtained, the percentage of inhibition was higher for chloramphenicol, followed by ketoconazole, nystatin, and amphotericin B. Regarding the eradication of the biofilm formed, the highest percentage was chloramphenicol, followed by ketoconazole and nystatin. Amphotericin B did not affect biofilm eradication, whereas fluconazole did not cause significant changes inhibiting or removing M. furfur biofilm. Therefore, except for fluconazole, all evaluated antimicrobials had inhibiting effects on the biofilm of M. furfur, either in its formation and/or eradication. Although the results achieved with chloramphenicol have been highlighted, further in vitro and in vivo studies are still needed in order to include this antimicrobial in the therapy of seborrheic dermatitis due to its toxicity, especially to the bone marrow.

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Seborrheic dermatitis is a chronic inflammatory disease caused by Malassezia yeast species that affects the regions of the body where the sebaceous glands are present. The combined use of different essential oils (EOs) can increase their spectrum of action. Thus, the present study aimed to evaluate the action of EOs alone and in combination with each other on M. furfur, in planktonic and biofilm form, and their anti-inflammatory and mutagenic potential, in addition to the effects on the viability of cells lines. Of the 40 evaluated EOs, 22 showed activity against M. furfur at 0.5 - 2.0 mg/mL concentrations. Among the most active species, a blend of essential oils (BEOs) composed of Cymbopogon martini (Roxb.) Will. Watson (MIC = 0.5 mg/mL) and Mentha × piperita L. (MIC = 1.0 mg/mL) was selected, which showed a synergistic effect against yeast when evaluated through the checkerboard assay. The fungicidal activity was maintained by the addition of anti-inflammatory oil from Varronia curassavica Jacq. to BEOs. The BEOs also showed activity in the inhibition of biofilm formation and in the eradication of the biofilm formed by M. furfur, being superior to the action of fluconazole. Furthermore, it did not show mutagenic potential and did not interfere with the cell viability of both evaluated cell lines (HaCaT and BMDMs). TNF-α levels were reduced only by C. martini; however, this property was maintained when evaluating BEOs. BEOs had no effect on IL-8 levels. Thus, the BEOs may be indicated for alternative treatments against seborrheic dermatitis.

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Dipteryx odorata and Dipteryx punctata are species native to the Amazonian, traded by extractivists to obtain coumarin. We aimed to analyze the presence of coumarin in the ethanolic extracts of leaves, branches and fruits of D. odorata and D. punctata and to evaluate the antimicrobial activity of these extracts against phytopathogenic fungi and bacteria of clinical interest. Chemical analyses were performed by thin layer chromatography (TLC) and by gas chromatography coupled to mass spectrometry (GC-MS). For the antifungal assays, the fungi used were Cercospora longissima, Colletotrichum gloeosporioides, two isolates of Fusarium spp. and Sclerotium rolfsii, and the antibacterial assay was performed using the minimum inhibitory concentration (MIC) test with Burkholderia cepacia, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus bacteria. In D. odorata seed extracts and in D. punctata husks, endocarps, and seeds, we identified 1,2-benzopyrone. D. odorata endocarp extracts and D. punctata seeds provided the greatest decrease in mycelial growth of the evaluated phytopathogens, showing promise as an alternative control. The husk and endocarp extracts of both species had a weak effect on E. coli. This research is the first to compare the different parts of species of the genus Dipteryx and to evaluate the use of husks and endocarps of D. punctata fruits to obtain coumarin. Chemical analyses used to quantify the compounds existing in the extracts, and tests with phytopathogens in vitro and in vivo are currently being carried out.

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Abstract Schinus terebinthifolia Raddi green fruits essential oil (EO) was evaluated regarding its phytochemical profile, antimicrobial and cytotoxic activities, and toxicity. Gas chromatography with mass spectrometry was applied to identify its constituents, thereafter the minimum inhibitory concentration, minimum bactericidal and fungicidal concentrations, and its antibiofilm activity were evaluated. The EO cytotoxicity was assessed in tumor and non-tumor human cells, and in vivo toxicity was evaluated in a Galleria mellonella model. The major constituents of S. terebinthifolia EO were alpha-phellandrene and beta-phellandrene. The EO had a weak activity against all strains of Candida albicans (MIC 1000µg/mL) and had no activity against non-albicans strains, bacteria, and C. albicans biofilm. Cytostatic activity against all tumor cell lines was shown. Additionally, cell viability remained at EO concentrations up to 62.5 µg/mL. At 16 mg/mL, 50% hemolysis was observed, and it had low toxicity in vivo. Overall, the S. terebinthifolia EO was characterized by low antimicrobial and antibiofilm activities, with no evidence of toxicity to human tumor and non-tumor cells

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This study investigated the vitamin C content, total phenolic compounds (TPC), and the potential bioactivities (antioxidant, antiproliferative, antibacterial activities, and inhibition capacity against N-nitrosation) of seven neglected and underutilized species (NUS): culantro (Eryngium foetidum), false roselle (Hibiscus acetosella), roselle (Hibiscus sabdariffa), tree basil (Ocimum gratissimum), Barbados Gooseberry (Pereskia aculeata), purslane (Portulaca oleracea), and tannia (Xanthosoma sagittifolium). Phenolic-rich extracts were obtained by a sequential optimization strategy (Plackett-Burman and Central Composite Design). O. gratissimum presented the highest TPC and X. sagittifolium the greater total vitamin C content. Overall, the plant extracts presented promising bioactive capacities, as scavenging capacity against HOCl, H2O2 and ROO• induced oxidation. P. oleracea demonstrated the highest cytostatic effect against ovarian and kidney tumor cells. O. gratissimum effectively inhibited S. Choleraesuis growth. Maximum inhibition on n-nitrosation was showed by O. gratissimum and E. foetidum. These results highlight the studied NUS as sources of potential health-promoting compounds.

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Enterococcus faecalis infections represent a health concern, mainly in oral diseases, in which treatments with chlorhexidine solution (0.2%) are often used; however, it presents high toxicity degree and several side effects. Based on this, the use of natural products as an alternative to treatment has been explored. Nonetheless, plant extracts have poor organoleptic characteristics that impair theirs in natura use. Therefore, this work aimed to evaluate the analytical profile, biological activity, and cytotoxicity in vitro of S. brasiliensis-loaded chitosan microparticles (CMSb) produced using different aspersion flow rates. The analytical fingerprint was obtained by FTIR and NIR spectra. Principal components analysis (PCA) was used to verify the similarity between the samples. The crystallinity degree was evaluated by X-ray diffraction (XRD). Phytochemical screening (PS) was performed to quantify phytocompounds. Antimicrobial activity was evaluated by minimum inhibitory concentration (MIC). Antibiofilm activity and bactericidal kinetics against E. faecalis (ATCC 29212 and MB 146-clinical isolated) were also assessed. The hemolytic potential was performed to evaluate the cytotoxicity. Data provided by FTIR, NIR, and PCA analyses revealed chemical similarity between all CMSb. Furthermore, the results from XRD analysis showed that the obtained CMSb present amorphous characteristic. Tannins and polyphenols were accurately quantified by the PS, but methodology limitations did not allow the flavonoid quantification. The low hemolytic potential assay indicates that all samples are safe. Antimicrobial assays revealed that CMSb were able to inhibit not only the E. faecalis ATCC growth but also the biofilm formation. Only one CMSb sample was able to inhibit the clinical strain. These results highlighted the CMSb antimicrobial potential and revealed this system as a promising product to treat infections caused by E. faecalis.

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The aim of this study was to evaluate in vitro the antifungal, antibiofilm and antiproliferative activities of the extract from the leaves of Guapira graciliflora Mart. The phytochemical characterization of the extract was performed using electrospray ionization mass spectrometry (ESI-MS). The antimicrobial activity of the extract and its fractions was evaluated using the broth microdilution method against species of Candida. The inhibition of C. albicans biofilm was evaluated based on the number of colony-forming units (CFU) and metabolic activity (MTT). The antiproliferative activity of the extract and its fraction was evaluated in the presence of human tumor and non-tumor cells, and the cytotoxicity of the extract was determined on the RAW 264.7 macrophage line - both using the sulforhodamine B method. The phytochemical characterization indicated the presence of the flavonoids rutin and kaempferol. The extract and the methanol fraction exhibited moderate antifungal activity against C. albicans, C. krusei, and C. glabrata, and strong activity against C. dubliniensis. In the biofilms at 24 and 48 hours, the concentration of 12500 µg/mL of the extract was the most effective at reducing the number of CFU s/mL (44.4% and 42.9%, respectively) and the metabolic activity of C. albicans cells (34.6% and 52%, respectively). The extract and its fractions had no antiproliferative effect on the tumor lines tested, with mean activity (log GI50) equal to or greater than 1.71 µg/mL. Macrophage cell viability remained higher than 80% for concentrations of the extract of up to 62.5 µg/mL. G. graciliflora has flavonoids in its chemical composition and demonstrates potential antifungal and antibiofilm activity, with no evidence of a significant change in the viability of human tumor and non-tumor cell lines.

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Abstract: The aim of this study was to evaluate in vitro the antifungal, antibiofilm and antiproliferative activities of the extract from the leaves of Guapira graciliflora Mart. The phytochemical characterization of the extract was performed using electrospray ionization mass spectrometry (ESI-MS). The antimicrobial activity of the extract and its fractions was evaluated using the broth microdilution method against species of Candida. The inhibition of C. albicans biofilm was evaluated based on the number of colony-forming units (CFU) and metabolic activity (MTT). The antiproliferative activity of the extract and its fraction was evaluated in the presence of human tumor and non-tumor cells, and the cytotoxicity of the extract was determined on the RAW 264.7 macrophage line - both using the sulforhodamine B method. The phytochemical characterization indicated the presence of the flavonoids rutin and kaempferol. The extract and the methanol fraction exhibited moderate antifungal activity against C. albicans, C. krusei, and C. glabrata, and strong activity against C. dubliniensis. In the biofilms at 24 and 48 hours, the concentration of 12500 µg/mL of the extract was the most effective at reducing the number of CFU s/mL (44.4% and 42.9%, respectively) and the metabolic activity of C. albicans cells (34.6% and 52%, respectively). The extract and its fractions had no antiproliferative effect on the tumor lines tested, with mean activity (log GI50) equal to or greater than 1.71 µg/mL. Macrophage cell viability remained higher than 80% for concentrations of the extract of up to 62.5 µg/mL. G. graciliflora has flavonoids in its chemical composition and demonstrates potential antifungal and antibiofilm activity, with no evidence of a significant change in the viability of human tumor and non-tumor cell lines.

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The increasing demand for safe food without preservatives or pesticides residues has encouraged several studies on natural products with antifungal activity and low toxicity. In this study, ethanolic extracts from leaves and fruit residues (peel and seeds) of three Brazilian savanna species (Acrocomia aculeata, Campomanesia adamantium and Caryocar brasiliense) were evaluated against phytopathogenic fungi. Additionally, the most active extract was chemically characterized by ESI-MS and its oral acute toxicity was evaluated. Extracts from C. brasiliense (pequi) peel and leaves were active against Alternaria alternata, Alternaria solani and Venturia pirina with minimal inhibitory concentrations between 350 and 1000 µg/mL. When incorporated in solid media, these extracts extended the lag phase of A. alternata and A. solani and reduced the growth rate of A. solani. Pequi peel extract showed better antifungal activity and their ESI-MS analysis revealed the presence of substances widely reported as antifungal such as gallic acid, quinic acid, ellagic acid, glucogalin and corilagin. The oral acute toxicity was relatively low, being considered safe for use as a potential natural fungicide.

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The authors report extracellular mycosynthesis of silver nanoparticles (AgNPs) by Phoma capsulatum, Phoma putaminum and Phoma citri. The AgNPs thus synthesised were characterised by UV-visible spectrophotometer, Fourier transform infrared spectroscopy, Nanosight LM20 and transmission electron microscopy, which confirmed the synthesis of mostly spherical and polydisperse nanoparticles capped with proteins. The size of AgNPs was found in the range of 10-80 , 5-80 and 5-90 nm with an average size of 31.85, 25.43 and 23.29 nm by P. capsulatum, P. putaminum and P. citri, respectively. Further, potential antimicrobial activity was reported against Aspergillus niger, Candida albicans, Salmonella choleraesuis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. The lowest minimal inhibitory concentration (MIC) (0.85 µg/ml) was reported for AgNPs synthesised from P. citri against S. choleraesuis. However, AgNPs synthesised from P. capsulatum showed the highest MIC (10.62 µg/ml) against S. choleraesuis, P. aeruginosa and E. coli (clinical isolate). The same MIC values (10.62 µg/ml) were also reported against P. aeruginosa and both clinical and standard isolates of E. coli for AgNPs synthesised from P. citri. It was also observed that all the silver nanoparticles showed remarkable antifungal and antibacterial activity against these tested pathogens as compared with the commercially available antifungal and antibacterial agents.

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