Search

a Universidade Regional do Cariri, URCA, Cel Ant^onio Luis, 1161, 63105-000, Pimenta, Crato, CE, Brazil b Universidade Federal do Paran a, UFPR, XV de Novembro, 1299, 80.060-000, Centro, Curitiba, PR, Brazil c Universidade Regional de Blumenau, FURB, Ant^onio da Veiga, 140, 89030-903, Itoupava Seca, Blumenau, SC, Brazil d Laborat orio de investiga¸c~ao em Gen etica e Hematologia Translacional, Instituto Gon¸calo Moniz (IGM), Funda¸c~ao Oswaldo Cruz (FIOCRUZ), Salvador, BA 40296- 710, Brazil e Centro Universit ario Doutor Le~ao Sampaio (Unile~ao), Av. Maria Leticia Leite Pereira s/n, Lagoa Seca, Juazeiro do Norte, Brazil

Background/Purpose The fractions were tested to investigate their chemical composition and antifungal potential in vitro. Methods/Results The results obtained through the chromatographic analysis allowed the identification of 28 compounds. Microbiological assays were carried out in order to determine the IC50, cell viability curve and inhibitory effect of the association of the fractions with Fluconazole (FCZ), against Candida spp. through the microdilution methodology. The assays for verification of change in morphology and Minimal Fungicidal Concentration were performed in solid media. The IC50 of the isolated and associated fractions were calculated to be between 5.10 and 926.56 μg/mL, when associated with FCZ the concentrations were reduced to 512 μg/mL and 1024 μg/mL, the IC50 value of the fractions associated with fluconazole varied between 1.38 and 925.56 μg/mL. Conclusions The fractions affect the morphological transition and have a relevant antifungal potential, as they caused fungal inhibition in isolated use and potentiated the action of FCZ.

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.

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 β-lactams as target antibiotics. The secretions in association with the antibiotics have a significant reduction in MIC, both the aminoglycosides and β-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.

Ethnopharmacological relevance The use of popular plants has guided pharmaceutical research aimed at combating pathogenic microorganisms. Psidium guajava L. is a plant of great versatility and it has been used both as food and as a therapeutic agent. Root, bark, leaves, fruits, flowers and seeds are used for medicinal purposes, especially in infusions and decoctions for oral and topical use . P. guajava is utilized in symptomatology treatment related to organ malfunction and of diseases caused by the action of pathogenic and/or opportunistic microorganisms. Many pharmacological studies have been conducted to scientifically assess its therapeutic potential. Aims of study The aim of the current study is to relate the popular use of this plant and its bioscientific assessment as a therapeutic agent in the treatment of diseases and symptoms caused by the action of protozoa, fungi, bacteria and viruses, and also evaluate the safety for the usage and the interaction with drugs. Materials and methods A bibliographic database the ethnobiology of Psidium guajava (2005–2015) and the pharmacological infections and parasitic diseases (2010–2015). Searches were done in scientific disclosure databases such as PubMed, Web of Science, and Scopus. Results P. guajava leaf extracts were scientifically investigated for the treatment of diseases caused by protozoa (leishmaniasis, malaria, giardiasis, amoebiasis and trichomoniasis), fungi (dermatosis, systemic and mucocutaneous diseases), bacteria (respiratory, mucocutaneous and gastrointestinal infections, cholera, gastritis and stomach ulcers, oral and periodontal infections, venereal diseases and urinary infections) and viruses (herpes, influenza, rotavirus disease and AIDS). The toxicity assays indicates the safet for usage. Conclusions Highlight and elucidate the therapeutic potential and versatility of P. guajava . They also justify using ethnobiology efficiency to guide pharmacological studies. Some limitations can be observed in this kind of study, as the lack for ethnobiological informations and the absence of some controls in the assays.

Introduction The survival and spreading of resistant bacterial strains has boosted research which focusses on discovering new antimicrobial agents derived from plant species. Several studies have demonstrated that substances present in plant extracts can modify the activity of antibiotics, increasing their efficacy. Species of the genus Psidium have been popularly used to treat bacterial infections. However, their modulatory effect on antibiotic activity remains to be elucidated. The aim of this study was to evaluate the modulatory effect of the hydroalcoholic extracts obtained from the leaves of Psidium guajava L. and Psidium brownianum Mart ex DC on bacterial proliferation, both separately and in combination with antibiotics. Methods The assays were performed using the microdilution method. The minimum inhibitory concentration (MIC) of the extracts and drugs were determined against standard and clinical isolates of Escherichia coli , Pseudomonas aeruginosa and Staphylococcus aureus . To verify the potentiation of the antibiotic activity, the MIC of the antibiotics were determined alone and in association with the extracts. Results The extracts of P. guajava and P. brownianum did not present clinically significant activity against the Gram negative bacteria evaluated, with MIC values against S. aureus of 256 and 512 μg/mL, respectively. However, when combined at sub-inhibitory concentrations with antibiotics, both extracts presented significantly synergistic effects. Conclusions Our results demonstrated the effectiveness of P. guajava and P. brownianum on modulating bacterial growth, suggesting that these natural products might be used in drug development in association with antibiotics, reducing bacterial resistance and thus, improving the treatment of bacterial infections.

The therapeutic combinations have been increasingly used against fungal resistance. Natural products have been evaluated in combination with pharmaceutical drugs in the search for new components able to work together in order to neutralize the multiple resistance mechanisms found in yeasts from the genus Candida. The aqueous and hydroethanolic extracts from Psidium brownianum Mart ex DC. and Psidium guajava L. species were evaluated for their potential to change the effect of commercial pharmaceutical drugs against Candida albicans and Candida tropicalis strains. The tests were performed according to the broth microdilution method. Plate readings were carried out by spectrophotometry, and the data generated the cell viability curve and IC50 of the extracts against the yeasts. A chemical analysis of all the extracts was performed for detection and characterization of the secondary metabolites. The total phenols were quantified in gallic acid eq/g of extract (GAE/g) and the phenolic composition of the extracts was determined by HPLC. Fluconazole and all extracts presented high Minimum Inhibitories Concentrations (MICs). However, when associated with the extracts at sub-inhibitory concentrations (MIC/16), fluconazole had its effect potentiated. A synergistic effect was observed in the combination of fluconazole with Psidium brownianum extracts against all Candida strains. However, for Psidium guajava extracts the synergistic effect was produced mainly against the Candida albicans LM77 and Candida tropicalis INCQS 400042 strains. The IC50 values of fluconazole ranged from 19.22 to 68.1 μg/mL when it was used alone, but from 2.2 to 45.4 μg/mL in the presence of the extracts. The qualitative chemical characterization demonstrated the presence of phenols, flavonoids and tannins among the secondary metabolites. The concentration of total phenols ranged from 49.25 to 80.77 GAE/g in the P. brownianum extracts and from 68.06 to 82.18 GAE/g in the P. guajava extracts. Our results indicated that both P. brownianum and P. guajava extracts are effective on potentiating the effect of fluconazole, and therefore, these plants have the potential for development of new effective drugs for treating fungal infections.

The search for natural substances such as plant extracts with antimicrobial properties has considerably increased, given that biofilms constitute a barrier against antifungal therapy, where these can be formed on any surface, such as acrylic resin prosthesis. The objective of this study was to identify the chemical composition of the Persea americana Mill. leaf ethanol extract (EEFPa) using the UPLC-QTOF-MS/MS technique, to verify its antifungal activity through a sensitivity test according to the conditions described in the documents in M27-A3 (CLSI, 2008) and M60 (CLSI, 2017), to induce biofilm formation in acrylic resin discs and quantify their formation using tetrazolium salt reduction (MTT), as well as to treat these with the extract and fluconazole. Ten of the twelve compounds present in the extract were identified. In the sensitivity test the lowest minimum inhibitory concentration observed was 512 μg/mL, while fluconazole concentrations ranged from 64 to 1 μg/mL. During biofilm induction, all the isolates were able to form biofilms within 48 h. During biofilm treatment, the extract was less effective at biofilm reduction than Fluconazole. The EEFPa showed significant antifungal activity against some of the strains in this study, however the extract showed lower effect when compared to fluconazole against the biofilm formation.

The Piper mikanianum species were investigated by the antimicrobial potential and chemical composition. Chemical analysis was performed by gas chromatography coupled to mass spectrometry (GC/MS). The Minimum Inhibitory Concentration (MIC) as well as the 50% Inhibitory Concentration against Candida strains were determined by microdilution. The effect of the drug-oil combination was also evaluated to verify possible synergism. The Minimum Fungicidal Concentration (MFC) was evaluated by subculturing the microdilution in Petri dishes and the anti-pleomorphism potential of the oil was tested in humid chambers. Chemical analysis revealed safrol as the major compound. The results from the intrinsic activity evaluation of the oil did not reveal a clinical importance, however, it presented a synergistic effect when associated with gentamicin against the multidrug resistant E. coli strain and when associated with fluconazole against fungal strains. Moreover, the oil possessed a fungistatic effect. Total inhibition of filamentous structures occurred in both Candida species in the anti-virulence test. The P. mikanianum essential oil showed a potentiating activity of drugs for which resistance exists and an inhibitory effect of one of the main virulence factors of the Candida genus, morphological transition, which has been previously shown to be responsible for causing invasive infections in human tissues.

In this study, the Piper cernuum Essential Oil (EOPC) was tested against bacterial and fungal strains using the microdilution method to evaluate its minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), as well as its antibiotic modifying effect, in addition to observing the oils ability to cause fungal dimorphism and to generate an IC50 cell viability curve. The EO was obtained through hydrodistillation using a Clevenger-type apparatus with the dry leaves and analyzed by GC-FID, allowing the identification of 14 compounds, with the main compound being 4-epi-cis-dihydromarofuran (28.97%). An EOPC intrinsic activity was identified only against Candida albicans 4127 (IC50 56.851 μg/mL). Given the MIC results from the EOPC intrinsic activity against Staphylococcus aureus 10 at the concentration of 406 μg/mL, its association with fluconazole potentiated it’s antifungal action. The action of gentamicin was potentiated by the addition of the EOPC to Staphylococcus aureus 10 and Escherichia coli 06 strains, both with MIC