A Potential New Source of Therapeutic Agents for the Treatment of Mucocutaneous Leishmaniasis: The Essential Oil of Rhaphiodon echinus.

Weeds are an important source of natural products; with promising biological activity. This study investigated the anti-kinetoplastida potential (in vitro) to evaluate the cytotoxicity (in vitro) and antioxidant capacity of the essential oil of Rhaphiodon echinus (EORe), which is an infesting plant species. The essential oil was analyzed by GC/MS. The antioxidant capacity was evaluated by reduction of the DPPH radical and Fe3+ ion. The clone Trypanosoma cruzi CL-B5 was used to search for anti-epimastigote activity. Antileishmanial activity was determined using promastigotes of Leishmania braziliensis (MHOM/CW/88/UA301). NCTC 929 fibroblasts were used for the cytotoxicity test. The results showed that the main constituent of the essential oil was γ-elemene. No relevant effect was observed concerning the ability to reduce the DPPH radical; only at the concentration of 480 µg/mL did the essential oil demonstrate a high reduction of Fe3+ power. The oil was active against L. brasiliensis promastigotes; but not against the epimastigote form of T. cruzi. Cytotoxicity for mammalian cells was low at the active concentration capable of killing more than 70% of promastigote forms. The results revealed that the essential oil of R. echinus showed activity against L. brasiliensis; positioning itself as a promising agent for antileishmanial therapies.

Effect of Carvacrol and Thymol on NorA efflux pump inhibition in multidrug-resistant (MDR) Staphylococcus aureus strains.

Undue exposure to antimicrobials has led to the acquisition and development of sophisticated bacterial resistance mechanisms, such as efflux pumps, which are able to expel or reduce the intracellular concentration of various antibiotics, making them ineffective. Therefore, inhibiting this mechanism is a promising way to minimize the phenomenon of resistance in bacteria. In this sense, the present study sought to evaluate the activity of the Carvacrol (CAR) and Thymol (THY) terpenes as possible Efflux Pump Inhibitors (EPIs), by determining the Minimum Inhibitory Concentration (MIC) and the association of these compounds in subinhibitory concentrations with the antibiotic Norfloxacin and with Ethidium Bromide (EtBr) against strains SA-1199 (wild-type) and SA-1199B (overexpresses NorA) of Staphylococcus aureus. In order to verify the interaction of the terpenes with the NorA efflux protein, an in silico molecular modeling study was carried out. The assays used to obtain the MIC of CAR and THY were performed by broth microdilution, while the Efflux Pump inhibitory test was performed by the MIC modification method of the antibiotic Norfloxacin and EtBr. docking was performed using the Molegro Virtual Docker (MVD) program. The results of the study revealed that CAR and THY have moderate bacterial activity and are capable of reducing the MIC of Norfloxacin antibiotic and EtBr in strains of S. aureus carrying the NorA efflux pump. The docking results showed that these terpenes act as possible competitive NorA inhibitors and can be investigated as adjuvants in combined therapies aimed at reducing antibiotic resistance.

Effect of hydroxyamines derived from lapachol and norlachol against Staphylococcus aureus strains carrying the NorA efflux pump.

Isolated substances and those organically synthesized have stood out over the years for their therapeutic properties, including their antibacterial activity. These compounds may be an alternative to the production of new antibiotics or may have the ability to potentiate the action of preexisting ones. In this context, the objective of this study was to evaluate the in vitro antibacterial and efflux pump inhibitory activity of hydroxyamines derived from lapachol and norlachol, more specifically the compounds 2-(2-Hydroxyethylamino)-3-(3-methyl-2-butenyl)-1,4 dihydro-1,4-naphthalenedione, 2-(2-Hydroxyethylamino)-3-(2-methyl-propenyl)[1,4]naphthoquinone and 2-(3-Hydroxypropylamino)-3-(3-methyl-2-butenyl)-[1,4]naphthoquinone, against Staphylococcus aureus strains carrying the NorA efflux pump mechanism. The substances were synthesized from 2-hydroxy-quinones, lapachol and nor-lapachol, obtaining the corresponding 2-methoxylated derivatives via dimethyl sulfate alkylation in a basic medium, which then reacted chemoselectively with 2-ethanolamine and 3-propanolamine to form the corresponding amino alcohols. All three molecules underwent a virtual structure-based analysis (docking). The antibacterial activity of the substances was measured by determining their Minimum Inhibitory Concentration (MIC) and a microdilution assay was performed to verify efflux pump inhibition using the substances at a sub-inhibitory concentration. The results were subjected to statistical analysis using an analysis of variance (ANOVA) followed by Bonferroni's post hoc test. The substances obtained MIC values ≥1024 µg/mL, however, a significant reduction of their MICs was observed when the substances were associated with norfloxacin and ethidium bromide, with this effect being attributed to efflux pump inhibition. Following a virtual analysis based on its structure (docking), information regarding the affinity of new ligands for the ABC efflux pump were observed, thus contributing to the understanding of their mechanism of molecular interactions and the discovery of functional ligands associated with a reduction in bacterial resistance.

GC-MS-FID characterization and antibacterial activity of the Mikania cordifolia essential oil and limonene against MDR strains.

The present study evaluated the effect of the essential oil of Mikania cordifolia (EOMc) and its major constituent limonene alone or associated with antibacterial drugs against Multidrug Resistant Bacteria (MDR). To evaluate the antibacterial activity, the minimum inhibitory concentrations (MIC) of the oil and limonene against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus were determined. The antibiotic-modulating activity was assessed using subinhibitory concentrations (MIC/8) of these substances in combination with conventional antibacterial drugs. Although no relevant antibacterial activity of the natural products was detected, both substances modulated the action of antibiotics against resistant bacteria. The EOMc demonstrated the best modulating effect against P. aeruginosa, presenting synergistic effects when associated with gentamicin and norfloxacin. In addition, the oil reduced the MIC of norfloxacin against E. coli as well as reduced the MIC of gentamicin against S. aureus. On the other hand, the best effect of limonene was obtained against S. aureus. Thus, it is concluded that the essential oil Mikania cordifolia and the isolated compound limonene do not have clinically significant antibacterial effect, but modulate the action of antibiotics against MDR bacteria.

Ximenia americana L. enhances the antibiotic activity and inhibit the development of kinetoplastid parasites.

OBJECTIVE: The objective of this work was evaluate the cytotoxic, leishmanicidal and tripanocidal activity, as well as to evaluate its antimicrobial and modulatory activity in association with different antibiotics of the hydroethanolic extract of the Ximenia Americana stem bark (EHXA). METHOD: In vitro tests against Trypanosoma cruzi, Leishmania sp. and citotoxicity were performed. The evaluation of the antibacterial and bacterial resistance modulatory effect was given by the microdilution method. RESULTS: The chemical profile show different classes of compounds with significant presence of quercetrin and caffeic acid. The EHXA demonstrated activity only in the concentration of 1000 µg/mL against the L. infantum and L. brasiliensis promastigotes, causing mortality percentage of 40.66 and 27.62%, respectively. The extract presented a significant toxicity only in the concentration of 1000 µg/mL, causing a mortality of 55.42% of fibroblasts. The antibacterial activity of the EHXA demonstrated a MIC value ≥1024 µg/mL against all the tested bacteria. However, in the modulation assay with EHXA in association with different antibiotics the extract had a synergistic effect against S. aureus strains when associated with norfloxacin. CONCLUSION: The results of this investigation demonstrate for the first time the chemical composition of the hydroethanolic extract of the Ximenia Americana stem bark, your potential antiparasitic and modulatory effect. The low cytotoxic and biological potential against S. aureus open therapeutic perspectives against leishmaniosis and bacterial infections.

Antibacterial and antibiotic modifying activity evaluation of ruminants' body fat used as zootherapeutics in ethnoveterinary practices in Northeast Brazil.

ETHNOPHARMACOLOGICAL RELEVANCE: Northeast Brazilian ethnoveterinary studies associated with the medicinal use of zootherapies have shown that ruminants' body fat such as sheep (Ovis aries), goats (Capra hircus) and cows (Bos taurus) are used in diseases affecting domestic animals. AIM OF THE STUDY: The objective of this study was to evaluate the antibacterial activity of the fixed oils from these ruminants in isolation and in association with antibiotics. RESULTS: Ovis aries (OFOA), Capra hircus (OFCH) and Bos taurus (OFBT) fixed oils were extracted using a Soxhlet apparatus with hexane as the solvent. Through the use of gas chromatography coupled to mass spectrometry (GC-MS) the methyl esters from the ruminants' fixed oils were obtained and the fatty acids present in these oils were indirectly determined. The OFOA, OFCH and OFBT antibacterial and antibiotic modifying activities against standard and multi-resistant bacterial strains were carried out using the broth microdilution test. The fixed oils from these species did not present antibacterial activity when tested in isolation, obtaining Minimal Inhibitory Concentration (MICs) values ≥ 1024 µg/mL. However, when associated with antibiotics, OFBT and OFCH showed a synergistic activity for the Amicacin, Amoxicillin, Norfloxacin and Oxytetracycline antibiotics. CONCLUSION: The OFOA promoted a synergistic action for the same antibiotics with the exception of Norfloxacin.

Photoprotective potential of medicinal plants from Cerrado biome (Brazil) in relation to phenolic content and antioxidant activity.

Photooxidative damage affects cellular lipids, proteins and DNA in addition to being involved in the pathobiochemistry of erythema formation, premature skin aging, photodermatoses development and skin cancer. Phenolic compounds, flavonoids and hydroxycinnamic acid esters protect plant tissues against harmful UV-radiation. This study aimed to evaluate the sun protection factor of several Brazilian plant extracts in relation to UVB radiation absorption, which causes skin cancer, and to correlate the findings with their antioxidant activity, as well as with total phenol and flavonoid content. The antioxidant activity of the extracts were evaluated using the DPPH radical scavenging test. The photoprotective effect was evaluated using the methodology developed by Mansur. The antioxidant activity from the extracts showed IC50 values ranging from 4.91 to 132.24 µg/mL when compared to the standard quercetin with an IC50 of 5.01 µg/mL; the phenolic content varied from 3.77 to 57.14 mg GAE/g extract while flavonoid content varied from 1.80 to 5.89 mg EQ/g extract. Almost all extracts showed a potential for UVB radiation absorption in accordance with the ANVISA (Agência Nacional de Vigilância Sanitária) technical regulation for cosmetic sunscreens. The extracts with greater sun protection factors were those originating from Lippia microphylla (SPF = 26.82) and Dimorphandra gardneriana (SPF = 20.12). A sun protection factor of 15 or higher contributes to protect the skin, where the presence of sakuranetin flavonoids and quercetin glycosides contribute to this action.

Antitrypanosomal, antileishmanial and cytotoxic activities of Brazilian red propolis and plant resin of Dalbergia ecastaphyllum (L) Taub.

The treatment for leishmaniasis and Chagas disease can be hard and painful, such that many patients give up on the treatment. In order to find an alternative path for the treatment of these diseases, researchers are using natural products to fight these parasites. The aim of this study was to evaluate the antiprotozoan and cytotoxic activities of red propolis samples collected from different Brazilian states and seasons whilst searching for possible activity differences. We also compared the red propolis results with the ones obtained for the plant resin extract collected from Dalbergia ecastaphyllum trees. The hydroethanolic red propolis extracts from Pernambuco and Alagoas, and the D. ecastaphyllum resin were evaluated regarding their antileishmanial, antitrypanosomal and cytotoxic activity. All extracts showed antiprotozoan and cytotoxic activity. RP-PER showed to be more cytotoxic against protozoan parasites and fibroblast cells. All propolis extracts showed a higher cytotoxic activity when compared to resin extracts. The propolis sample collected in Pernambuco during the rainy season killed the parasites with lower concentrations than the sample collected in the dry season. The IC50 observed against the parasites could be used without high fibroblast cell damage.

Anti-inflammatory and anti-edematogenic action of the Croton campestris A. St.-Hil (Euphorbiaceae) essential oil and the compound ß-caryophyllene in in vivo models.

BACKGROUND: Inflammation makes up a set of vascularized tissue reactions acting in the defense of the body against harmful stimuli. Natural products are a lower cost alternative with better benefit, often used in popular medicine in the treatment of inflammatory processes. Several species from the genus Croton have scientifically proven anti-inflammatory action. PURPOSE: This study aims to analyze the chemical composition of the Croton campestris A. St.-Hil essential oil (EOCC), derived from fresh leaves, as well as to evaluate the anti-inflammatory potential and the possible mechanisms of action of the EOCC and its constituent ß-caryophyllene. METHODS: The assays were performed in in vivo models of acute and chronic inflammation. Initially, the chemical composition of the EOCC was determined and its oral toxicity was evaluated, followed by the evaluation of its topical antiedematogenic effect through acute and chronic ear edema induced by Croton oil. For the systemic verification of an anti-inflammatory action, the abdominal contortions, formalin test, paw edema induced by carrageenan, dextran, histamine and arachidonic acid models, as well as a peritonitis test, vascular permeability and granuloma assays were performed. RESULTS: The evaluation of the essential oil chemical composition revealed the presence of ß-caryophyllene (15.91%), 1,8-cineol (16.98%) and germacrene-D (14.51%) as its main constituents. The EOCC had no relevant clinical toxicity on oral administration, with an LD50 of more than 5000 mg/kg. The tested substances showed anti-inflammatory action in the abdominal contortions, paw edema induced by carrageenan, dextran, histamine and arachidonic acid models, the formalin test, peritonitis test and vascular permeability; however, ß-caryophyllene had no significant effect on the granuloma assay. This suggests as a hypothesis that both substances tested showed significant influence on the arachidonic acid and histamine pathway reducing edema in these models. CONCLUSION: The tested substances have a clinically safe profile, additionally the EOCC and ß-caryophyllene presented relevant anti-inflammatory activity. This study supports the hypothesis that ß-caryophyllene, in association with other constituents present in the EOCC such as 1,8-cineole, contributed to the anti-inflammatory effect observed, in addition to suggesting that one of the mechanisms of action probably involves the inhibition of cytokines with the involvement of the arachidonic acid and histamine pathways.

Toxicity against Drosophila melanogaster and antiedematogenic and antimicrobial activities of Alternanthera brasiliana (L.) Kuntze (Amaranthaceae).

Bioactive phytocompounds are studied by several bioactivities demonstrated, as their cytotoxic effects. The aim of this work was to evaluate the phytochemical profile, the toxic effect using the Drosophila melanogaster animal model and the anti-inflammatory and antimicrobial effect of the Alternanthera brasiliana (EEAB) ethanol extract. The phytochemical profile was performed using HPLC. The cytotoxic effect was evaluated in vivo using D. melanogaster. The anti-inflammatory effect was determined by neurogenic and antiedematogenic assays, and the antimicrobial activity was assayed using a microdilution method to determine the minimum inhibitory concentration (MIC) of the EEAB alone and in association with antibiotics. The main compound identified on the EEAB was luteolin (1.93%). Its cytotoxic effect was demonstrated after 24 h in the concentrations of 10, 20 and 40 mg/mL. The extract demonstrated an antiedematogenic effect, with a reduction of the edema between 35.57 and 64.17%. The MIC of the extract was ≥1.024 µg/mL, thus being considered clinically irrelevant. However, when the EEAB was associated with gentamicin, a synergism against all bacterial strains assayed was observed: Staphylococcus aureus (SA10), Escherichia coli (EC06) and Pseudomonas aeruginosa (PA24). Due to these results, the EEAB demonstrated a low toxicity in vivo and anti-inflammatory and synergistic activities. These are promising results, mainly against microbial pathogens, and the compounds identified can be a source of carbon backbones for the discovery and creation of new drugs.

Chemical composition, antibacterial and modulatory action of the essential oil of Croton rhamnifolioides leaves Pax and Hoffman / Composição química, ação antibacteriana e moduladora do óleo essencial das folhas de Croton rhamnifolioides Pax and Hoffman

The species Croton rhamnifolioides is a shrub popularly known as "quebra faca", utilized in teas or infusions for the treatment of gastrointestinal disorders as ulcers, gastric discomfort, vomiting and hemorrhagic diarrhea. This work has as its main objective to evaluate the chemical composition of the essential oil of the Croton rhamnifolioides leaves (EOC), antibacterial activity and modulatory activity of antibiotic resistance, against bacterial strains of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and, and antifungal activity against Candida albicans, Candida krusei and Candida tropicalis. The chemical composition was determined through chromatography with a gas phase coupled with mass spectrometry (CG/MS), whereas antimicrobial activity and modulation were determined by microdilution assay. The chemical composition of the oil revealed 21 compounds, with the major compounds being spathulenol (22.46%) and 1,8-cineol (18.32%). The antimicrobial activity was not significant with MIC>1024 µg/mL, however, was observed a synergistic interference when essential oil associated with the antibiotics aminoglycoside and -lactam, and the antifungal polyene.

Croton rhamnifolioides is é um arbusto conhecido popularmente como "quebra-faca" e utilizado como chá ou infusão para o tratamento de problemas gastro-intestinais como úlceras, desconforto gástrico, vômitos e diarréias hemorrágicas. O objetivo deste trabalho foi avaliar a composição química do óleo essencial das folhas de Croton rhamnifolioides (OEC), atividade antibacteriana, moduladora da resistência bacteriana, contra linhagens bacterianas de Escherichia coli, Staphylococcus aureus e Pseudomonas aeruginosa e, atividade antifúngica contra Candida albicans, C. krusei e C. tropicalis. A composição química foi determinada através de Espectroscopia de Massas acoplada a Cromatografia Gasosa (EM/CG), enquanto as atividades antimicrobianas e moduladoras foram determinadas pelo método de microdiluição. A composição química do OEC revelou a presença de 21 compostos, sendo os principais o Espatulenol (22,46%) e 1,8-cineol (18,32%). A atividade antimicrobiana não foi considerada significativa apresentando MIC > 1024 µg/mL, contudo, foi observado um sinergismo quando o óleo essencial foi associado com aminoglicosídios, -lactâmicos e antifúngicos poliênicos.

Avaliação da atividade antimicrobiana e moduladora do extrato etanólico de Libidibia ferrea (Mart. ex Tul.) L.P. Queiroz / Evaluación de la actividad antimicrobiana y modulatória del extracto etanólico de Libidibia ferrea (Mart. ex Tul.) L.P. Queiroz / Evaluation of antimicrobial and modulatory activity of the ethanol extract of Libidibia ferrea (Mart. ex Tul.) L.P. Queiroz

Introdução: Staphylococcus aureus é mencionada na literatura como um importante patógeno, algumas espécimes acarretam infecções oportunistas em muitos animais e homens. Escherichia coli é uma das principais causas de doenças infecciosas humanas. Pertencente à família das Enterobacteriaceae, compartilham diversos fatores de virulência descrita por sua resistência a vários antibióticos, as contaminações são provavelmente iniciadas por modificações de defesas do hospedeiro. Pseudomonas aeruginosaé conhecida por causar infecção aguda pela produção de toxinas. Objetivo: avaliar o efeito antimicrobiano do extrato etanólico de Libidibia ferrea (Mart. ex Tul.) L.P. Queiroz, e modulação da atividade antibiótica. Métodos: o material botânico de Libidibia ferrea foi coletado no município de Penaforte, Ceará, Brasil. Para a obtenção dos extratos foram coletadas entrecasca e vagem frescas, submersos em etanol separadamente por 72 h, sendo após esse período, filtrado e concentrado em condensador rotativo a vácuo. Foram realizados testes de atividade antimicrobiana e modulação da atividade antimicrobiana com cepas padrões e multirresistentes de bactérias. Resultados: o extrato demonstrou atividade moduladora quando combinados com alguns antimicrobianos contra algumas linhagens testadas. Conclusões: portanto, é sugerido que o extrato de L. ferrea pode ser utilizada como uma fonte de produtos naturais na terapêutica antimicrobiana e no combate a multirresistência bacteriana(AU)

Introducción: Staphylococcus aureus se menciona en la literatura como un patógeno importante, algunos provocan infecciones oportunistas en animales y hombres. Escherichia coli es una de las principales causas de enfermedades infecciosas humanas. Ambas pertenecen a la familia Enterobacteriaceae, comparten muchos factores de virulencia y se caracterizan por su resistencia a múltiples antibióticos, su contaminación tal vez iniciada por la modificación de las defensas del hospedero. Pseudomonas aeruginosa causa de infección aguda mediante la producción de toxinas. Objetivo: evaluar el efecto antimicrobiano del extracto de etanol de Libidibia ferrea (Mart ex Tul.) LP Queiroz, y la modulación de la actividad antibiótica. Métodos: L. ferrea fue recopilada en el municipio de Penaforte, Ceará, Brasil. Para obtener los extractos se recogieron corteza y frutos frescos, sumergidos en etanol por separado durante 72 h, después se filtraron y se concentraron en un condensador rotatorio. Se realizaron pruebas de actividad antimicrobiana y la modulación de la actividad antimicrobiana con cepas multirresistentes de bacterias. Resultados: los extractos mostraron actividad moduladora cuando se combina con algunos antibióticos contra algunas cepas ensayadas. Conclusión: por lo tanto, se sugiere que el extracto de L. ferrea puede ser utilizado como una fuente de productos naturales en la terapia antimicrobiana y en la resistencia a múltiples fármacos bacteriana combate(AU)

Introduction: Staphylococcus aureus is mentioned in the literature as an important pathogen, some opportunistic bacteria may cause several problems in many animals and humans. Escherichia coli is a leading cause of human infectious diseases. Belonging to the family Enterobacteriaceae, share many virulence factors described by their resistance to multiple antibiotics, the contamination is probably initiated by modifications in the host defenses. Pseudomonas aeruginosa is known to cause acute infection by producing toxins. Objective: evaluate the antimicrobial effect of the ethanol extract of Libidibia ferrea (Mart ex Tul.) LP Queiroz, and modulation of antibiotic activity. Methods: L. ferrea was collected in the municipality of Penaforte, Ceará, Brazil. To obtain the extracts were collected bark and fruits, submerged in ethanol separately for 72 h, after this period, filtered and concentrated in a rotary vacuum condenser. Antimicrobial activity tests were performed and modulation of antimicrobial activity with standards and multiresistant strains of bacteria. Results: the extract showed antibacterial activity when combined with some antibiotics against the assayed strains, demonstrating a modulatory potential. Conclusion: therefore, it is suggested that L. ferrea extract can be used as a source of natural products in the antimicrobial therapy and in the combat bacterial multidrug resistance(AU)

Efeito antibacteriano e anti-inflamatório tópico do extrato metanólico de Chenopodium ambrosioides L / Antibacterial and topical anti-inflammatory effect of methanol extract of Chenopodium ambrosioides L

A utilização de plantas medicinais é uma prática comum nos países, fazendo parte da cultura popular como forma de tratamento de diferentes patologias. A planta Chenopodium ambrosioides L., conhecida popularmente como mastruz, é utilizada na medicina popular no tratamento de bronquite crônica, tuberculose, contusões, hérnias e fraturas, tendo algumas atividades comprovadas cientificamente como ação vermífuga e antimicrobiana. Dessa forma, o presente estudo teve como objetivo avaliar o perfil químico e investigar a atividade antibacteriana, moduladora de antibióticos e anti-inflamatória tópica do extrato metanólico obtido das folhas de Chenopodium ambrosioides L. Na prospecção fitoquímica do extrato, foram verificados diferentes metabólitos que possuem várias atividades biológicas, e na dosagem dos fenóis totais foram verificados 21,0 mg/g equivalente de ácido gálico, sendo a quantificação de flavonoides encontrado um total de 135,4 mg/g de quercetina. Não houve atividade antibacteriana, porém detectou-se modulação quando o extrato foi associado aos aminoglicosídeos contra cepas de E. coli e Staphylococcus aureus. Nos testes para inflamação aguda, o extrato apresentou um potencial antiedematogênico nas concentrações de 25 e 50 mg. Diante dos resultados, pode-se correlacionar o conhecimento empírico das pessoas, às propriedades biológicas observadas nessa pesquisa, esta podendo ser importante para futura validação dessas propriedades etnomedicinais.(AU)

The use of medicinal plants is a common practice in countries as part of popular culture as a treatment of different pathologies. The Chenopodium ambrosioides L. plant, popularly known as Mastruz, is used in folk medicine to treat chronic bronchitis, tuberculosis, bruises, fractures and hernias, and some activities scientifically proven as anthelmintic and antimicrobial action. Thus, this study aimed to evaluate the chemical profile and investigate the antibacterial activity, modulator of antibiotics and topical anti-inflammatory of methanol extract obtained from Chenopodium ambrosioides L. leaves. In the phytochemical extract prospecting, they were checked different metabolites that have multiple biological activity, and the dosage of total phenols were checked 21.0 mg / g gallic acid equivalent, and the quantification of flavonoids found a total of 135.4 mg / g quercetin. There was no antibacterial activity, but modulation was detected when the extract was associated with aminoglycosides against strains of E. coli and Staphylococcus aureus. In tests for acute inflammation, the extract showed an antiedematogenic potential at concentrations of 25 and 50 mg. Given the results, we can correlate the empirical knowledge of people; the biological properties observed in this study, this may be important for future validation of these ethnomedicinal properties.(AU)

Fumigant activity of the Psidium guajava var. pomifera (Myrtaceae) essential oil in Drosophila melanogaster by means of oxidative stress.

The guava fruit, Psidium guajava var. pomifera (Myrtaceae family), is a native plant from South America. Its leaves and fruits are widely used in popular medicine in tropical and subtropical countries. Drosophila melanogaster has been used as one of the main model organisms in genetic studies since the 1900s. The extensive knowledge about this species makes it one of the most suitable organisms to study many aspects of toxic compound effects. Due to the lack of studies on the effects of the bioactive compounds present in the P. guajava var. pomifera essential oil, we performed a phytochemical characterization by CG-MS and evaluated the toxicity induced by the essential oil in the D. melanogaster insect model. In order to understand the biochemical mechanisms of toxicity, changes on the Nrf2 signaling as well as hallmarks of oxidative stress response were followed in the exposed flies. Our results showed that exposure of insects to the P. guajava oil increased mortality and locomotor deficits in parallel with an oxidative stress response signaling. Therefore, it suggested a bioinsecticidal activity for P. guajava volatile compounds by means of oxidative stress. Further studies are ongoing to identify which oil compounds are responsible for such effect.