Larvicidal Activity of Essential Oils Against Aedes aegypti (Diptera: Culicidae).

The Aedes aegypti is responsible for the transmission of arboviruses, which compromise public health. In the search for synthetic product alternatives, essential oils (OEs) have been highlighted by many researchers as natural insecticides. This systematic review (SR) was performed according to PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and its objective was to evaluate studies addressing OEs with larvicidal properties against Ae. aegypti, through electronic database searches (Pubmed, Science Direct and Scielo), covering an overview of the plant sources OEs, which plant parts were used, the extraction methods, analytical techniques, major and/or secondary constituents with greater percentages, as well as the LC50s responsible for larval mortality. Following study analysis, plants distributed across 32 families, 90 genera and 175 species were identified. The Lamiaceae, Myrtaceae, Piperaceae, Asteraceae, Rutaceae, Euphorbiaceae and Lauraceae families obtained the highest number of species with toxic properties against larvae from this vector. Practically all plant parts were found to be used for OE extraction. Hydrodistillation and steam distillation were the main extraction methods identified, with GC-MS/GC-FID representing the main analytical techniques used to reveal their chemical composition, especially of terpene compounds. In this context, OEs are promising alternatives for the investigation of natural, ecologically correct and biodegradable insecticides with the potential to be used in Ae. aegypti control programs.

LC-MS analysis and cytoprotective effect against the mercurium and aluminium toxicity by bioactive products of Psidium brownianum Mart. ex DC.

This study aimed to verify the chelating, antioxidant and cytoprotective activities of Psidium brownianum Mart. Ex DC against mercury and aluminum. The ethanolic extract, as well as the tannic and flavonoid fractions, were prepared and subjected to liquid chromatography-mass spectrometry analysis. Ferric ion reduction and antioxidant activity measurement using the FRAP method were performed with P. brownianum. After determining the sub-allelopathic doses, germination tests using Lactuca sativa (lettuce) seeds were performed. The main compounds identified in the extract and fractions were: quercetin and its derivatives; myricetin and its derivatives; gallic acid; ellagic acid; quinic acid and gallocatechin. The Minimum Inhibitory Concentration (MIC) for all samples were ≥ 1024 µg/mL. The flavonoid fraction in association with mercury chloride demonstrated cytoprotection (p < 0.001). The sub-allelopathic concentration used was 64 µg/mL. The extract and fractions were cytoprotective for radicles and caulicles when assayed in association with mercury and against aluminum for radicles. This suggests that the P. brownianum extract and its fractions present cytoprotective activity, possibly related to the antioxidant effect of secondary metabolites, especially flavonoids.

Phytotoxicity reduction of the mercury chloride effect by natural products from Eugenia jambolana Lam.: A new strategy against the toxic metal pollution.

The objective of this work was to evaluate the antioxidant, metal chelating and cytoprotective activity of the Eugenia jambolana Lam. extract, as well as of its flavonoid and tannic fractions, against the action of Mercury Chloride (HgCl2). Flavonoids were quantified and an LC-MS chromatographic analysis was performed to identify secondary metabolites. Fe2+ and Fe3+ chelation tests and antioxidant activity were carried out using the FRAP method. Microbiological tests were performed by microdilution to determine the Minimum Inhibitory Concentration (MIC). From these results the Minimum Bactericidal (MBC) and Minimum Fungicide Concentration (MFC) were evaluated. The allelopathy and cytoprotection assays were performed using eukaryotic and prokaryotic models. The results revealed the presence of phenolic acids and flavonoids in the E. jambolana extract and fractions. The sub-allelopathic concentration (64 µg/mL) was used and the results demonstrated the E. jambolana potential cytoprotective effect against mercury chloride.

Antibacterial activity and antibiotic modulating potential of the essential oil obtained from Eugenia jambolana in association with led lights.

Bacterial resistance has risen as an important health problem with impact on the pharmaceutical industry because many antibiotics have become ineffective, which has affected their commercialization. The Brazilian biodiversity is marked by a vast variety of natural products with significant therapeutic potential, which could bring new perspectives in the treatment of infections caused by resistant microorganisms. The present study aimed to evaluate the antibacterial effect of the essential oil obtained from Eugenia jambolana (EjEO) using the method of microdilution method to determine the Minimum Inhibitory Concentration (MIC). The modulatory effect of this oil on antibiotic activity was determined using both the broth microdilution and gaseous contact methods. The antibacterial effect of the association of the gaseous contact and the use of a LED unit with red and blue lights was also determined. The chemical components of the EjEO were characterized by HPLC, which revealed the presence of α-pinene as a major constituent. The EjEO presented a MIC≥128µg/mL against S. aureus and ≥1024µg/mL against E. coli. The combination of the EjEO with antibiotics presented synergism against E. coli and antagonism against S. aureus. An antagonistic effect was obtained from the association of EjEO with amikacin and erythromycin by the method of gaseous contact. On the other hand, the association of EjEO with ciprofloxacin presented a synergistic effect against S. aureus and E. coli exposed to LED lights. A similar effect was observed in the association of the EjEO with norfloxacin presented synergism against S. aureus in the same conditions. In conclusion, our results demonstrated that the essential oil obtained from Eugenia jambolana interfere with the action of antibiotics against bacteria exposed to LED lights. Thus, further researches are required to elucidate the mechanisms underlying these effects, which could open new perspectives in the development of new antibacterial therapies.

Inhibition of the TetK efflux-pump by the essential oil of Chenopodium ambrosioides L. and α-terpinene against Staphylococcus aureus IS-58.

The use of natural products is crucial to suppress the development of these micro-organisms and to reduce the concentration necessary to inhibit these microrganisms, reducing the toxicity risks also. In this study, the essential oil from Chenopodium ambrosioides Leaves and its main constituent α-Terpinene were used in the antibacterial and potentiating activity of antibiotics and ethidium bromide assays, against the bacterial strains Staphylococcus aureus IS-58, carriers of efflux pumps. The Minimum Inhibitory Concentration (MIC) was determined using a microdilution method. The capacity of the aforementioned was also tested in combination with tetracycline and ethidium bromide, with the aim of improving the activity of the antibacterials. The MIC of the C. ambrosioides L. essential oil and of α-Terpinene were above 1024 µg/mL, comprising a clinically irrelevant value. However, when associated with the antibiotics, the C. ambrosioides L. essential oil, significantly decreased the MIC of tetracycline and ethidium bromide. The efflux pump is the only mechanism the bacteria possesses to reduce the toxicity of ethidium bromide, and thus this reduction in the MIC demonstrates that the C. ambrosioides L. essential oil is an effective option in the inhibition of the efflux pump present in these micro-organisms.

Avaliação da atividade antioxidante e citoprotetora dos extratos de Eugenia uniflora Lineau e Psidium sobraleanum Proença & landrum contra metais pesados / Evaluación de la actividad citoprotectora y antioxidante de los extractos de Eugenia uniflora Lineau e Psidium sobraleanum Proença & Landrum contra metales pesados / Evaluation of the Cytoprotective and Antioxidant Activity of the Extracts of Eugenia Uniflora Lineau e Psidium Sobraleanum Proença & Landrum Against Heavy Metals

Objetivo: Estudos recentes apontam a utilização de plantas na forma de sucos ou chás como fontes de agentes antioxidantes naturais que apresentam baixo risco podendo ser utilizado no auxílio do tratamento de várias doenças. Materiais e métodos: Neste contexto, avaliaram-se os potenciais antioxidantes, in vitro, dos extratos de Eugenia uniflora e Psidium sobraleanum, além de quantificar fenóis e flavonoides presentes nos extratos. Resultados: De acordo com os resultados obtidos, observou-se uma melhor atividade antioxidante para o extrato de Eugenia uniflora, para o teste de TBARS com fosfolipídio de ovo, os extratos reduziram os níveis basais no processo de peroxidação lipídica, e quando induzidos por Fe2+ o extrato de Psidium sobraleanum mostrouse mais eficiente. Conclusões: Portanto, através destes ensaios pode-se verificar que os extratos das folhas das espécies, Eugenia uniflora e Psidium sobraleanum, apresentam uma atividade antioxidante, diretamente relacionada com substâncias fenólicas produzidas a partir do seu metabolismo secundário.

Objetivo: Estudios recientes reportan la utilización de plantas en forma de zumos o té como fuente de agentes antioxidantes naturales que presentan bajo riesgo, pudiendo ser utilizados como complemento del tratamiento de diversas enfermedades. Materiales y métodos: En este contexto, se evaluarán in vitro, los potenciales antioxidantes, de los extractos de Eugenia uniflora y Psidium sobraleanum, además de cuantificar fenoles y flavonoides presentes en los extractos. Resultados: De acuerdo con los resultados obtenidos, se observó una mejor actividad antioxidante con el extracto de Eugenia uniflora, en el test de TBARS con fofolípidos de huevo, los extractos redujeron los niveles basales en el proceso de peroxidación lipídica; y cuando fue inducida con Fe+2, el extracto de Psidium sobraleanum se mostró más eficiente. Conclusiones: Por lo tanto, a través de estos ensayos se pudo comprobar que los extractos de las hojas de las especies Eugenia uniflora y Psidium sobraleanum presentan actividad antioxidante, directamente relacionada con sustancias fenólicas producidas a partir de sus metabolitos secundarios.

Objective: Evaluation of antioxidant activity has been an important issue considering its importance in human health. Recent studies show that the use of plants in the form of juices or teas as sources of natural antioxidants with low risk can be used as an aid to the treatment of various diseases. Material and Methods: Evaluation of the antioxidant potential in vitro, extracts of Eugenia uniflora and Psidium sobraleanum, as well as the quantification of phenols and flavonoids present in the extracts. Results: Findings showed a better antioxidant activity for the extract of Eugenia uniflora. In the TBARS test with egg phospholipids, extracts presented a reduction in the basal levels in the lipid peroxidation process; and when the Fe2 + extract was inducted, Psidium sobraleanum proved to be more efficient.. Conclusions: These tests proved that the extracts of leaves of the species Eugenia uniflora and Psidium sobraleanum present antioxidant activity which is directly related to phenolic substances produced in its secondary metabolism.

Atividade antiparasitária in vitro e citotóxica de cariofileno e eugenol contra Trypanossoma cruzi e Leishmania brasiliensis / Actividad antiparasitaria in vitro citotóxica de cariofileno y eugenol contra Trypanosoma cruzi y Leishmania brasiliensis / In vitro cytotoxic and antiparasitic activity of caryophyllene and eugenol against Trypanosoma cruzi and Leishmania brasiliensis

Introdução: as doenças negligenciadas persistem por conta de falhas da ciência e acometem principalmente países em desenvolvimento, como exemplos podemos citar a doença de Chagas e a leishmaniose. Objetivo: avaliar o potencial antiparasitário in vitro de um terpenóide componente de óleo essencial, o cariofileno e o eugenol, contra as formas epimastigota e promastigota de T. cruzi e L. brasiliensis, respectivamente, bem como verificar sua citotoxicidade em células de mamíferos. Métodos: para os estudos in vitro de T. cruzi, foi usado o clone B5-CL, estavelmente transfectadas com o gene de Escherichia coli ß-galactosidase (lacZ). Os ensaios de inibição de promastigotas foram realizadas utilizando a estirpe de L. braziliensis, cultivadas a 22 ºC em meio de Schneider de Drosophila suplementado com FBS a 20 %. Para os testes de atividade antiepimastigota, antipromastigota foram utilizados placas de 96 poços com culturas que não tinham atingido a fase estacionária. Os ensaios de citotoxicidade utilizado estirpe de fibroblastos NCTC929 cultivadas em Meio Essencial Mínimo (Sigma). A viabilidade dessas linhagens através da utilização de resazurina como um método colorimétrico. Resultados: as substâncias cariofileno e eugenol foram testadas quanto à atividade antiepimastigota, antipromastigota e quanto à citotoxidade. Foi visto um efeito clinicamente relevante do cariofileno contra os parasitas T. cruzi e L. brasiliensi. Conclusões: os resultados mostram que o cariofileno obteve um melhor resultado quando comparado ao eugenol, sendo capaz de inibir o crescimento dos parasitas testados mostrando uma alternativa contra T. cruzi e L. brasiliensi. Em relação à citotoxidade novos testes deverão ser realizados para futuros testes in vivo.

Introducción: las enfermedades desatendidas persisten debido a los fracasos de la ciencia y afectan principalmente a los países en desarrollo, como ejemplos se pueden citar la enfermedad de Chagas y la leishmaniasis. Objetivo: evaluar el potencial de un componente in vitro terpenoide antiparasitario aceite esencial, el cariofileno y eugenol contra epimastigotes y promastigotes de Trypanosoma cruzi y Leishmania brasiliensis, respectivamente, así como comprobar su citotoxicidad en células de mamífero. Métodos: para los estudios in vitro de Trypanosoma cruzi, se utilizó el clon B5-CL, transfectadas establemente con el gen de la ß galactosidasa de Escherichia coli-(lacZ). Los ensayos de inhibición se realizaron con la cepa promastigotes de Leishmania braziliensis, se cultivó a 22 °C en medio de Schneider de Drosophila suplementado con FBS 20 %. Para la actividad de las pruebas antiepimastigota y antipromastigota, se utilizaron placas de 96 pocillos con cultivos que no habían alcanzado la fase estacionaria. En los ensayos de citotoxicidad se utilizó NCTC929, cepa de fibroblastos cultivados en medio esencial mínimo (Sigma). La viabilidad de estas cepas se evaluó mediante el uso de la resazurina como un método colorimétrico. Resultados: las sustancias cariofileno y eugenol se ensayaron para determinar la actividad antiepimastigota y antipromastigota, respecto a citotoxicidad. Se observó un efecto clínicamente relevante de cariofileno contra los parásitos Trypanosoma cruzi y Leishmania brasiliensis. Conclusiones: los resultados muestran que con el cariofileno se ha obtenido un mejor resultado en comparación con eugenol, siendo capaz de inhibir el crecimiento de parásitos que presentan una alternativa probada contra Trypanosoma cruzi y Leishmania brasiliensis. En cuanto a las pruebas de citotoxicidad, nuevos estudios deben llevarse a cabo para realizar más pruebas in vivo.

Introduction: neglected diseases continue to exist due to failures in science. They mainly affect developing countries. Two examples of neglected diseases are Chagas' disease and leishmaniasis. Objective: evaluate the potential of an in vitro antiparasitic terpenoid essential oil component, caryophyllene and eugenol, against epimastigotes and promastigotes of Trypanosoma cruzi and Leishmania brasiliensis, respectively, and verify their cytotoxicity in mammal cells. Methods: for in vitro studies of Trypanosoma cruzi, the B5-CL clone was used, stably transfected with the beta-galactosidase gene of Escherichia coli-(lacZ). Inhibition assays were performed on the promastigote strain of Leishmania braziliensis, cultured at 22°C in a Schneider's medium of Drosophila supplemented with 20% FBS. For anti-epimastigote and anti-promastigote activity tests, 96-well plates were used with cultures which had not reached their stationary stage. NCTC929 was used in cytotoxicity tests, a strain of fibroblasts cultured in minimum essential medium (Sigma). The viability of these strains was evaluated using resazurine as colorimetric method. Results: the substances caryophyllene and eugenol were assayed to determine their anti-epimastigote and anti-promastigote activity with respect to cytotoxicity. it was found that caryophyllene has a clinically relevant effect against the parasites Trypanosoma cruzi and Leishmania brasiliensis. Conclusions: results show that caryophyllene was more effective than eugenol, inhibiting the growth of parasites and thus constituting a proven alternative against Trypanosoma cruzi and Leishmania brasiliensis. As to cytotoxicity testing, new studies should be conducted in which more in vivo tests are performed.

Phytochemical screening, antibacterial activity and in vitro interactions between Costus cf. arabicus L. with UV-A and aminoglycosides.

In this study, the methanol extracts of of Costus cf. arabicus L. were evaluated for antibacterial activity against multiresistant strains of Escherichia coli and Staphylococcus aureus. The antibacterial and modulatory activity of the extracts was assayed by microdilution. The light-enhanced antibacterial activity was assayed by light regimen. The growth of the bacteria tested was not inhibited by the extracts. The minimum inhibitory concentration (MIC) values ranged from 512 to ≥1024 µg·m L(-1). However, the antibiotic activity of the aminoglycosides was synergistically enhanced when these extracts were associated in sub-inhibitory concentrations with the antibiotics. Both extracts showed activity against at two standard bacterial strains. Because of this, we suggest that the ethanol extracts of the stems and leaves of Costus cf. arabicus L. show potential antibacterial, light-induced and synergistic antibiotic activity. With such results, these extracts are proven to be a promising source of antibacterial and modulatory agents.

In vitro antibacterial, phototoxic, and synergistic activity of ethanol extracts from Costus cf. arabicus L.

In this study, ethanol extracts of stems and leaves of Costus cf. arabicus L. were evaluated for antibacterial activity against multidrug-resistant strains of Escherichia coli and Staphylococcus aureus. The antibacterial and modulatory activities of the extracts were assayed by microdilution. The light-enhanced antibacterial activity was assayed by a light regimen. The growth of the bacteria tested was not inhibited by the extracts. The minimum inhibitory concentration values were ≥1,024 µg/mL. However, the antibiotic activity of aminoglycosides was synergistically enhanced when these extracts at subinhibitory concentrations were combined with the antibiotics. Also, both extracts showed activity against the wild-type bacterial strains, but the leaf extract was the more active extract, being active against both S. aureus and E. coli. Therefore, we conclude that the ethanol extracts of stems and leaves of C. cf. arabicus L. have potential light-induced antibacterial activity and synergistic antibiotic activity. This study showed that these extracts may be a promising source of antibacterial and modulatory agents.