Chemical Composition and Antimicrobial Potential of Essential Oil of Acritopappus confertus (Gardner) R.M.King & H.Rob. (Asteraceae).

Microbial resistance has become a worrying problem in recent decades after the abusive use of antibiotics causing the selection of resistant microorganisms. In order to circumvent such resistance, researchers have invested efforts in the search for promising natural substances, such as essential oils. Thus, the objective of this work was to determine the chemical composition of the essential oil of Acritopappus confertus leaves, to evaluate its intrinsic effect and its effects in combination with drugs against pathogenic fungi and bacteria, in addition to verifying the inhibition of virulence in Candida strains. To this end, the oil was verified by gas chromatography coupled with mass spectrometry (GC/MS). Candida strains were used for antifungal assays by means of the serial microdilution technique, in order to determine the average inhibitory concentration (IC50), and for the modification assays, sub-inhibitory concentrations (MIC/8) were used. Finally, the natural product's ability to inhibit the formation of filamentous structures was evaluated. In antibacterial tests, the MIC of the oil against strains of Staphylococcus aureus and Escherichia coli and its modifying effects in association with gentamicin, erythromycin, and norfloxacin were determined. The major constituent of the essential oil was the monoterpene myrcene (54.71%). The results show that the essential oil has an antifungal effect, with C. albicans strains being the most susceptible. Furthermore, the oil can potentiate the effect of fluconazole against strains of C. tropicalis and C. albicans. Regarding its effect on micromorphology, the oil was also able to inhibit the filaments in all strains. In combination with antibiotics, the oil potentiated the drug's action by reducing the MIC against E. coli and S. aureus. It can be concluded that the essential oil of A. confertus has potential against pathogenic fungi and bacteria, making it a target for the development of an antimicrobial drug.

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.

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.

Phytochemical characterization and inhibition of Candida sp. by the essential oil of Baccharis trimera (Less.) DC.

This study aimed to investigate the chemical composition and antifungal potential of the essential oil of Baccharis trimera (Less.) DC. against Candida strains. The half maximal inhibitory concentration (IC50) was assessed by the microdilution method using the essential oil at a concentration range of 8192 to 8 µg/mL. The minimum fungicide concentration (MFC) was determined by subculture in solid medium. The ability of the essential oil to modulate the activity of antifungals was determined in wells treated simultaneously with the oil at a subinhibitory concentration (MFC/16) and fluconazole (FCZ). The fungal morphology was analyzed by microscopy. Gas chromatography coupled with mass spectrometry (GC/MS) was used to identify the chemical composition. The essential oil presented an CI50 of 11.24 and 1.45 µg/mL, which was found to potentiate the effect of FCZ against Candida albicans. On the other hand, this combined treatment resulted in antagonism against Candida tropicalis and no evident modulation against Candida krusei was observed. The essential oil significantly inhibited hyphae growth. However, with a MFC ≥ 16,384 µg/mL, it is assumed that it has a fungistatic action. The antifungal properties demonstrated in this study might be related to the presence of sesquiterpenes and monoterpenes, and the interaction between them. In conclusion, Baccharis trimera showed promising anti-Candida effects, in addition to potentiating the activity of FCZ against Candida albicans, affecting its morphological transition. Therefore, this species constitutes a source of chemical compounds with the potential to be used in the combat of fungal infections.

Astragalus species: Insights on its chemical composition toward pharmacological applications.

Astragalus L. is widely distributed throughout the temperate regions of Europe, Asia, and North America. The genus is widely used in folk medicine and in dietary supplements, as well as in cosmetics, teas, coffee, vegetable gums, and as forage for animals. The major phytoconstituents of Astragalus species with beneficial properties are saponins, flavonoids, and polysaccharides. Astragalus extracts and their isolated components exhibited promising in vitro and in vivo biological activities, including antiaging, antiinfective, cytoprotective, antiinflammatory, antioxidant, antitumor, antidiabesity, and immune-enhancing properties. Considering their proven therapeutic potential, the aim of this work is to give a comprehensive summary of the Astragalus spp. and their active components, in an attempt to provide new insight for further clinical development of these xenobiotics. This is the first review that briefly describes their ethnopharmacology, composition, biological, and toxicological properties.

Antioxidant, Antimicrobial, and Anticancer Effects of Anacardium Plants: An Ethnopharmacological Perspective.

Anacardium plants have received increasing recognition due to its nutritional and biological properties. A number of secondary metabolites are present in its leaves, fruits, and other parts of the plant. Among the diverse Anacardium plants' bioactive effects, their antioxidant, antimicrobial, and anticancer activities comprise those that have gained more attention. Thus, the present article aims to review the Anacardium plants' biological effects. A special emphasis is also given to their pharmacological and clinical efficacy, which may trigger further studies on their therapeutic properties with clinical trials.

Echinacea plants as antioxidant and antibacterial agents: From traditional medicine to biotechnological applications.

The genus Echinacea consists of 11 taxa of herbaceous and perennial flowering plants. In particular, Echinacea purpurea (L.) Moench is widely cultivated all over the United States, Canada, and in Europe, exclusively in Germany, for its beauty and reported medicinal properties. Echinacea extracts have been used traditionally as wound healing to improve the immune system and to treat respiratory symptoms caused by bacterial infections. Echinacea extracts have demonstrated antioxidant and antimicrobial activities, and to be safe. This survey aims at reviewing the medicinal properties of Echinacea species, their cultivation, chemical composition, and the potential uses of these plants as antioxidant and antibacterial agents in foods and in a clinical context. Moreover, the factors affecting the chemical composition of Echinacea spp. are also covered.

Chemical composition, antifungal activity and potential anti-virulence evaluation of the Eugenia uniflora essential oil against Candida spp.

The development of fungal resistance to antifungal drugs has been worsening over the years and as a result research on new antifungal agents derived from plants has intensified. Eugenia uniflora L. (pitanga) has been studied for its various biological actions. In this study the chemical composition and antifungal effects of the E. uniflora essential oil (EULEO) were investigated against Candida albicans (CA), Candida krusei (CK) and Candida tropicalis (CT) standard strains. The essential oil obtained through hydro-distillation was analyzed by gas chromatography coupled to mass spectrometry (GC-MS). To determine the IC50 of the oil, the cellular viability curve and the inhibitory effects were measured by means of the oil's association with Fluconazole in a broth microdilution assay with spectrophotometric readings. The Minimum Fungicidal Concentration (MFC) was determined by solid medium subculture with the aid of a guide plate while the assays used to verify morphological changes emerging from the action of the fractions were performed in microculture chambers at concentrations based on the microdilution. Two major oil constituents stand out from the chemical analysis: selina-1,3,7(11)-trien-8-one (36.37%) and selina-1,3,7(11)-trien-8-one epoxide (27.32%). The concentration that reduced microorganismal growth was ≥8,192 µg/mL while the IC50 varied, this being between 1892.47 and 12491.80 µg/mL (oil), 10.07 - 80.78 µg/mL (fluconazole) and 18.53 - 295.60 µg/mL (fluconazole + oil). The combined activity (fluconazole + oil) resulted in indifference and antagonism. A MFC of the oil in association with fluconazole was recorded at the concentration of 8,192 µg/mL against CA and CK. The oil caused the inhibition of CA and CT morphological transition. In view of the results obtained, additional research is needed to elucidate the activity of the E. uniflora oil over genetic and biochemical processes regarding its effect on Candida spp. virulence.

Chemical Characterization and Trypanocidal, Leishmanicidal and Cytotoxicity Potential of Lantana camara L. (Verbenaceae) Essential Oil.

Drug resistance in the treatment of neglected parasitic diseases, such as leishmaniasis and trypanosomiasis, has led to the search and development of alternative drugs from plant origins. In this context, the essential oil extracted by hydro-distillation from Lantana camara leaves was tested against Leishmania braziliensis and Trypanosoma cruzi. The results demonstrated that L. camara essential oil inhibited T. cruzi and L. braziliensis with IC50 of 201.94 µg/mL and 72.31 µg/mL, respectively. L. camara essential oil was found to be toxic to NCTC929 fibroblasts at 500 µg/mL (IC50 = 301.42 µg/mL). The composition of L. camara essential oil analyzed by gas chromatography-mass spectrometry (GC/MS) revealed large amounts of (E)-caryophyllene (23.75%), biciclogermacrene (15.80%), germacrene D (11.73%), terpinolene (6.1%), and sabinene (5.92%), which might be, at least in part, responsible for its activity. Taken together, our results suggest that L. camara essential oil may be an important source of therapeutic agents for the development of alternative drugs against parasitic diseases.

Avaliação in Vitro da atividade antimicrobiana do carvacrol através dos métodos de contato direto e gasoso / Evaluation In vitro of antimicrobial activity of carvacrol by the direct and gaseous contact methods

Nas últimas décadas, a resistência bacteriana frente aos antimicrobianos se constituiu em um sério problema para a saúde pública, impondo barreiras ao controle de diversas espécies de microrganismos. O carvacrol é um composto fenólico geralmenete encontrado como componente majoritário do óleo essencial de algumas plantas como Origanum vulgare (orégano), Lippia graveolens (Lípia) e Lipia sidoides (alecrim-pimenta). Estudos demonstram a atividade antibacteriana do orégano, possivelmente devido ao carvacrol. Para avaliar a ação antimicrobiana desse composto, foram utilizadas linhagens padrão bacterianas (Staphylococcus aureus ATCC25923 e Pseudomonasa aeruginosa ATCC15442) e fúngicas (Candida albicans ICB12, C. krusei ATCC6258 e C. tropicalis ATCC13803). Os métodos de microdiluição em caldo e de contato gasoso foram utilizados para determinar a concentração inibitória mínima (CIM) e a dose inibitória mínima (DIM) respectivamente, bem como a atividade moduladora da ação antibiótica através de ambos os métodos. O carvacrol, combinado em concentrações subinibitórias com as drogas antimicrobianas apresentou resultados relevantes frente às cepas de Staphylococcus aureus e Candida albicans, por tanto este estudo permitiu comprovar a atividade moduladora do carvacrol.

In the last decades, the bacterial resistance to antimicrobials becomes a serious problem of public health, creating several difficulties to control several microrganisms with nosocomial interest. The carvacrol, the main phenol compound of many plants as Origanum vulgare, Lippia graveolens and Lipia sidoides. Studies demonstrated and intensive antibacterial activity of O. vulgare, probably due the carvacrol. To evaluate the antimicrobial activity of this compound, were assayed microbial strains of Staphylococcus aureus ATCC25923, Pseudomonas eruginosa ATCC15442, Candida albicans ICB12, C. krusei ATCC6258 and C. tropicalis ATCC 13803. Using the microdilution and the gaseous contact method, were determined the minimum inhibitory concentration (MIC) and the minimum inhibitory dose (DIM), respectively as well as the modulatory activity with both methods. The carvacrol, used in subinhibitory concentrations associated with antimicrobial drugs demonstrated an interesting modulatory activity against Staphylococcus aureus and Candida albicans strains, indicating the antimicrobial and modulatory activity of this compound.

Avaliação In vitro da atividade antimicrobiana e moduladora dos extratos etanólico e hexânico de bulbo de Costus arabicus / In vitro evaluation of antimicrobial activity and modulating the ethanol and hexane extracts of Costus arabicus bulb

Neste estudo, extratos etanólicos e hexânicos de bulbo de Costus arabicus foram utilizados com o objetivo de avaliar a atividade antibacteriana, antifúngica e moduladora da resistencia de antibacterianos e antifúnicos contra cepas bactecterianas de Escherichia Coli, Staphylococcus aureus, Pseudomonas aeruginosa e cepas fúngicas de Candida Albicans. Candida Krusei, Candida Tropicalis. A atividade antibacteriana e modulatória foi determinada por microdiluição. A inibição do crescimento das bactérias e fungos testados com extrato foi ≥1024. A atividade de alguns antibióticos e antifúngicos foi reforçada sinergicamente quando estes extratos foram associados em concentrações subinibitórias com antimicrobianos. Portanto, sugerimos que os extratos etanólicos e hexânicos de bulbo de Costus arabicus podem ser utilizados como fonte de produtos naturais com o objetivo de modificar a resistência desses microorganismos aos antimicrobianos.

In this study, ethanol and hexane extracts of the bulbs from Costus Arabicus were assayed to antibacterial, antifungal and modulatory activity against antibacterial and antifungal drugs using bacterial and fungal strains of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, C. krusei and C. tropicalis. The antimicrobial and modulatory activity was evaluated by microdilution method. The activity of some antimicrobial drugs was synergistically enhanced when sub-inhibitory concentrations of these extracts were associated with antimicrobial drugs. Therefore, we suggest that ethanol and hexane extracts of bulbs from Costus Arabicus can be used as a source of natural products in order to modify the resistance of these microorganisms to antimicrobials, demonstrating an interesting strategy to combat drug-resistant infectious agents.