Cymbopogon citratus essential oil: effect on polymicrobial caries-related biofilm with low cytotoxicity

Abstract The objective of this study was to evaluate the effects of Cymbopogon citratus essential oil and its main compound (citral) against primary dental colonizers and caries-related species. Chemical characterization of the essential oil was performed by gas chromatography/mass spectroscopy (GC/MS), and the main compound was determined. Antimicrobial activity was tested against Actinomyces naeslundii, Lactobacillus acidophilus, S. gordonii, S. mitis, S. mutans, S. sanguinis and S. sobrinus. Minimum inhibitory and bactericide concentrations were determined by broth microdilution assay for streptococci and lactobacilli reference, and for clinical strains. The effect of the essential oil on bacterial adhesion and biofilm formation/disruption was investigated. Negative (without treatment) and positive controls (chlorhexidine) were used. The effect of citral on preformed biofilm was also tested using the same methodology. Monospecies and microcosm biofilms were tested. ANOVA or Kruskal-Wallis tests were used (α=0.05). Cytotoxicity of the essential oil to human keratinocytes was performed by MTT assay. GC/MS demonstrated one major component (citral). The essential oil showed an inhibitory effect on all tested bacterial species, including S. mutans and L. acidophilus. Essential oil of C. citratus (10X MIC) reduced the number of viable cells of lactobacilli and streptococci biofilms (p < 0.05). The essential oil inhibited adhesion of caries-related polymicrobial biofilm to dental enamel (p < 0.01). Citral significantly reduced the number of viable cells of streptococci biofilm (p < 0.001). The essential oil showed low cytotoxicity to human keratinocytes. Based on these findings, this study can contribute to the development of new formulations for products like mouthwash, against dental biofilms.

Antiproliferative activity, antioxidant capacity and chemical composition of extracts from the leaves and stem of Chresta sphaerocephala

AbstractIn this study, antiproliferative and antioxidant activities of crude extracts (hexane, ethyl acetate and methanol) from leaves and stem of Chresta sphaerocephala DC., Asteraceae, were investigated. Antiproliferative activity was tested in vitro against ten human cancer cells and against VERO (no cancer cell). Antioxidant activities were determined using DPPH and ORAC-FL assays and the total phenolic content was estimated by Folin–Ciocalteu method. Hexane and ethyl acetate extracts (leaves and stem) exhibited antiproliferative activity against cancer cell lines with total growth inhibition (TGI) between 50.40 and 250 µg/ml. For VERO cell, TGI values were >250 µg/ml for all extracts, except to hexane extract of the stem (TGI 80.92 µg/ml). In an initial evaluation, ethyl acetate and methanol extracts (leaves and stem) have shown levels of phenolic compounds between 6.94 and 30.96 mg GAE/kg in Folin–Ciocalteu assay, DPPH free-radical scavenging activity with SC50 in the range of 75.22 and 400 µg/ml and antioxidant capacity between 290.08 and 1088 µmol TE/g of extract in ORAC-FL assay. HPLC-DAD and ESI-MS analysis allowed the identification of flavonoids in the methanol extract from the leaves of C. sphaerocephala. Three steroids and nine triterpenoids were identified in the bioactive hexane extracts using HRGC.

Applications of the hexanic fraction of Agave sisalana Perrine ex Engelm (Asparagaceae): control of inflammation and pain screening

The present study evaluated the anti-inflammatory and analgesic properties of Agave sisalana Perrine in classic models of inflammation and pain. The hexanic fraction of A. sisalana (HFAS) was obtained by acid hydrolysis followed by hexanic reflux. Anti-inflammatory properties were examined in three acute mouse models (xylene ear oedema, hind paw oedema and pleurisy) and a chronic mouse model (granuloma cotton pellet). The antinociceptive potential was evaluated in chemical (acetic-acid) and thermal (tail-flick and hot-plate test) models of pain. When given orally, HFAS (5, 10, 25 and 50 mg/kg) reduced ear oedema (p < 0.0001; 52%, 71%, 62% and 42%, respectively). HFAS also reduced hind paw oedema at doses of 10 mg/kg and 25 mg/kg (p < 0.05; 42% and 58%, respectively) and pleurisy at doses of 10 mg/kg and 25 mg/kg (41% and 50%, respectively). In a chronic model, HFAS reduced inflammation by 46% and 58% at doses of 10 mg/kg and 25 mg/kg, respectively. Moreover, this fraction showed analgesic properties against the abdominal writhing in an acetic acid model (at doses of 5-25 mg/kg) with inhibitory rates of 24%, 54% and 48%. The HFAS also showed an increased latency time in the hot-plate (23% and 28%) and tail-flick tests (61% and 66%) for the 25 mg/kg and 50 mg/kg doses, respectively. These results suggest that HFAS has anti-inflammatory and analgesic properties.

Avaliação das atividades antiproliferativa e antioxidante em frutos de Campomanesia pubescens / Evaluation of antioxidant and antiproliferative activities in fruits of Campomanesia pubescens

A investigação química dos extratos bioativos dos frutos de Campomanesia pubescens (Myrtaceae)resultou no isolamento de duas chalconas. Os compostos isolados foram identificados pelas análises espectroscópicas (1H, 13C e 2D RMN) e, por comparação com os dados descritos na literatura. A capacidade antioxidante dos extratos e frações foi determinada utilizando-se os ensaios de capacidade de absorção de oxigênio radical (ORAC-FL) e de DPPH; e os teores de fenólicos solúveis foram medidos utilizando-seo reagente de Folin-Ciocalteau. Os efeitos antiproliferativos dos extratos e de isolados de chalconas 1 e2 foram determinados in vitro contra as seguintes células cancerosas humanas U251 (glioma), UACC-62 (melanoma), MCF-7 (mama), NC1-ADR/RES (ovário resistente), 786,0 (rim), NCI-H460 (pulmão),PC-3 (próstata), OVCAR-3 (ovário), HT-29 (cólon) e K562 (leucemia), e contra linhagem celular não cancerígena VERO. O extrato hexânico e os compostos isolados de chalconas 1 e 2 demonstraram efeito antiproliferativo potente contra linhagens de células cancerosas com valores de inibição de crescimento total (TGI) menores dos aqueles observados na linhagem celular controle. A atividade mais elevada das chalconas 1 e 2 foi detectada nas células MCF-7, PC-3 e HT-29.

Chemical investigation on the bioactive extracts from fruits of Campomanesia pubescens (Myrtaceae)resulted in the isolation of two chalcones. The isolated compounds were identified by means of spectroscopicanalysis (1H, 13C and 2D NMR), and by comparing with the data reported in the specific literature.Antioxidant capacity of extracts and fractions was determined using the oxygen radical absorbancecapacity (ORAC-FL) and DPPH assays; and the total soluble phenolic contents were measured by usingFolin-Ciocalteau reagent. The anti-proliferative effects of the extracts and of the chalcone isolates 1 and2 were determined in vitro against human cancer cells lineages U251 (glioma), UACC-62 (melanoma),MCF-7 (breast), NC1-ADR/RES (ovarian-resistant), 786.0 (kidney), NCI-H460 (lung), PC-3 (prostate),OVCAR-3 (ovarian), HT-29 (colon) and K562 (leukemia), and against non-cancerous cell line VERO.Hexanic extract and chalcone isolated compounds 1 and 2 showed potent antiproliferative effect againstcancer cell lineages with lower total growth inhibition (TGI) values than those found in control cell line.The highest activity of the chalcones 1 and 2 was observed against the MCF-7, PC-3 and HT-29 cell lines.

Chemical composition and cytotoxic activity of the essential oil from the leaves of Casearia lasiophylla

The essential oil obtained by hydrodistillation from fresh leaves of Casearia lasiophylla Eichler, Salicaceae, was analyzed by gas capillary (GC/FID and GC/MS). The cytotoxicity of the leaves essential oil was tested in vitro againstU251 (glioma), UACC-62 (melanoma), MCF-7 (breast), NC1-ADR/RES (ovarian-resistant), NCI-H460 (lung), PC03 (prostate), OVCAR-3 (ovarian), HT-29 (colon) and K562 (leukemia) human cancer cells and against VERO (no cancer cell). The yield of oil was 0.02 percent. Fifty two compounds were identified, representing 87.1 percent of the total of the oil. The main components were identified as germacrene D (18.6 percent), β-caryophyllene (14.7 percent), δ-cadinene (6.2 percent), and α-cadinol (5.4 percent). The oil exhibited antiproliferative activity against all cell lines (TGI<100 µg/mL), with exception of NCI-H460 cell line (TGI 191.31 µg/mL). The highest activity was observed against UACC-62 (TGI 7.30 µg/mL), and K562 (TGI 7.56 µg/mL) cell lines. The observed activity could be related to high content of germacrene D and β-caryophyllene, compounds known as cytotoxic.

Atividade antifúngica do óleo essencial de Cymbopogon citratus frente a cepas de Candida albicans e Candida tropicalis isoladas de infecções nosocomiais / Antifungal activity of Cymbopogon citratus essential oil on Candida albicans and Candida tropicalis strains isolated from nosocomial infections

O óleo essencial de Cymbopogon citratus tem sido alvo de vários estudos em função do potencial antimicrobiano. Neste estudo, a atividade desse componente foi investigada em cepas do gênero Candida isoladas de infecções hospitalares. Para a condução do estudo, foram analisadas 24 isolados de Candida albicans e 15 isolados de Candida tropicalis, originados de pacientes com suspeitas de infecção hospitalar e uma cepa padrão de C. albicans ATCC 10231, por meio da técnica de difusão em ágar. O óleo essencial de C. citratus apresentou atividade antifúngica em 100% dos isolados a partir da concentração de 25% (v/v), o que indica sua ação positiva sobre as cepas hospitalares. Sugere-se a realização de estudos farmacológicos e toxicológicos desse componente para avaliar a possível aplicação clínica.

Antioxidant activity and physical-chemical properties of spray and spouted bed dried extracts of bauhinia forficata / Atividade antioxidante e propriedades físico-químicas de spray e leito de jorro extratos secos de bauhinia forficata

Two distinct drying methods (spouted bed and spray drying) were used for production of dried extracts of Bauhinia forficata Link (Leguminosae, Caesalpinoideae). High-quality powder products in terms of physical and chemical properties were obtained. HPLC fingerprints revealed that the chromatographic profiles of flavonoid compounds present in the dried extract did not change significantly, due to drying. In general, the spouted bed drying caused a degradation of total flavonoids than was lower than that of the spray drying. Antioxidant properties of the dried extract, examined by their radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPHò) and inhibition of lipid peroxidation induced by Fe+2 assays (LPO), confirmed their antioxidant potential. The slight reduction in scavenging activity of the dried extracts may be associated with the occurrence of oxidative reactions, decomposition or losses of thermolabile compounds, induced by the heat.

Neste trabalho foram utilizados dois distintos secadores (leito de jorro e spray dryer) para a produção de extratos secos de Bauhinia forficata Link (Leguminosae, Caesalpinoideae) obtendo-se um produto seco com elevada qualidade em termos de suas propriedades físicas e químicas. Análises qualitativas obtidas por CLAE revelam que os perfis cromatográficos dos compostos flavonóides presentes nos extratos secos não apresentaram significativas mudanças durante a secagem quando comparados aos perfis obtidos para os extratos concentrados. Em geral, a secagem por leito de jorro acarreta menores perdas dos flavonóides totais do que a secagem em spray drying. A atividade antioxidante dos extratos secos foi examinada pelos métodos de (DPPHò) e peroxidação lipídica induzida por Fe+2 (LPO). Uma pequena redução na atividade sequestradora de radicais livres observada para os extratos secos pode ser associada com a ocorrência de reações oxidativas, decomposição e/ou perdas de compostos termolábeis induzidas pelo calor.

Evaluation of immunomodulatory and anti-inflammatory effects and phytochemical screening of Alternanthera tenella Colla (Amaranthaceae) aqueous extracts

Alternanthera tenella Colla extracts are used in Brazilian traditional folk medicine to treat a variety of infectious diseases as well as inflammation and fever. In this work, the immunomodulatory, anti-inflammatory and potential toxic effects of cold (CAE) and hot (HAE) aqueous extracts of A. tenella were investigated in vivo. In addition, we analyzed the phytochemical properties of both extracts. BALB/c mice were immunized in vivo with sheep red blood cells and concomitantly inoculated intraperitoneally (i.p.) with each extract (50, 100 or 200 mg/kg). Specific antibody-producing cells were enumerated using plaque-forming cell assays (PFC) and anti-SRBC IgG and IgM serum levels were measured via enzyme-linked immunosorbent assay. Body and lymphoid organ weights were determined after treatments in order to evaluate toxic effects. Carrageenan-induced paw edema was employed to investigate anti-inflammatory activity in mice inoculated i.p. with CAE or HAE (200 or 400 mg/kg). Phytochemical screening was performed using spectrometric and chromatographic approaches and revealed that CAE possessed higher tannin and flavonoid levels than HAE. PFC numbers were increased after treatment with CAE (100 mg/kg) four days after immunization, as were the serum antibody titers after four and seven days, suggesting immunostimulatory activity through modulation of B lymphocyte functions. Body and organ weights did not show major changes, suggesting that extracts administered to mice did not induce significant toxicity. Both extracts had significant anti-inflammatory activity in the paw edema assay. These results suggested that aqueous extracts from A. tenella contained several chemical compounds that possess positive and/or negative modulator effects on the immune system, which appeared to correlate with tannin and flavonoid levels in those extracts. In summary, these studies provide important insight into the biological activities of A. tenella.

Effect of extracts and isolated compounds from Chresta scapigera on viability of Leishmania amazonensis and Trypanosoma cruzi

Fractionation of bioactive crude extracts of Chresta scapigera led to the isolation of four triterpenes and five flavonoids, among them beta-amyrin acetate (1), 11alpha,12alpha-oxidetaraxeryl acetate (2) and lupeol (3), as well as the flavonoids apigenin (6), kaempferol (7), crysoeriol (8) and luteolin (9) were active against Leishmania amazonensis amastigotes-like stages, while only the flavonoids (6), (7) and (9) showed toxicity towards bloods trypomastigote forms of Trypanosoma cruzi.

O fracionamento dos extratos bioativos de Chresta scapigera proporcionou o isolamento de triterpenos e flavonóides, dentre os quais acetato de beta-amirina (1), acetate de 11alfa,12-oxidotaraxeril (2) e lupeol (3), assim como os flavonóides apigenina (6), caenferol (7), crisoeriol (8) e luteolina (9) mostraram-se ativos contra formas amastigotas de Leishmania amazonensis, enquanto, apenas os flavonóides (6), (7) e (9) apresentaram toxicidade contra as formas tripomastigotas de Trypanosoma cruzi.

Biological activities and chemical composition of crude extracts from Chresta exsucca

As atividades tripanocida, leishmanicida, antibacteriana e antifungica dos extratos brutos de Chresta exsucca foram investigadas. Formas tripomastigotas do Trypanosoma cruzi, formas amastigotas de Leishmania amazonensis e vinte cepas de microrganismos, incluindo bactérias Gram-positivas, Gram-negativas e leveduras, foram utilizadas nos ensaios biológicos. Os melhores resultados foram obtidos para a atividade leishmanicida. A composição química dos extratos hexânicos e etanólicos dessa espécie foi determinada empregando-se técnicas cromatográficas como HRGC e HPLC-ESI-MS, respectivamente. Esteróides, triterpenos e flavonóides foram identificados.

Antimicrobial activity of flavonoids and steroids isolated from two Chromolaena species

The crude extracts (dichloromethanic and ethanolic) and some compounds (8 flavonoids and 5 steroids) isolated from Chromolaena squalida (leaves and stems) and Chromolaena hirsuta (leaves and flowers) have been evaluated against 22 strains of microorganisms including bacteria (Gram-positive and Gram-negative) and yeasts. All crude extracts, flavonoids and steroids evaluated have been shown actives, mainly against Gram-positive bacteria