Chemical composition and in vitro antibacterial activity of essential oils from Murraya paniculata (L. ) Jack (Rutaceae) ripe and unripe fruits against bacterial genera Mycobacterium and Streptococcus

This study aims to investigate chemical composition of essential oils from Murraya paniculata (L.) Jack (Rutaceae) ripe and unripe fruits and determine their in vitro antibacterial activity. Essential oils were extracted by hydrodistillation from Murraya paniculata (L.) Jack ripe and unripe fruits collected in the Cerrado, in Rio Verde, southwestern Goiás, Brazil. They were analyzed by gas chromatography with flame ionization detector (GC-FID) and by gas chromatography-mass spectrometry (GC-MS). Sesquiterpenes, which represent the most abundant class of compounds in oils, predominated in both ripe and unripe fruits. Major constituents of essential oils extracted from ripe fruits (RF-EO) were (-caryophyllene (21.3%), (-ylangene (13.3%), germacrene-D (10.9%) and (-zingiberene (9.7%) whereas the ones of unripe fruits (UF-EO) were sesquithujene (25.0%), (-zingiberene (18.2%), germacrene-D (13.1%) and (-copaene (12.7%). In vitro antibacterial activity of essential oils was evaluated in terms of its minimum inhibitory concentration (MIC) values by the broth microdilution method in 96-well microplates. Both essential oils under investigation showed moderate anti-streptococcal activity against the following bacteria: Streptococcus mutans, S. mitis, S. sanguinis, S. sobrinus and S. salivarius. MIC values ranged between 100 and 400 µg/mL. Regarding the antimycobacterial activity, essential oils from M. paniculata (L.) Jack unripe and ripe fruits were active against Mycobacterium kansasii (MIC = 250 µg/mL), moderately active against M. tuberculosis (MIC = 500 µg/mL) and inactive against M. avium (MIC = 2000 µg/mL). This study was pioneer in revealing similar chemical profiles of both essential oils extracted from Murraya paniculata (L.) Jack unripe and ripe fruits, besides describing their in vitro anti-streptococcal and antimycobacterial activities.

Effects of the encapsulation of usnic acid into liposomes and interactions with antituberculous agents against multidrug-resistant tuberculosis clinical isolates

Mycobacterium tuberculosis (Mtb) has acquired resistance and consequently the antibiotic therapeutic options available against this microorganism are limited. In this scenario, the use of usnic acid (UA), a natural compound, encapsulated into liposomes is proposed as a new approach in multidrug-resistant tuberculosis (MDR-TB) therapy. Thus the aim of this study was to evaluate the effect of the encapsulation of UA into liposomes, as well as its combination with antituberculous agents such as rifampicin (RIF) and isoniazid (INH) against MDR-TB clinical isolates. The in vitro antimycobacterial activity of UA-loaded liposomes (UA-Lipo) against MDR-TB was assessed by the microdilution method. The in vitro interaction of UA with antituberculous agents was carried out using checkerboard method. Minimal inhibitory concentration values were 31.25 and 0.98 µg/mL for UA and UA-Lipo, respectively. The results exhibited a synergistic interaction between RIF and UA [fractional inhibitory concentration index (FICI) = 0.31] or UA-Lipo (FICI = 0.28). Regarding INH, the combination of UA or UA-Lipo revealed no marked effect (FICI = 1.30-2.50). The UA-Lipo may be used as a dosage form to improve the antimycobacterial activity of RIF, a first-line drug for the treatment of infections caused by Mtb.

Antimycobacterial natural products from Moroccan medicinal plants: Chemical composition, bacteriostatic and bactericidal profile of Thymus satureioides and Mentha pulegium essential oils

Objective To evaluate the susceptibility of Mycobacterium aurum and Mycobacterium smegmatis in vitro to the essential oils obtained from two medicinal plants: Thymus satureioides (T. satureioides) and Mentha pulegium (M. pulegium), and to study their chemical composition. Methods The aerial parts of T. satureioides and M. pulegium (leaves and stems) were hydro-distillated using a Clevenger-type apparatus and essential oils were analyzed and identified by gas chromatography-mass spectrometry. Antimycobacterial screening of essential oils was performed on the basis of the inhibition zone diameter by disc diffusion method against two mycobacterial strains whereas the minimal inhibitory concentration and minimal bactericidal concentration were determined by using the micro-dilution method. Results Chemical analysis of their aerial part's essential oils gave as major compounds, borneol (34.26%), carvacrol (31.21%) and thymol (3.71%) for T. satureioides and R(+)-pulegone (75.48%), carvone (6.66%) and dihydrocarvone (4.64%) for M. pulegium. Thereafter their antimycobacterial effect evaluation, using the micro-dilution method, indicated that minimal inhibitory concentration values of T. satureioides essential oil ranged from 0.062% to 0.015% (v/v) and from 0.125% to 0.031% (v/v) for M. pulegium respectively against Mycobacterium aurum and Mycobacterium smegmatis. Conclusions It is clearly evident from the results obtained that the Moroccan medicinal plants have great potential to be used as anti-tuberculosis agents. These findings may help scientists to undertake several research projects to discover useful natural product as new anti-tuberculosis drug.

Antimycobacterial natural products from Moroccan medicinal plants：Chemical composition, bacteriostatic and bactericidal profile of Thymus satureioides and Mentha pulegium essential oils

Objective: To evaluate the susceptibility of Mycobacterium aurum and Mycobacterium smegmatis in vitro to the essential oils obtained from two medicinal plants: Thymus satureioides (T. satureioides) and Mentha pulegium (M. pulegium), and to study their chemical composition. Methods: The aerial parts of T. satureioides and M. pulegium (leaves and stems) were hydro-distillated using a Clevenger-type apparatus and essential oils were analyzed and identified by gas chromatography-mass spectrometry. Antimycobacterial screening of essential oils was performed on the basis of the inhibition zone diameter by disc diffusion method against two mycobacterial strains whereas the minimal inhibitory concentration and minimal bactericidal concentration were determined by using the micro-dilution method. Results: Chemical analysis of their aerial part's essential oils gave as major compounds, borneol (34.26%), carvacrol (31.21%) and thymol (3.71%) for T. satureioides and R(+)-pulegone (75.48%), carvone (6.66%) and dihydrocarvone (4.64%) for M. pulegium. Thereafter their antimycobacterial effect evaluation, using the micro-dilution method, indicated that minimal inhibitory concentration values of T. satureioides essential oil ranged from 0.062%to 0.015%(v/v) and from 0.125%to 0.031%(v/v) for M. pulegium respectively against Mycobacterium aurum and Mycobacterium smegmatis. Conclusions: It is clearly evident from the results obtained that the Moroccan medicinal plants have great potential to be used as anti-tuberculosis agents. These findings may help scientists to undertake several research projects to discover useful natural product as new anti-tuberculosis drug.

Comparative antimycobacterial activity of some Indonesian medicinal plants against multi-drug resistant Mycobacterium tuberculosis.

This study has been carried out to compare antimycobacterial activity of five selected Indonesian endogenous medicinal plants of Andrographis paniculata, Annona muricata, Centella asiatica, Pluchea indica, and Rhoeo spathacea against clinical isolate of multi-drug resistant (MDR) Mycobacterium tuberculosis. The aqueous extracts of leaves of Andrographis paniculata, Annona muricata, Centella asiatica, Pluchea indica, and Rhoeo spathacea were obtained by maceration, and the phytochemical constituents of each extract were screened. Antimycobacterial activity of aqueous plant extracts were determined by proportion methods using Lowenstein Jensen (L-J) medium. Our study exhibited that all extracts of five selected plants showed inhibited activity against Mycobacterium tuberculosis H37Rv strain and multi drug resistant (MDR) strain. The proportion inhibition of aqueous extract of Andrographis paniculata, Annona muricata, Centella asiatica, Pluchea indica, and Rhoeo spathacea, against Mycobacterium tuberculosis H37Rv strain were 100%, 82.1%, 78.5%, 100%, and 100% respectively, whereas against MDR strain were 93.7%, 50.0%, 50.0%, 100%, and 100% respectively. The phytochemical analysis showed that the extracts were predominantly contains flavonoids, alkaloids, saponins, tannins and glycosides. Pluchea indica, and Rhoeo spathacea showed good antimycobacterial activity against MDR strains and could be useful as complementary alternative therapy in combating the emergence of MDR strains of Mycobacterium tuberculosis.

Avaliação da atividade antimicobacteriana da lignana diidrocubebina extraída da Piper cubeba e de seus derivados semissintéticos / Evaluation of antimycobacterial activity of dihydrocubebin lignan extracted from Piper cubeba and its semisynthetic derivatives

RESUMO: A atividade antimicobacteriana de diidrocubebina (1), uma lignana dibenzilbutanodioica obtida a partir de extrato etanólico de sementes da Piper cubeba, e seus derivados foram avaliados in vitro contra três diferentes cepas de Mycobacterium utilizando o método de microdiluição. Dentre as lignanas avaliadas 3 e 4 foram as mais ativas, exibindo valores de CIM de 62,5 µg/mL contra M. avium e M. tuberculosis, respectivamente. Os derivados 2-6 obtidos por síntese parcial possuem diferentes substituintes nos carbonos 9 e 9 ', que alteram polaridade, solubilidade e limitam as rotações livres entre C8-C8' em relação de material (1) de partida. As diferenças estruturais entre estes compostos podem fornecer informações importantes sobre a relação estrutura-atividade antimicobacteriana do esqueleto dibenzilbutanodioico, obtido a partir de fonte natural, como um possível alvo para o desenvolvimento de drogas mais potentes contra a tuberculose

ABSTRACT: Evaluation of antimycobacterial activity of dihydrocubebin lignan extracted from Piper cubeba and its semisynthetic derivatives. The antimycobacterial activity of the dihydrocubebin (1), a dibenzylbutanedioiclignan obtained from ethanolic extract of Piper cubeba seeds, and its derivatives were examined in vitro against three different strains of Mycobacterium using amicrodilution method. Among the lignans evaluated, the 3 and 4 samples were the most active ones, displaying MIC values of 62.5 µg/mL against M. avium and M. tuberculosis, respectively. The derivatives 2-6, obtained for partial synthesis, had different substituents in the carbons 9 and 9', fact thatalters the polarity, solubility and restricts the free rotations between the bonds C8-C8' in relation to the starting material (1). The structural differences among these compounds provide important information about the antimycobacterial structure-activity relationship of the dibenzylbutanodioic skeleton, obtained from natural source, such as a possible target for the development of more powerful drugs against tuberculosis

Anti-Mycobacterium tuberculosis activity of fungus Phomopsis stipata

Our purpose was to determine the anti-Mycobacterium tuberculosis activity of the metabolites produced by the endophitic fungus Phomopsis stipata (Lib.) B. Sutton, (Diaporthaceae), cultivated in different media. The antimycobacterial activity was assessed through the Resazurin Microtiter Assay (REMA) and the cytotoxicity test performed on macrophage cell line. The extracts derived from fungi grown on Corn Medium and Potato Dextrose Broth presented the smallest values of Minimum Inhibitory Concentration (MIC) and low cytotoxicity, which implies a high selectivity index. This is the first report on the chemical composition and antitubercular activity of metabolites of P. stipata, as well as the influence of culture medium on these properties.

Análise fitoquímica e atividade antimicobacteriana de extratos metanólicos de Jacaranda cuspidifolia Mart. (Bignoniaceae) / Phytochemical analysis and antimycobacterial activity of methanol extracts from Jacaranda cuspidifolia Mart. (Bignoniaceae)

Jacaranda cuspidifolia Mart., conhecida popularmente como "caroba", "jacarandá" ou "bolacheira", é utilizada medicinalmente para o tratamento da sífilis e da gonorréia. A atividade antimicobacteriana dessa espécie foi avaliada em ensaios in vitro com os extratos metanólicos das cascas e folhas, segundo o Método Analítico Alamar Blue (MABA). Os valores de concentração inibitória mínima para os extratos metanólicos das cascas e das folhas de J. cuspidifolia foram iguais a CIM = 250 μg mL-1 para ambos os extratos. A análise fitoquímica, por Cromatografia em Camada Delgada de gel de sílica, dos extratos metanólicos das cascas e folhas revelou a presença de taninos, flavonóides, terpenos, cumarinas e esteróides. A análise dos perfis dos extratos metanólicos por Cromatografia Líquida de Alta Eficiência de Fase Reversa registrou a presença de compostos fenólicos derivados do verbascosídeo sugerindo a provável responsabilidade pela ação antimicobacteriana.

Jacaranda cuspidifolia Mart., popularly known as "caroba", "jacaranda" or "bolacheira", is used as medicine for the treatment of syphilis and gonorrhea. The antimycobacterial activity of this species was assessed by means of in vitro assays with methanol extracts of barks and leaves according to the Microplate Alamar Blue Assay (MABA). The minimal inhibitory concentration values for methanol extracts of barks and leaves from J. cuspidifolia were MIC = 250 μg mL-1 for both extracts. Phytochemical analysis, by Thin Layer Chromatography on silica gel, of methanol extracts of barks and leaves revealed the presence of tannins, flavonoids, terpenes, cumarins and steroids. Analysis of the profiles of methanol extracts by High Performance Liquid Chromatography - Reversed Phase recorded the presence of phenolic compounds derivatives of verbascoside, suggesting their probable responsibility for the antimycobacterial action.

The activity of flavones and oleanolic acid from Lippia lacunosa against susceptible and resistant Mycobacterium tuberculosis strains

Tuberculosis (TB), caused by Mycobacterium tuberculosis, is the world's number one killer among infectious diseases. The search for new naturalproducts that can act as drugs against TB has received increased attention duringthe last years. In this work we describe the isolation and identification of the active antimycobacterial principles of the dichloromethane extract from Lippia lacunosa Mart. & Schauer, Verbenaceae. Compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis (susceptible and rifampicin resistantstrain) using a redox bioassay. From the dichloromethane extract of L. lacunosa leaves, seven methoxy-flavones named cirsimaritin (1), eupatilin (2), eupatorin (3), salvigenin (4), 3'-O-methyl-eupatorin (5), 3',7-dimethoxy-5,6,4'- trihydroxyflavone (6), and 7'-O-methylapigenin (7), and one triterpene, named oleanolic acid (8), were isolated. All compounds were found to display antimycobacterial activity against susceptible strain, with MIC ranging from 25 to 200 µg/mL. None of them was active against rifampicin resistant strain. This is the first report in the antimycobacterial activity of 6-substituted flavones, as well as the first report of the occurrence of these substances in L. lacunosa.

In vitro synergic effect of beta-lapachone and isoniazid on the growth of Mycobacterium fortuitum and Mycobacterium smegmatis

Nontuberculous mycobacteria are ubiquitous and saprophytic organisms that have been implicated in a wide spectrum of diseases due to an increasing number of immunocompromised patients. The natural resistance of atypical mycobacteria to classical antituberculous drugs has encouraged research into new chemotherapeutic agents and drug combinations. The aim of this study was to determine the in vitro antimycobacterial activities of ²-lapachone alone and in combination with isoniazid against Mycobacterium fortuitum and Mycobacterium smegmatis via the Time-Kill Curve method. A 2 log10 CFU/mL reduction in the M. smegmatis culture was observed 72 h after adding ²-lapachone at its minimum inhibitory concentration. This drug sterilised the culture in 120 h. For M. fortuitum, a reduction of 1.55 log10 CFU/mL occurred in 24 h, but regrowth was seen in contact with ²-lapachone. Both microorganisms were resistant to isoniazid. Regrowth of M. fortuitum and M. smegmatis was observed at 48 h and 72 h, respectively. In combination, these two drugs had a bactericidal effect and sterilised both cultures in 96 h. These results are valuable because antibiotic-resistant bacteria are a major public health problem.

Immunological and microbiological activity of Davilla elliptica St. Hill. (Dilleniaceae) against Mycobacterium tuberculosis

Mycobacterium tuberculosis is responsible for over 8 million cases of tuberculosis (TB) annually. Natural products may play important roles in the chemotherapy of TB. The immunological activity of Davilla elliptica chloroform extract (DECE) was evaluated in vitro by the determination of hydrogen peroxide (H2O2), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-alpha) release in peritoneal macrophages cultures. DECE was also tested for its antimycobacterial activity against M. tuberculosis using the microplate alamar blue assay. DECE (50, 150, 250 mug/ml) stimulated the production of H2O2 (from 1,79 ± 0,23 to 7,27 ± 2,54; 15,02 ± 2,86; 20,5 ± 2,1 nmols) (means ± SD), NO (from 2,64 ± 1,02 to 25,59 ± 2,29; 26,68 ± 2,41; 29,45 ± 5,87 mumols) (means ± SD) and TNF-alpha (from 2,44 ± 1,46 to 30,37 ± 8,13; 38,68 ± 1,59; 41,6 ± 0,90 units/ml) (means ± SD) in a dose-dependent manner and also showed a promising antimycobacterial activity with a minimum inhibitory concentration of 62,5 mug/ml. This plant may have therapeutic potential in the immunological and microbiological control of TB.

Screening of Central and South American plant extracts for antimycobacterial activity by the Alamar Blue test / Triagem de extratos de plantas das Américas Central e do Sul para atividade antimicobacteriana pelo teste do Alamar Blue

Forty eight ethanolic crude extracts and fractions (hexane, dichloromethane, ethyl acetate and n-butanol) from ten Brazilian plants (Leguminosae, Monimiaceae and Verbenaceae), 1 from Costa Rica (Verbenaceae) and 1 from Argentina (Verbenaceae) were screened for anti-mycobacterium activity against Mycobacterium tuberculosis (ATCC-27294H37Rv), by the Alamar Blue test, at a fixed concentration of 100 µg/mL. Out of the forty eight, seven were active at this concentration, corresponding to Lantana trifolia (hexane and dichloromethane extracts from leaves), Vitex cooperi (methanol:water, 1:1 extract from barks), Lippia lacunosa (hexane and dichloromethane extracts from leaves) and Lippia rotundifolia (hexane and dichloromethane extracts from leaves), all from the Verbenaceae family.

Quarenta e oito extratos brutos etanólicos e frações (em hexano, diclorometano, acetato de etila e n-butanol) de dez plantas brasileiras pertencentes às famílias Leguminosae, Monimiaceae e Verbenaceae; uma da Costa Rica (Verbenaceae) e uma da Argentina (Verbenaceae) foram ensaiados para verificação da atividade anti-micobacteriana contra Mycobacterium tuberculosis (ATCC-27294H37Rv), pelo teste do Alamar Blue, a uma concentração fixa de 100 µg/mL. Dentre os quarenta e oito extratos e frações estudados, sete mostraram-se ativos na concentração ensaiada - frações em hexano e diclorometano de folhas de Lantana trifolia, extrato em metanol:água, 1:1 de cascas de Vitex cooperi, frações em hexano e diclorometano de folhas de Lippia lacunosa e de Lippia rotundifolia, sendoque todas essas plantas pertencem à família Verbenaceae.