EVALUATION OF THE ANTI-MYCOBACTERIAL ACTIVITY OF ALLIUM ASCALONICUM AND ALLIUM SATIVUM

Mycobacterium tuberculosis (MTB), the organism causing tuberculosis (TB) remains a major cause of morbidity and mortality. Plant-based drugs have been used worldwide in traditional medicines for the treatment of various diseases including tuberculosis. Medicinal plants are an important source of new antimicrobial agents and remain an attractive alternative strategy. The present study was performed to evaluate anti-MTB activity of two medicinal plants viz., Allium ascalonicum, and Allium sativum. Different concentrations of extracts of these plants were tested for their anti MTB activity against MTBH37Rv strain and the inhibitory activity was expressed as CFU inhibition, % inhibition and IC50. In our study Allium sativum showed higher anti TB activity however this bactericidal property was not signi?cantly different between each groups. The overall anti mycobacterial activity of these extracts might be attributed due to the presence of ?avonoids, saponins, steroids, terpenoids, tannins and other phytoconstituents. The extract of the plant also exhibited promising antitubercular activity.

Synthesis, characterization, anti-mycobacterial activity and in silico study of new 2,5-disubstituted-1,3,4-oxadiazole derivatives

@#A series of new 2,5-disubstituted-1,3,4-oxadiazole derivatives (5a-j and 6a-j) have been designed and synthesized in four-steps. Sixteen compounds among the twenty compounds are reported for the first time. The compounds were characterized and confirmed by the FTIR, 1D- and 2D-NMR and HRMS analyses, and were tested against Mycobacterium smegmatis and Mycobacterium tuberculosis H37Ra. Compound 5d was the most active against M. smegmatis with MIC value of 25 µM, and exhibited cidal activity with MBC of 68 µM, respectively. The time-kill assay showed the good killing rate at 77% with the combination of isoniazid (INH). In addition, checkboard assay confirmed the interaction of compound 5d was categorised as additive. Docking simulation has been performed to position 5d into the pantothenate synthetase active site with binding free energy value –8.6 kcal mol-1. It also occupied the same active site as that of standard native ligand with similar interactions, which clearly indicate their potential as pantothenate synthetase inhibitor.

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.

Potential applications of lactic acid bacteria and bacteriocins in anti-mycobacterial therapy

Tuberculosis (TB) is a communicable disease caused by Mycobacterium tuberculosis (M. tuberculosis). WHO estimated that 10.4 million new (incident) TB cases worldwide in year 2016. The increased prevalence of drug resistant strains and side effects associated with the current anti-tubercular drugs make the treatment options more complicated. Hence, there are necessities to identify new drug candidates to fight against various sub-populations of M. tuberculosis with less or no toxicity/side effects and shorter treatment duration. Bacteriocins produced by lactic acid bacteria (LAB) attract attention of researchers because of its 'Generally recognized as safe' status. LAB and its bacteriocins possess an effective antimicrobial activity against various bacteria and fungi. Interestingly bacteriocins such as nisin and lacticin 3147 have shown antimycobacterial activity in vitro. As probiotics, LAB plays a vital role in promoting various health benefits including ability to modulate immune response against various infectious diseases. LAB and its metabolic products activate immune system and thereby limiting the M. tuberculosis pathogenesis. The protein and peptide engineering techniques paved the ways to obtain hybrid bacteriocin derivatives from the known peptide sequence of existing bacteriocin. In this review, we focus on the antimycobacterial property and immunomodulatory role of LAB and its metabolic products. Techniques for large scale synthesis of potential bacteriocin with multifunctional activity and enhanced stability are also discussed.

Biological activities and phytochemical profile of Passiflora mucronata from the Brazilian restinga

ABSTRACT In general, Passiflora species have been reported for their folk medicinal use as sedative and anti-inflammatory. However, P. caerulea has already been reported to treat pulmonary diseases. Severe pulmonary tuberculosis, generally caused by Mycobacterium tuberculosis strains resistant to multiple drugs, can lead to deleterious inflammation and high mortality, encouraging new approaches in drug discovery. Thus, the aim of this work was to evaluate the Passiflora mucronata Lam., Passifloraceae, potential for tuberculosis treatment. Specifically, related to antimycobacterial activity and anti-inflammatory related effects (based on inhibition of nitric oxide, tumor necrosis factor-alpha production and antioxidant potential), as well as the chemical profile of P. mucronata. High performance liquid chromatography coupled with diode-array ultraviolet and mass spectrometer analyses of crude hydroalcoholic extract and ethyl acetate fraction showed the presence of flavonoids. Ethyl acetate fraction showed to be as antioxidant as Ginkgo biloba standard extract with EC50 of 14.61 ± 1.25 µg/ml. One major flavonoid isolated from ethyl acetate fraction was characterized as isoorientin. The hexane fraction and its main isolated compound, the triterpene β-amyrin, exhibited significant growth inhibitory activity against Mycobacterium bovis BCG (MIC50 1.61 ± 1.43 and 3.93 ± 1.05 µg/ml, respectively). In addition, Passiflora mucronata samples, specially hexane and dichloromethane fractions, as well as pure β-amyrin, showed a dose-related inhibition of lipopolysaccharide (LPS)-induced nitric oxide production. In conclusion, Passiflora mucronata presented relevant biological potential and should be considered for further studies using in vivo pulmonary tuberculosis model.

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.

Anti-infective Activities of Secondary Metabolites from Vitex pinnata.

The phytochemical investigation of Vitex pinnata led to the isolation of a mixture of steroids β-sitosterol and stigmasterol (1a and 1b) and three known flavonoid identified as 5-hydroxy-3, 7, 4’-trimethoxyflavone (2), 5-hydroxy-7,4’-dimethoxy-flavone (3) and 5-hydroxy-3,3’,4’,7-tetramethoxyflavone (4). The structures of all isolated compounds were carried out by NMR and mass spectrometry. The isolated compounds were evaluated for their anti-infective activities against Trypanosoma brucei brucei and Mycobacterium marinum. Compound 1-4 showed moderate antitrypanosomal activity with MIC values of 6.25μg/ml, 19.0, 21.0 and 17.0μM, respectively while no activity observed on anti-mycobacterial. This study is the first to report the presence of three flavones and their antitrypanosomal activity from V. pinnata.

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.

Furan type lignans with antimycobacterial activity / Lignanos del tipo furano con actividad antimicobacterial

Compounds such as triclosan, diclofenac and trimetropin posses antibacterial activity, including mycobacterial; their structures are based on two aromatic rings joined by a methylene or a heteroatom. Since a similar structural system is found in natural diarylfuran- based lignans, we studied plants known with this type of lignans, as potential active against Mycobacterium tuberculosis. Fractions of the active extracts were tested for anti-TB activity and their chemical constituents analyzed by NMR spectroscopy. Several extracts and chromatographical fractions exhibited > 90 percent inhibition of M. tuberculosis at 128 ug/mL. Methylpluviatilol, a pure compound isolated from Virola sebifera, was active at this concentration.. These findings suggest that plant species of the families here studied may yield novel lead compounds for the development of antimycobacterial agents.

Compuestos tales como triclosan, diclofenac y trimetoprim poseen actividad antibacterial, incluyendo la antimicobacterial; sus estructuras están basadas en dos anillos aromáticos unidos por un metileno o un heteroátomo. Debido a que en la naturaleza se encuentra un sistema estructural similar del tipo diarilfurano en los lignanos, así como otros subtipos, nosotros estudiamos plantas contra Mycobacterium tuberculosis, de las que se sabe contienen lignanos Las fracciones cromatográficas de los extractos activos fueron ensayadas para actividad anti.Tb y sus constituyentes químicos se analizaron por espectroscopía de RMN. Varios extractos y fracciones cromatográficas exhibieron una inhibición superior al 90 por ciento a 128 ug/mL; el compuesto metilpluviatilol, aislado de mostró una inhibición del 99 por ciento a esa concentración. Esos hechos sugieren que las especies de plantas de las familias aquí estudiadas podrían suministrar nuevos compuestos líderes para el desarrollo de agentes antimicobacteriales.

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.

Antimycobacterial and cytotoxicity activity of microcystins

Background: The present work aimed to evaluate the antimycobacterial activity and cytotoxicity of Microcystis aeruginosa toxins, the MC-LR variant and purified extract of [D-Leu1] microcystin-LR. Methods: The antimicrobial activity of M. aeruginosa extract and microcystin was evaluated by resazurin microtiter assay against Mycobacterium tuberculosis, M. terrae, M. chelonae and M. kansasii. The cytotoxicity assay was performed by trypan blue exclusion against the HTC cell line. Results: Antimicrobial activity was observed in the hexanic extract of M. aeruginosa (RST 9501 strain) against M. tuberculosis, including sensitive and resistant strains with minimal inhibitory concentrations (MIC) between 1.93 μM and 0.06 μM. The high activity of M. aeruginosa hexanic extract could be attributed to the major presence of the toxins MC-LR and [D-Leu1] MC-LR that showed activity at MIC between 53 and 0.42 μM against tested mycobacterial strains. Even at the highest concentration tested, no toxicity of M. aeruginosa extracts was identified against HTC cells. Conclusions: These preliminary results suggest that [D-Leu1] MC-LR is a promising candidate for the development of a new antimycobacterial agent.

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

Tolerance Tests of Alcaligenes faecalis BW1 Extract.

Aims: To highlight whether metabolites of Alcaligenes faecalis BW1 extract can be administered orally for their possible antimycobacterial effects. Study Design: Study of the influence of certain parameters on the extract of Alcaligenes faecalis by using either discs or well diffusion methods against M. smegmatis. Place and duration of study: Laboratory of Microbial Biotechnology, Department of Biology, Faculty of Sciences and Technical, University Sidi Mohamed Ben Abdellah, BP 2202, Road of Immouzer, Fez, Morocco. From April to August, 2012. Methodology: The impact of acidic pH of gastric juice, bile, hydrogen peroxide, pancreatic enzymes and lysozyme on the antimycobacterial activity of Alcaligenes faecalis BW1 extract was evaluated by agar diffusion method. Detection whether or not antibacterial metabolites having a synergistic effect with rifampicin against M. smegmatis was also explored. Results: Antibacterial metabolites of Alcaligenes faecalis BW1 extract resist to the action of gastric pH, gallbladder bile and hydrogen peroxide. In addition, they are not affected by pancreatic enzymes and lysozyme. Moreover, they have a synergistic effect with rifampicin against M. smegmatis. Conclusion: Anti-mycobacterial metabolites of Alcaligenes faecalis BW1 extract are compatible with rifampicin and could be administered orally as antitubercular agents after their purification, identification in further work.

Tricyclic Pyrazoles: Synthesis, Characterization, Antimicrobial, Antituberculosis, and Antitumor Activity of N,1-Diphenyl-1,4-dihydrothiochromeno[ 4,3-c]pyrazole-3-carboxamide-5,5-dioxide Derivatives.

Aims: A series of N,1-diphenyl-1,4-dihydrothiochromeno[4,3-c]pyrazole-3-carboxamide 5,5-dioxide derivatives (6a-m) were synthesized and evaluated for anticancer, antibacterial, and antifungal activity. Methodology: Reaction of 2,3-dihydro-4H-thiochromen-4-one 1,1-dioxide 2 with diethyl oxalate in ethanol in the presence of a base afforded the Claisen condensation product 3. Subsequent reaction of 3 with phenylhydrazine hydrochloride at reflux in ethanol afforded ethyl 1-phenyl-1,4-dihydrothiochromeno[4,3-c]pyrazole-3-carboxylate 5,5-dioxide (4). Alkaline hydrolysis of 4 furnished the corresponding 1-phenyl-1,4- dihydrothiochromeno[4,3-c]pyrazole-3-carboxylic acid 5,5-dioxide 5. The pyrazole acid 5 was converted into the corresponding acid chloride followed by treatment with an excess of the appropriate amine to give 6a-m. Results: Compound 6k showed better activity than chloroamphenicol against Klebsiella pneumoniae and Escherichia coli and equipotent to clotrimazole in inhibiting the growth of Candida albicans (MIC 3.125 μg/mL). All compounds were screened for their cytotoxic activity against two tumor cell lines, namely, human colon tumor cell line (HCT116) and human cervical cancer cell line (HeLa) using the colorimetric MTT assay. Most of the tested compounds exhibited potent antitumor activity. Particularly, compound 6k displayed the highest activity among the tested compounds with IC50 equal to 17 μM (HeLa) and 15 μM (HCT116) respectively. Among the tested compounds, 6k was found to be more active against M. tuberculosis, (H37Rv) with minimum inhibitory concentration (7.8 μM). Conclusion: The chloro- (6b and 6c), 2-aminobenzothiazole- (6l), and 4-aminoantipyrine- (6k) linkages exhibited better antimicrobial activity than their counterparts. Compound 6k was found to possess comparatively more antimicrobial, antituberculosis, and antitumor activity against the other derivatives.

Genome-wide transcription analyses in Mycobacterium tuberculosis treated with lupulone

Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis, still causes higher mortality than any other bacterial pathogen until now. With the emergence and spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR-TB) strains, it becomes more important to search for alternative targets to develop new antimycobacterial drugs. Lupulone is a compound extracted from Hops (Hurnulus lupulus), which exhibits a good antimicrobial activity against M. tuberculosis with minimal inhibitory concentration (MIC) value of 10 µg/mL, but the response mechanisms of lupulone against M. tuberculosis are still poorly understood. In this study, we used a commercial oligonucleotide microarray to determine the overall transcriptional response of M. tuberculosis H37Rv triggered by exposure to MIC of lupulone. A total of 540 genes were found to be differentially regulated by lupulone. Of these, 254 genes were upregulated, and 286 genes were downregulated. A number of important genes were significantly regulated which are involved in various pathways, such as surface-exposed lipids, cytochrome P450 enzymes, PE/PPE multigene families, ABC transporters, and protein synthesis. Real-time quantitative RT-PCR was performed for choosed genes to verified the microarray results. To our knowledge, this genome-wide transcriptomics approach has produced the first insights into the response of M. tuberculosis to a lupulone challenge.

In Vitro Evaluation of the Antimicrobial and Antimycobacterial Activities of Solanum guaraniticum A. St.-Hil. Leaves.

With the emergence of antimicrobial resistance, it becomes necessary to search for new alternatives for the treatment of infectious diseases. Solanum guaraniticum is a shrub known as jurubeba or false jurubeba that has hepatoprotective and antioxidant activities, used in popular medicine for the treatment of various diseases. The aim of this study was to evaluate the in vitro antimicrobial and antimycobacterial activities of crude extract, chloroforn, ethyl acetate and butanol fractions from its leaves. Good activities were observed for the ethyl acetate fraction against Staphylococcus intermedius and Listeria monocytogenes (MIC = 64 μg/mL) and for the crude extract against Micrococcus luteus (MIC = 32 μg/mL). In general, the extracts showed moderate activity against Gram-positive bacteria, and were inactive against Gram-negative bacteria and fungi. It was also verified considerable activity against Mycobacterium smegmatis, mainly by chloroform fraction (MIC = 156 μg/mL). These results are probably due to the good antioxidant activity and to the presence of high contents of polyphenols, tannins and alkaloids, metabolites known to possess antimicrobial activity. Studies aiming the isolation of compounds are necessary in order to know the main component involved in these activities, since the plant has an antimicrobial potential.

Antimycobacterial activity of a Brevibacillus Laterosporus strain isolated from a moroccan soil

The treatment of tuberculosis has become more difficult with the worldwide spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis. Moreover, the prevalence of human disease caused by atypical mycobacteria has also increased in the past two decades and has further complicated the problem of the treatment of mycobacterial infections. It is therefore urgent to develop new highly active molecules against these bacteria. The present study reports the isolation from a Moroccan soil of a Bacillus strain that exhibits an important antimycobacterial activity. The strain was identified as Brevibacillus laterosporus using DNA sequencing of the 16S ribosomal RNA gene. The antimycobacterial activity was assigned to a substance with a protein nature. This nature was revealed using a liquid-liquid extraction with organic solvents, precipitation with ammonium sulfate and treatment with a protease. This study suggested the identification and the characterization of this active metabolite enabling therapeutic investigations further.

Pharmacokinetics of isoniazid with or without ofloxacin.

Objective of the resent study was to determine the effect of ofloxacin (OXC) on the pharmacokinetics of isoniazid (INH). Five healthy volunteers aged 18 – 39 years participated in this study after an informed consent. The study was carried out in two phases with an interval of one-week drug wash out period in between phases. In phase one (INH alone), each subject received 300mg of isoniazid (INH) with 350ml of water after an overnight fast. The subjects were made to fast 2 hours post drug. In phase two (INH + OXC), each subject was administered with 300mg of INH in combination with 200mg of OXC observing all the protocol in phase one. The concentration of INH in plasma, saliva and urine of the subjects at predetermined time intervals were measured spectrophotometrically in the two phases over a period of 0 - 48 hours. Various pharmacokinetics parameters were calculated. From the study it is evident that Ofloxacin (OXC) increased the rate and extent of absorption of isoniazid. The absorption half-life (t1/2a) and the maximum concentration and absorption time (Cmax, Tmax) of isoniazid (INH) were increased in the presence of OXC. The urinary excretion of isoniazid was also increased by ofloxacin. The salivary concentration of isoniazid was less than the corresponding plasma drug concentrations, a pattern also found in similar studies. Thus it can be concluded that Ofloxacin increases absorption kinetics and urinary excretion of Isoniazid.

Anti-Mycobacterial and Toxicity Activities of Some Priority Medicinal Plants from Lake Victoria Basin, Tanzania.

Aims: This study has evaluated ethanol extracts from five medicinal plants selected through ethnobotanical study from Lake Victoria basin, Tanzania for their in vitro antimycobacterial activity against two Mycobacterium species and cytotoxicity against brine shrimp larvae. Study Design: Laboratory experimental tests. Place and Duration of Study: Institute of Traditional Medicine, Muhimbili University of Health and Allied Sciences, P.O. Box 65001, Dar es Salaam, Tanzania, between July 2010 and July 2011. Methodology: Five medicinal plants were selected from the priority list obtained from Lake Victoria basin, Tanzanian side. Collection, processing and drying of plant samples were done in the field with the assistance of a botanist while extraction and concentration of plant samples to obtain crude extracts were done in the laboratory following standard procedures. The plants included in this study are Antidesma membranaceum, Crassocephalum manii, Entada abyssinica, Croton dichogamus and Rubia cordifolia. The two fold microdilution method was used to determine the MIC values of extracts against two Mycobacterium marker strains (Mycobacterium indicus pranii and Mycobacterium madagascariense). The cytotoxicity of plant extract was evaluated against brine shrimp larvae. Furthermore, the extracts were screened phytochemicaly to establish the group of compounds responsible for the activity. Results: Among the tested extracts, the stem bark of A. membranaceum and C. manii showed moderate to mild activity against M. indicus pranii (MIC = 0.3125 mg/ml) and M. madagascariense (MIC = 0.625 mg/ml) respectively. Furthermore, A. membranaceum exhibited significant toxicity activity with LC50 value of 36.134 μg/ml against brine shrimp larvae. Other plants were moderately active when tested in vitro against the above organisms. Phytochemical screening of extracts indicated the presence of different classes of compounds. Conclusion: This study has shown the potential of the priority medicinal plant extracts to be the source of possible lead compounds and anti‐TB drug candidates needed for the management of Tuberculosis. Isolation of active principles from active fractions will be further undertaken.