RESUMEN
Current long duration treatment options and the emergence of drug resistance in tuberculosis (TB) have led to renewed interest in discovery of novel anti-tubercular agents or the scaffolds exhibiting enhanced efficacy with current anti-TB drugs. Herein, dinactin, a potent bioactive macrotetrolide isolated from Streptomyces puniceus AS13, was evaluated against Mycobacterium tuberculosis H37Rv and other susceptible and drug-resistant clinical isolates of M. tuberculosis. In vitro pharmacological assays showed that dinactin is bactericidal against laboratory standard strain M. tuberculosis H37Rv (minimum inhibitory concentration [MIC] 1 µg/mL and minimum bactericidal concentration [MBC] 4 µg/mL). Dinactin also retained its activity against various clinical isolates, including multidrug-resistant strains of M. tuberculosis. Whole cell interaction assays with standard first- and second-line anti-TB drugs showed the synergistic interaction of dinactin with rifampicin or amikacin, reflecting its suitability for use in combination regimens. The killing kinetics studies of dinactin against M. tuberculosis H37Rv revealed that it has strong concentration-dependent anti-TB activity that is also dependent on time. The kill curve also showed dynamic killing capacity of dinactin as it exhibited bactericidal potential at all concentrations tested. Kill curve data demonstrated that dinactin, like isoniazid, exerts its strong tuberculocidal activity within the first two days of exposure. This evidence strongly supports further evaluation of dinactin as a new option in the treatment of TB.
Asunto(s)
Antituberculosos/farmacología , Macrólidos/farmacología , Mycobacterium tuberculosis/efectos de los fármacos , Macrólidos/química , Pruebas de Sensibilidad Microbiana , Estructura MolecularRESUMEN
Bovine mastitis is globally recognized as the most common and costly disease affecting dairy herds. The disease causes huge ï¬nancial losses to dairy industries by reduced yield and milk quality, deaths and culling of affected cows and also by associated treatment costs. The disease occurs due to invasion of the mammary glands by pathogenic bacteria followed by their multiplication in the milk producing tissues. The most common treatment method available against bovine mastitis is the intra-mammary infusion of antibiotics. However, their use is associated with the problem of antimicrobial resistance. This scenario has made search for alternative treatment approaches necessary. Medicinal plants with their well-established history are an excellent natural product resource used as an alternative therapy. Antibacterial agents from plants can act as important sources of novel antibiotics, efflux pump inhibitors, compounds that target bacterial virulence or can be used in combination with existing drugs. The plants form an essential component of ethno-veterinary medicine used in the treatment of different diseases like bovine mastitis. This review article attempts to provide an overview of the different medicinal plants used in the treatment of bovine mastitis. Antimicrobial studies of these plant species and some of their isolated constituents have been reviewed in detail. It highlights the logic and precedence behind mining this important natural product resource. Our own research findings in this direction and future scope of research are also discussed briefly.
Asunto(s)
Mastitis Bovina/tratamiento farmacológico , Plantas Medicinales , Animales , Antibacterianos/uso terapéutico , Bacterias/efectos de los fármacos , Bovinos , Industria Lechera , Farmacorresistencia Bacteriana , Femenino , Leche/microbiologíaRESUMEN
Endophytes represent a hidden world within plants. Almost all plants that are studied harbor one or more endophytes, which help their host to survive against pathogens and changing adverse environmental conditions. Fungal and bacterial endophytes with distinct ecological niches show important biological activities and ecological functions. Their unique physiological and biochemical characteristics lead to the production of niche specific secondary metabolites that may have pharmacological potential. Identification of specific secondary metabolites in adverse environment can also help us in understanding mechanisms of host tolerance against stress condition such as biological invasions, salt, drought, temperature. These metabolites include micro as well as macromolecules, which they produce through least studied yet surprising mechanisms like xenohormesis, toxin-antitoxin system, quorum sensing. Therefore, future studies should focus on unfolding all the underlying molecular mechanisms as well as the impact of physical and biochemical environment of a specific host over endophytic function and metabolite elicitation. Need of the hour is to reshape the focus of research over endophytes and scientifically drive their ecological role toward prospective pharmacological as well as eco-friendly biological applications. This may help to manage these endophytes especially from untapped ecoregions as a useful undying biological tool to meet the present challenges as well as lay a strong and logical basis for any impending challenges.
Asunto(s)
Bacterias/metabolismo , Endófitos/química , Endófitos/fisiología , Hongos/fisiología , Plantas/microbiología , Fenómenos Ecológicos y Ambientales , Endófitos/clasificación , Humanos , Percepción de Quorum , Metabolismo Secundario , Sistemas Toxina-AntitoxinaRESUMEN
The aim of the present study was to isolate and evaluate the antimicrobial potential of soil actinomycetes of Kashmir Himalayas. The secondary metabolites of actinomycetes are the prominent source of antibiotics. A total of 121 morphologically different actinomycete strains were isolated and screened for antimicrobial activity against various human pathogens. The ethyl acetate extract of fermented broth an actinomycete strain, identified as Streptomyces pratensis exhibited significant antimicrobial activity against Staphylococcus aureus ATCC 29213 with MIC 0.25 µg/ml and Mycobacterium tuberculosis Strain H37Rv with MIC 0.062 µg/ml. The strain S. pratensis IIIM06 was grown on large scale and their broth was extracted with ethyl acetate. The extract was subjected to various chromatography techniques which led to the isolation of four compounds whose structures were established as actinomycin C1, actinomycin C2, actinomycin C3 and actiphenol on the basis of spectral data analysis. Actinomycin C1, C2 and C3 exhibited potent antimicrobial activity against S. aureus as well as M. tuberculosis. The isolated indigenous actinomycetes exhibited good antibacterial activity and the study reveals that IIIM06 is a promising strain and could be of great potential for industrial applications.
Asunto(s)
Actinobacteria/química , Actinobacteria/aislamiento & purificación , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Microbiología del Suelo , Actinobacteria/clasificación , Actinobacteria/genética , Antiinfecciosos/química , ADN Bacteriano/genética , Dactinomicina/análogos & derivados , Dactinomicina/química , Dactinomicina/aislamiento & purificación , Dactinomicina/farmacología , Evaluación Preclínica de Medicamentos , Fermentación , India , Pruebas de Sensibilidad Microbiana , Mycobacterium tuberculosis/efectos de los fármacos , Filogenia , ARN Ribosómico 16S/genética , Suelo , Staphylococcus aureus/efectos de los fármacos , Streptomyces/química , Streptomyces/clasificación , Streptomyces/genética , Streptomyces/aislamiento & purificaciónRESUMEN
A new eudesmane sesquiterpenoid (1), and a new homologue of virginiae butanolide E (2) along with butyl isobutyl phthalate (3) were isolated from, actinomycete-Lentzea violacea strain AS08 isolated from north western Himalayas by stressing on modified one strain-many compounds (OSMAC) method. The structures of the new compounds were elucidated by extensive spectroscopic analyses including 1D, 2D NMR along with HR-ESI-MS and FT-IR data. Herein, a distinctive method was added for inspecting secretory profile of the strain by quantification of extract value of cell free supernatant in different types of culture media fallowed by HPLC profiling of respective extracts, which revealed a highly altered metabolic profile of the strain and formed the base for the selection of media. The compounds 1 and 2 showed moderate activity against Gram negative (MIC â¼32-64µgml-1) in comparison to Gram positive bacterial pathogens. Compound 1 exhibited significant activity in human cancerous cell lines (IC50 â¼19.2µM).
Asunto(s)
Actinobacteria/química , Antibacterianos/química , Antineoplásicos/química , Sesquiterpenos de Eudesmano/química , Actinobacteria/metabolismo , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Antineoplásicos/aislamiento & purificación , Antineoplásicos/toxicidad , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Humanos , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Sesquiterpenos de Eudesmano/aislamiento & purificación , Sesquiterpenos de Eudesmano/farmacología , Espectrometría de Masa por Ionización de Electrospray , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
The ethyl acetate extract from the fermentation broth of an actinomycete strain, identified as Streptomyces scabrisporus isolated from soil of Kashmir Himalayas - India, exhibited significant cytotoxic activity against a panel of human cancer cell lines. The active fraction subjected to column chromatography led to the isolation of pharmacologically potent anticancer compound whose structure was established to be alborixin on the basis of spectral data analysis. The compound exhibited antiproliferative activity against panel of cell lines N2a, MCF-7, MiaPaca-2, PC-3, HCT-116, MDA-MB-231, HL-60 and A-549 cells with IC50 of 9.7, 15.4, 7.2, 8.1, 3.2, 9.7, 7.5 and 11.5 µM respectively. Alborixin displayed the maximum cytotoxic activity against HCT-116 human colon carcinoma cells and therefore further studies were carried on this cell line. Alborixin decreased the clonogenic potential of HCT-116 cells in a dose dependent manner. It induced apoptotic cell death in HCT116 cells that were confirmed by Flow cytometric analysis of Annexin V/PI staining and microscopic examination of cellular morphology through DAPI-stained cells. Biochemical evidence of apoptosis came from elevating the intracellular ROS level that was accompanied by mitochondrial membrane potential loss, decreasing the expression profile of anti-apoptotic protein Bcl-2, whereas it augments cleavage of caspase-3 and PARP-1, activates caspase-8 and 9 with concomitant increase in expression of proapoptotic protein Bax in a dose dependent manner. These results indicate that alborixin obtained from Streptomyces scabrisporus IIIM55 induces apoptotic cell death in colon cancer cells HCT-116 and can be further evaluated for its potential as an anticancer agent.
Asunto(s)
Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Neoplasias del Colon/tratamiento farmacológico , Streptomyces/química , Antineoplásicos/química , Caspasa 3/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Colon/efectos de los fármacos , Colon/metabolismo , Colon/patología , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Células HCT116 , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Piranos/química , Piranos/aislamiento & purificación , Piranos/farmacología , Especies Reactivas de Oxígeno/metabolismoRESUMEN
ETHNO-PHARMACOLOGICAL RELEVANCE: The roots of Thalictrum minus are traditionally used in the treatment of inflammation and infectious diseases such as bovine mastitis. However, there are no reports available in literature till date regarding the antibacterial studies of T. minus against bovine mastitis. AIM OF THE STUDY: The present study was undertaken to evaluate the antibacterial potential of crude extract of T. minus (root) and some of its isolated constituents against bovine mastitis in order to scientifically validate its traditional use. MATERIALS AND METHODS: A total of three alkaloid compounds were isolated from the DCM: MeOH extract of roots of T. minus using silica gel column chromatography. Structural elucidation of the isolated compounds was done by using spectroscopic techniques like mass spectrometry and NMR spectroscopy. Pathogens were isolated from cases of bovine mastitis and identified by using 16S rRNA gene sequencing. The broth micro-dilution method was used to evaluate the antibacterial activities of DCM: MeOH extract and isolated compounds against mastitis pathogens. RESULTS: The three isolated compounds were identified as benzylisoquinoline alkaloids (1) 5'-Hydroxythalidasine, (2) Thalrugosaminine and (3) O-Methylthalicberine. Compounds (2) and (3) are reported for the first time from the roots of T. minus. Five mastitis pathogens viz., Staphylococcus xylosus, Staphylococcus lentus, Staphylococcus equorum, Enterococcus faecalis and Pantoea agglomerans were identified on the basis of sequence analysis of isolates using the nucleotide BLAST algorithm. This study reports for the first time the isolation and molecular characterization of mastitis pathogens from Kashmir valley, India. The DCM: MeOH extract exhibited broad spectrum antibacterial activities that varied between the bacterial species (MIC=250-500µg/ml). 5'-Hydroxythalidasine and Thalrugosaminine showed promising antibacterial activity with MIC values of 64-128µg/ml while Staphylococcus species were found to be the most sensitive strains. CONCLUSIONS: The antibacterial activities of the DCM: MeOH extract and isolated compounds support the traditional use of T. minus in the treatment of bovine mastitis.
Asunto(s)
Antibacterianos/uso terapéutico , Bencilisoquinolinas/uso terapéutico , Mastitis Bovina/tratamiento farmacológico , Animales , Antibacterianos/química , Bencilisoquinolinas/química , Espectroscopía de Resonancia Magnética con Carbono-13 , Bovinos , Femenino , Espectroscopía de Protones por Resonancia Magnética , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
ETHNO-PHARMACOLOGICAL RELEVANCE: The underground parts of Aquilegia fragrans are traditionally used for the treatment of wounds and various inflammatory diseases like bovine mastitis. However, there are no reports on the phytochemical characterization and antibacterial studies of A. fragrans. AIM OF THE STUDY: To isolate compounds from the methanol extract of the underground parts of A. fragrans and determine their antibacterial activity against the pathogens of bovine mastitis. The study was undertaken in order to scientifically validate the traditional use of A. fragrans. MATERIALS AND METHODS: Five compounds were isolated from the methanol extract of the underground parts of A. fragrans using silica gel column chromatography. Structural elucidation of the isolated compounds was done using spectral data analysis and comparison with literature. High performance liquid chromatography (HPLC) was used for the qualitative and quantitative determination of isolated compounds in the crude methanol extract. The methanol extract and isolated compounds were evaluated for antibacterial activities against mastitis pathogens using broth micro-dilution technique. RESULTS: The five isolated compounds were identified as (1) 2, 4-dihydroxyphenylacetic acid methyl ester (2) ß-sitosterol (3) Aquilegiolide (4) Glochidionolactone-A and (5) Magnoflorine. A quick and sensitive HPLC method was developed for the first time for qualitative and quantitative determination of four isolated marker compounds from A. fragrans. The crude methanol extract and compound 5 exhibited weak antibacterial activities that varied between the bacterial species (MIC=500-3000 µg/ml). CONCLUSIONS: The above results show that the crude methanol extract and isolated compounds from A. fragrans exhibit weak antibacterial activities. Further phytochemical and pharmacological studies are required for proper scientific validation of the folk use of this plant species in the treatment of various inflammatory diseases like bovine mastitis.
Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Aquilegia/química , Mastitis Bovina/tratamiento farmacológico , Extractos Vegetales/química , Extractos Vegetales/farmacología , Animales , Aporfinas/química , Benzofuranos/química , Bovinos , Cromatografía Líquida de Alta Presión , Femenino , Metanol/química , Pruebas de Sensibilidad Microbiana/métodos , Sitoesteroles/químicaRESUMEN
Concerns about the erroneous diagnosis of death and premature burial have been expressed from times immemorial. Patients with brain stem death have absolutely no chance of recovery. brain death is considered at par with death in most of the countries. General public in most parts of the world shows reluctance to accept this concept due to different social, cultural and religious backgrounds and state of literacy and awareness. The criteria for the diagnosis of brain death have been established which include certain pre-conditions, exclusions and tests of the brain stem function. These criteria are universally accepted. The criteria in children are somewhat different from the adults. The subject is intimately related with organ transplantation. If the patient is registered as organ donor or the family consents, organs can be harvested from brain dead patients for transplantation. Pakistan is amongst the few countries where no legislation exists to accept brain death as being at par with death of an individual, and to facilitate and regulate, cadaveric organ donation and transplantation.