Antitubercular specific activity of ibuprofen and the other 2-arylpropanoic acids using the HT-SPOTi whole-cell phenotypic assay

Objectives: Lead antituberculosis (anti-TB) molecules with novel mechanisms of action are urgently required to fuel the anti-TB drug discovery pipeline. The aim of this study was to validate the use of the high-throughput spot culture growth inhibition (HT-SPOTi) assay for screening libraries of compounds against Mycobacterium tuberculosis and to study the inhibitory effect of ibuprofen (IBP) and the other 2-arylpropanoic acids on the growth inhibition of M tuberculosis and other mycobacterial species. Methods: The HT-SPOTi method was validated not only with known drugs but also with a library of 47 confirmed anti-TB active compounds published in the ChEMBL database. Three over-the-counter non-steroidal anti-inflammatory drugs were also included in the screening. The 2-arylpropanoic acids, including IBP, were comprehensively evaluated against phenotypically and physiologically different strains of mycobacteria, and their cytotoxicity was determined against murine RAW264.7 macrophages. Furthermore, a comparative bioinformatic analysis was employed to propose a potential mycobacterial target. Results: IBP showed antitubercular properties while carprofen was the most potent among the 2-arylpropanoic class. A 3,5-dinitro-IBP derivative was found to be more potent than IBP but equally selective. Other synthetic derivatives of IBP were less active, and the free carboxylic acid of IBP seems to be essential for its anti-TB activity. IBP, carprofen and the 3,5-dinitro-IBP derivative exhibited activity against multidrug-resistant isolates and stationary phase bacilli. On the basis of the human targets of the 2-arylpropanoic analgesics, the protein initiation factor infB (Rv2839c) of M tuberculosis was proposed as a potential molecular target. Conclusions: The HT-SPOTi method can be employed reliably and reproducibly to screen the antimicrobial potency of different compounds. IBP demonstrated specific antitubercular activity, while carprofen was the most selective agent among the 2-arylpropanoic class. Activity against stationary phase bacilli and multidrug-resistant isolates permits us to speculate a novel mechanism of antimycobacterial action. Further medicinal chemistry and target elucidation studies could potentially lead to new therapies against TB

Novel indole-thiazolidinone conjugates: Design, synthesis and whole-cell phenotypic evaluation as a novel class of antimicrobial agents

In connection with our research program on the development of novel anti-tubercular candidates, herein we report the design and synthesis of two different sets of indole-thiazolidinone conjugates (8a,b; 11a-d) and (14a-k; 15a-h). The target compounds were evaluated for their in vitro antibacterial and antifungal activities against selected human pathogens viz. Staphylococcus aureus (Gram positiveve), Pseudomonas aeruginosa, Escherichia coli (Gram negative), Mycobacterium tuberculosis (Acid-fast bacteria), Aspergillus fumigates and Candida albicans (fungi). Moreover, eukaryotic cell-toxicity was tested via an integrated ex vivo drug screening model in order to evaluate the selective therapeutic index (SI) towards antimicrobial activity when microbes are growing inside primary immune cells. Also, the cytotoxicity towards a panel of cancer cell lines and human lung fibroblast normal cell line, WI-38 cells, was explored to assure their safety. Compound 15b emerged as a hit in this study with potent broad spectrum antibacterial (MIC: 0.39-0.98 µg/ml) and antifungal (MIC: 0.49-0.98 µg/ml) activities, in addition to its ability to kill mycobacteria M. aurum inside an infected macrophage model with good therapeutic window. Moreover, compound 15b displayed promising activity towards resistant bacteria strains MRSA and VRE with MIC values equal 3.90 and 7.81 µg/mL, respectively. These results suggest compound 15b as a new therapeutic lead with good selectivity for further optimization and development

Characterisation of a putative AraC transcriptional regulator from Mycobacterium smegmatis

MSMEG_0307 is annotated as a transcriptional regulator belonging to the AraC protein family and is located adjacent to the arylamine N-acetyltransferase (nat) gene in Mycobacterium smegmatis, in a gene cluster, conserved in most environmental mycobacterial species. In order to elucidate the function of the AraC protein from the nat operon in M. smegmatis, two conserved palindromic DNA motifs were identified using bioinformatics and tested for protein binding using electrophoretic mobility shift assays with a recombinant form of the AraC protein. We identified the formation of a DNA:AraC protein complex with one of the motifs as well as the presence of this motif in 20 loci across the whole genome of M. smegmatis, supporting the existence of an AraC controlled regulon. To characterise the effects of AraC in the regulation of the nat operon genes, as well as to gain further insight into its function, we generated a ΔaraC mutant strain where the araC gene was replaced by a hygromycin resistance marker. The level of expression of the nat and MSMEG_0308 genes was down-regulated in the ΔaraC strain when compared to the wild type strain indicating an activator effect of the AraC protein on the expression of the nat operon genes

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Not AvailableKhesari dhal (Lathyrus sativus L) or grass pea is one of the richest source of protein among pulses, however its utilization is limited owing to the presence of a neurotoxin i.e. β-Oxalyl-di-amino propionic acid (β-ODAP). β-ODAP is a water soluble neurotoxin, hence, aqueous extraction of protein followed by isolation through precipitation may reduce/remove its concentration in protein isolates. . This study was aimed to optimize the process parameters for production of protein isolates from Khesari dhal (var. Mahateora). Four process parameters i. e extraction pH (8–10), extraction duration (40–80 min), extraction temperature (40–60 °C) and salt (sodium chloride) concentration (0.1–0.3%) were selected. Experiments were designed using response surface methodology (RSM) and executed accordingly. Maximum protein extraction (94.66%), recovery (81.04%), yield (23.10%) and purity (92.91%) was obtained at, pH 9; extraction duration, 58 min; temperature, 53 °C and salt concentration of 0.2% at khesari dhal: water ratio of 1:10. β-ODAP was not detectable in protein isolates and functional properties namely protein solubility, foaming and emulsification capacity, water and oil absorption capacity and least gelling concentration were at par with other legumes protein isolates.Not Availabl

International Journal of Pharma and Bio Sciences RESEARCH ARTICLE PATHOLOGY HISTOLOGICAL CHANGES IN PLACENTAE IN PREGNANCIES COMPLICATED BY PRE-ECLAMPSIA AND ECLAMPSIA AND CORELATION WITH FOETAL OUTCOME

Pre eclampsia, the clinical state prior to full blown eclampsia (siezures), is one of the toxemias of pregnancy. The basic clinical definition is that it is a pregnancy specific condition of increased blood pressure accompanied by proteinuria, edema or both. Many phenomena have been investigated, but the recurring theme appears to be an abnormally low blood flow into the placenta. The present study was designed to determine the histological changes in pregnancies complicated by pregnancy induced hypertension and to correlate the changes with foetal outcome. A study of sixty placentae was done with the collaboration of Department of Obstetrics and Gynaecology, to find out the histological changes of placenta in 30 women suffering from pregnancy induced hypertension in comparison to 30 women with uncomplicated gestation. The main histological features noted were cytotrophoblastic proliferation, basement membrane thickening, vasculosyncytial membrane deficiency which correlated well with the foetal outcome. The other features noted were syncytial knot formation, fibrinoid necrosis and stromal fibrosis. This article can be downloaded from www.ijpbs.ne

Antimycobacterials from natural sources: ancient times, antibiotic era and novel scaffolds

Mycobacteria are a group of aerobic, non-motile, acid fast bacteria that have a characteristic cell wall composed of a mycolyl-arabinogalactan-peptidoglycan complex. They display different phenotypic attributes in their growth, color and biochemistry. Tuberculosis (TB) is defined as the infection with Mycobacterium tuberculosis complex and was declared a global health emergency principally because of the appearance of multidrug-resistant strains and the associated risk of infection in immune-compromised population. There is an urgent clinical need for novel, potent and safe anti-TB drugs. Natural products have been used since antiquity for treating diverse complaints and novel pharmacophores are discovered every year. Two of the most potent used antimycobacterials, the rifamycins and streptomycin, were first detected in Streptomyces bacteria. Plants are also the source of an exquisite variety of antimicrobials that can lead to useful therapeutics in the future. In this review, natural preparations used since antiquity for treating tuberculosis are described, together with a rapid view of the 20th century antibiotic development against TB. Finally a summary of the most potent recent natural antimycobacterials is displayed

Mycobacterium tuberculosis: immune evasion, latency and reactivation

One-third of the global human population harbours Mycobacterium tuberculosis in dormant form. This dormant or latent infection presents a major challenge for global efforts to eradicate tuberculosis, because it is a vast reservoir of potential reactivation and transmission. This article explains how the pathogen evades the host immune response to establish a latent infection, and how it emerges from a state of latency to cause reactivation disease. This review highlights the key factors responsible for immune evasion and reactivation. It concludes by identifying interesting candidates for drug or vaccine development, as well as identifying unresolved questions for the future research

Antimycobacterials from Lovage Root (Ligusticum officinale Koch)

The n-hexane extract of Lovage root was found to significantly inhibit the growth of both Mycobacterium smegmatis mc2155 and Mycobacterium bovis BCG, and therefore a bioassay-guided isolation strategy was undertaken. (Z)-Ligustilide, (Z)-3-butylidenephthalide, (E)-3-butylidenephthalide, 3-butylphthalide, α-prethapsenol, falcarindiol, levistolide A, psoralen and bergapten were isolated by chromatographic techniques, characterized by NMR spectroscopy and MS, and evaluated for their growth inhibition activity against Mycobacterium tuberculosis H37Rv using the whole-cell phenotypic spot culture growth inhibition assay (SPOTi). Cytotoxicity against RAW 264.7 murine macrophage cells was employed for assessing their degree of selectivity. Falcarindiol was the most potent compound with a minimum inhibitory concentration (MIC) value of 20 mg/L against the virulent H37Rv strain; however, it was found to be cytotoxic with a half-growth inhibitory concentration (GIC50) in the same order of magnitude (SI < 1). Interestingly the sesquiterpene alcohol α-prethapsenol was found to inhibit the growth of the pathogenic mycobacteria with an MIC value of 60 mg/L, being more specific towards mycobacteria than mammalian cells (SI ~ 2). Colony forming unit analysis at different concentrations of this phytochemical showed mycobacteriostatic mode of action