A novel screening method based on menadione mediated rapid reduction of tetrazolium salt for testing of anti-mycobacterial agents

Singh, Upasana; Akhtar, Shamim; Mishra, Abhishek; Sarkar, Dhiman

doi:10.1016/j.mimet.2010.11.013

Cited by 101 publications

(68 citation statements)

References 19 publications

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“…The plates were incubated at 37°C without shaking. An XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt] reduction assay was performed to determine the survival of bacterial cells at 36 h, as previously described (18). The MICs of PAS for the wild-type M. tuberculosis H37Ra in the presence of different concentrations of H 2 Pte (3 and 10 g/ml) were also determined.…”

Section: Methodsmentioning

confidence: 99%

Binding Pocket Alterations in Dihydrofolate Synthase Confer Resistance to para -Aminosalicylic Acid in Clinical Isolates of Mycobacterium tuberculosis

Zhao

Wang

Erber

et al. 2014

Antimicrob Agents Chemother

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gThe mechanistic basis for the resistance of Mycobacterium tuberculosis to para-aminosalicylic acid (PAS), an important agent in the treatment of multidrug-resistant tuberculosis, has yet to be fully defined. As a substrate analog of the folate precursor paraaminobenzoic acid, PAS is ultimately bioactivated to hydroxy dihydrofolate, which inhibits dihydrofolate reductase and disrupts the operation of folate-dependent metabolic pathways. As a result, the mutation of dihydrofolate synthase, an enzyme needed for the bioactivation of PAS, causes PAS resistance in M. tuberculosis strain H37Rv. Here, we demonstrate that various missense mutations within the coding sequence of the dihydropteroate (H 2 Pte) binding pocket of dihydrofolate synthase (FolC) confer PAS resistance in laboratory isolates of M. tuberculosis and Mycobacterium bovis. From a panel of 85 multidrug-resistant M. tuberculosis clinical isolates, 5 were found to harbor mutations in the folC gene within the H 2 Pte binding pocket, resulting in PAS resistance. While these alterations in the H 2 Pte binding pocket resulted in reduced dihydrofolate synthase activity, they also abolished the bioactivation of hydroxy dihydropteroate to hydroxy dihydrofolate. Consistent with this model for abolished bioactivation, the introduction of a wild-type copy of folC fully restored PAS susceptibility in folC mutant strains. Confirmation of this novel PAS resistance mechanism will be beneficial for the development of molecular method-based diagnostics for M. tuberculosis clinical isolates and for further defining the mode of action of this important tuberculosis drug.

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Section: Methodsmentioning

confidence: 99%

Binding Pocket Alterations in Dihydrofolate Synthase Confer Resistance to para -Aminosalicylic Acid in Clinical Isolates of Mycobacterium tuberculosis

Zhao

Wang

Erber

et al. 2014

Antimicrob Agents Chemother

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“…25 177) using the XTT Reduction Menadione Assay protocol and M. bovis (ATCC No. 35 745) using the Nitrate Reductase assay protocol [19][20][21]. Protocol details are given in Supporting Information.…”

mentioning

confidence: 99%

Leucas mollissima, a Source of Bioactive Compounds with Antimalarial and Antimycobacterium Activities

et al. 2015

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!A phytochemical investigation of the acetone extract from the aerial parts of Leucas mollissima afforded one new (−)epi-marmelo lactone, (2 S, 4R, 6 S)-2,6-dimethyl-6 hydroxy-7-ene-4-olide (1), along with five known compounds, schensianol A (2), vanillin (3), β-hydroxy propiovanillone (4), lanost-9(11),25-diene-3β,24β-diol (5), and lanost-9(11),23E(24)-diene-3β,25-diol (6). Similarly, an investigation of the methanol extract of the aerial parts of L. mollissima resulted in the isolation of three known compounds, (+)-syringaresinol (7), anisofolin A (8), and apigenin 7-O-β-D(− 6′′-p-E-coumaroyl)-glucoside (9). Structure elucidation of the isolated compounds was carried out using detailed analysis of 1D and 2D nuclear magnetic resonance. All compounds were evaluated for antimalarial activity against Plasmodium falciparum (3D7) and for antimycobacterium activity against Mycobacterium tuberculosis H37Ra and Mycobacterium bovis. Compound 8 was found to have promising antimalarial activity (IC 50 4.39 ± 0.25 µM), promising antimycobacterium activity [IC 50 4.50 ± 0.75 µM (3.31 µg/mL)] against M. tuberculosis H37Ra and at 100 µg/mL, showed 55.6 % inhibition of M. bovis. Compound 9 showed moderate inhibition of P. falciparum growth (35% inhibition at 10 µM) with respect to the positive control atovaquone and 67.4 % inhibition against M. bovis at 100 µg/mL with respect to the positive control rifampicin.

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“…The data was analyzed with the help of AOT425 Software. As there were no signs of mortality or any tetrazolium-5-carboxanilide (XTT) and menadione (XRMA) assay using microplate reader [11]. The in vitro immunomodulatory activity evaluation was performed for the most active antitubercular xanthene viz.…”

Section: Determination Of Lethal Dose (Ld 50 )mentioning

confidence: 99%

Exploring the potential of xanthene derivatives for antitubercular activity

Ts¹,

Vm²,

Kd³

et al. 2017

Glob Drugs Therap

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A novel screening method based on menadione mediated rapid reduction of tetrazolium salt for testing of anti-mycobacterial agents

Cited by 101 publications

References 19 publications

Binding Pocket Alterations in Dihydrofolate Synthase Confer Resistance to para -Aminosalicylic Acid in Clinical Isolates of Mycobacterium tuberculosis

Binding Pocket Alterations in Dihydrofolate Synthase Confer Resistance to para -Aminosalicylic Acid in Clinical Isolates of Mycobacterium tuberculosis

Leucas mollissima, a Source of Bioactive Compounds with Antimalarial and Antimycobacterium Activities

Exploring the potential of xanthene derivatives for antitubercular activity

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