Husain FM et al. (2013) J Biosci "Influence of clove oil on certain quorum-sensing-regulated functions and biofilm of Pseudomonas aeruginosa and Aeromonas hydrophila."

Ahmad I, Asif M, Tahseen Q, Husain FM

[J Biosci, 2013]

Quorum sensing (QS) plays an important role in virulence, biofilm formation and survival of many pathogenic bacteria including Pseudomonas aeruginosa. This signalling pathway is considered as novel and promising target for anti-infective agents. In the present investigation, effect of the Sub-MICs of clove oil on QS regulated virulence factors and biofilm formation was evaluated against P. aeruginosa PAO1 and Aeromonas hydrophila WAF-38 strain. Sub-inhibitory concentrations of the clove oil demonstrated statistically significant reduction of las- and rhl-regulated virulence factors such as LasB, total protease, chitinase and pyocyanin production, swimming motility and exopolysaccharide production. The biofilm forming capability of PAO1 and A. hydrophila WAF-38 was also reduced in a concentration-dependent manner at all tested sub-MIC values. Further, the PAO1-preinfected Caenorhabditis elegans displayed an enhanced survival when treated with 1.6 percent v/v of clove oil. The above findings highlight the promising anti-QS-dependent therapeutic function of clove oil against P. aeruginosa.

Husain FM et al. (2017) Front Microbiol "Leaf Extracts of Mangifera indica L. Inhibit Quorum Sensing - Regulated Production of Virulence Factors and Biofilm in Test Bacteria."

Al-Thubiani AS, Aqil F, AlHazza IM, Abulreesh HH, Ahmad I, Husain FM

[Front Microbiol, 2017]

Quorum sensing (QS) is a global gene regulatory mechanism in bacteria for various traits including virulence factors. Disabling QS system with anti-infective agent is considered as a potential strategy to prevent bacterial infection. Mangifera indica L. (mango) has been shown to possess various biological activities including anti-QS. This study investigates the efficacy of leaf extracts on QS-regulated virulence factors and biofilm formation in Gram negative pathogens. Mango leaf (ML) extract was tested for QS inhibition and QS-regulated virulence factors using various indicator strains. It was further correlated with the biofilm inhibition and confirmed by electron microscopy. Phytochemical analysis was carried out using ultra performance liquid chromatography (UPLC) and gas chromatography-mass spectrometry (GC-MS) analysis. In vitro evaluation of anti-QS activity of ML extracts against Chromobacterium violaceum revealed promising dose-dependent interference in violacein production, by methanol extract. QS inhibitory activity is also demonstrated by reduction in elastase (76%), total protease (56%), pyocyanin (89%), chitinase (55%), exopolysaccharide production (58%) and swarming motility (74%) in Pseudomonas aeruginosa PAO1 at 800 g/ml concentration. Biofilm formation by P. aeruginosa PAO1 and Aeromonas hydrophila WAF38 was reduced considerably (36-82%) over control. The inhibition of biofilm was also observed by scanning electron microscopy. Moreover, ML extracts significantly reduced mortality of Caenorhabditis elegans pre-infected with PAO1 at the tested concentration. Phytochemical analysis of active extracts revealed very high content of phenolics in methanol extract and a total of 14 compounds were detected by GC-MS and UPLC. These findings suggest that phytochemicals from the ML could provide bioactive anti-infective and needs further investigation to isolate and uncover their therapeutic efficacy.

Husain FM et al. (2015) Front Microbiol "Sub-MICs of Mentha piperita essential oil and menthol inhibits AHL mediated quorum sensing and biofilm of Gram-negative bacteria."

Khan MS, Ahmad E, Alshabib NA, Husain FM, Tahseen Q, Ahmad I

[Front Microbiol, 2015]

Bacterial quorum sensing (QS) is a density dependent communication system that regulates the expression of certain genes including production of virulence factors in many pathogens. Bioactive plant extract/compounds inhibiting QS regulated gene expression may be a potential candidate as antipathogenic drug. In this study anti-QS activity of peppermint (Mentha piperita) oil was first tested using the Chromobacterium violaceum CVO26 biosensor. Further, the findings of the present investigation revealed that peppermint oil (PMO) at sub-Minimum Inhibitory Concentrations (sub-MICs) strongly interfered with acyl homoserine lactone (AHL) regulated virulence factors and biofilm formation in Pseudomonas aeruginosa and Aeromonas hydrophila. The result of molecular docking analysis attributed the QS inhibitory activity exhibited by PMO to menthol. Assessment of ability of menthol to interfere with QS systems of various Gram-negative pathogens comprising diverse AHL molecules revealed that it reduced the AHL dependent production of violacein, virulence factors, and biofilm formation indicating broad-spectrum anti-QS activity. Using two Escherichia coli biosensors, MG4/pKDT17 and pEAL08-2, we also confirmed that menthol inhibited both the las and pqs QS systems. Further, findings of the in vivo studies with menthol on nematode model Caenorhabditis elegans showed significantly enhanced survival of the nematode. Our data identified menthol as a novel broad spectrum QS inhibitor.

Husain FM et al. (2015) Evid Based Complement Alternat Med "Trigonella foenum-graceum (Seed) Extract Interferes with Quorum Sensing Regulated Traits and Biofilm Formation in the Strains of Pseudomonas aeruginosa and Aeromonas hydrophila."

Al-Shabib NA, Khan MS, Ahmad I, Husain FM

[Evid Based Complement Alternat Med, 2015]

Trigonella foenum-graecum L. (Fenugreek) is an important plant of the Leguminosae family known to have medicinal properties. However, fraction based antiquorum sensing and antibiofilm activities have not been reported from this plant. In the present study T. foenum-graecum seed extract was sequentially fractionated and sub-MICs were tested for above activities. The methanol fraction of the extract demonstrated significant inhibition of AHL regulated virulence factors: protease, LasB elastase, pyocyanin production, chitinase, EPS, and swarming motility in Pseudomonas aeruginosa PAO1 and PAF79. Further, QS dependent virulence factor in the aquatic pathogen Aeromonas hydrophila WAF38 was also reduced. Application of T. foenum-graecum seed extract to PAO1, PAF79, and WAF38 decreased the biofilm forming abilities of the pathogens by significant levels. The extract also exhibited reduced AHL levels and subsequent downregulation of lasB gene. In vivo study showed an enhanced survival of PAO1-preinfected C. elegans after treatment with extract at 1mg/mL. Further, the major compound detected by GC-MS, caffeine, reduced the production of QS regulated virulence factors and biofilm at 200g/mL concentration indicating its role in the activity of the methanol extract. The results of the present study reveal the potential anti-QS and antibiofilm property of T. foenum-graceum extract and caffeine.

Husain FM et al. (2018) Front Cell Infect Microbiol "Seed Extract of Psoralea corylifolia and Its Constituent Bakuchiol Impairs AHL-Based Quorum Sensing and Biofilm Formation in Food- and Human-Related Pathogens."

Al-Shabib NA, Lobb KA, Alajmi MF, Husain FM, Hussain A, Baig MH, Rehman MT, Ahmad I, Khan FI

[Front Cell Infect Microbiol, 2018]

The emergence of multi-drug resistance in pathogenic bacteria in clinical settings as well as food-borne infections has become a serious health concern. The problem of drug resistance necessitates the need for alternative novel therapeutic strategies to combat this menace. One such approach is targeting the quorum-sensing (QS) controlled virulence and biofilm formation. In this study, we first screened different fractions of <i>Psoralea corylifolia</i> (seed) for their anti-QS property in the <i>Chromobacterium violaceum</i> 12472 strain. The methanol fraction was found to be the most active fraction and was selected for further bioassays. At sub-inhibitory concentrations, the <i>P. corylifolia</i> methanol fraction (PCMF) reduced QS-regulated virulence functions in <i>C. violaceum</i> CVO26 (violacein); <i>Pseudomonas aeruginosa</i> (elastase, protease, pyocyanin, chitinase, exopolysaccharides (EPS), and swarming motility), <i>A. hydrophila</i> (protease, EPS), and <i>Serratia marcescens</i> (prodigiosin). Biofilm formation in all the test pathogens was reduced significantly (<i>p</i> 0.005) in a concentration-dependent manner. The -galactosidase assay showed that the PCMF at 1,000 g/ml downregulated <i>las</i>-controlled transcription in PAO1. <i>In vivo</i> studies with <i>C. elegans</i> demonstrated increased survival of the nematodes after treatment with the PCMF. Bakuchiol, a phytoconstituent of the extract, demonstrated significant inhibition of QS-regulated violacein production in <i>C. violaceum</i> and impaired biofilm formation in the test pathogens. The molecular docking results suggested that bakuchiol efficiently binds to the active pockets of LasR and RhlR, and the complexes were stabilized by several hydrophobic interactions. Additionally, the molecular dynamics simulation of LasR, LasR-bakuchiol, RhlR, and RhlR-bakuchiol complexes for 50 ns revealed that the binding of bakuchiol to LasR and RhlR was fairly stable. The study highlights the anti-infective potential of the PCMF and bakuchiol instead of bactericidal or bacteriostatic action, as the extract targets QS-controlled virulence and the biofilm.

Kanteti R et al. (2014) BMC Cancer "Role of PAX8 in the regulation of MET and RON receptor tyrosine kinases in non-small cell lung cancer."

Sharma J, Vokes EE, El-Hashani E, Salgia R, Sharma S, Dhanasingh I, Tretiakova M, Husain AN, Kanteti R

[BMC Cancer, 2014]

BACKGROUND: Non-small cell lung cancers (NSCLC) are highly heterogeneous at the molecular level and comprise 75% of all lung tumors. We have previously shown that the receptor tyrosine kinase (RTK) MET frequently suffers gain-of-function mutations that significantly promote lung tumorigenesis. Subsequent studies from our lab also revealed that PAX5 transcription factor is preferentially expressed in small cell lung cancer (SCLC) and promotes MET transcription. PAX8, however, is also expressed in NSCLC cell lines. We therefore investigated the role of PAX8 in NSCLC. METHODS: Using IHC analysis, PAX8 protein expression was determined in archival NSCLC tumor tissues (n = 254). In order to study the effects of PAX8 knockdown on NSCLC cellular functions such as apoptosis and motility, siRNA against PAX8 was used. Confocal fluorescence microscopy was used to monitor the localization of MET, RON and PAX8. The combinatorial effect of PAX8 knockdown and MET inhibition using SU11274 was investigated in NSCLC cell viability assay. RESULTS: Relative levels of PAX8 protein were elevated ( + 2 on a scale of 0-3) in adenocarcinoma (58/94), large cell carcinoma (50/85), squamous cell carcinoma (28/47), and metastatic NSCLC (17/28; lymph node). Utilizing early progenitors isolated from NSCLC cell lines and fresh tumor tissues, we observed robust overexpression of PAX8, MET, and RON. PAX8 knockdown A549 cells revealed abrogated PAX8 expression with a concomitant loss in MET and the related RON kinase expression. A dramatic colocalization between the active form of MET (also RON) and PAX8 upon challenging A549 cells with HGF was visualized. A similar colocalization of MET and EGL5 (PAX8 ortholog) proteins was found in embryos of C. elegans. Most importantly, knockdown of PAX8 in A549 cells resulted in enhanced apoptosis (~6 fold) and decreased cell motility (~45%), thereby making PAX8 a potential therapeutic target. However, the combinatorial approach of PAX8 knockdown and treatment with MET inhibitor, SU11274, had marginal additive effect on loss of NSCLC cell viability. CONCLUSION: PAX8 provides signals for growth and motility of NSCLC cells and is necessary for MET and RON expression. Further investigations are necessary to investigate the therapeutic potential of PA8 in NSCLC.

Loganathan S et al. (2011) J Carcinog "Role of protein kinase C and vascular endothelial growth factor receptor in malignant pleural mesothelioma: Therapeutic implications and the usefulness of Caenorhabditis elegans model organism."

Vokes EE, Natarajan V, Siddiqui SS, Tretiakova M, Salgia R, Vigneswaran H, Cervantes G, Loganathan S, Kindler HL, El-Hashani E, Husain AN, Kanteti R

[J Carcinog, 2011]

PURPOSE: To examine the role of both protein kinase C (PKC)- and vascular endothelial growth factor receptor (VEGFR)-2 in malignant pleural mesothelioma (MPM) using respective inhibitors, enzastaurin and KRN633. MATERIALS AND METHODS: MPM cell lines, control cells, and a variety of archived MPM tumor samples were used to determine the protein expression levels of PKC-, VEGFR-2, VEGF, and p-AKT. Effects of enzastaurin and KRN633 on phosphorylation status of key signaling molecules and viability of the mesothelioma cells were determined. The common soil nematode, Caenorhabditis elegans, was treated with enzastaurin to determine its suitability to screen for highly potent kinase inhibitors. RESULTS: PKC-1, PKC-2 and VEGFR-2/KDR were overexpressed in MPM cell lines and MPM tumor tissues. Enzastaurin treatment resulted in significant loss in viability of VEGF induced cell proliferation; however, the effect of KRN633 was much less. Enzastaurin also dramatically decreased the phosphorylation of PKC-, its downstream target p-AKT, and surprisingly, the upstream VEGFR-2. The combination of the two drugs at best was additive and similar results were obtained with respect to cell viability. Treatment of C. elegans with enzastaurin resulted in clear phenotypic changes and the worms were hypermotile with abnormal pattern and shape of eggs, suggesting altered fecundity. CONCLUSIONS: PKC-1 and VEGFR-2 are both excellent therapeutic targets in MPM. Enzastaurin was better at killing MPM cells than KRN633 and the combination lacked synergy. In addition, we show here that C. elegans can be used to screen for the next generation inhibitors as treatment with enzastaurin resulted in clear phenotypic changes that could be assayed.

Herman RK et al. (1994) Worm Breeder's Gazette "Toward and Electronic Worm Breeder's Gazette."

Herman RK, Avery L, Stiernagle TL

[Worm Breeder's Gazette, 1994]

Toward an Electronic Worm Breeder's Gazette

Avery L et al. (1994) Worm Breeder's Gazette "M3 is an Inhibitory Glutamatergic Pharyngeal Motoneuron."

Avery L, Dent JA, Davis MW, Hess GP, Denk W

[Worm Breeder's Gazette, 1994]

M3 is an inhibitory glutamatergic pharyngeal motoneuron.

Ferguson KC et al. (1995) Worm Breeder's Gazette "SL1 Performs An Essential Function In Early Embryogenesis."

Ferguson KC, Rothman JH, Heid PJ

[Worm Breeder's Gazette, 1995]

SL1 PERFORMS AN ESSENTIAL FUNCTION IN EARLY EMBRYOGENESIS