scholarly journals Inhibitory Effects of Commercial and Enriched Green Tea Extracts on the Growth of Brochothrix thermosphacta, Pseudomonas putida and Escherichia coli

2012 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
Elodie Rozoy ◽  
Laurent Bazinet ◽  
Monica Araya-Farias ◽  
Anthony Guernec ◽  
Linda Saucier
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Putida ◽  
Green Tea ◽  
Antimicrobial Properties ◽  
Epigallocatechin Gallate ◽  
Brain Heart Infusion ◽  
Broth Culture ◽  
Meat Spoilage ◽  
Brochothrix Thermosphacta

<p>The major catechin found in green tea, called epigallocatechin gallate (EGCG), have been reported to have antimicrobial properties. In this study, we examined <em>in vitro </em>the antimicrobial effects of a commercial green tea extract sold in a capsule form, and two prepared green tea extracts enriched in catechins against <em>Brochothrix thermosphacta</em>, <em>Pseudomonsas putida</em> and <em>Escherichia coli</em> which have been associated with meat spoilage. The antimicrobial activity of the different tea extracts was evaluated by Spot-On-Lawn and Well Diffusion assays and the Minimum Inhibitory Concentration (MIC) was also determined in Brain Heart Infusion broth. The three methods used showed an inhibition of <em>Brochothrix thermosphacta</em>, whereas the inhibition of <em>Pseudomonas putida</em> and <em>Escherichia coli</em> was only detected with the MIC assay. The determination of the MIC in broth culture appeared to be the most reliable method to determine the inhibitory activity of catechin compounds. <strong></strong></p>

Isolation of Epigallocatechin Gallate from Green Tea and its Effects on Probiotics and Pathogenic Bacteria

2017 ◽  
Vol 17 (1) ◽  
pp. 69-77
Author(s):  
Tu Lijun ◽  
Sun Hanju ◽  
He Shudong ◽  
Zhu Yongsheng ◽  
Yu Ming ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Escherichia Coli ◽  
Green Tea ◽  
Lactobacillus Acidophilus ◽  
Pathogenic Bacteria ◽  
Epigallocatechin Gallate ◽  
Microbial Populations ◽  
Medium Ph ◽  
Bioactive Substance ◽  
Tea Extract

The aim of this study was to investigate epigallocatechin gallate (EGCG) prebiotics activities systematically which was reported as a bioactive substance. Therefore, EGCG was separated by water extraction, resin purification and prep-HPLC. Then the production of EGCG was confirmed by HPLC and mass spectrometry (MS) analysis and its purify was 97.23%. EGCG extractive and green tea extract (GTE) were further incubated with Bifidobacterium infantis, B. adolescentis, B. bifidum and Lactobacillus acidophilus to study its effect on microbial populations and medium pH. Finally, Escherichia coli, Salmonella, Staphylococcus aureus and Candida albicans were employed as pathogenic bacteria to explore the antimicrobial activity of EGCG and GTE. The results demonstrated that EGCG extractive could be beneficial for the proliferation of Bifidobacterium and L. acidophilus and also inhibit some pathogenic bacteria. In conclusion, both EGCG extractive and GTE had prebiotics activities and the effects of EGCG extractive were superior to those of GTE.

Green tea extract and its major component epigallocatechin gallate inhibits hepatitis B virus in vitro

2008 ◽  
Vol 78 (3) ◽  
pp. 242-249 ◽  
Author(s):  
Jun Xu ◽  
Jue Wang ◽  
Fei Deng ◽  
Zhihong Hu ◽  
Hualin Wang
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Green Tea Extract ◽  
B Virus ◽  
Tea Extract

High Pressure Inactivation of Escherichia coli, Campylobacter jejuni, and Spoilage Microbiota on Poultry Meat

2012 ◽  
Vol 75 (3) ◽  
pp. 497-503 ◽  
Author(s):  
YANG LIU ◽  
MIRKO BETTI ◽  
MICHAEL G. GÄNZLE
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Campylobacter Jejuni ◽  
Resistant Mutant ◽  
Poultry Meat ◽  
E Coli ◽  
Cell Counts ◽  
Meat Spoilage ◽  
Brochothrix Thermosphacta ◽  
Pressure Resistance

This study evaluated the high pressure inactivation of Campylobacter jejuni, Escherichia coli, and poultry meat spoilage organisms. All treatments were performed in aseptically prepared minced poultry meat. Treatment of 19 strains of C. jejuni at 300 MPa and 30°C revealed a large variation of pressure resistance. The recovery of pressure-induced sublethally injured C. jejuni depended on the availability of iron. The addition of iron content to enumeration media was required for resuscitation of sublethally injured cells. Survival of C. jejuni during storage of refrigerated poultry meat was analyzed in fresh and pressure-treated poultry meat, and in the presence or absence of spoilage microbiota. The presence of spoilage microbiota did not significantly influence the survival of C. jejuni. Pressure treatment at 400 MPa and 40°C reduced cell counts of Brochothrix thermosphacta, Carnobacterium divergens, C. jejuni, and Pseudomonas fluorescens to levels below the detection limit. Cell counts of E. coli AW1.7, however, were reduced by only 3.5 log (CFU/g) and remained stable during subsequent refrigerated storage. The resistance to treatment at 600 MPa and 40°Cof E. coli AW1.7 was compared with Salmonella enterica, Shiga toxin–producing E. coli and nonpathogenic E. coli strains, and Staphylococcus spp. Cell counts of all organisms except E. coli AW 1.7 were reduced by more than 6 log CFU/g. Cell counts of E. coli AW1.7 were reduced by 4.5 log CFU/g only. Moreover, the ability of E. coli AW1.7 to resist pressure was comparable to the pressure-resistant mutant E. coli LMM1030. Our results indicate that preservation of fresh meat requires a combination of high pressure with high temperature (40 to 60°C) or other antimicrobial hurdles.

scholarly journals Green tea phytocompounds targets Lansterol 14-α demethylase against ergosterol biosynthesis in Candida glabrata

2021 ◽  
Vol 12 (3) ◽  
pp. 1793-1797
Author(s):  
Priyanka Sirari ◽  
Jigisha Anand ◽  
Devvret ◽  
Ashish Thapliyal ◽  
Nishant Rai
Keyword(s):  
Green Tea ◽  
Candida Glabrata ◽  
Scientific Evidence ◽  
Epigallocatechin Gallate ◽  
Ergosterol Biosynthesis ◽  
Epicatechin Gallate ◽  
P450 Monooxygenase ◽  
Antifungal Potential ◽  
Inhibitory Potential

Green tea is credited as one of the world’s healthiest drinks with enriched antioxidants. It is known for its multi-beneficial health benefits against diabetes, blood pressure, hypertension, gastro-intestinal upset and is bestowed with significant antimicrobial potential. There are previous scientific evidence highlighting the antifungal potential of green tea and has identified it as a potential inhibitor of non-albicans Candida species. Lansterol 14-α demethylase (Erg 11) or CYP51 protein belongs to the cytochrome P450 monooxygenase (CYP) superfamily. Erg 11 is involved in ergosterol biosynthesis and has a significant role in azole drug resistance in Candida glabrata. The present study attempted to identify the inhibitory potential of green tea phytocompounds against inhibition of Erg 11 in Candida glabrata using bioinformatics tool viz., autodock vina software. Out of 15 green tea phytocompounds investigated, the study identified, Rutin (-10.5 kcal) Kaempferitrin (-9.4kcal), Epigallocatechin gallate (-10kcal), Epicatechin gallate (-8.7kcal), and Coumaroylquinic acid (-8.6kcal) acid as the potent phytocompounds which showed significant molecular interaction with Erg 11 in Candida glabrata. In attribution to the constant emergence of azole-resistant isolates, this preliminary analysis therefore, indicated the potential of green tea phytocompounds against inhibition of non-albicans Candida specific candidiasis. However, further, in vitro antimicrobial efficacy of these phytocompounds, the dose regime, drug likeliness, and cytotoxic analysis are required to be investigated and validated.

scholarly journals In Vitro Growth- and Encystation-Inhibitory Efficacies of Matcha Green Tea and Epigallocatechin Gallate Against Acanthameoba Castellanii

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 763
Author(s):  
Ameliya Dickson ◽  
Elise Cooper ◽  
Lenu B. Fakae ◽  
Bo Wang ◽  
Ka Lung Andrew Chan ◽  
...  
Keyword(s):  
Green Tea ◽  
Colorimetric Assay ◽  
Epigallocatechin Gallate ◽  
Acanthamoeba Castellanii ◽  
Inhibitory Effect ◽  
Response To Treatment ◽  
Ftir Microscopy ◽  
Sulforhodamine B ◽  
Chemical Fingerprinting

We examined the inhibitory effect of matcha green tea (Camellia sinensis) and epigallocatechin gallate (EGCg; the most abundant catechin in tea) on the vegetative growth and encystation of Acanthamoeba castellanii T4 genotype. The sulforhodamine B (SRB) stain-based colorimetric assay and hemocytometer counting were used to determine the reduction in A. castellanii trophozoite proliferation and encystation, in response to treatment with C. sinensis or EGCg. Fourier transform infrared (FTIR) microscopy was used to analyze chemical changes in the trophozoites and cysts due to C. sinensis treatment. Hot brewed and cold brewed matcha inhibited the growth of trophozoites by >40% at a 100 % concentration. EGCg at concentrations of 50 to 500 µM significantly inhibited the trophozoite growth compared to control. Hot brewed matcha (100% concentration) also showed an 87% reduction in the rate of encystation compared to untreated control. Although 500 µM of EGCg increased the rate of encystation by 36.3%, 1000 µM reduced it by 27.7%. Both percentages were not significant compared to control. C. sinensis induced more cytotoxicity to Madin Darby canine kidney cells compared to EGCg. FTIR chemical fingerprinting analysis showed that treatment with brewed matcha significantly increased the levels of glycogen and carbohydrate in trophozoites and cysts.

scholarly journals Aβ42 fibril formation from predominantly oligomeric samples suggests a link between oligomer heterogeneity and fibril polymorphism

2019 ◽  
Vol 6 (7) ◽  
pp. 190179 ◽  
Author(s):  
Christine Xue ◽  
Joyce Tran ◽  
Hongsu Wang ◽  
Giovanna Park ◽  
Frederick Hsu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Amyloid Β ◽  
Lag Time ◽  
Aβ Oligomers ◽  
Wide Range ◽  
Aβ Aggregation

Amyloid-β (Aβ) oligomers play a central role in the pathogenesis of Alzheimer's disease. Oligomers of different sizes, morphology and structures have been reported in both in vivo and in vitro studies, but there is a general lack of understanding about where to place these oligomers in the overall process of Aβ aggregation and fibrillization. Here, we show that Aβ42 spontaneously forms oligomers with a wide range of sizes in the same sample. These Aβ42 samples contain predominantly oligomers, and they quickly form fibrils upon incubation at 37°C. When fractionated using ultrafiltration filters, the samples enriched with smaller oligomers form fibrils at a faster rate than the samples enriched with larger oligomers, with both a shorter lag time and faster fibril growth rate. This observation is independent of Aβ42 batches and hexafluoroisopropanol treatment. Furthermore, the fibrils formed by the samples enriched with larger oligomers are more readily solubilized by epigallocatechin gallate, a main catechin component of green tea. These results suggest that the fibrils formed by larger oligomers may adopt a different structure from fibrils formed by smaller oligomers, pointing to a link between oligomer heterogeneity and fibril polymorphism.

Effect of the green tea polyphenol epigallocatechin gallate (EGCG) on growth and IL-6 signalling pathways in malignant plasma cells

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 8114-8114
Author(s):  
R. Burger ◽  
H. Czekalla ◽  
K. Richter ◽  
T. Ahrens ◽  
A. Guenther ◽  
...  
Keyword(s):  
Cell Lines ◽  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Myeloma Cell ◽  
Signalling Pathways ◽  
Dependent Manner ◽  
Green Tea Polyphenol ◽  
Dose Dependent ◽  
Human Myeloma Cell

8114 Background: Epigallocatechin gallate (EGCG) is the predominant polyphenolic constituent of green tea leaves that possesses antitumor, antiinflammatory, and antioxidant activity. EGCG exerts its effects through potentially multiple mechanisms including inhibition of growth factor receptor signalling. The compound is currently under investigation in a phase I/II clinical trial for treatment of patients with early stage chronic lymphocytic leukemia at Mayo Clinic. The goal of our study was to examine the in vitro effects of EGCG in multiple myeloma (MM). Methods: A panel of human myeloma cell lines (n=6) including the IL-6 dependent INA-6 cell line was used to evaluate the sensitivity to EGCG. Cells were cultured for three days in the absence or presence of EGCG at concentrations between 6.25 μM and 100 μM. Cell viability was determined in a colorimetric tetrazolium (MTS) based assay and by trypanblue exclusion. For signalling experiments, INA-6 cells were IL-6 and serum starved and then treated with EGCG for two hours before IL-6 was added. Whole cell lysates were prepared and subjected to SDS-PAGE and Western blot analysis. Results: EGCG inhibited the in vitro growth of human myeloma cell lines by inducing cell death in a time and dose-dependent manner. IC50 concentrations were between 12,5 μM and 50 μM. IL-6 mediated growth of INA-6 cells was inhibited at similar doses. The addition of excess amounts of IL-6 could not protect from EGCG induced cytotoxicity. Pretreatment of INA-6 cells with EGCG resulted in a dose-dependent inhibition of IL-6 induced STAT3 tyrosine phosphorylation. In these cells, stimulation with IL-6 leads to upregulation of Mcl-1 expression. In contrast, phosphorylation of p44/p42 MAPK, which is constitutively activated in INA-6 cells, was not affected. Conclusion: EGCG has growth inhibitory activity on myeloma cells. Specific inhibition of signalling pathways that regulate expression of anti-apoptotic proteins could be one mechanism how EGCG exerts its activity. Our work provides the rationale for further studies to evaluate the effect of EGCG not only in B-CLL, but also in plasma cell tumors. No significant financial relationships to disclose.

scholarly journals Synthesis, Molecular Docking and Antimicrobial Activities of 5-(4-substituted-benzyl)-2-(furan/thiophen-2-ylmethylene hydrazono)thiazolidin-4-ones

2021 ◽  
Vol 11 (4) ◽  
pp. 12434-12446
Keyword(s):  
Escherichia Coli ◽  
Molecular Docking ◽  
1H Nmr Spectroscopy ◽  
Antimicrobial Properties ◽  
Antimicrobial Activities ◽  
Docking Studies ◽  
Binding Affinities ◽  
Bacterial Strains ◽  
Effective Synthesis

In our present work, we reported an effective synthesis, molecular docking, and antimicrobial properties of novel 5-(4-substituted-benzyl)-2-(furan/thiophen-2-ylmethylene hydrazono) thiazolidin-4-ones (6a-g) and (7a-i). The structures of the synthesized compounds (6a-g) and (7a-i) were elucidated by 1H-NMR spectroscopy. The molecular docking studies were performed for all the synthesized compounds against GlcN-6P using AutoDock-tools-1.5.6 and recorded the extent of H-bonding and binding affinities. The preselected compounds via molecular docking were further tested for in vitro antimicrobial activity against five bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus) and two fungal strains (Candida albicans and Cryptococcus neoformans). The antimicrobial findings exhibited that the compounds possessed significant antimicrobial potential.

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