Activity Of Green Tea Extract Research Articles

Green Tea Extract Reduced Lipopolysaccharide-Induced Inflammation in L2 Cells as Acute Respiratory Distress Syndrome Model Through Genes and Cytokine Pro-Inflammatory.

Acute Respiratory Distress Syndrome (ARDS) is a severe lung inflammatory condition that has the capacity to impair gas exchange and lead to hypoxemia. This condition is found to have been one of the most prevalent in patients of COVID-19 with a more serious condition. Green tea (Camellia sinensis L.) contains polyphenols that possess many health benefits. The purpose of this study was to assess the anti-inflammatory activities of green tea extract in Lipopolysaccharide (LPS)-induced lung cells as ARDS cells model. In this study, rat lung cells (L2) were induced by LPS to mimic the inflammation observed in ARDS and later treated with green tea extract. Pro-inflammatory cytokines such as Interleukin (IL)-12, C-Reactive Protein (CRP) as well as Tumor Necrosis Factor-α (TNF-α) were investigated using the ELISA method. Gene expression of NOD-Like Receptor Protein 3 (NLRP-3), Receptor for Advanced Glycation End-product (RAGE), Toll-like Receptor-4 (TLR-4), and Nuclear Factor-kappa B (NF-κB) were evaluated by qRTPCR. Apoptotic cells were measured using flow cytometry. The results showed that green tea extract treatment can reduce inflammation by suppressing gene expressions of NF-κB, NLRP-3, TLR-4, and RAGE, as well as pro-inflammatory cytokines such as IL-12, TNF-α, and CRP, an acute phase protein. Apoptosis levels of inflamed cells also found to be lowered when green tea extract was administered; thus, also increasing live cells compared to non-treated cells. These findings could lead to the future development of supplements from green tea to help alleviate ARDS symptoms, especially during critical moments such as the current pandemic.

Camellia sinensis L. Extract Suppresses Inflammation on Acute Respiratory Distress Syndrome Cells Models via Decreasing IL-1ß, IL-6 and COX-2 Expressions

Acute Respiratory Distress Syndrome (ARDS) is one of the clinical manifestations in severe COVID-19 patients characterized by acute inflammation resulting in respiratory failure and death. Camellia sinensis L. or green tea extract has many beneficial secondary metabolites including polyphenols which have anti-inflammatory and anti-viral roles. This study was aimed to investigate the activity of green tea extract (GTE) as an anti-inflammatory on ARDS model cells. In this study, rat lung alveolar type II epithelial cells line (L2) was induced by lipopolysaccharide (LPS) to mimic the inflammation process in ARDS. These cells were then treated with GTE to determine the GTE effectiveness in reducing the inflammation. The GTE polyphenol constitutions were first confirmed using Liquid Chromatography with Tandem Mass Spectrometry (LC-MS/MS). The cytotoxic assay was conducted using MTS assay kit to determine the safe range of GTE concentrations that used in the next assay. The effectiveness of the GTE was determined by measuring pro-inflammatory cytokines (IL-1ß and IL-6) and inflammation-mediated enzymes (COX-2), both of which were by ELISA method. Furthermore, this study measured the ACE-2 and TMPRSS-2 gene expressions by qRT-PCR method. The results showed that GTE treatment significantly reduced pro-inflammatory cytokines IL-1ß, IL-6, inflammation-mediated enzyme COX-2, and significantly increased ACE-2 and TMPRSS-2 mRNA expressions. In short, green tea extract possesses the potential to alleviate inflammation. HIGHLIGHTS Acute Respiratory Distress Syndrome (ARDS) is one of clinical manifestations in severe COVID-19 patients characterized by acute inflammation results in respiratory failure and death In lung inflammation, the Angiotensin Converting Enzyme-2 (ACE-2) and Trans-Membrane Protease Serine-2 (TMPRSS-2) genes were lowly expressed, then causes alveolar tissue collapse High levels of inflammatory mediator cytokines would be secreted in respiratory tracts, such as Interleukin (IL)-1β, IL-6, and Cyclooxygenases (COX)-2 Polyphenols in green tea (Camelia sinensis L.) have been reported to have anti-inflammatory activities GRAPHICAL ABSTRACT

In vitro compositional and phytochemical analysis of green and black tea

The traditional beverage that people consume more after water is a tea. The ethanolic extract of green and black tea have antioxidant and antimicrobial activity and these activities may differ in their processing methods. In this study, physiochemical analysis of green and black tea was carried out. The physiochemical analysis showed that green tea has higher moisture content, crude fat and crude fiber except for crude protein and ash content which is found higher in black tea. The maceration process was used for extraction purposes. This extract was used to analyze the total phenolic and flavonoid content, antioxidant potential, and antimicrobial activity. A significant difference was found in the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity of green and black tea. The flavonoids and phenolic content in T1 (ethanol 100%) acquired average and significant in the extract of green and black tea. The maximum value of TPC was observed in green tea extract 152.17a ± 0.28 mg GAE/g in treatment T1, and the value of TFC in green tea was found 40.26±11.387mg QE/g and the minimum value was found in black tea at 36.85±13.68 mg QE/g of extract. Antioxidant activity of green tea extract ranged from 90.64% to 69.07%, and black tea extract ranged from 89.05% to 50.93% in each extract. The parallel determination of the inhibitory effect of gram-negative and positive bacterial strains (Streptococcus pyogenes, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa) was found sensitivity and resistivity towards extract of tea. The positive and negative effect was found in antimicrobial activity by using antibiotics against these bacterial strains.

Anti-microbial activity of Green Tea Extracts and Nicotine on the Growth, Biofilm Formation of Salivary Mutans Streptococci (In-vitro study)

Background: The green tea have antimicrobial activity against many types of bacteria It is considered a natural substance with few side effect. Aim of the Study: An in vitro study was carried out to investigate the ability of green tea extract and nicotine to inhibit growth, biofilm formation by salivary Mutans streptococci. Methods: This study included a convenient sample of 40 healthy Iraqi volunteers aged 18–23 years old from College of Dentistry / University of Baghdad. Green tea and nicotine aqueous extract were prepared in different concentration to use in agar diffusion method to detect the activity of extract, and ELISA reader in multi titer plate was used to determine the ability of salivary mutans Streptococci to form biofilm in the presence and absence of the extracts.to measure the biofilm inhibition rate. Results: Mutans Streptococci were sensitive to green tea and nicotine in different concentrations the diameters of the inhibition zone were effective in a dose dependent manner significantly. There was a significant difference between the concentrations of each extracts, antibacterial activity was in a dose dependent manner for the extracts. The minimum bactericidal concentration of green tea was (280 mg/ml) and minimum bactericidal concentration of nicotine was (45mg/ml). The study found that biofilm formation by Mutans Streptococci was markedly decreased in the presence of 1/2 minimum bactericidal concentration of both green tea and nicotine with mean of O.D 590 nm = 0.54 in comparison with green tea extracts and nicotine alone O.D 590 nm = 0.15, 0.68 respectively. Conclusions green tea and nicotine extracts in different concentration effectively reduced the biofilm formation of salivary Mutans streptococci. While the presence of nicotine has negatively impacted on the ability of green tea extracts in the inhibition of biofilm formation by Mutans Streptococci in vitro.

Determination of Epigallocatechin Gallate (EGCG) and Antibacterial Activities of Commercially Available Tanzanian Green Tea (Camellia sinensis)

This paper presents the results of the antibacterial activity of green tea extract (Camellia sinensis) against Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), and Klebsiella pneumoniae (ATCC 708903). Quantitative and qualitative measurements of epigallocatechin gallate (EGCG) have also been reported. The analysis by High Performance Thin Layer Chromatography (HPTLC) revealed the presence of epigallocatechin gallate (EGCG) in the green tea extracts ranging from 13.16 to 18.64 mg/g. Crude extracts GT 01–GT 03 inhibited a greater number of microorganisms and presented the lowest values of MIC against Staphylococcus aureus (0.625 mg/mL), Escherichia coli (0.625 mg/mL), and Klebsiella pneumoniae (1.25 mg/mL). Crude extract GT 04 presented the highest values of MIC against Staphylococcus aureus (1.25 mg/mL), Escherichia coli (1.25 mg/mL), and Klebsiella pneumoniae (2.5 mg/mL). This study demonstrates that the popular use of green tea can be an effective and sustainable alternative for the prevention and treatment of various bacterial infections.
 Keywords: Camellia sinensis, Antibacterial, Epigallocatechin gallate, HPTLC

A Comparative Antimicrobial Potential Of Camellia Sinensis And Vachellia Nilotica Formulation Based Mouthwash And Commercial Mouthwash

Background: Camellia sinensis (Green tea) has good antioxidant, antimicrobial activity and it is used for evasion of periodontal disease development. Microbial dysbiosis of oral microflora containing gram-positive and gram-negative anaerobic microorganisms and these organisms can bring about the advancement of cariogenic dental plaque on the teeth and commencement of dental caries. Green tea leaves contain a high convergence of fluorides, which contribute towards its cariostatic activity alongside different parts present in the tea. Vachellia nilotica (Babul) contains rich content of fiber and proteins. It has good antimicrobial activity. It is very helpful for treating mouth ulcers.
 Aims: To compare antimicrobial potential of Camellia sinensis and Vachellia nilotica herbal formulated mouthwash and commercial mouthwash.
 Materials and Methods: The plant extract was prepared with 1g dried green tea leaves and 1g powder of Babul mixed with 100ml distilled water and boiled for 10 minutes, at 60-80°C on a heating mantle. The extract was filtered using Whatman No.1 filter paper. Further the herbal formulation of Green tea and Babul and commercial mouthwash was subjected to determine the antimicrobial activity.
 Results: Antimicrobial activity of green tea extract and Babul formulated mouthwash has good Antibacterial activity as there is a high zone of inhibition in Enterococcus faecalis and Streptococcus aureus. Commercial mouthwash has good Antibacterial activity as there is a high zone of inhibition in Streptococcus mutans.
 Conclusions: Green tea and Babul herbal formulated mouthwash has good antimicrobial activity when compared to commercial mouthwash.

The Catechins Profile of Green Tea Extracts Affects the Antioxidant Activity and Degradation of Catechins in DHA-Rich Oil.

This study investigated the effect of the catechins profile on the antioxidant activity of green tea extracts (GTEs) by comparing the antioxidant activity of an EGC-rich GTE (GTE1, catechin content: 58% EGC, 30.1% EGCG, 7.9% EC, and 3.9% ECG) and an EGCG-rich GTE (GTE2, catechin content: 60.6% EGCG, 17.7% EGC, 11.8% ECG, and 9.8% EC) in a DHA-rich oil. The effects of the individual catechins (EGC, EC, EGCG, and ECG) and reconstituted catechins mixtures (CatMix), prepared to contain the same amount of major catechins as in the GTEs, were also measured. All treatments (GTE1, CatMix1, GTE2, CatMix2, EGC250, EC250, EGCG250, and ECG250), each containing epistructured catechins at a concentration of 250 ppm, as well as the control (oil with no added antioxidant), were stored at 30 °C for 21 days with sampling intervals of 7 days. The antioxidant activity was assessed by measuring the peroxide value (PV) and p-anisidine value (p-AV) of oils. Changes in fatty acid content and catechins content were also monitored. Both GTEs enhanced the oxidative stability of the DHA-rich oil, but GTE1 demonstrated a stronger antioxidant activity than GTE2. No significant difference was observed between the PV of treatments with GTE1 and CatMix1 during storage, whereas the PV of oil with GTE2 was significantly higher than that with CatMix2 after 21 days. Among the individual catechins, EGC was the strongest antioxidant. Overall, the antioxidant activities of the extracts and catechins were observed in the decreasing order GTE1 ≈ EGC250 ≈ CatMix1 > GTE2 > EGCG250 ≈ CatMix2 > ECG250 > EC250. A significant change in fatty acid content was observed for the control and EC250 samples, and the catechins were most stable in GTE1-supplemented oil. Our results indicate that the EGC-rich GTE is a more potent antioxidant in DHA-rich oil than the EGCG-rich GTE.

Thermoreversible gel of green tea extract: Formulation and evaluation for the management of periodontitis

Plant products have been extensively investigated for their application in the treatment of periodontitis owing to their therapeutic benefits with no major side effects. Further, increasing antimicrobial resistance associated with a constant intake of synthetic antimicrobials has led to a change in paradigm towards the use of phytochemical based formulations as antimicrobial therapy in periodontitis. With this background, our present investigation focuses on developing a novel thermoreversible gel of green tea extract (GT) which is well known for its antimicrobial and antioxidant potential. In the first stage, the antimicrobial activity of GT was assessed against a panel of microbes (S. mutans, P. gingivalis, P. intermedia, F. nucleatum and A. actinomycetemcomitans). Antimicrobial activity of GT extract showed MBC value of 1.25 w/v % with desirable antiadhesion (34–69%) and antibiofilm activity (47–69%). In time kill assay, GT demonstrated time dependent killing varying sensitivity against tested pathogens. In the second stage, based on the MBC value, the thermoreversible gel of GT (GTTG) was formulated using thermosensitive polymer poloxamer 407 (19.5% w/v) and mucoadhesive polymer carbopol 934 (0.4%w/v). Formulated GTTG showed gelation temperature of 29 ± 1 °C, gelation time of 44.67 ± 1.15 s, gelation strength of 45 ± 1 g, the viscosity of 1659 ± 86 cPs and mucoadhesive strength of 1960 dyne/cm2. GTTG showed maximum release and permeation of marker phytochemical Epigallocatechin gallate in 48 and 96 h respectively. Finally, formulated GTTG when compared with gold standard antiplaque agent chlorhexidine gel for its antimicrobial potential showed greater zone of inhibition (ZOI) when tested against key periodontal pathogen P. gingivalis. Hence, the formulated novel GTTG could serve as an effective alternative local drug delivery with ease of administration and accurate dosing for the treatment of periodontitis.

N-hexane Extract and Fraction of Green Tea as Antiproliferation of MCM-B2 Breast Cancer Cells In Vitro

Green tea (Camellia sinensis) is one of tradisional plants that have potential as anticancer. Thesample used in this research was commercial green tea extract. The purpose of this study was to test theantiproliferation activity of green tea extract on breast cancer cell MCM-B2 in vitro. Green tea extract wasfractionated using three solvents, ie water, ethanol 70%, and n-hexane. Extract and water fraction of greentea have Lethality Concentration 50 (LC50) value of more than 1000 ppm. Fractions of ethanol 70% and nhexane had an LC50 value of 883.48 ppm and 600.56 ppm, respectively. The results of phytochemicalscreening of green tea extract are flavonoids, tannins, and saponins, while the phytochemical screeningresults of n-hexane fraction are flavonoids and tannins. Antiproliferation activity was tested on breast cancercells MCM-B2 and normal cells Vero by tripan blue staining method. The highest MCM-B2 cell inhibitoryactivity was achieved at a concentration of 13000 ppm green tea extract and 1000 ppm of n-hexane fraction,59% and 59%, respectively. The extract and n-hexane fraction of green tea are not toxic to normal Verocells characterized by not inhibiting normal cell proliferation.

Antioxidant effects of green tea extracts on lipid oxidation of half-dried eels

In order to explore the change of lipid oxidation of half-dried eels treated with green tea extracts and stored frozen, acid values, peroxide values, carbonyl values, and TBA values were measured. The eels were placed into the plastic bag and soaked for 1 hr in the solution mixed with distilled water and green tea extracts, and also vacuumed and stored frozen at –18 ∼ –20°C for 9 months after being dried with a hot-air blower for 15 hrs at 35°C (Aw 90-91). The control consisted of eels prepared in the same way without any pretreatment. At the end of the 1st month, 3rd month, 6th month, and 9th month, eel oil obtained from the samples were tested for its lipid oxidation. The activity of green tea extracts 1 mL was very similar to Vitamin C 500 μM 0.8 mL. The acid values, peroxide values, carbonyl values, and TBA values of eels treated with green tea extracts were lower than those of the control during 9 months of frozen storage (p<0.05). While the acid values and peroxide values of the control and eels treated with green tea extracts highly increased after the first month of frozen storage, the TBA values increased greatly on the third month of frozen storage. Compared to the control, the pre-application of green tea extracts to half-dried eels meaningfully prevented the generation of TBA compound during the frozen storage (p<0.01). In conclusion, pre-application of green tea extracts was effective in delaying early-stage peracid inducement and preventing the generation of secondary oxidation compounds, such as carbonyl compound and TBA compound, in the course of the drying and frozen storage

Changes in vitro rumen fermentation, methane production and microbial populations in response to green tea extract

This research was conducted to evaluate the influence of adding increasing levels (0, 250, 500,750, and 1000 μg/mL buffered rumen fluid) of green tea ethanol extract (GTEE) to a basal substrate (50% roughage: 50% concentrate formulated with 50% barley and 50% corn grain) on rumen fermentation, methane emissions, and population of microorganism under in vitro experiment. The potential of gas production (A), methane emission, and methane ratio (mL/mL total gas 24 h) were linearly decreased by increasing the dose of GTEE (p<.001). The control group has the highest methane emission (p<.05), while it was the lowest (p<.05) at a dose of 1000 GTEE (47.74 versus 24.23 mL/g DM). In vitro digestibility of dry and organic matter were negatively affected by GTEE (L and Q; p<.001). The addition of GTEE significantly decreased total volatile fatty acids (TVFA) and N-NH3 concentration (L, p<.001), and also changed the VFA profile compared to the control group by decreasing and increasing the acetate and the propionate proportions (p<.001). The highest decrease in total protozoa population (93%), total fungi (38%), and methanogenic archaea (95%) compared to the control group was observed at the highest dose (1000) of GTEE. The addition of GTEE stimulates the population of Prevotella ruminicola and Selenomonas ruminantium, but Butyrivibrio fibrisolvent population was inhibited, in different supplementation doses. The lowest supplementation level (250 μg/mL) seems to have the most benefits on the in vitro fermentation parameters with minimum negative effects on nutrient digestibility. It can be concluded that GTEE can potentially be used to manipulate ruminal fermentation patterns. Highlights Reducing the methane concentration through the anti-protozoal activity of green tea extract improve rumen fermentation patterns by decreasing acetate and N-NH3 concentration and increasing the propionate proportions. Although the in vitro anti-acidosis potential of GTEE is not as much as monensin, the anti-acidosis potential is significantly increased by increasing GTEE dose compared to the control. The decrease in in vitro total gas, CH4 production, and dry- and organic-matter digestibility on the addition of GTEE could be attributed to the antimicrobial action of GTEE.

In vitro antibacterial activity of green tea (Camellia sinensis) extract against staphylococcus aureus and MRSA

Context: There is a worldwide emergence of multi drug resistant bacteria. Recently no new antibiotics have been approved for use, although some are in the pipeline, undergoing phase 2 or 3 clinical trials. There is need for alternate compounds for treatment; one such agent is green tea. Green tea has antimicrobial effects against a variety of Gram positive and Gram negative bacteria (e.g., Staphylococcus aureus, Enterococcus sp, Escherichia coli, Salmonella sp.) Aims: To determine the antibacterial activity of green tea extract against Methicillin resistant and sensitive Staphylococcus aureus (MRSA &MSSA) Settings and Design: Department of Microbiology, Cross sectional study Materials and Methods: A total of 15 consecutive laboratory isolates of S. aureus (MSSA) and MRSA each, isolated between August to September 2017 were inoculated in media containing Green tea extract [epigallocatechin gallate (EGCG)] in concentrations of 2.5mg/ml, 5mg/ml, 10mg/ml. After overnight incubation the bacterial broth was subcultured using standard calibrated loop (0.01ml) onto Mueller Hinton agar. The lowest concentration of EGCG in which no growth occurred was considered as the minimum bactericidal concentration (MBC). Results: EGCG had antimicrobial activity against S. aureus ATCC-25923, P. aeruginosa ATCC-27853, K.pneumoniae ATCC-BAA 1705 and E.coli ATCC-25922- MBC 99.9% was 5mg/ml. But for E.faecalis ATCC 29212 MBC 99.9% was 10mg/ml. EGCG was effective against clinical isolates of MSSA and MRSA with MBC of 5mg/ml except 2 MRSA isolates for which MBC was 10mg/ml. Conclusions: Green tea extract- EGCG has antibacterial activity not only against standard bacterial strains but also against clinical isolates of S.aureus and MRSA. Keywords: Camellia sinensis, S.aureus, Minimum bactericidal concentration.

Development and Optimization of Epigallocatechin-3-Gallate (EGCG) Nano Phytosome Using Design of Experiment (DoE) and Their In Vivo Anti-Inflammatory Studies.

Inflammation is responsible for the development of many diseases that make up a significant cause of death. The purpose of the study was to develop a novel nanophytosomal preparation of epigallocatechin-3-gallate (EGCG) and egg phospholipid complex that has a lower particle size with higher drug loading capability, physical stability and anti-inflammatory activities. The impact of different factors and material characteristics on the average particle size was studied along with the drug loading of phytosome using design of experiment (DoE). The in vivo anti-inflammatory study was evaluated using a rat model to investigate the performance of EGCG nanophytosome. UHPLC results showed that 500 µg of EGCG were present in 1 mL of green tea extract. SEM data exhibited that phytosome (phospholipid-drug complex) was in the nanosize range, which was further evident from TEM data. Malvern Zetasizer data showed that the average particle size of the EGCG nanophytosome was in the range of 100–250 nm. High drug loading (up to 90%) was achieved with optimum addition rate, stirring temperature and phospholipid concentration. Stability study data suggest that no significant changes were observed in average particle size and drug loading of nanophytome. The in vivo anti-inflammatory study indicated a significant anti-inflammatory activity of green tea extract, pure EGCG and its phytosomal preparations (p ≤ 0.001) against acute paw edema.

Controlling the Antioxidant Activity of Green Tea Extract through Encapsulation in Chitosan-Citrate Nanogel

Applying bioactive ingredients in the formulation of foods instead of artificial preservatives is problematic because bioactive ingredients are unstable and sensitive to environmental conditions. The present study aimed to control the antioxidant activity of green tea extract (GT) through encapsulating in chitosan nanoparticles (CS-NP). The synthesized nanoparticles were analyzed by using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The encapsulation efficiency (EE), particle size, zeta potential, and polydispersity index (PDI) of GT-loaded CS-nanoparticles (CS-NP-GT) were assessed. Based on the results, the particle size and zeta potential related to the ratio of CS to GT of 1 : 0.5 were obtained as 135.43 ± 2.52 nm and 40.40 ± 0.2 mV, respectively. Furthermore, the results of FT-IR and XRD confirmed the validity of encapsulating GT in CS-NP. In addition, the antioxidant activity of GT increased after nanoencapsulation since the IC50 value of CS-NP-GT decreased to 6.13 ± 0.12 μg/ml. Finally, applying these particles for delivering GT polyphenols in foods is regarded as promising.

The Role of Extracting Solvents in the Recovery of Polyphenols from Green Tea and Its Antiradical Activity Supported by Principal Component Analysis.

Green tea contains a variety of biologically active constituents that are widely used in the pharmaceutical and food industries. Among them, simple catechins constitute a major group of compounds that is primarily responsible for the high biologic activity of green tea extracts. Therefore, the application of optimized extraction conditions may result in obtaining high value extracts. The main purpose of the study was to compare the content of polyphenols, mainly catechins, and the antioxidant activity of green tea extracts obtained by three different extraction methods: simple maceration, ultrasound extraction and accelerated solvent extraction using six various solvent systems. The quality of the extracts was evaluated by LC-ESI-Q-TOF-MS methodologies and spectrophotometric determinations. The obtained results revealed that catechins’ extraction efficiency was identical for the three techniques studied. However, larger quantitative differences among the samples were observed when using different solvents. The total content of major catechins and gallic acid was within a very wide range of 10.2–842 mg/L. Ethyl acetate was by far the least effective extractant, regardless of the extraction technique used. After all, the solvent system composed of ethanol:water (1:1 v/v) was proven to be the best to recover catechins and to deliver extracts with the highest antiradical activity.

Antibacterial effect of green tea extract against multi drug resistant Escherichia coli isolated from urine sample of patients visiting tertiary care hospital of Eastern Nepal

Urinary tract infections (UTIs) caused by drug resistant (DR) Uropathogenic Escherichia coli have become a significant worldwide public health problem. Green tea (Camellia sinensis), has been reported to have antimicrobial activities against various pathogenic bacteria. The main aim of our study was to estimate the antibacterial effect of green tea extract against drug resistant Uropathogenic E. coli isolated from urine samples of patients visiting in tertiary care hospital from eastern Nepal. During the study 360 urine samples were collected from UTI suspected patients visiting a tertiary care hospital of Biratnagar. Urine samples were cultured by using semi-quantitative culture technique and bacteria was identified by standard microbiological procedure. Antibiotic susceptibility testing was done by Kirby-Bauer Disk Diffusion method according to NCCLS (2011) guidelines. The antibacterial effect of green tea extract was performed by preparing the 95% ethanol extract in Soxhlet apparatus which was dispensed in DMSO solution and sterilized by membrane filtration. Antibacterial activity of Green Tea Extract against MDR Uropathogenic Escherichia coli was performed by making different concentration of green tea. The overall prevalence of E. coli was 27.22% in study population whereas the prevalence of MDR E. coli was 21.08%. All the isolated E. coli exhibited 100% sensitivity towards Nitrofurantoin and it was still a drug of choice for the treatment of Urinary tract infection caused by E. coli. The green tea extracts exhibited effective antibacterial activity against MDR E. coli. The MIC of Green Tea Extract was found to be 600µg/ml for 24 MDR isolates and 1000µg/ml for remaining 11 isolates. Based on the present study it is concluded that Green Tea extracts have great potential as an antimicrobial agent against E. coli.&#x0D; Int. J. Appl. Sci. Biotechnol. Vol 8(1): 45-51

Green Tea Extract Reduces Rat Lung Fibrotic

BackgroundPulmonary fibrosis is often found in infectious diseases and chemical exposure in the work environment. Antifibrotic effects can befibropreventive and fibrolysis. Bleomycin can cause inflammation and pulmonary fibrosis. Catechin is proven can repair liverdamages due to alcohol induction. The aim of this study is to examine the effect of antifibrotic green tea catechin on reducing thearea of rat lung fibrotic.MethodsThis research was carried out in vivo experimentally in the Laboratory Animal Management Unit at Faculty of Veterinary MedicineIPB in 4 groups of rat experiments, consisting of 3 rats in the negative control group, 3 rats in the positive control group, 3 rats in thegroup of rats given bleomycin on the 8th day and 28thwith green tea extract every day from day 0 to 49 days (fibropreventive), 3groups of rats given bleomycin days 0 and 21 with green tea extract every day from day 15 to 49 (fibrolysis). Histopathologicalexamination was performe for all groups of rats.ResultsThis study showed that administration of green tea extract in fibropreventive groups and fibrolysis groups could reduce the fibrosisarea in rat lungs based on Aschroft's modified scale.ConclusionBased on the results of this study it was found that the anti-fibrotic activity of green tea extract was proven to be able to suppressthe development of pulmonary fibrosis both by fibropreventive and fibrolysis

Effects of Food Processing on In Vivo Antioxidant and Hepatoprotective Properties of Green Tea Extracts.

Food processing can affect the nutrition and safety of foods. A previous study showed that tannase and ultrasound treatment could significantly increase the antioxidant activities of green tea extracts according to in vitro evaluation methods. Since the results from in vitro and in vivo experiments may be inconsistent, the in vivo antioxidant activities of the extracts were studied using a mouse model of alcohol-induced acute liver injury in this study. Results showed that all the extracts decreased the levels of aspartate transaminase and alanine aminotransferase in serum, reduced the levels of malondialdehyde and triacylglycerol in the liver, and increased the levels of catalase and glutathione in the liver, which can alleviate hepatic oxidative injury. In addition, the differences between treated and original extracts were not significant in vivo. In some cases, the food processing can have a negative effect on in vivo antioxidant activities. That is, although tannase and ultrasound treatment can significantly increase the antioxidant activities of green tea extracts in vitro, it cannot improve the in vivo antioxidant activities, which indicates that some food processing might not always have positive effects on products for human benefits.

Natural organic antioxidants from green tea inhibit corrosion of steel reinforcing bars embedded in mortar

Natural antioxidants with multiple polar atoms and electron-rich bonds are potential mixed-type corrosion inhibitors and ‘green’ alternatives to commercial inorganic corrosion inhibitors. Green tea is one of the richest sources of natural antioxidants. Therefore, this paper compares the corrosion inhibition efficiency (IE) of green tea extract (GT) against commercial calcium nitrite corrosion inhibitor (CI), on steel reinforcing bars (rebars) embedded in mortar. Rebar corrosion was accelerated with impressed current and cyclic wetting-drying, and corrosion development was measured with linear polarization resistance. Selected CI dosages encompassed four chloride-to-nitrite ratios, and the IE of CI and GT were compared at: 1) similar concentration and 2) equal volume. At similar concentration, CI and GT demonstrated a similar IE (51–70%). However, at equal volume, GT exhibited a higher IE than CI (75–80% vs. 14–24%), due to a significant increase in rebar polarization resistance and reduction in iron oxidation rate (anodic slope). Meanwhile, oxygen reduction rate (cathodic slope) and open circuit potential did not change significantly. The changes in anodic and cathodic slope without a significant open circuit potential change suggested that GT was a mixed-type corrosion inhibitor as hypothesized, which formed a protective layer on rebar surface and increased the polarization resistance of the rebars. Based on liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry analyses, it is hypothesized that (-)-epigallocatechin gallate, (-)-epicatechin gallate, and catechin or (-)-epicatechin are responsible for the anti-corrosion activity of GT as a mixed-type corrosion inhibitor.

Effects of Tannase and Ultrasound Treatment on the Bioactive Compounds and Antioxidant Activity of Green Tea Extract

The present study investigated the effects of tannase and ultrasound treatment on the bioactive compounds and antioxidant activity of green tea extract. The single-factor experiments and the response surface methodology were conducted to study the effects of parameters on antioxidant activity of green tea extract. The highest antioxidant activity was found under the optimal condition with the buffer solution pH value of 4.62, ultrasonic temperature of 44.12 °C, ultrasonic time of 12.17 min, tannase concentration of 1 mg/mL, and ultrasonic power of 360 W. Furthermore, phenolic profiles of the extracts were identified and quantified by high-performance liquid chromatography. Overall, it was found that tannase led to an increase in gallic acid and a decrease in epigallocatechin gallate, and ultrasounds could also enhance the efficiency of enzymatic reaction.