Effect Of Green Tea Extract Research Articles

Host-mediated beneficial effects of phytochemicals for prevention of avian coccidiosis.

Both in vitro and in vivo studies were conducted to evaluate the beneficial effects of green tea extract (GT), cinnamon oil (CO), and pomegranate extract (PO) on avian coccidiosis. In experiment (EXP) 1, an in vitro culture system was used to investigate the individual effects of GT, CO, and PO on the proinflammatory cytokine response and integrity of tight junction (TJ) in chicken intestinal epithelial cells (IEC), on the differentiation of quail muscle cells and primary chicken embryonic muscle cells, and anticoccidial and antibacterial activities against Eimeria tenella sporozoites and Clostridium perfringens bacteria, respectively. In EXP 2 and 3, in vivo trials were carried out to study the dose-dependent effect of blended phytochemicals (GT, CO, PO) on coccidiosis in broiler chickens infected with E. maxima. For EXP 2, one hundred male broiler chickens (0-day-old) were allocated into the following five treatment groups: Control group for non-infected chickens (NC), Basal diet group for E. maxima-infected chickens (PC), PC group supplemented with phytochemicals at 50 (Phy 50), 100 (Phy 100), and 200 (Phy 200) mg/kg feed diets for E. maxima-infected chickens. For EXP 3, one hundred twenty male broiler chickens (0-day-old) were allocated into the following six treatment groups: NC, PC, PC supplemented with phytochemicals at 10 (Phy 10), 20 (Phy 20), 30 (Phy 30), and 100 (Phy 100) mg/kg feed for E. maxima-infected chickens. Body weights (BW) were measured on days 0, 7, 14, 20, and 22, and jejunum samples were used to measure cytokine, TJ protein, and antioxidant enzyme responses at 8 days post-infection (dpi). Fecal samples for oocyst enumeration were collected from 6 to 8 dpi. In vitro, CO and PO reduced LPS-induced IL-1β and IL-8 in IEC, respectively, and GT enhanced the gene expression of occludin in IEC. PO at 1.0 and 5.0 mg/mL exerted antimicrobial effect against E. tenella sporozoites and C. perfringens bacteria, respectively. In vivo, chickens fed a diet supplemented with phytochemicals showed enhanced BW, reduced oocyst shedding, and decreased proinflammatory cytokines following E. maxima challenge. In conclusion, the combination of GT, CO, and PO in the diet of broiler chickens infected with E. maxima induced enhanced host disease resistance including innate immunity and gut health, which contributed to improved growth and reduced disease responses. These findings provide scientific support for the development of a novel phytogenic feed additive formula that enhances the growth and intestinal health of broiler chickens infected with coccidiosis.

Green tea extract prevents CPT-11-induced diarrhea by regulating the gut microbiota

Irinotecan (CPT-11) is an anticancer drug with indications for use in treating various cancers, but severe diarrhea develops as a side effect. We investigated the effects of green tea extract (GTE) on CPT-11-induced diarrhea, focusing on β-glucuronidase and intestinal UGT1A1. When CPT-11 was administered to rats alone, the fecal water content was approximately 3.5-fold higher in this group than in the control group, and diarrhea developed. The fecal water content in the GTE-treated group was significantly higher than that in the control group, but the difference was smaller than that between the group treated with CPT-11 alone and the control group, and diarrhea improved. When CPT-11 was administered alone, the abundances of Bacteroidesfragilis and Escherichiacoli, which are β-glucuronidase-producing bacteria, increased and interleukin-6 and interleukin-1β mRNA levels in the colon increased, but GTE suppressed these increases. CPT-11 decreased colon UGT1A1 and short-chain fatty acid levels; however, this decrease was suppressed in the GTE-treated group. The findings that GTE decreases the abundance of β-glucuronidase-producing bacteria and increases colon UGT1A1 levels, thereby decreasing the production of the active metabolite SN-38 in the intestinal tract, indicate that GTE ameliorates CPT-11-induced diarrhea.

Effects of green tea extract epigallocatechin-3-gallate (EGCG) on orthodontic tooth movement and root resorption in rats

ObjectiveTo study the effect of EGCG on tooth movement and root resorption during orthodontic treatment in rats. MethodsA total of thirty six male Wistar rats were randomly and equally divided into three groups: control, 50 mg/kg EGCG, and 100 mg/kg EGCG. During the experiment, the subjects were submitted to an orthodontic tooth movement (OTM) model, rats in the experimental groups were given the corresponding dose of EGCG, while rats in the control group were administrated with an equal volume of normal saline solution by gavage. After 14 days of OTM, the rats were sacrificed by transcardial perfusion. Micro-CT of rat maxillaes was taken to analyze OTM distance and root resorption. The maxillary samples were prepared as histological sections for H&E staining, tartrate-resistant acid phosphatase (TRAP) staining and immunohistochemical (IHC) staining to be observed and analyzed. ResultsThe OTM distance and root resorption of rats in the dosed group decreased, and the number of TRAP positive cells in their periodontium decreased significantly. The expression level of RANKL was decreased in the EGCG group compared to the control group, while that of OPG, OCN and Runx2 was increased. Effects were more pronounced in 100 mg/kg group than in 50 mg/kg group. ConclusionEGCG reduces OTM and orthodontic induced root resorption (OIRR) in rats, and is able to attenuate osteoclastogenesis on the pressure side and promote osteogenesis on the tension side.

Antibacterial activity of green tea leaves extracts against specific bacterial strains

ObjectivesThere is an increase interest in the beneficial effects of green tea extracts which exhibits great activity against several diseases due to the presence of beneficial bioactive compounds. Green tea extracts were investigated for their anti microbial activity using specified Gram positive and Gram negative bacterial strains by specific methods. Therefore, this study aimed at evaluation of green tea aqueous, ethanol, and methanol extracts efficiency against potential gram positive and gram negative bacterial strains. MethodsFifty grams of dry leaves powder were used to prepare three different solutions with three different solvents; 80% ethanol, methanol, and sterile water; with a final concentration of 20% (g/ml). The flasks were placed for two days in a vibrator at 350 rpm at 15 °C. Four bacterial strains - two of them are gram positive and the other two are gram negative strains- were honored from King Fahd Educational Hospital. Qualitative phytochemical analysis technique was used to insure the presence of active compounds such as flavonoids, saponin, and tannins in plant extracts. Also, Gas chromatography mass spectrometry assay was used to determine extracts bioactive compounds. Seven types of antibiotics were used to determine minimum inhibitory concentration with two-fold dilution of plant extracts, by using agar plate method. While the minimum bactericidal concentration was performed using the pour plate technique. ResultsThe three types of plant extracts showed high effectiveness against pathogenic bacterial strains. The highest value of inhibition was (4.3 ± 0.3) mm with ethanol extract against Bacillus subtilis. Gentamicin, Neomycin and Ciprofloxacin showed good values of inhibition against Gram-positive and gram-negative bacteria, while gram-negative bacteria showed resistance to Chloramphenicol, Methicillin, Vancomycin. On the other hand, Gram positive bacteria showed resistance to the Colistin only. ConclusionGreen tea extracts showed effective anti microbial activity against different types of gram positive and negative bacterial strains as they have a good inhibitory and bactericidal activity due to the presence of special bioactive components such as ECGC and catechins.

Possible Effect of Green Tea Extract on Trans-differentiation of Adipose Stem Cells in Induced Diabetes Type I Keratopathy Rat Model

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Green tea extract ameliorates macrophage-driven emphysematous lesions in chronic obstructive pulmonary disease induced by cigarette smoke condensate.

Chronic obstructive pulmonary disease (COPD) is an important lung disease characterized by complicated symptoms including emphysema. We aimed to explore the mechanisms underlying the protective effect of green tea extract (GTE) on cigarette smoke condensate (CSC)-induced emphysema by demonstrating the reduction of macrophage-induced protease expression through GTE treatment in vivo and in vitro. Mice were intranasally administered 50 mg/kg CSC once a week for 4 weeks, and doses of 100 or 300 mg/kg GTE were administered orally once daily for 4 weeks. GTE significantly reduced macrophage counts in bronchoalveolar lavage fluid and emphysematous lesions in lung tissues in CSC-exposed mice. In addition, GTE suppressed CSC-induced extracellular signal-regulated kinase (ERK)/activator protein (AP)-1 phosphorylation followed by matrix metalloproteinases (MMP)-9 expression as revealed by western blotting, immunohistochemistry, and zymography in CSC-instilled mice. These underlying mechanisms related to reduced protease expression were confirmed in NCI-H292 cells stimulated by CSC. Taken together, GTE effectively inhibits macrophage-driven emphysematous lesions induced by CSC treatment, and these protective effects of GTE are closely related to the ERK/AP-1 signaling pathway, followed by a reduced protease/antiprotease imbalance. These results suggest that GTE can be used as a supplementary agent for the prevention of emphysema progression in COPD patients.

Green tea extract and Piper retrofractum attenuate deoxycholic acid-induced damage and enhance the tight junction barrier: An analysis in a Caco-2 cell culture model and a DSS coinduced mouse model

This study investigated the effect of green tea extract (GTE) and green tea–Piper retrofractum complex (GPX), on tight junctions (TJs) in a cellular model of deoxycholic acid (DCA)-induced intestinal barrier disruption and a mouse DSS + DCA-induced colitis model. Green tea and P. retrofractum were extracted and coadministered to examine the bioavailability and effects of combined catechins and piperine on colonic TJ damage. The ability of GPX to alleviate TJ damage was determined by comparing the transepithelial electrical resistance (TEER), FITC-dextran flux, and mRNA expression of TJ-related components and target expression pathway in the GTE and GPX groups. Compared with the DCA-treated group, the GTE- and GPX-treated groups showed significantly enhanced TEER, FITC-dextran flux, and TJ-related mRNA expression (p < 0.05). Cell treatment also downregulated the mRNA encoding bile acid receptor and decreased ERK1/2 phosphorylation. Compared with the GTE-treated group, the GPX-treated group showed higher mRNA expression of zonula occludens-1, occludin, claudin-3, and claudin-4; greater restoration of TJs, as determined by immunofluorescence; and better modulation of ERK1/2 activation. In the in vivo model, GPX-pretreated mice showed an improved intestinal damage index and colon length compared with mice in the other colitis-induced groups. Both extracts recovered the distal colon mRNA expression of zonula occludens-1 and claudin-1. These results suggest that GTE improves intestinal health by protecting TJs from secondary bile acid damage and that P. retrofractum may potentiate the bioactivity of green tea catechins.

LAMBDA CYHALOTHRIN INDUCED OXIDATIVE STRESS ON BRAIN TISSUES OF RATTUS NORVEGICUS AND ITS AMELIORATION BY GREEN TEA EXTRACT

Lambda cyhalothrin is one of the most important agricultural pesticides extensively used around the world. Pyrethroids are specially recommended insecticides as they have low mammalian toxicity, but they are known to cause an alteration in biochemical parameters and affect the oxidative status of the body through producing free radicals. However, it has been found that some herbal extracts can ameliorate the toxicity induced by the pesticides and other chemicals but the search for such compounds will always be an urgent need to achieve the optimum degree of amelioration. For this purpose, the present study was designed to evaluate the oxidative stress produced by lambda cyhalothrin, a synthetic type-II pyrethroid and ameliorating effect of green tea extract in albino rats.

LAMBDA CYHALOTHRIN INDUCED OXIDATIVE STRESS ON BRAIN TISSUES OF RATTUS NORVEGICUS AND ITS AMELIORATION BY GREEN TEA EXTRACT

Lambda cyhalothrin is one of the most important agricultural pesticides extensively used around the world. Pyrethroids are specially recommended insecticides as they have low mammalian toxicity, but they are known to cause an alteration in biochemical parameters and affect the oxidative status of the body through producing free radicals. However, it has been found that some herbal extracts can ameliorate the toxicity induced by the pesticides and other chemicals but the search for such compounds will always be an urgent need to achieve the optimum degree of amelioration. For this purpose, the present study was designed to evaluate the oxidative stress produced by lambda cyhalothrin, a synthetic type-II pyrethroid and ameliorating effect of green tea extract in albino rats.

Evaluation of the effect of green tea extract on postoperative pain management following surgical removal of impacted mandibular third molar.

Pain following surgical removal of impacted molars has remained a principal concern among practitioners. Since green tea has anti-inflammatory and anti-bacterial properties, the current study aimed to evaluate the efficacy of green tea extract local application in controlling postoperative pain following surgical extraction of the impacted mandibular third molar teeth. In a double-blinded randomized controlled trial study with a split-mouth design, 32 patients underwent bilateral removal of impacted third molars in a 2-month time interval; afterward, the sterile gauzes impregnated with green tea extract and saline were applied randomly to the surgical sites. Postoperative pain was evaluated 6, 12, 24, and 48 h after surgery using a questionnaire based on the Visual Analog Scale (VAS) and the number of analgesics used after surgery. Data were subjected to exact and Chi-square tests with the significance level set at 0.05. There was a decrease in the mean scores of the VAS and the mean number of analgesic consumptions in the first 2 days after surgery. Chi-square test results showed a significant reduction in the VAS scores after applying the green tea extract only 6 and 12 h after surgery (P < 0.05). Moreover, the number of analgesic consumptions was significantly lower in the green tea group compared to the control group. Green tea extract may be an appropriate and safe choice for postoperative pain control after surgical extraction of the impacted mandibular third molar teeth.

Analytical Study in Split-Plot Design with Application on an Agricultural Laboratory Experiment

Agricultural experiments play a major role for workers in the agricultural field in terms of experimentation and analysis in order to reach the most important factors affecting plant productivity and agriculture, and play a fundamental role in the economic sector. However, some countries suffer from a shortage of these crops due to the exposure of some cultivated areas to a range of environmental factors such as drought and salinity, which reached about 33% of the cultivated land, as these environmental phenomena affect the various stages of plant growth and development and its various physiological functions with their physical and chemical properties. In recent years, the harmful effects of saline environments in weak lands have been overcome by some means, such as the use of chemical growth regulators by soaking the seeds before planting or spraying plants. The study aimed to find out the effect of green tea extract on cucumber production by planting cucumber seeds in four different time periods (0, 6, 12, and 24 hours) in different salt concentrations (0, 1.5, 2.5, 3.5 dsm / m) and in three different concentrations (0.1, 0.01, 0.001) from green tea solution before germination. The experiment was conducted according to a split-plots design (4 *4*3* 3), after implementing the Normal Distribution test for the data, and then implementing the Variance Analysis and calculate the effects of the factors. The results of the study showed that green tea extract had a significant effect on the length of the Vegetative total. The best level was the first level (0.1), We note that Factor (B), the time factor, which is the duration of plant infusion in green tea, has a significant effect on response rates, and the best duration gave a response is the (12) hours period, and Factor (C), which is the salt concentration ratios in the plant, has a significant effect on the response rates. The best response level is the second concentration (1.5), and the interaction between them was significant and influencing to the plant. Also, the double and the triple interactions are significant and not independent in their effect on the response rates represented by the length of the Vegetative total.

In Vitro Antithrombotic, Antitumor and Antiangiogenic Activities of Green Tea Polyphenols and Its Main Constituent Epigallocatechin-3-gallate

The balance between embolic risk and bleeding represents a clinical challenge in cancer patient treatment, encouraging studies on adjuvant oncologic treatments. Thereby, this study evaluated the in vitro effect of green tea extract (GTE) and epigallocatechin-3-gallate (EGCG) on hemostasis modulation and the antineoplastic effect on melanoma cells (B16-F10) by applying platelet aggregation, angiogenesis and viability cell assays. The results displayed a significant platelet antiaggregant effect, corresponding to 50 and 80% for the extract and EGCG, respectively, compared to the negative control. Furthermore, both GTE and EGCG exhibited antitumor effects by reducing melanoma cell growth by 25 and 50%, respectively, verified by cellular apoptosis. Regarding angiogenesis, these substances inhibited blood vessel formation, reaching about 25% and 99% for GTE and EGCG at 100 μg/mL, respectively. Moreover, TNF-α cell stimulation evidenced VEGF and IL-8 secretion inhibition at 55 and 20% with GTE, while EGCG promoted an inhibition around 78% for both VEGF and IL-8. The results indicate the promising performance of GTE and EGCG as an option for treating cancer and its side effects. Nonetheless, further studies are required to elucidate their action mechanism on clotting, cell death and angiogenesis.

A Brief Review on Green Tea

Green Tea, which is produced from the leaves of the Camellia sinensis plant and belongs to the family Theaceae, is one of the most popular beverages worldwide. In This paper, the phytochemistry, Pharmacology, and toxicology of green tea are reviewed systematically and comprehensively. Key findings Green Tea has been demonstrated to be good for human health. Nowadays, multiple pharmacologically active components have been isolated and identified from green tea, including tea polyphenols, alkaloids, amino acids, polysaccharides, and volatile components. Recent studies have demonstrated that green tea shows versatile pharmacological activities, such as antioxidant, anticancer, hypoglycemic, antibacterial, antiviral and neuroprotective. Studies on the toxic effects of green tea extract and its main ingredients have also raised concerns including hepatotoxicity and DNA damage. Additionally, Green tea polyphenols induce autophagy, thereby revitalizing the overall health of the organism consuming it. Green tea was able to activate autophagy in HL-60 Xenographs by increasing the activity of P13 kinase and BECLIN-1. This manuscript describes the reported anti-photoaging, stress resistance, and neuroprotective and autophagy properties of one of the most widely known functional foods-green tea.

Effects of green tea extract treatment on erythropoiesis and iron parameters in iron-overloaded β-thalassemic mice.

β-Thalassemia is characterized by ineffective erythropoiesis leading to chronic anemia. Thus, increased iron absorption from the duodenum and via blood transfusions is required to maintain normal blood hemoglobin (Hb) levels and iron chelators in the removal of excessive iron. Certain agents are also needed for the improvement of stress erythropoiesis and iron dysregulation. Green tea extract (GTE), which is rich in epigallocatechin-3-gallate (EGCG), is known to possess radical scavenging and iron-chelating activities. We aimed to assess the effects of green tea extract on erythroid regulators, iron mobilization and anti-lipid peroxidation in the liver, spleen, and kidneys of iron-loaded β-globin gene knockout thalassemic (BKO) mice. Our results indicate that treatments of green tea extract and/or deferiprone (DFP) diminished levels of plasma erythropoietin (EPO) and erythroferrone (ERFE), and consistently suppressed kidney Epo and spleen Erfe mRNA expressions (p < .05) in iron- loaded BKO mice when compared with untreated mice. Coincidently, the treatments decreased plasma ferritin (Ft) levels, iron content levels in the liver (p < .05), spleen (p < .05), and kidney tissues of iron-loaded BKO mice. Furthermore, lipid-peroxidation products in the tissues and plasma were also decreased when compared with untreated mice. This is the first evidence of the orchestral role of green tea extract abundant with epigallocatechin-3-gallate in improving ineffective erythropoiesis, iron dysregulation and oxidative stress in iron-overloaded β-thalassemic mice.

Green tea (Camellia sinensis) leaf extract maintained spermatozoa plasma membrane integrity, viability, and motility of mice (Mus musculus) exposed to cigarette smoke

Cigarette smoke chemicals caused oxidative stress by increasing Reactive Oxygen Species (ROS). ROS exposure could be neutralized by antioxidants, such as green tea (Camellia sinensis) leaf extract. This study aimed to determine the effect of green tea extract (GTE) on spermatozoa plasma membrane integrity, spermatozoa viability, and spermatozoa motility of mice (Mus musculus) exposed to cigarette smoke. Twenty-five mice were randomly divided into five groups. Group C- mice were given a placebo (1% Sodium carboxymethyl cellulose, Na-CMC). Group C+, T1, T2, and T3 mice were exposed to cigarette smoke and given 0, 20, 40, and 60 mg/kg BW GTE respectively. Cigarette smoke exposure used a clove cigarette per day. GTE in 1% Na-CMC solution was administered at 0.5 mL orally using a gastric probe. The treatment was conducted daily for 36 days, and on day 37, all mice were euthanized for spermatozoa evaluation. The results showed that all parameters evaluated in the C+ group were lower (p &lt;0.05) than in C- group. Administration of GTE in the T2 group increased (p &lt;0.05) all parameters compared to mice in the C+ group. However, administration of GTE to mice in the T3 group caused a decrease (p &lt;0.05) in all parameters than those of the T2 group and was not significantly different (p &gt;0.05) compared to those of the C+ group. It could be concluded that the administration of GTE at 40 mg/kg BW has maintained the spermatozoa plasma membrane integrity, spermatozoa viability, and spermatozoa motility of mice exposed to cigarette smoke.

The effect of green tea extract and oleogels on the physico-chemical properties and oxidative stability of short-dough biscuits during storage

The goal of this research was to analyze the possibility of replacing palm fat (PF) by a novel and “healthier” alternative – high-oleic rapeseed oil oleogels in short-dough biscuits in terms of the oxidative stability of lipids. Oleogelators ethylcellulose (EC), candelilla wax (CLX) and monoacyloglycerol (MAG) were used in the research. In order to decrease the oxidation of the oleogels green tea extract (GTE) was added. Biscuits with oleogels and GTE that had similar oxidative stability were used in the control with PF. The anisidine value of the lipid fractions obtained from biscuits with GTE was lower. The biggest changes during the storage of the fatty acids profile were found for the lipid fraction of biscuits with PF. However, according to the accelerated oxidative test the best stability index was that of biscuits with PF, this test also confirmed the positive effect of GTE on oxidative stability. The recipe composition influenced the color of the products. Biscuits with GTE had lower values of total color differences after 15 weeks of storage. Products with MAG oleogel had the highest values of breaking strength. Finally, biscuits with CLX had the most similar texture to the control sample with PF.

Effect of green tea polyphenols on the techno-functional and nutraceutical properties of himalayan rice (Mushk Budji)

This study explores the effect of green tea extract (GTE) on the properties of rice starch. The GTE was obtained using ultrasonication and incorporated in rice starch at different concentrations (5, 10, 15, and 20%) to make a green tea extract-starch complex (GTES). The morphology and structure of GTES were studied using scanning electron microscopy (SEM) and attenuated total reflectance fourier transform infra-spectroscopy (ATR-FTIR). With the increase in the concentration of GTE, GTES depicted a decrease in transmittance corresponding to the wavelength of 3300 cm−1, 2926 cm−1, and 1695 cm−1 representing O-H, C–H, and C–O stretching vibrations, respectively. Scanning electron microscopy (SEM) displayed an irregular, polyhedral and rough surface of GTES. The resistant starch (RS) and syneresis of GTES increased with the increase in the concentration of GTE. GTES displayed significantly low (p ≤ 0.05) amylose content, solubility, and swelling index. The nutraceutical potential of GTES was evaluated in terms of antioxidant potential which revealed that as the GTE concentration increased, the antioxidant potential increases. Overall the GTE-starch complex can be utilized to produce functional foods with improved RS and antioxidant potential.

Effect of administration of green tea extract on regeneration of the testicular parenchyma of Wistar rats submitted to heat stress

Objective: This study evaluated the effects of green tea extract (GTE) on the recovery of testicular parenchyma of adult Wistar rats submitted to heat stress (HS). Methodology: Animals (n=84) were distributed and treated, according to the experimental group (G1: unstressed and untreated; G2: stressed and untreated; G3: unstressed and treated; G4: stressed and treated). Results: The overall mean of testicular weight, epithelial height and tubular diameter were lower (P&lt;0.05) in G2 and G4, and day 60 presented a higher value (P&lt;0.05) to the two first parameters. The gonadosomatic index and the volumes of the seminiferous epithelium were lower (P&lt;0.05) in G2 and G4. The overall means of proper tunica volume was lower (P&lt;0.05) on day 30. The seminiferous tubule on days 15 and 30 presented lower values (P&lt;0.05) in G2 and G4, although with higher values (P&lt;0.05) on day 60. The volume of lymphatic space was higher (P&lt;0.05) in G2 and G4, being day 60 higher (P&lt;0.05) than day 15. Greater preservation and recovery of seminiferous epithelium occurred in G4, compared to G2. Conclusion: Thus, the GTE administration is an effective way to improving tissue recovery after testicular damage, induced by short-term heat.

Green tea extract exhibits antidiabetic effects partly through regulating dipeptidyl peptidase-4 expression in adipose tissue

The antidiabetic effects of green tea have been demonstrated in clinical trials and epidemiological studies. This study investigated the antidiabetic effects of green tea extract (GTE) and its underlying molecular mechanisms using a leptin receptor-deficient db/db mouse model (Leprdb/db). Treatment with GTE for 2 weeks improved glucose tolerance and insulin sensitivity in Leprdb/db mice. In addition, GTE treatment reduced the body weight and adiposity of Leprdb/db mice. Furthermore, GTE treatment reduced pro-inflammatory gene expression, including nuclear factor kappa B (NF-κB) in white adipose tissue (WAT), and also reduced dipeptidyl peptidase-4 (DPP4) expression levels in WAT as well as in the serum. The promoter region of Dpp4 contains the NF-κB binding site, and DPP4 was found to be a direct target of NF-κB. Consistently, in vitro treatment of cells with GTE or its main constituent epigallocatechin gallate reduced lipopolysaccharide-induced NF-κB/DPP4 expression in 3T3-L1 adipocytes and RAW264.7 cells. Overall, our data demonstrated that GTE exerts an anti-diabetic effect by regulating the expression levels of NF-κB and DPP4 in WAT.

Effect of Green Tea Extract Ingestion on Fat Oxidation during Exercise in the Menstrual Cycle: A Pilot Study.

In women, fat oxidation during exercise changes with the menstrual cycle. This study aimed to investigate the effect of green tea extract (GTE) ingestion on fat oxidation during exercise depending on the menstrual cycle phase. Ten women with regular menstrual cycles participated in this randomized, double-blind, crossover study. GTE or placebo was administered during the menstrual cycle’s follicular phase (FP) and luteal phase (LP). Participants cycled for 30 min at 50% maximal workload, and a respiratory gas analysis was performed. Serum estradiol, progesterone, free fatty acid, plasma noradrenaline, blood glucose, and lactate concentrations were assessed before, during, and after the exercise. Fat oxidation, carbohydrate oxidation, and the respiratory exchange ratio (RER) were calculated using respiratory gas. Fat oxidation during the exercise was significantly higher in the FP than in the LP with the placebo (p < 0.05) but did not differ between the phases with GTE. Carbohydrate oxidation, serum-free fatty acid, plasma noradrenaline, blood glucose, and lactate concentrations were not significantly different between the phases in either trial. Our results suggest that GTE ingestion improves the decrease in fat oxidation in the LP.