Administration Of Green Tea Extract Research Articles

Exploring the protective role of green tea extract against cardiovascular alterations induced by chronic REM sleep deprivation via modulation of inflammation and oxidative stress

BackgroundChronic Rapid eye movement (REM) sleep deprivation has been associated with various cardiovascular alterations, including disruptions in antioxidant defense mechanisms, lipid metabolism, and inflammatory responses. This study investigates the therapeutic potential of green tea extract (GTE) in mitigating these adverse effects.MethodsA total of 24 male Wistar albino rats were used in this study and divided into the control group (n = 8), Chronic-REM Sleep Deprivation (CRSD) Group (n = 8) and Chronic-REM SD + Green Tea 200 (CRSD + GTE200) Group (n = 8). After 21 days, a comprehensive analysis of paraoxonase (PON1), arylesterase (ARE), malondialdehyde (MDA), glutathione (GSH), nitric oxide (NOx), proinflammatory cytokines, and lipid profiles in aortic tissue, heart tissue, and serum was conducted in a sleep-deprived rat model.ResultsChronic REM sleep deprivation led to a significant reduction in PON1 and ARE levels in aortic (p = 0.046, p = 0.035 respectively) and heart tissues (p = 0.020, p = 0.019 respectively), indicative of compromised antioxidant defenses. MDA levels increased, and NOx levels decreased, suggesting oxidative stress and impaired vascular function. Lipid profile alterations, including increased triglycerides and total cholesterol, were observed in serum. Elevated levels of inflammatory cytokines (IL-6 and TNF-alpha) further indicated an inflammatory response (p = 0.007, p = 0.018 respectively). GTE administration demonstrated a protective role, restoring antioxidant enzyme levels, suppressing lipid peroxidation, and improving NOx levels.ConclusionThese findings suggest the therapeutic potential of GTE in alleviating the cardiovascular impairments of chronic REM sleep deprivation, emphasizing its candidacy for further clinical exploration as a natural intervention in sleep-related disorders and associated cardiovascular risks.

Green tea extract suppresses airway inflammation via oxidative stress-driven MAPKs/MMP-9 signaling in asthmatic mice and human airway epithelial cells.

The anti-inflammatory effect of green tea extract (GTE) has been confirmed in asthmatic mice, however, the pharmacological mechanism is not fully elucidated. To investigate the therapeutic efficacy of GTE in asthma and identify specific pathways, murine model of allergic asthma was established by ovalbumin (OVA) sensitization and the challenge for 4 weeks, with oral treatment using GTE and dexamethasone (DEX). Inflammatory cell counts, cytokines, OVA-specific IgE, airway hyperreactivity, and antioxidant markers in the lung were evaluated. Also, pulmonary histopathological analysis and western blotting were performed. In vitro, we established the model by stimulating the human airway epithelial cell line NCI-H292 using lipopolysaccharide, and treating with GTE and mitogen-activated protein kinases (MAPKs) inhibitors. The GTE100 and GTE400 groups showed a decrease in airway hyperresponsiveness and the number of inflammatory cells in the bronchoalveolar lavage fluid (BALF) compared to the OVA group. GTE treatment also reduced interleukin (IL)-13, IL-5, and IL-4 levels in the BALF, and OVA-specific immunoglobulin E levels in the serum compared to those in the OVA group. GTE treatment decreased OVA-induced mucus secretion and airway inflammation. In addition, GTE suppressed the oxidative stress, and phosphorylation of MAPKs, which generally occurs after exposure to OVA. GTE administration also reduced matrix metalloproteinase-9 activity and protein levels. GTE effectively inhibited asthmatic respiratory inflammation and mucus hyperproduction induced by OVA inhalation. These results suggest that GTE has the potential to be used for the treatment of asthma.

Amelioration of Functional, Metabolic, and Morphological Deterioration in the Retina following Retinal Detachment by Green Tea Extract.

Retinal detachment (RD) can result in the loss of photoreceptors that cause vision impairment and potential blindness. This study explores the protective effects of the oral administration of green tea extract (GTE) in a rat model of RD. Various doses of GTE or epigallocatechin gallate (EGCG), the most active ingredient in green tea catechins, were administered to Sprague Dawley (SD) rats with experimentally induced retinal detachment. The rats received sub-retinal injections of hyaluronic acid (0.1%) to induce RD and were given different doses of GTE and EGCG twice daily for three days. Notably, a low dose of GTE (142.9 mg/kg) caused significantly higher signal amplitudes in electroretinograms (ERGs) compared to higher GTE doses and any doses of EGCG. After administration of a low dose of GTE, the outer nuclear layer thickness, following normalization, of the detached retina reduced to 82.4 ± 8.2% (Mean ± SEM, p < 0.05) of the thickness by RD treatment. This thickness was similar to non-RD conditions, at 83.5 ± 4.7% (Mean ± SEM) of the thickness following RD treatment. In addition, the number of TUNEL-positive cells decreased from 76.7 ± 7.4 to 4.7 ± 1.02 (Mean ± SEM, p < 0.0001). This reduction was associated with the inhibition of apoptosis through decreased sphingomyelin levels and mitigation of oxidative stress shown by a lowered protein carbonyl level, which may involve suppression of HIF-1α pathways. Furthermore, GTE showed anti-inflammatory effects by reducing inflammatory cytokines and increasing resolving cytokines. In conclusion, low-dose GTE, but not EGCG, significantly alleviated RD-induced apoptosis, oxidative stress, inflammation, and energy insufficiency within a short period and without affecting energy metabolism. These findings suggest the potential of low-dose GTE as a protective agent for the retina in RD.

Therapeutic Potency of Camellia sinensis Extract on Neurochemical and Oxidative Changes Correlates to Autistic Disorder in Rat Pups Model

Background: Prenatal exposure to valproate is capable of inducing experimental autism in rat pups. This study aimed to investigate the role of Camellia sinensis green tea extract (GTE) in ameliorating the neurochemical changes induced by autism. Methods: Pregnant rats were treated with a single intraperitoneal dose of sodium valproate (600 mg/kg) on the 12.5th gestational day. The treatment with GTE (300 mg/kg) orally in autistic rat pups at postnatal day 15 for 20 days. Result: Induction of autism resulted in a significant decrease in the cerebellum and cortical 5-HT, DA, NE, GABA, glycine and taurine and a decrease in brain cholesterol and antioxidants enzymes (GSH, SOD and CAT) at P less than 0.05. However, it showed a significant increase in MAO, AChE, glutamate, aspartate, serine and lipid peroxidation in addition to elevation in inflammatory biomarkers in brain tissue. Treatment with GTE extract showed significant decrease in AChE and MAO in addition to reduction in the excitatory amino acid GABA in brain tissue which in accordance resulted in marked elevation in cerebellar and cortical monoamine contents. Furthermore, administration of GTE improved the antioxidant defence system in cerebellum and cerebral cortex by activating the level of GSH, SOD and CAT. These results are accompanied by marked reduction in oxidative stress biomarker (NO and MDA) and lowering in the level of TNF-α and IL-6. In conclusion, it could be stated that GTE exerts an ameliorative effect on autistic rat pups possibly due to antioxidant and anti-inflammatory effects and could be effective in the management of autism.

Toxicological Effect of Green Tea (Camelia sinensis) on Haematological Parameters in Wistar Rats

Introduction: Green tea, derived from the leaves of Camellia sinensis, has gained significant attention due to its potential health benefits. It contains various bioactive compounds, such as polyphenols, flavonoids, and catechins, which have antioxidant, anti-inflammatory, and anticancer properties. Despite its widespread consumption and positive reputation, limited information is available regarding the potential toxicological effects of green tea. In this study, the toxicological impact of green tea extract on haematological parameters was investigated using Wistar rats as an animal model.&#x0D; Method: Forty-eight adult male rats were randomly divided into four groups (n=12 per group). The control group received a vehicle solution, while the treatment groups were orally administered different doses of green tea extract (low dose: 100 mg/kg, moderate dose: 200 mg/kg, high dose: 400 mg/kg) once daily for 28 consecutive days. Haematological analysis was performed at baseline (day 0) and on days 7, 14, 21, and 28 of the study. Blood samples were collected from the retro-orbital plexus under light isoflurane anaesthesia, and various haematological parameters were assessed using automated Hematology analyzers.&#x0D; Results: The results of the haematological analysis showed that the administration of green tea extract did not significantly affect haemoglobin levels, packed cell volume, red blood cell count, eosinophil count, lymphocyte count, and neutrophil count compared to the control group throughout the study period. However, the white blood cell (WBC) count and its differential count exhibited some variations among the treatment groups. The low and moderate doses of green tea extract resulted in a slight increase in the WBC count compared to the control group, although the difference was not statistically significant. On the other hand, the high dose of green tea extract led to a slight decrease in the WBC count compared to the control group. Regarding platelet count, the low and moderate doses of green tea extract resulted in a significant increase compared to the control group. In contrast, the high dose of green tea extract caused a significant decrease in platelet count.&#x0D; Conclusions: Based on the findings of this study, it can be concluded that the administration of green tea extract did not have significant adverse effects on the assessed haematological parameters in Wistar rats, except for some minor variations in the WBC count and platelet count at higher doses. These results suggest that green tea consumption may not cause significant haematological toxicity in rats. However, further studies are warranted to evaluate the long-term effects and safety of green tea consumption in humans.

Green Tea Extract has a Protective Effect on Leptin and Lipid Profile Levels Due to the Induction of Depot Medroxyprogesterone Acetate.

Depot medroxyprogesterone acetate (DMPA) is a progesterone derivative synthesized in the laboratory. This substance has the ability to suppress ovulation, induce endometrial shrinkage, and even affect the hypothalamic-pituitary-gonadal axis in the reproductive system. The purpose of this study was to investigate the effects of administration of green tea extract on reducing visceral fat, increasing leptin levels, and improving the lipid profile in female rats injected with depot medroxyprogesterone acetate (DMPA). This study was to look into the effects of green tea extract administration on visceral fat reduction, leptin levels, and lipid profile improvement as a result of DMPA administration. Analysis of HDL and LDL levels was performed by spectrophotometry. DMPA induced a significant increase in leptin levels compared with the control group (p 0.05). All doses of green tea extract can reduce this increase, with the highest doses reaching levels comparable to the control group (p > 0.05). DMPA significantly increased LDL levels compared to the control group (p < 0.05), and the highest green tea extract dose restored levels similar to the control group. DMPA triggered a decrease in HDL level that was significantly different from the control group (p < 0.05). The first dose of green tea extract can achieve HDL levels comparable to the control group (p > 0.05). It was concluded that green tea extract can protect the metabolic status through decreased leptin and an improvement of the lipid profile induced by DMPA.

LITERATURE REVIEW: GREEN TEA EXTRACT POTENCY (Camellia sinensis) in LOWERING GLYCEMIC INDEX OF A WISTAR RAT

The aim of the research is to determine the potency of green tea extract (Camellia sinesis) to decrease blood glucose levels in diabetes mellitus model Wistar rats. A systematic review based on PRISMA-P 2020 with a literature search strategy using Google Scholar, PubMed, Science Direct, and Scopus databases. Literature quality was assessed using the JBI Critical Appraisal Checklist which produced 12 comprehensive potential literatures based on selection with inclusion and exclusion criteria. Analysis of 12 journals found that there were 11 studies that showed a significant decrease in blood glucose levels after administration of green tea extract (Camellia sinensis). Green tea extract (Camellia sinensis) has the potential to reduce blood glucose levels in Wistar strain rats with diabetes mellitus model. The mechanism underlying the antihyperglycemic effect is proven to be due to the protective and antidiabetic effects of the compounds contained in green tea extract, especially the flavonoid group, namely catechins. The minimum dose of green tea extract observed to cause an antihyperglycemic effect in experimental animals was 40 mg/kgBW.

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.

In Vivo Treatment with a Standardized Green Tea Extract Restores Cardiomyocyte Contractility in Diabetic Rats by Improving Mitochondrial Function through SIRT1 Activation.

Background. Green tea catechins are known to promote mitochondrial function, and to modulate gene expression and signalling pathways that are altered in the diabetic heart. We thus evaluated the effectiveness of the in vivo administration of a standardized green tea extract (GTE) in restoring cardiac performance, in a rat model of early streptozotocin-induced diabetes, with a focus on the underlying mechanisms. Methods. Twenty-five male adult Wistar rats were studied: the control (n = 9), untreated diabetic animals (n = 7) and diabetic rats subjected to daily GTE administration for 28 days (n = 9). Isolated ventricular cardiomyocytes were used for ex vivo measurements of cell mechanics and calcium transients, and molecular assays, including the analysis of functional protein and specific miRNA expression. Results. GTE treatment induced an almost complete recovery of cardiomyocyte contractility that was markedly impaired in the diabetic cells, by preserving mitochondrial function and energy availability, and modulating the expression of the sarcoplasmic reticulum calcium ATPase and phospholamban. Increased Sirtuin 1 (SIRT1) expression and activity substantially contributed to the observed cardioprotective effects. Conclusions. The data supported the hypothesis that green tea dietary polyphenols, by targeting SIRT1, can constitute an adjuvant strategy for counteracting the initial damage of the diabetic heart, before the occurrence of diabetic cardiomyopathy.

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.

Exposure of Fexofenadine, but Not Pseudoephedrine, Is Markedly Decreased by Green Tea Extract in Healthy Volunteers.

Green tea (GT) alters the disposition of a number of drugs, such as nadolol and lisinopril. However, it is unknown whether GT affects disposition of hydrophilic anti‐allergic drugs. The purpose of this study was to investigate whether pharmacokinetics of fexofenadine and pseudoephedrine are affected by catechins, major GT components. A randomized, open, 2‐phase crossover study was conducted in 10 healthy Japanese volunteers. After overnight fasting, subjects were simultaneously administered fexofenadine (60 mg) and pseudoephedrine (120 mg) with an aqueous solution of green tea extract (GTE) containing (−)‐epigallocatechin gallate (EGCG) of ~ 300 mg or water (control). In vitro transport assays were performed using HEK293 cells stably expressing organic anion transporting polypeptide (OATP)1A2 to evaluate the inhibitory effect of EGCG on OATP1A2‐mediated fexofenadine transport. In the GTE phase, the area under the plasma concentration‐time curve and the amount excreted unchanged into urine for 24 hours of fexofenadine were significantly decreased by 70% (P < 0.001) and 67% (P < 0.001), respectively, compared with control. There were no differences in time to maximum plasma concentration and the elimination half‐life of fexofenadine between phases. Fexofenadine was confirmed to be a substrate of OATP1A2, and EGCG (100 and 1,000 μM) and GTE (0.1 and 1 mg/mL) inhibited OATP1A2‐mediated uptake of fexofenadine. On the contrary, the concomitant administration of GTE did not influence the pharmacokinetics of pseudoephedrine. These results suggest that intake of GT may result in a markedly reduced exposure of fexofenadine, but not of pseudoephedrine, putatively by inhibiting OATP1A2‐mediated intestinal absorption.

The influence of green tea extract on nintedanib’s bioavailability in patients with pulmonary fibrosis

Nintedanib is an oral small-molecule kinase inhibitor and first-line treatment for idiopathic pulmonary fibrosis. Nintedanib is a substrate of the drug efflux transporter ABCB1. Green tea flavonoids --especially epigallocatechin gallate (EGCG)-- are potent ABCB1 modulators. We investigated if concomitant administration of green tea extract (GTE) could result in a clinically relevant herb-drug interaction.Patients were randomized between A-B and B-A, with A being nintedanib alone and B nintedanib with GTE. Both periods lasted 7 days, in which nintedanib was administered twice daily directly after a meal. In period B, patients additionally received capsules with GTE (500 mg BID, >60% EGCG). Pharmacokinetic sampling for 12 h was performed at day 7 of each period. Primary endpoint was change in geometric mean for the area under the curve (AUC0–12 h). A linear mixed model was used to analyse AUCs and maximal concentration (Cmax).In 26 included patients, the nintedanib AUC0–12 h was 21% lower (95% CI −29% to −12%; P < 0.001) in period B (with GTE) compared to period A. Cmax did not differ significantly between periods; − 14% (95% CI −29% to +4%; P = 0.12). The detrimental effect was predominant in patients with the ABCB1 3435 C>T wild type variant. No differences in toxicities were observed.Exposure to nintedanib decreased with 21% when administered 60 min after GTC for only 7 days. This is a statistically significant interaction which could potentially impair treatment efficacy. Before patients and physicians should definitely be warned to avoid this combination, prospective clinical validation of an exposure-response relationship is necessary.

Effect of Green Tea Extract and Soy Isoflavones on the Pharmacokinetics of Rosuvastatin in Healthy Volunteers.

Background and AimGreen tea and soy products are extensively consumed in daily life. Research has shown that green tea catechins and soy isoflavones may influence the activity of drug metabolizing enzymes and drug transporters. We examined whether regular consumption of green tea extract or soy isoflavones affected the pharmacokinetics of a single dose of rosuvastatin in healthy subjects and whether any interactions were influenced by the polymorphism in the drug transporter ABCG2.Study DesignThis was an open-label, three-phase randomized crossover study with single doses of rosuvastatin.MethodsHealthy Chinese male subjects were given a single dose of rosuvastatin 10 mg on 3 occasions: 1. without herbs; 2. with green tea extract; 3. with soy isoflavone extract. The green tea and soy isoflavone extract were given at a dose containing EGCG 800 mg once daily or soy isoflavones−80 mg once daily for 14 days before statin dosing and at the same time as the statin dosing with at least 4-weeks washout period between phases.ResultsTwenty healthy male subjects completed the study and the intake of green tea extract significantly reduced the systemic exposure to rosuvastatin by about 20% reducing AUC0−24h from [geometric mean (% coefficient of variation)] 108.7 (28.9) h·μg/L to 74.1 (35.3) h·μg/L and Cmax from 13.1 (32.2) μg/L to 7.9 (38.3) μg/L (P < 0.001 for both), without affecting the elimination half-life. The ABCG2 421C>A polymorphism had a significant effect on rosuvastatin exposure but no impact on the interaction with green tea. Soy isoflavones had no significant effect on rosuvastatin pharmacokinetics.ConclusionThis study showed that repeated administration of green tea extract significantly reduced the systemic exposure of rosuvastatin in healthy volunteers. These effects might be predicted to either reduce or increase the lipid-lowering effect of rosuvastatin depending on the mechanism of the effect.

Green Tea Extract Increases Soluble RAGE and Improves Renal Function in Patients with Diabetic Nephropathy.

One of the proposed mechanisms for the development of diabetic nephropathy (DN) is the increase of end products of advanced glycosylation (AGEs), which bind to its receptor (RAGE), favoring nephron cellular damage. An isoform of this receptor is soluble RAGE (sRAGE), which can antagonize AGE-altered intracellular signaling. It has known that green tea extract (GTE) increases the expression of sRAGE, but it is unknown whether this could improve kidney function. The objective of this study was to evaluate the effect of the administration of GTE on the concentrations of sRAGE, renal function, and metabolic profile in patients with type 2 diabetes mellitus (T2DM) and DN. A randomized, double-blinded, placebo-controlled clinical trial was carried out in 39 patients who received GTE (400 mg every 12 h) or placebo for 3 months. sRAGE levels, renal function, and metabolic parameters were determined before and after the intervention. In the GTE group, there were statistically significant increase on sRAGE (320.55 ± 157.63 pg/mL vs. 357.59 ± 144.99 pg/mL; P = .04) and glomerular filtration rate (GFR; 66.44 ± 15.17 mL/min/1.73 m2 vs. 71.70 ± 19.33 mL/min/1.73 m2; P = .04), and a statistically significant decrease in fasting serum glucose (7.62 ± 3.00 mmol/L vs. 5.86 ± 1.36 mmol/L; P ≤ .01) and triacylglycerols (1.91 ± 0.76 mmol/L vs. 1.58 ± 0.69; P = .02). Administration of GTE increases the serum concentration of sRAGE and the GFR and decreases the concentration of fasting serum glucose and triacylglycerols. The study was registered in ClinicalTrials.gov with the identifier NCT03622762.

(Poly)phenol toxicity in vivo following oral administration: A targeted narrative review of (poly)phenols from green tea, grape, and anthocyanin-rich extracts.

Fruit- and vegetable-derived (poly)phenols are secondary plant metabolites that may have beneficial effects on human health when consumed regularly. Recent years have seen rapid growth in both consumer demand for and research interest in (poly)phenol-rich dietary supplements, natural colorants, and functional foods. As these products continue to enter the marketplace and (poly)phenol intake patterns change from traditional food products to these sources, attention must be paid to the potential for toxicity from consuming elevated doses of (poly)phenols. To date, much remains unknown regarding the safety of high doses of (poly)phenols, especially in vivo. In this targeted narrative review, we summarize evidence from in vivo investigations of (poly)phenol toxicity after oral administration of green tea extracts, grape-derived phenolics, and anthocyanin-rich extracts. There is limited evidence of overt toxicity from oral ingestion of these (poly)phenol-rich sources, though more research on the safety of high doses-as well as defining what constitutes a "high" dose of both individual and complex mixtures of (poly)phenols-is needed before these observations can be used to create dietary guidance for consumers.

Green Tea Extract Concurrent with an Oral Nutritional Supplement Acutely Enhances Muscle Microvascular Blood Flow without Altering Leg Glucose Uptake in Healthy Older Adults.

Postprandial macro- and microvascular blood flow and metabolic dysfunction manifest with advancing age, so vascular transmuting interventions are desirable. In this randomised, single-blind, placebo-controlled, crossover trial, we investigated the impact of the acute administration of green tea extract (GTE; containing ~500 mg epigallocatechin-3-gallate) versus placebo (CON), alongside an oral nutritional supplement (ONS), on muscle macro- and microvascular, cerebral macrovascular (via ultrasound) and leg glucose/insulin metabolic responses (via arterialised/venous blood samples) in twelve healthy older adults (42% male, 74 ± 1 y). GTE increased m. vastus lateralis microvascular blood volume (MBV) at 180 and 240 min after ONS (baseline: 1.0 vs. 180 min: 1.11 ± 0.02 vs. 240 min: 1.08 ± 0.04, both p < 0.005), with MBV significantly higher than CON at 180 min (p < 0.05). Neither the ONS nor the GTE impacted m. tibialis anterior perfusion (p > 0.05). Leg blood flow and vascular conductance increased, and vascular resistance decreased similarly in both conditions (p < 0.05). Small non-significant increases in brachial artery flow-mediated dilation were observed in the GTE only and middle cerebral artery blood flow did not change in response to GTE or CON (p > 0.05). Glucose uptake increased with the GTE only (0 min: 0.03 ± 0.01 vs. 35 min: 0.11 ± 0.02 mmol/min/leg, p = 0.007); however, glucose area under the curve and insulin kinetics were similar between conditions (p > 0.05). Acute GTE supplementation enhances MBV beyond the effects of an oral mixed meal, but this improved perfusion does not translate to increased leg muscle glucose uptake in healthy older adults.

Potential role of green tea extract and epigallocatechin gallate in preventing bisphenol A-induced metabolic disorders in rats: Biochemical and molecular evidence

BackgroundBisphenol A (BPA) is an artificial chemical widely used in the production of polycarbonate plastics and epoxy resins. Accumulating evidence indicates that BPA exposure is associated with metabolic disorders. The beneficial effects of green tea and epigallocatechin gallate (EGCG), major catechin present in green tea, on alleviating BPA-induced metabolic disorders have been shown in various studies. PurposeProtective effects of green tea extract and EGCG on BPA-induced metabolic disorders and possible underlying mechanisms were investigated. MethodsRats were randomly divided into control, green tea extract (50 and 100 mg/kg, IP), EGCG (20 and 40 mg/kg, IP), BPA (10 mg/kg, gavage), BPA plus green tea extract (25, 50, and 100 mg/kg, IP), BPA plus EGCG (10, 20, and 40 mg/kg, IP), and BPA plus vitamin E (200 IU/kg, IP). After two months, body weight, blood pressure, biochemical blood tests, hepatic malondialdehyde (MDA), and glutathione (GSH) were assessed. By enzyme-linked immunosorbent assay, serum levels of insulin, leptin, adiponectin, TNFα, and IL-6, and by western blotting, hepatic insulin signaling (IRS-1, PI3K, Akt) were measured. ResultsBPA increased body weight, blood pressure, and MDA, decreased GSH, elevated serum levels of low-density lipoprotein cholesterol, total cholesterol, triglyceride, glucose, insulin, leptin, TNFα, IL-6, and liver enzymes including alanine aminotransferase and alkaline phosphatase, and lowered high-density lipoprotein cholesterol and adiponectin levels. In western blot, decreased phosphorylation of IRS-1, PI3K, and Akt was obtained. Administration of green tea extract, EGCG, or vitamin E with BPA reduced the detrimental effects of BPA. ConclusionThese findings indicate that green tea extract and EGCG can be effective in preventing or reducing metabolic disorders induced by BPA linked to their antioxidant and anti-inflammatory activity, regulating the metabolism of lipids, and improving insulin signaling pathways.

Microencapsulation of green tea extract (Camellia sinensis var assamica) to increase the bioaccessibility of bioactive compounds and gastroprotective effects

Green tea has polyphenols and flavonols as its main bioactive constituents, nonetheless, these compounds present sensitivity to external factors. Microencapsulation is a technique that can be used to protect the main bioactive constituents of green tea. This research was carried out aiming to obtain scientific evidence on the in vitro simulated gastrointestinal digestion (SGD) of the green tea extract (Camellia sinensis var assamica) microencapsulated with cashew gum and maltodextrin and the gastroprotective action of these microcapsules in an experimental model of gastric lesion induced by ethanol in mice. The microencapsulation (GTM) process was able to increase the bioaccessible percentage of polyphenols and antioxidant activity of green tea after SGD in vitro, resulting in values equal to 28.2 and 24.2%, respectively. On the other hand, the bioaccessible percentage obseverd for green tea extract (GTE) was equal to 25.9 and 14% for the phenolic compounds and antioxidant activity, respectively. It was verified an action dose-way dependent related to the administration of GTE and GTM and their gastroprotective effects. The concentration of 10 mg/kg presented effective protection of the gastric mucosa, providing the maintenance of glutathione in the tissues after the alcoholic induced lesion and in the same concentration, the samples were able to avoid the lipidic peroxidation due to the reduction of malonaldehyde levels in the tissues. In general, GTM presented a great potential to contribute to the obtention of new products enriched with green tea, presenting also gastroprotective effect being beneficial to the consumer's health.

Effect of prenatal exposure of green tea extract on the developing central nervous system of rat fetuses; histological, immune-histochemical and ultrastructural studies.

Although, several health benefits were associated with green tea, these effects may be beneficial up to a certain dose. Higher doses of green tea may cause several adverse effects. So, there is a need to test the potential negative effects of green tea during pregnancy. This study was designated to evaluate the effect of prenatal exposure of green tea extract on the development of the central nervous system of 20-day old rat fetuses. The pregnant rats were divided into 4 groups; the control group (received distal water) and the other 3 groups received green tea extract at different doses (200, 600 & 1000 mg/kg/day, respectively) from the 6th to 15th day of gestation i.e., during the organogenesis phase of development. Cerebral cortex, cerebellum and spinal cord specimens were subjected to histological, immunohistochemical and ultrastructure investigations. The body weight of both mothers and fetuses was significantly decreased in the groups that received 600 and 1000 mg green tea extract. Also, the neuronal tissues displayed various signs of degeneration which were evident with the 600 and 1000 mg doses. Green tea extract also increases the glial fibrillary acidic protein (GFAP) and decreases the proliferating cell nuclear antigen (PCNA) which were directly proportional with increasing the dose. Administration of green tea extract during rat organogenesis period induced various histological, immunohistochemical and ultrastructural degenerative changes in the cerebral cortex, cerebellum and spinal cord of 20-day old rat fetuses. These deleterious changes were directly proportional to increasing the green tea extract dose. Thus, it should be stressed that the effect of green tea is dose-dependent and therefore it can be either beneficial or adverse.

55. PREVENTION OF LIPOPOLYSACCHARIDE-INDUCED ENDOTHELIAL DYSFUNCTION IN HUVEC CELLS: COMPARISON BETWEEN DECAFFEINATED LIGHT ROASTED GREEN COFFEE EXTRACT AND GREEN TEA EXTRACT

Background: Endothelial dysfunction contributes to hypertension complications. Coffee consumption still gave rise to conflicting data regarding its preventive action on endothelial dysfunction. Objective: This study aimed to compare the effect of decaffeinated light roasted green coffee extract (GCE) and green tea extract (GTE) on endothelial dysfunction biomarkers in lipopolysaccharide (LPS) treated HUVEC cells. Methods: The HUVEC cells were maintained in M200 medium containing 2% LSGS and 1% penicillin streptomycin. The cells were seeded in 6-well plate with 1 × 106 cells/well density. At 80% confluency, the cells were treated for 48 hours with either GCE or GTE at the dose of 125, 250, and 500 μg/mL and 1 mg/mL of Simvastatin. The cells were then treated with 1 mg/mL LPS for another 48 hours. Finally the cells were harvested and the gene expression of NOX-1, TNFα, ENOS, INOS, and MCP-1 were analysed by RT-PCR method Results: The gene expression of NOX-1, TNFα, INOS, and MCP-1 were significantly lower in all GCE, GTE, and simvastatin group (P &lt; 0.000). The ENOS gene expression were significantly higher in all GCE and GTE group (P &lt; 0.000) compared to LPS treated HUVEC. In general, the administration of GCE significantly improved the endothelial dysfunction biomarkers compared to that of GTE administration in the same doses. Administration of GCE 250 μg/mL resulted in significantly lower NOX-1, TNFα, INOS, and MCP-1 expression (P &lt; 0.000) and significantly higher ENOS expression (P &lt; 0.000) compared to those of GCE 250 μg/mL administration Conclusion: GCE administration significantly prevented endothelial dysfunction through improvement of NOX-1, TNFα, ENOS, INOS, and MCP-1 compared to that of GTE administration in LPS treated HUVEC cells.