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result(s) for
"Catechins"
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Water-Mediated Synthesis of -N-phenethylacrylamide, a Caffeic Acid Phenethyl Amide Analogue
2024
Caffeic acid phenethyl ester (CAPE) is a phenolic natural product with diverse biological activities, notably anticancer properties. However, its ester group is metabolically unstable. The amide derivative, CAPA, offers improved metabolic stability to esterases but still possesses a metabolically liable catechol group. In this work, we describe the synthesis of a novel CAPA analogue in which the catechol is replaced with a benzimidazole bioisostere via a water-mediated Wittig reaction.
Journal Article
Health effects of green tea catechins in overweight and obese men: a randomised controlled cross-over trial
2011
Regular consumption of green tea may be cardioprotective. In the present study we investigated the health effects of dietary supplementation with green tea catechins and the potential modifying effect of the catechol-O-methyltransferase (COMT) Val/Met genotype. Subjects (sedentary males, aged 40–69 years, with BMI ≥ 28 and ≤ 38 kg/m2) were randomly assigned to consume decaffeinated green tea extract (DGT; 530 mg containing about 400 mg total catechins/capsule, twice daily) and placebo in a complete cross-over design. Ambulatory blood pressure and biomarkers of metabolic function (cholesterol, TAG, glucose and insulin) were measured at weeks 0 and 6. Although a marked increase in the concentration of plasma epigallocatechin gallate (EGCG), urinary epigallocatechin (EGC) and urinary 4′-O-methyl EGC was found after DGT treatment, no effect on blood pressure or biomarkers of metabolic function was observed. However, a period × treatment interaction (P < 0·05) was detected for body-weight change. Despite a similar increase in estimated energy intake during intervention period 1, body weight decreased by 0·64 (sd 2·2) kg and increased by 0·53 (sd 1·9) kg in the DGT and placebo groups, respectively (P = 0·025), suggesting a protective effect of green tea catechins on weight gain. Additionally, the COMT Val/Met genotype influenced urinary accumulation of EGC and 4′-O-methyl EGC (P < 0·01). Mean concentrations were lower in individuals homozygous for the high-activity G-allele, possibly reflecting increased metabolic flux and a more rapid conversion to downstream metabolic species, compared with individuals carrying at least one copy of the low-activity A-allele. Additional studies are needed to confirm these findings and further explore the modifying effect of genotype.
Journal Article
Evaluating the Effect of Epigallocatechin Gallate (EGCG) in Reducing Folate Levels in Reproductive Aged Women by MTHFR and DHFR Genotype in Combination With Letrozole or Clomiphene
2025
Previous epidemiological studies have suggested that green tea catechins, including Epigallocatechin‐3‐gallate (EGCG), the most abundant polyphenol in green tea, may be associated with reduced serum folate levels. This is of particular interest as women of childbearing age may be consuming EGCG from tea, dietary supplements, or involved in active clinical trials studying EGCG or green tea extract. EGCG was reported to shrink uterine fibroids in preclinical and clinical studies. This observation led to the development of a multicenter NICHD‐funded clinical trial to evaluate the safety of EGCG for treating women with fibroids and unexplained infertility (NCT04177693). To answer the question of whether green tea extract standardized to EGCG led to a reduction in folate, 39 women aged ≥ 18 to ≤ 40 years, with/without uterine fibroids, were evaluated. These women were randomized to receive either EGCG, EGCG + clomiphene, or EGCG + letrozole for 30 days. A daily dose of 720 mg of highly characterized green tea extract containing EGCG was used. Participants were genotyped for polymorphisms at positions 677 and 1298 in MTHFR and for the −19 bp deletion polymorphism of DHFR. During the intervention with EGCG, folate levels remained in the normal range in all subjects. Our data suggest that in reproductive‐age women, a 30‐day course of EGCG 720 mg daily taken alone or in combination with clomiphene citrate or letrozole (for 5 days) is well‐tolerated and is not associated with folate deficiency even in the presence of MTHFR and/or DHFR polymorphisms known to negatively impact folate synthesis. Trial Registration: Clinical trial: NCT 01311869
Journal Article
A Pilot Study to Evaluate the Safety and Efficacy of an Oral Dose of (−)-Epigallocatechin-3-Gallate–Rich Polyphenon E in Patients With Mild to Moderate Ulcerative Colitis
by
Dryden, Gerald W.
,
McClain, Craig J.
,
Qazzaz, Hassan H.
in
Administration, Oral
,
Adolescent
,
Adult
2013
Green tea and its main polyphenolic component, (−)-epigallocatechin-3-gallate (EGCG), exert powerful anti-inflammatory effects that are protective against both inflammatory diseases and cancer. Research with animal and human cell lines provide plausible support for these claims. Poor absorption results in low systemic bioavailability of EGCG after oral administration but high colonic mucosal exposure.MethodsPatients with mild to moderate ulcerative colitis (UC) were randomized to daily doses of oral Polyphenon E (400 mg or 800 mg of total EGCG daily, administered in split doses) or placebo in a double-blinded, placebo-controlled pilot study. Response was measured by the UC disease activity index and the inflammatory bowel disease questionnaire on day 56.ResultsTwenty patients were randomized to active therapy or placebo in a 4:1 ratio. Nineteen subjects received >1 dose of study medication (15 Polyphenon E, 4 placebo). The mean UC disease activity index score at study entry was 6.5 ± 1.9 in the treatment group and 7.3 ± 1.7 in the placebo group. After 56 days of therapy, the response rate was 66.7% (10 of 15) in the Polyphenon E group and 0% (0 of 4) in the placebo group (P = 0.03). The active treatment remission rate was 53.3% (8 of 15) compared with 0% (0 of 4) for placebo (P = 0.10). Polyphenon E treatment resulted in only minor side effects.ConclusionsAdministration of Polyphenon E resulted in a therapeutic benefit for patients who were refractory to 5-aminosalicylic and/or azathioprine. This agent holds promise as a novel option for the treatment of patients with UC with mild to moderately active disease.
Journal Article
Epigallocatechin Gallate (EGCG): Pharmacological Properties, Biological Activities and Therapeutic Potential
by
Rigano, Daniela
,
Maresca, Viviana
,
Bontempo, Paola
in
Animals
,
Anti-Inflammatory Agents - chemistry
,
Anti-Inflammatory Agents - pharmacology
2025
Epigallocatechin gallate (EGCG), the predominant catechin in green tea, comprises approximately 50% of its total polyphenol content and has garnered widespread recognition for its significant therapeutic potential. As the principal bioactive component of Camellia sinensis, EGCG is celebrated for its potent antioxidant, anti-inflammatory, cardioprotective, and antitumor properties. The bioavailability and metabolism of EGCG within the gut microbiota underscore its systemic effects, as it is absorbed in the intestine, metabolized into bioactive compounds, and transported to target organs. This compound has been shown to influence key physiological pathways, particularly those related to lipid metabolism and inflammation, offering protective effects against a variety of diseases. EGCG’s ability to modulate cell signaling pathways associated with oxidative stress, apoptosis, and immune regulation highlights its multifaceted role in health promotion. Emerging evidence underscores EGCG’s therapeutic potential in preventing and managing a range of chronic conditions, including cancer, cardiovascular diseases, neurodegenerative disorders, and metabolic syndromes. Given the growing prevalence of lifestyle-related diseases and the increasing interest in natural compounds, EGCG presents a promising avenue for novel therapeutic strategies. This review aims to summarize current knowledge on EGCG, emphasizing its critical role as a versatile natural bioactive agent with diverse clinical applications. Further exploration in both experimental and clinical settings is essential to fully unlock its therapeutic potential.
Journal Article
The combined effect of green tea and α-glucosyl hesperidin in preventing obesity: a randomized placebo-controlled clinical trial
2021
Green tea, a widely consumed beverage in Asia, contains green tea catechins effective against obesity, especially epigallocatechin-3-
O
-gallate (EGCG), but must be consumed in an impractically huge amount daily to elicit its biological effect. Meanwhile, citrus polyphenols have various physiological effects that could enhance EGCG functionality. Here we investigated the antiobesity effect of a combination of EGCG and α-glucosyl hesperidin, a citrus polyphenol, at doses that have not been previously reported to exert antiobesity effects by themselves in any clinical trial. In a randomized, placebo-controlled, double-blinded, and parallel-group-designed clinical trial, 60 healthy Japanese males and females aged 30–75 years consumed green tea combined with α-glucosyl hesperidin (GT-gH), which contained 178 mg α-glucosyl hesperidin and 146 mg EGCG, for 12 weeks. Physical, hematological, blood biochemical, and urine examinations showed that GT-gH is safe to use. At week 12, GT-gH prevented weight gain and reduced body mass index (BMI) compared with the placebo. Especially in those aged < 50 years, triglyceride and body fat percentage decreased at week 6, visceral fat level and body fat percentage decreased at week 12; body weight, BMI, and blood LDL/HDL ratio also decreased. In conclusion, taking GT-gH prevents weight gain, and the antiobesity effect of GT-gH was more pronounced in people aged < 50 years.
Journal Article
Effect of matcha green tea on cognitive functions and sleep quality in older adults with cognitive decline: A randomized controlled study over 12 months
2024
Lifestyle habits after middle age significantly impact the maintenance of cognitive function in older adults. Nutritional intake is closely related to lifestyle habits; therefore, nutrition is a pivotal factor in the prevention of dementia in the preclinical stages. Matcha green tea powder (matcha), which contains epigallocatechin gallate, theanine, and caffeine, has beneficial effects on cognitive function and mood. We conducted a randomized, double-blind, placebo-controlled clinical study over 12 months to examine the effect of matcha on cognitive function and sleep quality.
Ninety-nine participants, including 64 with subjective cognitive decline and 35 with mild cognitive impairment were randomized, with 49 receiving 2 g of matcha and 50 receiving a placebo daily. Participants were stratified based on two factors: age at baseline and APOE genotype. Changes in cognitive function and sleep quality were analyzed using a mixed-effects model.
Matcha consumption led to significant improvements in social acuity score (difference; -1.39, 95% confidence interval; -2.78, 0.002) (P = 0.028) as evaluated by the perception of facial emotions in cognitive function. The primary outcomes, that is, Montreal Cognitive Assessment and Alzheimer's Disease Cooperative Study Activity of Daily Living scores, showed no significant changes with matcha intervention. Meanwhile, Pittsburgh Sleep Quality Index scores indicated a trend toward improvement with a difference of 0.86 (95% confidence interval; -0.002, 1.71) (P = 0.088) between the groups in changes from baseline to 12 months.
The present study suggests regular consumption of matcha could improve emotional perception and sleep quality in older adults with mild cognitive decline. Given the widespread availability and cultural acceptance of matcha green tea, incorporating it into the daily routine may offer a simple yet effective strategy for cognitive enhancement and dementia prevention.
Journal Article
Gut microbiota composition in relation to the metabolic response to 12-week combined polyphenol supplementation in overweight men and women
2017
Background/Objectives:
The intestinal microbiota may have a profound impact on host metabolism. As evidence suggests that polyphenols affect substrate utilization, the present study aimed to investigate the effects of polyphenol supplementation on intestinal microbiota composition in humans. Furthermore, we examined whether (changes in) gut microbiota composition may determine the metabolic response to polyphenol supplementation.
Subjects/Methods:
In this randomized, double-blind, placebo (PLA)-controlled trial, 37 overweight and obese men and women (18 males/19 females, 37.8±1.6 years, body mass index: 29.6±0.5 kg/m
2
) received either epigallocatechin-3-gallate and resveratrol (EGCG+RES, 282 and 80 mg/day, respectively) or PLA for 12 weeks. Before and after intervention, feces samples were collected to determine microbiota composition. Fat oxidation was assessed by indirect calorimetry during a high-fat mixed meal test (2.6 MJ, 61 energy% fat) and skeletal muscle mitochondrial oxidative capacity by means of
ex vivo
respirometry on isolated skeletal muscle fibers. Body composition was measured by dual-energy X-ray absorptiometry.
Results:
Fecal abundance of Bacteroidetes was higher in men as compared with women, whereas other assessed bacterial taxa were comparable. EGCG+RES supplementation significantly decreased Bacteroidetes and tended to reduce
Faecalibacterium prausnitzii
in men (
P
=0.05 and
P
=0.10, respectively) but not in women (
P
=0.15 and
P
=0.77, respectively). Strikingly, baseline Bacteroidetes abundance was predictive for the EGCG+RES-induced increase in fat oxidation in men but not in women. Other bacterial genera and species were not affected by EGCG+RES supplementation.
Conclusions:
We demonstrated that 12-week EGCG+RES supplementation affected the gut microbiota composition in men but not in women. Baseline microbiota composition determined the increase in fat oxidation after EGCG+RES supplementation in men.
Journal Article
Comparative Kinetics of Acetyl- and Butyryl-Cholinesterase Inhibition by Green Tea Catechins|Relevance to the Symptomatic Treatment of Alzheimer’s Disease
2020
Alzheimer’s disease (AD) is characterised by the apoptosis of cholinergic neurons and the consequent attenuation of acetylcholine mediated neurotransmission, resulting in neurodegeneration. Acetyl-cholinesterase (AChE) and butyryl-cholinesterase (BuChE) are attractive therapeutic targets in the treatment of AD since inhibition of these enzymes can be used to restore synaptic concentrations of acetylcholine. Whilst inhibitors for these enzymes such as galantamine and rivastigmine have been approved for use, none are able to halt the progression of AD and are responsible for the production of troublesome side-effects. Efficacious cholinesterase inhibitors have been isolated from natural plant-based compounds with many demonstrating additional benefits beyond cholinesterase inhibition, such as antioxidation and anti-inflammation, which are key parts of AD pathology. In this study, five natural flavan-3-ol (catechin) compounds: ((-)-epicatechin (EC), catechin, (-)-epicatechin-3-gallate (ECG),) (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-gallate (EGCG), isolated from green tea, were screened for their cholinesterase inhibitory activity using the Ellman assay. The kinetics of inhibition was determined using reciprocal Lineweaver-Burk plots. EGCG was the only compound found to produce statistically significant, competitive inhibition, of both AChE (p < 0.01) and BuChE (p < 0.01) with IC50 values of 0.0148 µmol/mL and 0.0251 µmol/mL respectively. These results, combined with previously identified antioxidative and anti-inflammatory properties, highlight the potential use of EGCG in the treatment of AD, provided it can be delivered to cholinergic neurons in therapeutic concentrations. Further testing of EGCG in vivo is recommended to fully characterise the pharmacokinetic properties, optimal method of administration and efficacy of this novel plant-based compound.
Journal Article
Epigallocatechin gallate enhances sympathetic heart rate variability and decreases blood pressure in obese subjects: a randomized control trial
by
Wilasrusmee, Kittikorn Tommy
,
Maikaew, Pailin
,
Sitticharoon, Chantacha
in
631/443
,
631/443/319
,
631/443/592
2024
This study aimed to investigate effects of epigallocatechin gallate (EGCG) on blood pressure (BP) and autonomic nervous system, indicated by 5-min heart rate variability (HRV) measurement in obese subjects, and determine correlations of BP with metabolic factors. In a double-blind, randomized controlled trial, obese subjects (n = 30) were randomly allocated to receive 150 mg EGCG (n = 15) or placebo (n = 15) twice a day without dietary restrictions. After 8-week EGCG treatment, systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) significantly decreased, while the low-frequency (LF) to high-frequency power (HF) ratio (LF/HF ratio) significantly increased (P < 0.05 all), indicating a shift toward sympathetic dominance, either directly or indirectly after BP lowering. SBP had positive correlations with obesity parameters, leptin, insulin, and insulin resistance but had a negative correlation with insulin sensitivity. DBP was positively correlated with age and HF in normalized unit, but negatively correlated with height and LF in ms
2
. High-density lipoprotein cholesterol (HDL-C) was negatively correlated with SBP, DBP, and MAP reflecting its protective effect against elevated BP. In conclusion, the 8-week EGCG treatment decreased BP and increased the LF/HF ratio, reflecting increased sympathetic activity, either a direct EGCG effect or an indirect compensatory response following BP reduction.
Journal Article