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

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3895
Author(s):  
Ushnah S. U. Din ◽  
Tanvir S. Sian ◽  
Colleen S. Deane ◽  
Ken Smith ◽  
Amanda Gates ◽  
...  

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.

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1646
Author(s):  
Tanvir S Sian ◽  
Ushnah S U Din ◽  
Colleen S Deane ◽  
Ken Smith ◽  
Amanda Gates ◽  
...  

Ageing is associated with postprandial muscle vascular and metabolic dysfunction, suggesting vascular modifying interventions may be of benefit. Reflecting this, we investigated the impact of acute cocoa flavanol (450–500 mg) intake (versus placebo control) on vascular (via ultrasound) and glucose/insulin metabolic responses (via arterialised/venous blood samples and ELISA) to an oral nutritional supplement (ONS) in twelve healthy older adults (50% male, 72 ± 4 years), in a crossover design study. The cocoa condition displayed significant increases in m. vastus lateralis microvascular blood volume (MBV) in response to feeding at 180 and 240-min after ONS consumption (baseline: 1.00 vs. 180 min: 1.09 ± 0.03, p = 0.05; 240 min: 1.13 ± 0.04, p = 0.002), with MBV at these timepoints significantly higher than in the control condition (p < 0.05). In addition, there was a trend (p = 0.058) for MBV in m. tibialis anterior to increase in response to ONS in the cocoa condition only. Leg blood flow and vascular conductance increased, and vascular resistance decreased in response to ONS (p < 0.05), but these responses were not different between conditions (p > 0.05). Similarly, glucose uptake and insulin increased in response to ONS (p < 0.05) comparably between conditions (p > 0.05). Thus, acute cocoa flavanol supplementation can potentiate oral feeding-induced increases in MBV in older adults, but this improvement does not relay to muscle glucose uptake.


2020 ◽  
Vol 11 (4) ◽  
pp. 3105-3111
Author(s):  
So-Hee Yoo ◽  
Yeong-Eun Lee ◽  
Jin-Oh Chung ◽  
Chan-Su Rha ◽  
Yong-Deog Hong ◽  
...  

Results from the current study suggested that whole green tea components rich in flavonols and polysaccharides could be potential hypoglycemic excipient ingredients into green tea catechins by enhancing catechin absorption.


2020 ◽  
Vol 21 (4) ◽  
pp. 1404 ◽  
Author(s):  
Yuchen Gu ◽  
Gautier Moroy ◽  
Jean-Louis Paul ◽  
Anne-Sophie Rebillat ◽  
Mara Dierssen ◽  
...  

Epigallocatechin gallate (EGCG) is an inhibitor of DYRK1A, a serine/threonine kinase considered to be a major contributor of cognitive dysfunctions in Down syndrome (DS). Two clinical trials in adult patients with DS have shown the safety and efficacy to improve cognitive phenotypes using commercial green tea extract containing EGCG (45% content). In the present study, we performed a preclinical study using FontUp®, a new nutritional supplement with a chocolate taste specifically formulated for the nutritional needs of patients with DS and enriched with a standardized amount of EGCG in young mice overexpressing Dyrk1A (TgBACDyrk1A). This preparation is differential with previous one used, because its green tea extract has been purified to up 94% EGCG of total catechins. We analyzed the in vitro effect of green tea catechins not only for EGCG, but for others residually contained in FontUp®, on DYRK1A kinase activity. Like EGCG, epicatechin gallate was a noncompetitive inhibitor against ATP, molecular docking computations confirming these results. Oral FontUp® normalized brain and plasma biomarkers deregulated in TgBACDyrk1A, without negative effect on liver and cardiac functions. We compared the bioavailability of EGCG in plasma and brain of mice and have demonstrated that EGCG had well crossed the blood-brain barrier.


Planta Medica ◽  
2011 ◽  
Vol 77 (05) ◽  
Author(s):  
A Ali ◽  
X Yang ◽  
Q Shi ◽  
J Greenhaw ◽  
WF Salminen

2017 ◽  
Vol 23 (4) ◽  
pp. 35-41
Author(s):  
Jeong Hee Park ◽  
Hang Yeon Jeong ◽  
Jeong Yong Cho ◽  
Jae Hak Moon

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Lisni Noraida Waruwu ◽  
Maria Bintang ◽  
Bambang Pontjo Priosoeryanto

Green tea (Camellia sinensis) is one of traditional plants that have the potential as an anticancer. The sample used in this research commercial green tea extract. The purpose of this study was to test the antiproliferation activity of green tea extract on breast cancer cell MCM-B2 in vitro. Green tea extract fractionated using three solvents, ie water, ethanol 70%, and n-hexane. Extract and fraction of green tea water have value Lethality Concentration 50 (LC50) more than 1000 ppm. The fraction of ethanol 70% and n-hexane had an LC50 value of 883.48 ppm and 600.56 ppm, respectively. The results of the phytochemical screening of green tea extract are flavonoids, tannins, and saponins, while the phytochemical screening results of n-hexane fraction are flavonoids and tannins. Antiproliferation activity was tested on breast cancer cells MCM-B2 and normal cells Vero by trypan blue staining method. The highest MCM-B2 cell inhibitory activity 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 Vero cells characterized by not inhibiting normal cell proliferation. Keywords: antiproliferative, cancer cell MCM-B2, commercial green tea, cytotoxicity


2020 ◽  
Vol 21 (1) ◽  
pp. 31-35
Author(s):  
Basma El-Desoky ◽  
Shaimaa El-Sayed ◽  
El-Said El-Said

Objective: Investigating the effect of green tea extract (GTE) on the testicular damage induced by cadmium chloride CdCl2 in male rats. Design: Randomized controlled study. Animals: 40 male Wistar rats. Procedures: Rats were randomly divided into four groups: A) control group (each rat daily received pellet diet); B) GTE group each rat daily received pellet diet as well as 3 ml of 1.5 % w/v GTE, C) CdCl2 group each rat was I/P injected a single dose of 1 mg/kg CdCl2, then daily received pellet diet, and D) CdCl2+GTE group each rat was I/P injected a single dose of 1 mg/kg CdCl2 then daily received pellet diet as well as 3 ml of 1.5 % w/v GTE. After 30 days, blood samples were collected for hormonal assays (testosterone, FSH, and LH). In addition, both testes were collected; one of them was used for quantification of 17-beta hydroxysteroid dehydrogenase III (17β-HSDIII) gene expression using a real-time PCR. The other testis was used for determination of catalase and reduced glutathione; GSH, Nitric oxide (NO) and malondialdehyde (MDA) levels. Results: CdCl2 decreased serum testosterone levels and its synthesis pathway (17β-HSDIII testicular gene expression). While antioxidants catalase and GSH were reduced, oxidants MDA were enriched in the testes of CdCl2-poisoned rats. This CdCl2-promoted testicular dysfunction was corrected via the administration of GTE to male rats. Conclusion and clinical relevance: GTE could be used as a remedy for protecting against CdCl2-induced testicular damage in male rats.


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