PMID: 

Nutr Diabetes. 2019 Aug 27 ;9(1):23. Epub 2019 Aug 27. PMID: 31455758

Abstract Title: 

Inhibitory effects of pu-erh tea on alpha glucosidase and alpha amylase: a systemic review.

Abstract: 

OBJECTIVE: Pu-erh tea was presumed to have anti-hyperglycemic effects via inhibition on alpha-amylase and alpha-glucosidase. However, no integerated literatures were published to substantiate such presumption.METHODS: Current study adopted systemic review method to validate inhibitory effects on alpha amylase and alpha-glucosidase. Five English databases (PubMed, EBSCO, SCOPUS, Cochrane Library, Web of Science) and three Chinese ones (Airti Library, CNKI Library, and Google Scholar) were searched up to 22 March 2018 for eligible literatures, using keywords of Pu-erh, Pu'er, alpha-amylase or alpha-glucosidase.RESULTS: Six studies exploring inhibitory effects on alpha-glucosidase and seven on alpha-amylase were included for systemic review. Though results showed pu-erh tea has significant inhibitory effects on alpha-amylase and alpha-glucosidase, high heterogeneity was detected among studies included.CONCLUSIONS: High heterogeneity may be due to complex alterations of chemicals under different degrees of fermentation. More future studies are required to further identify principal bioactive component(s) at work.

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PMID: 

Int J Immunopathol Pharmacol. 2019 Jan-Dec;33:2058738419872624. PMID: 31456460

Abstract Title: 

Green tea polyphenols protect PC12 cells against HO-induced damages by upregulating lncRNA MALAT1.

Abstract: 

It is of significance to alleviate oxidative damages for the treatment of spinal cord injury (SCI). Studies have ascertained that green tea polyphenols (GTPs) exert protective activities against oxidative damages. In this study, we aimed to investigate the protective effects of GTP against HO-caused injuries in PC12 cells as well as the molecular underpinnings associated with long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). PC12 cells were preincubated with GTP prior to HOstimulation. Furthermore, MALAT1-deficient PC12 cells were constructed by transfection and identified by quantitative real-time polymerase chain reaction (qRT-PCR) assay. Next, viability and apoptosis were detected by cell counting kit-8 and flow cytometry, respectively. Meanwhile, Western blot assay was carried out to monitor the expression alteration of proteins associated with apoptosis (Bcl-2, Bax, pro-Caspase-3/9, and cleaved Caspase-3/9) and autophagy (microtubule-associated protein 1 light chain 3 (LC3)-II, LC3-I, Beclin-1, and p62). Moreover, we examined the expression ofβ-catenin and dissected the phosphorylation of phosphatidylinositol 3'-kinase (PI3K) and protein kinase B (AKT). We found that HOdecreased the viability of PC12 cells while initiated apoptosis and autophagy processes. GTP-preincubated PC12 cells maintained the viability and resisted the apoptosis and autophagy induced by HO. Pointedly, GTP-pretreated PC12 cells showed an increase in MALAT1 after HOstimulation. Of note, the protective effects of GTP were buffered in MALAT1-deficient cells in response to HO. The expression ofβ-catenin and phosphorylation of PI3K and AKT were upregulated by GTP, while MALAT1 knockdown led to opposite results. To sum up, GTP protected PC12 cells from HO-induced damages by the upregulation of MALAT1. This process might be through activating Wnt/β-catenin and PI3K/AKT signal pathways.

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PMID: 

Biosci Biotechnol Biochem. 2019 Aug 29:1-8. Epub 2019 Aug 29. PMID: 31462168

Abstract Title: 

Dietary supplementation of a high-temperature-processed green tea extract attenuates cognitive impairment in PS2 and Tg2576 mice.

Abstract: 

Green tea intake is generally recognized as an effective supplement that promotes mental clarity and cognitive function. These health benefits of green tea have been attributed mainly to its effective component, epigallocatechin gallate (EGCG). Because various catechin derivatives potently enhance these health benefits, we manipulated the extraction process with a high-temperature intervention. High-temperature-processed green tea extract (HTP-GTE) showed an elevated proportion of gallocatechin gallate (GCG) content. To investigate the preventive effects of HTP-GTE on cognitive decline, we found its neuroprotective effects against amyloidβ (Aβ)-induced neurotoxicity in neurons and clarified that GCG significantly inhibited Aβ aggregation. Moreover, we showed that HTP-GTE intake attenuated several cognitive-decline phenotypes in a model mouse of Alzheimer's disease. These beneficial effects of HTP-GTE against cognitive decline were due to the distinctive composition of the extract and suggest the possibility that HTP-GTE supplementation could attenuate cognitive decline of Alzheimer's disease.

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PMID: 

Antioxidants (Basel). 2019 Jul 10 ;8(7). Epub 2019 Jul 10. PMID: 31295859

Abstract Title: 

Phenolic Profiles and Antioxidant Activities of 30 Tea Infusions from Green, Black, Oolong, White, Yellow and Dark Teas.

Abstract: 

Tea is among the most consumed drink worldwide, and its strong antioxidant activity is considered as the main contributor to several health benefits, such as cardiovascular protection and anticancer effect. In this study, the antioxidant activities of 30 tea infusions, which were obtained by the mimic of drinking tea of the public, from green, black, oolong, white, yellow and dark teas, were evaluated using ferric-reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, ranging from 504.80± 17.44 to 4647.47 ± 57.87 µmol Fe/g dry weight (DW) and 166.29± 24.48 to 2532.41 ± 50.18 µmol Trolox/g DW, respectively. Moreover, their total phenolic contents (TPC) were detected by Folin-Ciocalteu assay and were in the range of 24.77 ± 2.02 to 252.65 ± 4.74 mg gallic acid equivalent (GAE)/g DW. Generally, Dianqing Tea, Lushan Yunwu Tea, and Xihu Longjing Tea showed the strongest antioxidant activities among 30 teas. Furthermore, the phenolic compounds in tea infusions were identified and quantified, with catechins most commonly detected, especially in green tea infusions, which were main contributors to their antioxidant activities. Besides tea polyphenols, considerable content of caffeine also presented in 30 tea infusions.

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PMID: 

Biomed Rep. 2019 Aug ;11(2):79-84. Epub 2019 Jun 24. PMID: 31338194

Abstract Title: 

Catechin ameliorates depressive symptoms in Sprague Dawley rats subjected to chronic unpredictable mild stress by decreasing oxidative stress.

Abstract: 

Catechin is an active ingredient of green tea. It is reported to inhibit corticosteroid-induced anxiety and depression-like symptoms. Considering the complex nature of depression, effects of catechin need to be studied in a clinically relevant depression model. The present study was designed to explore the antidepressant effect of catechin in Sprague Dawley rats subjected to chronic unpredictable mild stress (CUMS). Animals were subjected to CUMS and treated with (+)-catechin (50 mg/kg) or escitalopram (10 mg/kg) orally; a CUMS control and a vehicle control that was not exposed to CUMS were also established. Various stressors were applied daily in an unpredictable manner for 8 weeks achieve CUMS. Sucrose preference test were performed after 4 and 8 weeks and forced swim tests (FSTs) were conducted at weeks 4, 6 and 8. At the end of week 8, animals were sacrificed and the brain homogenate was studied for antioxidant parameters. Compared with the vehicle control, animals of the CUMS control group showed a significant decrease in sucrose intake. Catechin and escitalopram treatment significantly improved the sucrose intake compared with the CUMS control. A similar trend was observed in the FSTs, where catechin and escitalopram treatment significantly reduced the immobility time, and antioxidant parameters, including catalase, glutathione and superoxide dismutase levels were recovered in treated animals compared with the CUMS control. Thus, it was concluded that catechin reverses CUMS-induced depression in rats by ameliorating oxidative stress, which may help to develop a novel treatment for major depressive disorder.

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PMID: 

Molecules. 2019 Aug 9 ;24(16). Epub 2019 Aug 9. PMID: 31404982

Abstract Title: 

The Inhibitory Effect of (-)-Epigallocatechin-3-Gallate on Breast Cancer Progression via ReducingMethylation and DNMT Activity.

Abstract: 

Epigenetic modifications are important mechanisms responsible for cancer progression. Accumulating data suggest that (-)-epigallocatechin-3-gallate (EGCG), the most abundant catechin of green tea, may hamper carcinogenesis by targeting epigenetic alterations. We found that signal peptide-CUB (complement protein C1r/C1s, Uegf, and Bmp1)-EGF (epidermal growth factor) domain-containing protein 2 (), a tumor suppressor gene, was hypermethylated in breast tumors. However, it is unknown whether EGCG regulatesmethylation, and the mechanisms remain undefined. This study was designed to investigate the effect of EGCG onmethylation in breast cancer cells. We reveal that EGCG possesses a significantly inhibitory effect on cell viability in a dose- and time-dependent manner and presents more effects than other catechins. EGCG treatment resulted in enhancement of thegene, along with elevated E-cadherin and decreased vimentin expression, leading to significant suppression of cell migration and invasion. The inhibitory effect of EGCG onknock-down cells was remarkably alleviated. Further study demonstrated that EGCG significantly decreased themethylation status by reducing DNA methyltransferase (DNMT) expression and activity. In summary, this study reported for the first time thatmethylation can be reversed by EGCG treatment, finally resulting in the inhibition of breast cancer progression. These results suggest the epigenetic role of EGCG and its potential implication in breast cancer therapy.

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PMID: 

Pharmacology. 2019 Aug 21:1-9. Epub 2019 Aug 21. PMID: 31434088

Abstract Title: 

Synergetic Effect of EP1 Receptor Antagonist and (-)-Epigallocatechin-3-gallate in Hepatocellular Carcinoma.

Abstract: 

Epigallocatechin-3-gallate (EGCG), the principal catechin of green tea, modulates different molecular mechanisms underlying hepatocellular carcinoma (HCC). Accumulating studies showed that the activation of prostaglandin (PG) receptor EP1 promotes cell migration and invasion in different cancers, which could be inverted by blocking the EP1 receptor. This study investigated the synergetic effects of EP1-selective antagonist ONO-8711 and EGCG treatment on HCC to better understand the potential strategy to treat HCC. We found that EGCG significantly inhibited PGE2 and EP1-selective agonist induced migration of HCC cells and increased the ratio of Bax/Bcl-2 even in the presence of ONO-DI-004 or PGE2. ONO-8711 significantly inhibited PGE2-induced HCC proliferation while increased the inhibitory effect of EGCG on HCC cell viability and migration ability compared with EGCG alone. These findings suggest that a combination of ONO-8711 and EGCG is a potential treatment for HCC therapy.

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PMID: 

In Vivo. 2019 Sep-Oct;33(5):1463-1468. PMID: 31471393

Abstract Title: 

Shining a Light on the Effects of the Combination of (-)-Epigallocatechin-3-gallate and Tapentadol on the Growth of Human Triple-negative Breast Cancer Cells.

Abstract: 

BACKGROUND/AIM: Breast cancer is characterized by a high rate of mortality and is considered one of the deadliest types of cancer. It is of note that (-)-epigallocatechin-3-gallate (EGCG), the principal catechin of green tea, is able to hinder the growth of MDA-MB-231 breast cancer cells by influencing different signaling pathways, including apoptosis. Furthermore, EGCG is also used in the treatment of bone cancer pain. Tapentadol, an opioid drug acting at the level of noradrenaline (norepinephrine) reuptake inhibition andμ-opioid receptor, is able to modulate bone cancer pain and influence cancer cell viability by regulating apoptosis.MATERIALS AND METHODS: In vitro assays were performed on triple-negative MDA-MB-231 cells treated with tapentadol (1, 5, 10, 20, 40 and 80μg/ml) and EGCG (1, 10, 20, 40, 80, 160 μmol/l), alone and in combination. The effects of EGCG and TAP on viability were determined by wound-healing and MTT assays, while cell migration was assessed by transwell migration.RESULTS: Cell proliferation, viability and apoptosis of MDA-MB-231 cells were impaired by the combination of EGCG and tapentadol. Specifically, our data show that EGCG and TAP reduced the proliferation of MDA-MB-231 cells by impairing cell-cycle progression (p

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PMID: 

J Periodontol. 2019 Aug 31. Epub 2019 Aug 31. PMID: 31473995

Abstract Title: 

Catechin ameliorates Porphyromonas gingivalis-induced inflammation via the regulation of TLR2/4 and inflammasome signaling.

Abstract: 

BACKGROUND: Porphyromonas gingivalis is a major periodontopathogen found in patients with chronic periodontitis that can lead to alveolar bone or tooth loss. Interleukin-1β (IL-1β), a pro-inflammatory cytokine, is most relevant to the pathogenesis of periodontitis. Catechin is one of the main polyphenol compounds found in green tea and possesses a range of health benefits. This study examined the anti-inflammatory effects of catechin in THP-1-derived macrophages infected with P. gingivalis as well as its effects on P. gingivalis-induced periodontitis in a mouse model.METHODS: The cytokine levels and relevant protein expression in THP-1 cells were measured using an enzyme-linked immunosorbent assay and Western blot analysis, respectively. An apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) pyroptosome formation was measured by confocal laser scanning microscopy. Micro-computed tomography was used to determine the level of bone loss induced by a P. gingivalis oral infection.RESULTS: Catechin attenuated the production of IL-1β by inhibiting pro-IL-1β expression via the down-regulation of nuclear factor-κB, p38 mitogen-activated protein kinase, and Toll-like receptor signaling. In addition, catechin inhibited the activation of inflammasomes induced by P. gingivalis, but did not affect the growth of P. gingivalis. Catechin reduced the level of alveolar bone loss in a P. gingivalis-induced periodontitis mouse model.CONCLUSIONS: Catechin possesses anti-inflammatory properties by reducing the level of IL-1β production, suggesting that it can potentially be used for the prevention and treatment of periodontal inflammation caused by P. gingivalis. This article is protected by copyright. All rights reserved.

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PMID: 

Dose Response. 2019 Apr-Jun;17(2):1559325819852243. Epub 2019 May 26. PMID: 31205459

Abstract Title: 

Cardioprotective Potential of Plant-Derived Molecules: A Scientific and Medicinal Approach.

Abstract: 

Since the beginning of human civilization, plants have been used in alleviating the human distress and it was recorded for about thousands of years ago that the plants are being used for medicinal purposes. Natural bioactive compounds called phytochemicals are obtained from medicinal plants, vegetables, and fruits, which functions to combat against various ailments. There is dire need to explore the plant biodiversity for its medicinal and pharmacological potentials. Different databases such as Google scholar, Medline, PubMed, and the Directory of Open Access Journals were searched to find the articles describing the cardioprotective function of medicinal plants. Various substances from a variety of plant species are used for the treatment of cardiovascular abnormalities. The cardioprotective plants contain a variety of bioactive compounds, including diosgenin, isoflavones, sulforaphane, carotinized, catechin, and quercetin, have been proved to enhance cardioprotection, hence reducing the risk of cardiac abnormalities. The present review article provides the data on the use of medicinal plants particularly against cardiac diseases and to explore the molecules/phytoconstituents as plant secondary metabolites for their cardioprotective potential.

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