GCG-Rich Tea Catechins are Effective in Lowering Cholesterol and Triglyceride Concentrations in Hyperlipidemic Rats

(-)-Gallocatechin Gallate: A Novel Chemical Marker to Distinguish Triadica cochinchinensis Honey

Triadica cochinchinensis honey (TCH) is collected from the nectar of the medicinal plant T. cochinchinensis and is considered the most important honey variety in southern China. TCH has significant potential medicinal properties and commercial value. However, reliable markers for application in the authentication of TCH have not yet been established. Herein, a comprehensive characterization of the botanical origin and composition of TCH was conducted by determining the palynological characteristics and basic physicochemical parameters. Liquid chromatography tandem-mass spectrometry (LC-MS/MS) was used to investigate the flavonoid profile composition of TCH, T. cochinchinensis nectar (TCN) and 11 other common varieties of Chinese commercial honey. (-)-Gallocatechin gallate (GCG) was identified as a reliable flavonoid marker for TCH, which was uniquely shared with TCN but absent in the other 11 honey types. Furthermore, the authentication method was validated, and an accurate quantification of GCG in TCH and TCN was conducted. Overall, GCG can be applied as a characteristic marker to identify the botanical origin of TCH.

(-)-Gallocatechin Gallate Mitigates Metabolic Syndrome-Associated Diabetic Nephropathy in db/db Mice

Metabolic syndrome (MetS) significantly predisposes individuals to diabetes and is a prognostic factor for the progression of diabetic nephropathy (DN). This study aimed to evaluate the efficacy of (-)-gallocatechin gallate (GCG) in alleviating signs of MetS-associated DN in db/db mice. We administered GCG and monitored its effects on several metabolic parameters, including food and water intake, urinary output, blood glucose levels, glucose and insulin homeostasis, lipid profiles, blood pressure, and renal function biomarkers. The main findings indicated that GCG intervention led to marked improvements in these metabolic indicators and renal function, signifying its potential in managing MetS and DN. Furthermore, transcriptome analysis revealed substantial modifications in gene expression, notably the downregulation of pro-inflammatory genes such as S100a8, S100a9, Cd44, Socs3, Mmp3, Mmp9, Nlrp3, IL-1β, Osm, Ptgs2, and Lcn2 and the upregulation of the anti-oxidative gene Gstm3. These genetic alterations suggest significant effects on pathways related to inflammation and oxidative stress. In conclusion, GCG demonstrates therapeutic efficacy for MetS-associated DN, mitigating metabolic disturbances and enhancing renal health by modulating inflammatory and oxidative responses.

The importance of choosing the appropriate cholesterol quantification method: enzymatic assay versus gas chromatography

Cholesterol is a major lipid of the animal realm with many biological roles. It is an important component of cellular membranes and a precursor of steroid hormones and bile acids. It is particularly abundant in nervous tissues, and dysregulation of cholesterol metabolism has been associated with neurodegenerative diseases such as Alzheimer's and Huntington's diseases. Deciphering the pathophysiological mechanisms of these disorders often involves animal models such as mice and Drosophila. Accurate quantification of cholesterol levels in the chosen models is a critical point of these studies. In the present work, we compare two common methods, gas chromatography coupled to flame-ionization detection (GC/FID) and a cholesterol oxidase-based fluorometric assay to measure cholesterol in mouse brains and Drosophila heads. Cholesterol levels measured by the two methods were similar for the mouse brain, which presents a huge majority of cholesterol in its sterol profile. On the contrary, depending on the method, measured cholesterol levels were very different for Drosophila heads, which present a complex sterol profile with a minority of cholesterol. We showed that the enzyme-based assay is not specific for cholesterol and detects other sterols as well. This method is therefore not suited for cholesterol measurement in models such as Drosophila. Alternatively, chromatographic methods, such as GC/FID, offer the required specificity for cholesterol quantification. Understanding the limitations of the quantification techniques is essential for reliable interpretation of the results in cholesterol-related research.

Serum Uric Acid Level as a Predictive Biomarker of Gestational Hypertension Severity; A Prospective Observational Case-Control Study

BACKGROUND

Pre-eclampsia poses a significant potential risk of hypertensive disorders during pregnancy, a leading cause of maternal deaths. Hyperuricemia is associated with adverse effects on endothelial function, normal cellular metabolism, and platelet aggregation and adhesion. This study was designed to compare serum urate levels in normotensive pregnant women to those with pregnancy-induced hypertension, and to evaluate its value as a potential predictive marker of hypertension severity during pregnancy.

METHODS

A prospective, observational, case-control study conducted on 100 pregnant women in their third trimester. Pregnant women were classified into two groups (n=50) according to arterial blood pressure measurements: group I had normal blood pressure, and group II had a blood pressure of ≥ 140/90, which was further subdivided according to hypertension severity into IIa (pregnancy- induced hypertension, IIb (mild pre-eclampsia), and IIc (severe pre-eclampsia). Blood samples were obtained on admission. Serum urate, high sensitive C-reactive protein, and interleukin-1β levels, and lipid profile were compared among the groups.

RESULTS

A significant increase in the mean values of serum urate, C-reactive protein, and interleukin- 1β levels was detected in gestational hypertensives. In addition, there was a positive correlation between serum urate levels and C-reactive protein and interleukin-1β, as well as between serum urate levels and hypertension severity.

CONCLUSION

Hyperuricemia and increased C-reactive protein and interleukin-1β serum levels correlate with the severity of pregnancy-induced hypertension, and these biomarkers may play a role in the pathogenesis of pre-eclampsia. Serum urate measurement is sensitive, reliable markers that correlate well with the severity of hypertension in pregnant females with pre-eclampsia.

(-)-Gallocatechin gallate from green tea rescues cognitive impairment through restoring hippocampal silent synapses in post-menopausal depression

Post-menopausal depression (PMD) is a common psychological disorder accompanied by a cognitive deficit, which is caused by a series of uncontrolled emotional disruptions by strong environmental stressors during menopause. To overcome PMD-induced cognitive deficit, Green tea has been suggested as a dietary supplement because of its ameliorating effect on cognitive dysfunction induced by normal aging or neurodegenerative syndromes; however, its clinical use to improve PMD-accompanied cognitive deficit is still limited due to the controversy for the active ingredients and ambiguous mechanism of its action. Here, we developed modified high-temperature-processed green tea extract (HTP-GTE), which showed lower neuronal toxicity than the conventional green tea extract (GTE). We also demonstrated that HTP-GTE administration prevented the development of learned helplessness (LH) in a rat post-menopausal model. Additionally, HTP-GTE improved LH-induced cognitive impairments simultaneously with rescued the long-term synaptic plasticity. This occurred via the restoration of silent synapse formation by increasing the hippocampal BDNF-tyrosine receptor kinase B pathway in the helpless ovariectomized (OVX) rats. Likewise, we also identified that (-)-gallocatechin gallate was the main contributor of the HTP-GTE effect. Our findings suggested that HTP-GTE has a potential as a preventive nutritional supplement to ameliorate cognitive dysfunctions associated with PMD.

Yellow Tea Stimulates Thermogenesis in Mice through Heterogeneous Browning of Adipose Tissues

SCOPE

Large-leaf yellow tea (YT) exhibits interesting beneficial metabolic effects in previous studies. Here, the authors elucidated the actions of YT on thermogenesis, energy metabolism, and adipocyte metabolic conversion.

METHODS AND RESULTS

Five-week-old male C57BL/6 mice are fed low-fat diet, high-fat diet (HFD), and HFD supplemented with 0.5% or 2.5% YT. After treatment for 10 or 14 weeks, YT enhances energy expenditure, O2 consumption and CO2 production. YT strongly boosts thermogenic program in brown adipose tissue (BAT) and subcutaneous adipose tissue (SAT), while only weakly in epididymal adipose tissue (EAT). These are accompanied by higher body temperature, increased mitochondrial copy numbers, and upregulation of thermogenic genes (Ucp1, Pgc1α, etc.) and proteins. The classic brown adipocyte markers (Eva1, Zic1) are induced only in BAT, while beige adipocyte markers (Tbx1, Tmem26) are boosted only in SAT. Furthermore, subcutaneous-originated preadipocytes are induced by YT in vitro to differentiate to brown-like adipocytes - a browning effect.

CONCLUSION

Dietary YT induces adaptive thermogenesis through increasing mitochondrial biogenesis in EAT, inducing beigeing in SAT and enhancing browning in the BAT.

Catechin profile and hypolipidemic activity of Morinda citrifolia leaf water extract

Cardiovascular diseases (CVDs) are silent killers and hyperlipidemia is a high-risk factor. Morinda citrolia leaf (MCL), which is commonly consumed by many cultural groups and has high level of catechins, might exert antihyperlipidemic properties. In this study, the catechins profile of MCL water extract was determined via HPLC and ultraperformance liquid chromatography-traveling wave ion mobility-quadrupole time of flight mass spectrometry (UPLC-TWIMS-QTOF). The major catechin in MCL and the most widely studied catechin with hypolipidemic activity, epigallocatechin gallate (EGCG), was studied in a cytotoxicity test on HepG2 cells prior the in vitro anti-hyperlipidemic assay. The total catechins of MCL reached 141.88 ± 5.04 mg/g, with catechin gallate (CG) (75.27 ± 8.49 mg/g) as the major catechin. Catechin derivatives that were identified include epigallocatechin-3-O-gallate (EGCG) with m/z 459.0912 [M + H]+, epigallocatechin (EGC) with m/z 307.0818 [M + H]+, CG with m/z 443.0976 [M + H]+, epigallocatechin(4β→8)-gallocatechin with m/z 649.0951 [M + K]+, and gallocatechin(4α→8)-epicatechin with m/z 633.1 [M + K]+. Cell inhibitions of MCL, CG and EGCG were more than IC50 of 100 μg/ml. MCL increased LDL-c uptake up to 1.11 ± 0.03-fold, but this was insignificant relative to control. CG and EGCG significantly increased LDL-c uptake up to 1.37 ± 0.19-fold and 1.59 ± 0.19-fold, respectively. Thus, MCL with CG has shown potential for modulating hyperlipidemia.

Targeting Foam Cell Formation in Atherosclerosis: Therapeutic Potential of Natural Products

Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of atherosclerotic lesions. Targeting foam cell formation in the atherosclerotic lesions can be a promising approach to treat and prevent atherosclerosis. The formation of foam cells is determined by the balanced effects of three major interrelated biologic processes, including lipid uptake, cholesterol esterification, and cholesterol efflux. Natural products are a promising source for new lead structures. Multiple natural products and pharmaceutical agents can inhibit foam cell formation and thus exhibit antiatherosclerotic capacity by suppressing lipid uptake, cholesterol esterification, and/or promoting cholesterol ester hydrolysis and cholesterol efflux. This review summarizes recent findings on these three biologic processes and natural products with demonstrated potential to target such processes. Discussed also are potential future directions for studying the mechanisms of foam cell formation and the development of foam cell-targeted therapeutic strategies.

Stability and stabilization of (-)-gallocatechin gallate under various experimental conditions and analyses of its epimerization, auto-oxidation, and degradation by LC-MS

BACKGROUND

(-)-Gallocatechin gallate (GCG) shows multi-bioactivities. Its stability, however, has not been investigated systematically yet. Therefore, the objective of this study was to characterize the stability of GCG and to find ways to stabilize it in biological assays. Furthermore, the epimerization of the compound, its auto-oxidation and degradation were also analyzed by liquid chromatography mass spectrometry (LC-MS).

RESULTS

The stability of GCG was concentration-dependent and was sensitive to pH, temperature, bivalent cations, and dissolved oxygen level. The results also showed that GCG was not stable in common buffers (50 mmol L^-1 , pH 7.4, 37 °C) or in cell culture medium DMEM/F12 under physiological conditions (pH 7.4, 37 °C). Our experiments indicated that nitrogen-saturation and the addition of ascorbic acid (VC) could stabilize GCG in biological assays. In addition, LC-MS determination indicated that GCG was able to be epimerized to its epimer (-)-epigallocatechin gallate (EGCG). Meanwhile it was also able to be auto-oxidized to theasinensin and compound P2 and degraded to gallocatechin and gallic acid in pure water at 100 °C.

CONCLUSION

The stability of GCG should be seriously considered in research on the bioactivity of it to avoid possible artifacts. Nitrogen-saturation and use of VC are good ways to make GCG stable in biological assays. © 2019 Society of Chemical Industry.

Curcumin as a permeability enhancer enhanced the antihyperlipidemic activity of dietary green tea extract

Background

Green tea has polyphenols like flavonoids and catechins; mainly epigallocatechin-3-gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC) and epicatechin (EC), out of which EGCG is of higher abundance. EGCG has shown preventive role in hypercholesterolemia. However, due to low oral bioavailability, a need arises to improve its membrane permeability and transporter-mediated intestinal efflux. Therefore, an attempt was made to enhance permeability and bioavailability of EGCG using curcumin to treat hyperlipidemia. Further, it was formulated in herbal tea bags to achieve patient compliance.

Methods

EGCG extracted from green tea leaves was confirmed by High Performance Thin Layer Chromatography. Green tea extract (GTE), curcumin and their mixtures were subjected to Fourier Transform Infra-Red spectroscopy and Differential Scanning Calorimetry for compatibility studies. Powder formulation was prepared comprising GTE, curcumin, sucralose and cardamom.

Results

Ex-vivo study was performed on everted goat intestine, analyzed by HPLC and demonstrated highest permeation of GTE:curcumin (220:50) (53.15%) than GTE (20.57%). Antihyperlipidemic activity was performed in rats for 15 days. Blood sample analysis of rats of test groups (formulation and GTE solution) fed on high fat diet showed (mg/dl):cholesterol 80 and 90, triglycerides 73.25 and 85.5, HDL 50.75 and 46, LDL 43.9 and 46, VLDL 14.65 and 17.1 respectively with significant lipid regulating effect.

Conclusion

Curcumin enhanced permeability of EGCG. Therefore, P-glycoprotein pump inside intestine can be potential mechanism to enhance permeability of EGCG. Thus, EGCG-curcumin herbal tea bag is promising nutraceutical to treat hyperlipidemia in day-to-day life achieving patient compliance.

Roasting improves the hypoglycemic effects of a large-leaf yellow tea infusion by enhancing the levels of epimerized catechins that inhibit α-glucosidase

Teas contain bioactive polyphenols, such as (-)-epigallocatechin gallate (EGCG), which is not stable during the processing of tea. EGCG can be epimerized into (-)-gallocatechin gallate (GCG), which is present in very small amounts in fresh tea leaves. An infusion made from roasted large-leaf yellow tea inhibited α-glucosidase more significantly than an infusion of unroasted yellow tea, with IC50 values of 76.08 ± 8.96 and 170.17 ± 33.00 μg mL-1, respectively. After roasting, the content of GCG showed about a 5-fold increase, while EGCG showed a decrease of 56.6%. Of the two main α-glucosidase inhibitors, GCG exhibited a higher inhibitory effect on α-glucosidase than its corresponding epimer (EGCG), whose IC50 value was about 3-fold lower. Modeling of molecular docking suggested that GCG preferably binds to the target α-glucosidase protein; this was confirmed by in vitro protein-polyphenol binding, where GCG had a binding rate about 4 times higher than that of EGCG. Comparative in vivo studies using oral starch tolerance tests in mice verified that GCG exhibited lower postprandial blood glucose compared to EGCG. These results suggest that roasting is a simple and effective way to increase the capacity of large-leaf yellow tea to regulate postprandial blood glucose.

Hongyacha, a Naturally Caffeine-Free Tea Plant from Fujian, China

Hongyacha (HYC) is a type of new wild tea plant discovered in Fujian Province, China. This tea is helpful to the healing or prevention of disease in its original growing area. However, research on this tea is limited. Our results showed that HYC displayed obvious differences in its morphological characteristics compared with Cocoa tea ( Camellia ptilophylla Chang), a famous caffeine-free tea plant in China. Theobromine and trans-catechins, but not caffeine and cis-catechins, were the dominant purine alkaloids and catechins detected in HYC. HYC might contain abundant gallocatechin-(4 → 8)-gallocatechin gallate, 1,3,4,6-tetra- O-galloyl-β-d-glucopyranose, and (-)-gallocatechin-3,5-di- O-gallate, which were not detected in regular tea. We also found that the TCS1 of HYC was distinct, and the responding recombinant protein exhibited only theobromine synthase activity. The obtained results showed that HYC is a new kind of caffeine-free tea plant and may be used for scientific protection and efficient utilization in the future.

The Effect of Ultrasound, Oxygen and Sunlight on the Stability of (-)-Epigallocatechin Gallate

(-)-Epigallocatechin gallate (EGCG), is the main catechin found in green tea, and has several beneficial effects. This study investigated the stability of EGCG aqueous solution under different stored and ultrasonic conditions to determine whether it can be used with an ultrasonic dental scaler to treat periodontal infection. Four concentrations (0.05, 0.1, 0.15, 2 mg/mL) of EGCG aqueous solution were prepared and stored under four different conditions (A: Exposed to neither sunlight nor air, B: Exposed to sunlight, but not air, C: Not exposed to sunlight, but air, D: Exposed to sunlight and air) for two days. The degradation rate of EGCG was measured by high performance liquid chromatography (HPLC). On the other hand, an ultrasonic dental scaler was used to atomize the EGCG solution under four different conditions (a: Exposed to neither air nor sunlight, b: Not exposed to air, but sunlight, c: Not exposed to sunlight, but air, d: Exposed to air and sunlight), the degradation of EGCG was measured by HPLC. We found that the stability of EGCG was concentration-dependent in water at room temperature. Both sunlight and oxygen influenced the stability of EGCG, and oxygen had a more pronounced effect on stability of EGCG than sunlight. The most important conclusion was that the ultrasound may accelerate the degradation of EGCG due to the presence of oxygen and sunlight, but not because of the ultrasonic vibration. Thus, EGCG aqueous solution has the potential to be used through an ultrasonic dental scaler to treat periodontal infection in the future.

Wild Lonicera caerulea berry polyphenol extract reduces cholesterol accumulation and enhances antioxidant capacity in vitro and in vivo

The hypocholesterolemic effect of Lonicera caerulea berry extract rich in polyphenols (LCBP) on high cholesterol-induced hypercholesterolemia and lipoprotein metabolite changes was examined in Caco-2 cells and rats. Cyanidin-3-glucoside, catechin, and chlorogenic acid are the major phenolic components of LCBP. The cholesterol-reducing effect and antioxidant capacity of these components were compared in Caco-2 cells. LCBP (80 μg/mL) and cyanidin-3-glucoside, catechin, and chlorogenic acid (50 μM) were found to be effective (p < 0.05). Rats were fed a high cholesterol diet (HCD) with or without LCBP supplementation (75, 150, and 300 mg/kg body weight intragastrically once daily) for 12 weeks. Compared with the HCD control group, LCBP supplementation at 150 and 300 mg/kg decreased the levels of TC, TG, and LDL-C, but increased that of HDL-C. LCBP treatment promoted greater neutral and acidic sterol excretion (p < 0.05) and improved the antioxidant capacity of the colon tissue, colon contents, and blood. Moreover, trimethylamine N-oxide (TMAO) levels were decreased in serum (p < 0.05). NPC1L1, ACAT2, and MTP mRNA and protein expression were reduced and ABCG5/8 expression was increased (p < 0.05) after LCBP treatment. Our results suggest that LCBP could be used as a functional food for the prevention and treatment of diseases related to excessive cholesterol accumulation.

Can EGCG Alleviate Symptoms of Down Syndrome by Altering Proteolytic Activity?

Down syndrome (DS), also known as "trisomy 21", is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. Silencing these extra genes is beyond existing technology and seems to be impractical. A number of pharmacologic options have been proposed to change the quality of life and lifespan of individuals with DS. It was reported that treatment with epigallocatechin gallate (EGCG) improves cognitive performance in animal models and in humans, suggesting that EGCG may alleviate symptoms of DS. Traditionally, EGCG has been associated with the ability to reduce dual specificity tyrosine phosphorylation regulated kinase 1A activity, which is overexpressed in trisomy 21. Based on the data available in the literature, we propose an additional way in which EGCG might affect trisomy 21-namely by modifying the proteolytic activity of the enzymes involved. It is known that, in Down syndrome, the nerve growth factor (NGF) metabolic pathway is altered: first by downregulating tissue plasminogen activator (tPA) that activates plasminogen to plasmin, an enzyme converting proNGF to mature NGF; secondly, overexpression of metalloproteinase 9 (MMP-9) further degrades NGF, lowering the amount of mature NGF. EGCG inhibits MMP-9, thus protecting NGF. Urokinase (uPA) and tPA are activators of plasminogen, and uPA is inhibited by EGCG, but regardless of their structural similarity tPA is not inhibited. In this review, we describe mechanisms of proteolytic enzymes (MMP-9 and plasminogen activation system), their role in Down syndrome, their inhibition by EGCG, possible degradation of this polyphenol and the ability of EGCG and its degradation products to cross the blood-brain barrier. We conclude that known data accumulated so far provide promising evidence of MMP-9 inhibition by EGCG in the brain, which could slow down the abnormal degradation of NGF.

Formulation and characterization of EGCG for the treatment of superficial bladder cancer

In the United States, the annual incidence of bladder cancer is approximately 70,000 new cases, with a mortality rate of approximately 15,000/year. The most common subtype (70%) of bladder cancer is superficial, namely hte non-muscle invasive disease form limited to the urothelium. The rate of progression and recurrence is up to 40 and 70%, respectively. Urothelial cell carcinoma of the bladder is typically treated with transurethral resection. The cancerous cells can float onto the adjacent epithelium, increasing the risk of recurrence. The standard of care is to offer adjuvant intravesical agents to reduce the risk of progression and recurrence. Current intravesical treatments are costly and are associated with special biohazard handling protocols. Patients are treated with intravesical therapy with bacillus Calmetter-Guerin (BCG) bacterium, or mitomycin C (MMC) following resection, both of which can cause moderate to severe side-effects which are rarely life-threatening. We previously examined the efficacy of epigallocatechin-3-gallate (EGCG)in comparison with MMC to prevent tumor cell implantation/growth in an animal model of superficial bladder cancer. Experiments revile that EGCG is slightly more effective than MMC at decreasing tumor cell implantation and consequent cancer growth in a bladder. This treatment requires the stringent sterile requirement of EGCG. EGCG can be unstable when sterilized at high temperatures. Thus, we evaluated two low temperature sterilization methods, such as ionizing radiation or the filtration method followed by freeze-drying. Both methods ensure the sterility of the sample; however, infrared and HPLC analysis revealed a slightly better stability of irradiated EGCG over the filtration method. The concentration of stable free radicals following irradiation was low, which are unlikely to exert any damaging effects to EGCG. Therefore, we consider that radiation will be the preferred method of EGCG sterilization, and that this may prove useful for the effective use of EGCG in the treatment of bladder cancer.

Cocoa tea (Camellia ptilophylla) water extract inhibits adipocyte differentiation in mouse 3T3-L1 preadipocytes

Cocoa tea (Camellia ptilophylla) is a naturally decaffeinated tea plant. Previously we found that cocoa tea demonstrated a beneficial effect against high-fat diet induced obesity, hepatic steatosis, and hyperlipidemia in mice. The present study aimed to investigate the anti-adipogenic effect of cocoa tea in vitro using preadipocytes 3T3-L1. Adipogenic differentiation was confirmed by Oil Red O stain, qPCR and Western blot. Our results demonstrated that cocoa tea significantly inhibited triglyceride accumulation in mature adipocytes in a dose-dependent manner. Cocoa tea was shown to suppress the expressions of key adipogenic transcription factors, including peroxisome proliferator-activated receptor gamma (PPAR γ) and CCAAT/enhancer binding protein (C/EBP α). The tea extract was subsequently found to reduce the expressions of adipocyte-specific genes such as sterol regulatory element binding transcription factor 1c (SREBP-1c), fatty acid synthase (FAS), Acetyl-CoA carboxylase (ACC), fatty acid translocase (FAT) and stearoylcoenzyme A desaturase-1 (SCD-1). In addition, JNK, ERK and p38 phosphorylation were inhibited during cocoa tea inhibition of 3T3-L1 adipogenic differentiation. Taken together, this is the first study that demonstrates cocoa tea has the capacity to suppress adipogenesis in pre-adipocyte 3T3-L1 similar to traditional green tea.

The differential effects of green tea on dose-dependent doxorubicin toxicity

Background

Doxorubicin (DOX) is an anticancer drug displaying cardiac and hepatic adverse effects mostly dependent on oxidative stress. Green tea (GT) has been reported to play a protective role in diseases resulting from oxidative stress.

Objective

The objective of this study was to evaluate if GT protects against DOX-induced oxidative stress, heart and liver morphological changes, and metabolic disorders.

Methods

Male Wistar rats received intraperitoneal injection of DOX (1.0 or 2.0 mg/kg b.w.) for 7 weeks or concomitantly GT extract soluble in drinking water.

Results

There were multidirectional effects of GT on blood metabolic parameters changed by DOX. Among all tested biochemical parameters, statistically significant protection of GT against DOX-induced changes was revealed in case of blood fatty acid–binding protein, brain natriuretic peptide, and superoxide dismutase.

Conclusion

DOX caused oxidative stress in both organs. It was inhibited by GT in the heart but remained unchanged in the liver. DOX-induced general toxicity and histopathological changes in the heart and in the liver were mitigated by GT at a higher dose of DOX and augmented in rats treated with a lower dose of the drug.

Phase I study of topical epigallocatechin-3-gallate (EGCG) in patients with breast cancer receiving adjuvant radiotherapy

OBJECTIVE

The purpose of this study was to investigate the safety, tolerability and preliminary effectiveness of topical epigallocatechin-3-gallate (EGCG) for radiation dermatitis in patients with breast cancer receiving adjuvant radiotherapy.

METHODS

Patients with breast cancer who received radiotherapy to the chest wall after mastectomy were enrolled. EGCG solution was sprayed to the radiation field from the initiation of Grade 1 radiation dermatitis until 2 weeks after completion of radiotherapy. EGCG concentration escalated from 40 to 660 μmol l(-1) in 7 levels with 3-6 patients in each level. EGCG toxicity was graded using the NCI (National Cancer Institute Common Terminology Criteria for Adverse Events) v. 3.0. Any adverse event >Grade 1 attributed to EGCG was considered dose-limiting toxicity. The maximum tolerated dose was defined as the dose level that induced dose-limiting toxicity in more than one-third of patients at a given cohort. Radiation dermatitis was recorded weekly by the Radiation Therapy Oncology Group scoring and patient-reported symptoms.

RESULTS

From March 2012 to August 2013, 24 patients were enrolled. Acute skin redness was observed in 1 patient and considered to be associated with the EGCG treatment at 140 μmol l(-1) level. Three more patients were enrolled at this level and did not experience toxicity to EGCG. The dose escalation stopped at 660 μmol l(-1). No other reported acute toxicity was associated with EGCG. Grade 2 radiation dermatitis was observed in eight patients during or after radiotherapy, but all decreased to Grade 1 after EGCG treatments. Patient-reported symptom scores were significantly decreased at 2 weeks after the end of radiotherapy in pain, burning, itching and tenderness, p < 0.05.

CONCLUSION

The topical administration of EGCG was well tolerated and the maximum tolerated dose was not found. EGCG may be effective in treating radiation dermatitis with preliminary investigation.

ADVANCES IN KNOWLEDGE

EGCG solution seemed to be feasible for treating radiation dermatitis in patients with breast cancer after mastectomy. It should be tested as a way to reduce radiation-induced normal tissue toxicity and complications in future years.

Long non-coding RNAs expression profile in HepG2 cells reveals the potential role of long non-coding RNAs in the cholesterol metabolism

BACKGROUND

Green tea has been shown to improve cholesterol metabolism in animal studies, but the molecular mechanisms underlying this function have not been fully understood. Long non-coding RNAs (lncRNAs) have recently emerged as a major class of regulatory molecules involved in a broad range of biological processes and complex diseases. Our aim was to identify important lncRNAs that might play an important role in contributing to the benefits of epigallocatechin-3-gallate (EGCG) on cholesterol metabolism.

METHODS

Microarrays was used to reveal the lncRNA and mRNA profiles in green tea polyphenol(-)-epigallocatechin gallate in cultured human liver (HepG2) hepatocytes treated with EGCG and bioinformatic analyses of the predicted target genes were performed to identify lncRNA-mRNA targeting relationships. RNA interference was used to investigate the role of lncRNAs in cholesterol metabolism.

RESULTS

The expression levels of 15 genes related to cholesterol metabolism and 285 lncRNAs were changed by EGCG treatment. Bioinformatic analysis found five matched lncRNA-mRNA pairs for five differentially expressed lncRNAs and four differentially expressed mRNA. In particular, the lncRNA AT102202 and its potential targets mRNA-3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) were identified. Using a real-time polymerase chain reaction technique, we confirmed that EGCG down-regulated mRNA expression level of the HMGCR and up-regulated expression of AT102202. After AT102202 knockdown in HepG2, we observed that the level of HMGCR expression was significantly increased relative to the scrambled small interfering RNA control (P < 0.05).

CONCLUSIONS

Our results indicated that EGCG improved cholesterol metabolism and meanwhile changed the lncRNAs expression profile in HepG2 cells. LncRNAs may play an important role in the cholesterol metabolism.

Preventive role of green tea catechins from obesity and related disorders especially hypercholesterolemia and hyperglycemia

Background

During the last few years, scientific investigations have proposed diet based regimens to prevent several health ailments including obesity, hypercholesterolemia and diabetes. In this regard, a promising tool is the use of functional foods/nutraceuticals. Present research project was an attempt to explore nutraceutical worth of locally grown green tea variety (Qi-Men) against lifestyle related disorders.

Methods

Functional drinks (T₂ and T₃) were prepared by adding catechins and epigallocatechin gallate (EGCG) @ 550 mg/500 mL and compared with control (T₁). These functional drinks were tested in experimental rats modeling (Sprague Dawley). Based on diets, four studies were conducted i.e. trial-I (normal diet), trial-II (high cholesterol diet), trial-III (high sucrose diet), trial-IV (high cholesterol + high sucrose diet). Rats were monitored daily for their feed and drink intake while body weight was measured on weekly basis. After period of 56 days rats were sacrificed and evaluated their serum lipid (cholesterol, LDL and HDL), glucose and insulin levels.

Results

Results for feed consumption by rats revealed that highest feed intake was recorded in group provided control drink than other groups. However, non significant differences were noted among all groups for drink consumption. Functional drinks resulted in significant reduction in body weight with maximum lowering noted in trial-II and III i.e. 10.73 to 8.49% and 10.12 to 10.49%, respectively. Likewise, cholesterol and LDL were substantially reduced with 14.42% decrease observed in trial-IV and 30.43% in trial-II, respectively. Furthermore, serum glucose and insulin levels were also lowered significantly in the trial-III and IV while in trial-I and II differences were non-significant. In contrast to lipid profile, experimental drink containing EGCG reduced the trait better than catechins based functional drink.

Conclusions

The drinks supplemented with catechins and EGCG are effective against obesity, hypercholesterolemia and hyperglycemia.

Effect of Dietary Cocoa Tea (Camellia ptilophylla) Supplementation on High-Fat Diet-Induced Obesity, Hepatic Steatosis, and Hyperlipidemia in Mice

Recent studies suggested that green tea has the potential to protect against diet-induced obesity. The presence of caffeine within green tea has caused limitations. Cocoa tea (Camellia ptilophylla) is a naturally decaffeinated tea plant. To determine whether cocoa tea supplementation results in an improvement in high-fat diet-induced obesity, hyperlipidemia and hepatic steatosis, and whether such effects would be comparable to those of green tea extract, we studied six groups (n = 10) of C57BL/6 mice that were fed with (1) normal chow (N); (2) high-fat diet (21% butterfat + 0.15% cholesterol, wt/wt) (HF); (3) a high-fat diet supplemented with 2% green tea extract (HFLG); (4) a high-fat diet supplemented with 4% green tea extract (HFHG); (5) a high-fat diet supplemented with 2% cocoa tea extract (HFLC); and (6) a high-fat diet supplemented with 4% cocoa tea extract (HFHC). From the results, 2% and 4% dietary cocoa tea supplementation caused a dose-dependent decrease in (a) body weight, (b) fat pad mass, (c) liver weight, (d) total liver lipid, (e) liver triglyceride and cholesterol, and (f) plasma lipids (triglyceride and cholesterol). These data indicate that dietary cocoa tea, being naturally decaffeinated, has a beneficial effect on high-fat diet-induced obesity, hepatomegaly, hepatic steatosis, and elevated plasma lipid levels in mice, which are comparable to green tea. The present findings have provided the proof of concept that dietary cocoa tea might be of therapeutic value and could therefore provide a safer and cost effective option for patients with diet-induced metabolic syndrome.

Effects of (-)-gallocatechin-3-gallate on tetrodotoxin-resistant voltage-gated sodium channels in rat dorsal root ganglion neurons

The (−)-gallocatechin-3-gallate (GCG) concentration in some tea beverages can account for as much as 50% of the total catechins. It has been shown that catechins have analgesic properties. Voltage-gated sodium channels (Nav) mediate neuronal action potentials. Tetrodotoxin inhibits all Nav isoforms, but Nav1.8 and Nav1.9 are relatively tetrodotoxin-resistant compared to other isoforms and functionally linked to nociception. In this study, the effects of GCG on tetrodotoxin-resistant Na⁺ currents were investigated in rat primary cultures of dorsal root ganglion neurons via the whole-cell patch-clamp technique. We found that 1 μM GCG reduced the amplitudes of peak current density of tetrodotoxin-resistant Na⁺ currents significantly. Furthermore, the inhibition was accompanied by a depolarizing shift of the activation voltage and a hyperpolarizing shift of steady-state inactivation voltage. The percentage block of GCG (1 μM) on tetrodotoxin-resistant Na⁺ current was 45.1% ± 1.1% in 10 min. In addition, GCG did not produce frequency-dependent block of tetrodotoxin-resistant Na⁺ currents at stimulation frequencies of 1 Hz, 2 Hz and 5 Hz. On the basis of these findings, we propose that GCG may be a potential analgesic agent.

Green tea halts progression of cardiac transthyretin amyloidosis: an observational report

Background

Treatment options in patients with amyloidotic transthyretin (ATTR) cardiomyopathy are limited. Epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea (GT), inhibits fibril formation from several amyloidogenic proteins in vitro. Thus, it might also halt progression of TTR amyloidosis. This is a single-center observational report on the effects of GT consumption in patients with ATTR cardiomopathy.

Methods

19 patients with ATTR cardiomyopathy were evaluated by standard blood tests, echocardiography, and cardiac MRI (n = 9) before and after consumption of GT and/or green tea extracts (GTE) for 12 months.

Results

Five patients were not followed up for reasons of death (n = 2), discontinuation of GT/GTE consumption (n = 2), and heart transplantation (n = 1). After 12 months no increase of left ventricular (LV) wall thickness and LV myocardial mass was observed by echocardiography. In the subgroup of patients evaluated by cardiac MRI a mean decrease of LV myocardial mass (−12.5 %) was detected in all patients. This was accompanied by an increase of mean mitral annular systolic velocity of 9 % in all 14 patients. Total cholesterol (191.9 ± 8.9 vs. 172.7 ± 9.4 mg/dL; p < 0.01) and LDL cholesterol (105.8 ± 7.6 vs. 89.5 ± 8.0 mg/dL; p < 0.01) decreased significantly during the observational period. No serious adverse effects were reported by any of the participants.

Conclusions

Our observation suggests an inhibitory effect of GT and/or GTE on the progression of cardiac amyloidosis. We propose a randomized placebo-controlled investigation to confirm our observation.

Electronic supplementary material

The online version of this article (doi:10.1007/s00392-012-0463-z) contains supplementary material, which is available to authorized users.

Multiple antioxidants and L-arginine modulate inflammation and dyslipidemia in chronic renal failure rats

The kidney is an important source of L-arginine, the endogenous precursor of nitric oxide (NO). Surgical problems requiring extensive renal mass reduction (RMR) decrease renal NO production, leading to multiple hemodynamic and homeostatic disorders manifested by hypertension, oxidative stress, and increased inflammatory cytokines. Using the RMR model of chronic renal failure (CRF), we assessed the effects of twelve weeks' administration of L-arginine and/or a mixture of antioxidants (L-carnitine, catechin, vitamins E and C) on plasma cytokines, soluble intercellular adhesion molecule-1 (sICAM-1), nitrate and nitrites (NO(2)/NO(3)), lipid profile, blood pressure, and renal function. CRF rats showed increased plasma IL-1 alpha, IL1-beta, IL-6, TNF-alpha, and sICAM-1 levels and decreased anti-inflammatory cytokines IL-4 and 10 levels, hypertension, and dyslipidemia. L-arginine treatment improved kidney functions, decreased systolic blood pressure, and decreased inflammatory cytokines levels. Antioxidants administration decreased inflammatory cytokines and sICAM-1 levels and increased IL-4 levels. Combined use of both L-arginine and the antioxidant mixture were very effective in their tendency to recover normal values of kidney functions, plasma cytokines, sICAM-1, blood pressure, NO(2)/NO(3), cholesterol, and triglycerides concentrations. Indeed, the effects of L-arginine and the antioxidants on the reduction of proinflammatory cytokines may open new perspectives in the treatment of uremia.

Offset pi-pi interaction in crystal structure of (-)-gallocatechin-3-O-gallate

The single crystal of (-)-gallocatechin-3-O-gallate (GCg) was prepared using a solution containing an equimolecular amount of GCg and (-)-epigallocatechin-3-O-gallate (EGCg) in water. The crystal structure of GCg determined by X-ray crystallographic analysis was monoclinic with the space group P2(1) at 223 K. Offset pi-pi interactions formed between the A and A rings, B and B rings, and gallate and gallate rings of GCg, and five intermolecular hydrogen bonds formed between GCgs, GCg and water. The B ring of GCg bonded to C2 was in the axial position and the gallate ring of GCg bonded to C3 was in the pseudoaxial position with respect to the C ring of GCg.