Antiobesity effects of green tea catechins: a mechanistic review

Green preparation, safety control and intelligent processing of high-quality tea extract

Tea contains a variety of bioactive components, including catechins, amino acids, tea pigments, caffeine and tea polysaccharides, which exhibit multiple biological activities. These functional components in tea provide a variety of unique flavors, such as bitterness, astringency, sourness, sweetness and umami, which meet the demand of people for natural plant drinks with health benefits and pleasant flavor. Meanwhile, the traditional process of tea plantation, manufacturing and circulation are often accompanied by the safety problems of pesticide residue, heavy metal, organic solvents and other exogenous risks. High-quality tea extract refers to the special tea extract obtained by enriching the specific components of tea. Through green and efficient extraction technologies, diversed high-quality tea extracts such as high-fragrance and high-amino acid tea extracts, low-caffeine and high-catechin tea extracts, high-bioavailability and high-theaflavin tea extracts, high-antioxidant and high-tea polysaccharide tea extracts, high-umami-taste and low-bitter and astringent taste tea extracts are produced. Furthermore, rapid detection, green control and intelligent processing are applied to monitor the quality of tea in real-time, which guarantee the stability and safety of high-quality tea extracts with enhanced efficiency. These emerging technologies will realize the functionalization and specialization of high-quality tea extracts, and promote the sustainable development of tea industry.

Novel Therapeutic Approach for Obesity: Seaweeds as an Alternative Medicine with the Latest Conventional Therapy

The prevalence of overweight and obesity is increasing worldwide. Common comorbidities related to obesity, significantly polygenic disorders, cardiovascular disease, and heart conditions affect social and monetary systems. Over the past decade, research in drug discovery and development has opened new paths for alternative and conventional medicine. With a deeper comprehension of its underlying mechanisms, obesity is now recognized more as a chronic condition rather than merely a result of lifestyle choices. Nonetheless, addressing it solely through lifestyle changes is challenging due to the intricate nature of energy regulation dysfunction. The Federal Drug Administration (FDA) has approved six medications for the management of overweight and obesity. Seaweed are plants and algae that grow in oceans, rivers, and lakes. Studies have shown that seaweed has therapeutic potential in the management of body weight and obesity. Seaweed compounds such as carotenoids, xanthophyll, astaxanthin, fucoidans, and fucoxanthin have been demonstrated as potential bioactive components in the treatment of obesity. The abundance of natural seaweed bioactive compounds has been explored for their therapeutic potential for treating obesity worldwide. Keeping this view, this review covered the latest developments in the discovery of varied anti-obese seaweed and its bioactive components for the management of obesity.

Nutrition and diet for dry eye disease: Insights toward holistic management

Dry eye disease (DED) is one of the most common eye problems in the aging population. Hyperosmolarity triggers the immune response in DED and consequently activates the self-perpetuating immune cycle, leading to chronic damage of the ocular surface. This event causes symptoms such as a burning sensation, irritation, redness, photophobia, and blurred vision in DED patients. Subsequently, the quality of life gets significantly affected. The rising demand for DED management and treatment solutions, and the desirable outcomes from innovative therapies that draw global interest provide evidence to demonstrate the role of diet and nutrition in DED. Nutritional deficiency and a Westernized diet contribute to the chronic systemic progression of DED symptoms. It has been revealed in several published studies that the use of nutrients and dietary supplements improves the ocular surface and acts as a protective factor against DED. - We reviewed nutrition and dietary aspects in managing DED and its associated consequences, based on published studies, and reached an evidence-based conclusion.

Unveiling the total catechin profile in tea leaves: a novel one-step extraction method empowered by UPLC-IDX-Orbitrap mass spectrometry

More catechins are found in green tea than in any other type of tea, with its predominant production taking place in Asian nations. Consumption of green tea has been strongly correlated with a reduced risk of many diseases. This study introduces a new, efficient, and reliable method for extracting total catechins using ultra-high-performance liquid chromatography coupled with an ID-X-Orbitrap Mass spectrometer (UHPLC-IDX-Orbitrap-MS). The method was then applied to quantify the catechin content in green tea, yielding results comparable to previously published studies. Among the various sources of green tea analyzed, the lowest average catechin content was observed in Vietnam, Japan (2: Matcha), and Morocco, ranging between 346 and 322 mg/L. Conversely, the highest average catechin content (between 424 and 422 mg/L) was found in Sri Lanka and Japan (1: Sencha). For the remaining green tea extracts, the catechin levels ranged from 367 to 410 mg/L, exhibiting similar values. These findings demonstrate the high reproducibility of the proposed extraction procedure, with a relative standard deviation (RSD) error of less than 15% for the catechin standard. Additionally, the limit of detection for catechins was determined to be 1 ng mL-1. This study serves as a pilot investigation for extracting catechins from various green tea sources. Future research will focus on identifying all active compounds present. Furthermore, it is worth noting that this study aligns with the goals set forth in Saudi Vision 2030, which aims to diversify the country's economy and promote scientific advancements in various fields, including healthcare and agriculture.

Habitual consumption of high-fibre bread fortified with bean hulls increased plasma indole-3-propionic concentration and decreased putrescine and deoxycholic acid faecal concentrations in healthy volunteers

Only 6 to 8 % of the UK adults meet the daily recommendation for dietary fibre. Fava bean processing lead to vast amounts of high-fibre by-products such as hulls. Bean hull fortified bread was formulated to increase and diversify dietary fibre while reducing waste. This study assessed the bean hull: suitability as a source of dietary fibre; the systemic and microbial metabolism of its components and postprandial events following bean hull bread rolls. Nine healthy participants (53·9 ± 16·7 years) were recruited for a randomised controlled crossover study attending two 3 days intervention sessions, involving the consumption of two bread rolls per day (control or bean hull rolls). Blood and faecal samples were collected before and after each session and analysed for systemic and microbial metabolites of bread roll components using targeted LC-MS/MS and GC analysis. Satiety, gut hormones, glucose, insulin and gastric emptying biomarkers were also measured. Two bean hull rolls provided over 85 % of the daily recommendation for dietary fibre; but despite being a rich source of plant metabolites (P = 0·04 v. control bread), these had poor systemic bioavailability. Consumption of bean hull rolls for 3 days significantly increased plasma concentration of indole-3-propionic acid (P = 0·009) and decreased faecal concentration of putrescine (P = 0·035) and deoxycholic acid (P = 0·046). However, it had no effect on postprandial plasma gut hormones, bacterial composition and faecal short chain fatty acids amount. Therefore, bean hulls require further processing to improve their bioactives systemic availability and fibre fermentation.

Transcriptome analysis reveals the effect of acidic environment on adventitious root differentiation in Camellia sinensis

The generation of adventitious roots (ARs) is the key to the success of cuttings. The appropriate environment for AR differentiation in tea plants is acidic. However, the mechanism is unclear. In this study, pH 4.5 was suitable condition for the differentiation of AR in tea plants. At the base of cuttings, the root primordia differentiated ARs more rapidly at pH 4.5 than pH 7.0, and nine AR differentiation-related genes were found to be differentially expressed in 30 days, the result was also validated by qRT-PCR. The promoter regions of these genes contained auxin and brassinosteroid response elements. The expression levels of several genes which were involved in auxin and brassinosteroid synthesis as well as signaling at pH 4.5 compared to pH 7.0 occurred differential expression. Brassinolide (BL) and indole-3-acetic acid (IAA) could affect the differentiation of ARs under pH 4.5 and pH 7.0. By qRT-PCR analysis of genes during ARs generation, BL and IAA inhibited and promoted the expression of CsIAA14 gene, respectively, to regulate auxin signal transduction. Meanwhile, the expression levels of CsKNAT4, CsNAC2, CsNAC100, CsWRKY30 and CsLBD18 genes were up-regulated upon auxin treatment and were positively correlated with ARs differentiation.This study showed that pH 4.5 was the most suitable environment for the root primordia differentiation of AR in tea plant. Proper acidic pH conditions promoted auxin synthesis and signal transduction. The auxin initiated the expression of AR differentiation-related genes, and promoted its differentiated. BL was involved in ARs formation and elongation by regulating auxin signal transduction.

Effects of green tea catechin on the blood pressure and lipids in overweight and obese population-a meta-analysis

Background

Overweight and obesity as main health problems harm human beings worldwide. The number of people diagnosed with overweight and obese is gradually increasing. Green tea catechin has been reported to effectively help control body weight in overweight and obese population, and is protectively against the blood pressure and lipids in people with type 2 diabetes and metabolic syndrome.

Methods

We retrieved 4 English databases (PubMed, Web of science, Cochrane, Scoups) from inception to April 20, 2023. Two reviewers independently determined eligibility, assessed the reporting quality of included studies, and extracted the data. Data were extracted from eleven studies. The results were presented with the weighted mean differences (WMDs), and the confidence intervals (CIs) was 95 %. The random-effects or fixed-effects model was applied according to the heterogeneity. The subgroup analysis was used to identify the source of heterogeneity. Publication bias was evaluated using funnel plots, Egger's test, and Begg's test.

Results

Eleven randomized controlled trials (RCTs) inclusion studies were screened from 3072 literature articles, involving 613 overweight and obese patients. After combining all studies, it was found that in overweight and obese people green tea catechin could reduce waist circumference (WC) (pooled WMD = -1.37 cm, 95 % CI: -2.52 to -0.22 cm, p = 0.019), and triglyceride (TG) (pooled WMD = -0.18 mmol/L, 95 % CI: -0.35 to -0.02 mmol/L, p = 0.032), and increase high density lipoprotein cholesterol (HDL-c) (pooled WMD = 0.07 mmol/L, 95 % CI: 0.01-0.14 mmol/L, p = 0.031).

Conclusion

Green tea catechin supplement effectively reduced WC and TG levels and improved HDL-c levels. However, it did not show the significant effect on the blood pressure in overweight and obese people. The present meta-analysis showed a moderate benefit of green tea catechin supplementation on lipid profiles in overweight and obese people.

Research Trends in the Effect of Caffeine Intake on Fat Oxidation: A Bibliometric and Visual Analysis

In the last few decades, numerous studies pertaining to research groups worldwide have investigated the effects of oral caffeine intake on fat oxidation at rest, during exercise, and after exercise. However, there is no bibliometric analysis to assess the large volume of scientific output associated with this topic. A bibliometric analysis of this topic may be used by researchers to assess the current scientific interest in the application of caffeine as a nutritional strategy to augment fat oxidation, the journals with more interest in this type of publication, and to draw international collaborations between groups working in the same area. For these reasons, the purpose of this study was to assess the research activity regarding oral caffeine intake and fat oxidation rate in the last few decades by conducting a bibliometric and visual analysis. Relevant publications from 1992 to 2022 were retrieved from the Web of Science (WoS) Core Collection database. Quantitative and qualitative variables were collected, including the number of publications and citations, H-indexes, journals of citation reports, co-authorship, co-citation, and the co-occurrence of keywords. There were 182 total publications, while the number of annual publications is saw-shaped with a modest increase of 11.3% from 2000 to 2009 to 2010 to 2019. The United States was the country with the highest number of publications (24.17% of the total number of articles), followed by the Netherlands (17.03%). According to citation analyses, the average number of citations per document is 130, although there are 21 documents that have received more than 100 citations; the most cited document reached 644 citations. These citation data support the overall relevance of this topic in the fields of nutrition and dietetics and sport sciences that when combined harbored 85.71% of all articles published in the WoS. The most productive author was Westerterp-Plantenga with 16 articles (8.79% of the total number of articles). Nutrients was the journal that published the largest number of articles on this topic (6.59% of the total number of articles). Last, there is a tendency to include keywords such as "performance", "carbohydrate", and "ergogenic aid" in the newer articles, while "obesity", "thermogenic", and "tea" are the keywords more commonly included in older documents. Although research into the role of caffeine on fat oxidation has existed since the 1970s, our analysis suggests that the scientific output associated with this topic has progressively increased since 1992, demonstrating that this is a nutritional research area with a strong foundational base of scientific evidence. Based on the findings of this bibliometric analysis, future investigation may consider focusing on the effects of sex and tolerance to caffeine to widen the assessment of the effectiveness of oral caffeine intake as a nutritional strategy to augment the use of fat as a fuel, as these terms rarely appear in the studies included in this analysis. Additionally, more translational research is necessary as the studies that investigate the effect of oral caffeine intake in ecologically valid contexts (i.e., exercise training programs for individuals with excessive adiposity) are only a minor part of the studies on this topic.

Recent advancements in pharmacological strategies to modulate energy balance for combating obesity

The prevalence of obesity along with its related metabolic diseases has increased globally in recent decades. Obesity originates from a heterogeneous physiological state, which is further complicated by the influence of factors such as genetic, behavioural, and environmental. Lifestyle interventions including exercise and diet have limited success, necessitating the development of pharmacological approaches. Mechanistically, strategies target either reducing energy intake or increasing consumption through metabolism boosting. Current drugs lower energy intake via inducing satiety or inhibiting substrate absorption, while targeting mitochondria or cytosolic energy sensors has shown limited success due to toxicity. Nonshivering thermogenesis (NST) has provided hope for activating these processes selectively without significant side effects. The internet-based marketing of plant-based formulations for enhancing metabolism has surged. This review compiles scientific articles, magazines, newspapers, and online resources on anti-obesity drug development. Combination therapy of metabolic boosters and established anti-obesity compounds appears to be a promising future approach that requires further research.

In-silico annotation of the chemical composition of Tibetan tea and its mechanism on antioxidant and lipid-lowering in mice

BACKGROUND/OBJECTIVES

Tibetan tea is a kind of dark tea, due to the inherent complexity of natural products, the chemical composition and beneficial effects of Tibetan tea are not fully understood. The objective of this study was to unravel the composition of Tibetan tea using knowledge-guided multilayer network (KGMN) techniques and explore its potential antioxidant and hypolipidemic mechanisms in mice.

MATERIALS/METHODS

The C57BL/6J mice were continuously gavaged with Tibetan tea extract (T group), green tea extract (G group) and ddH₂O (H group) for 15 days. The activity of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) in mice was detected. Transcriptome sequencing technology was used to investigate the molecular mechanisms underlying the antioxidant and lipid-lowering effects of Tibetan tea in mice. Furthermore, the expression levels of liver antioxidant and lipid metabolism related genes in various groups were detected by the real-time quantitative polymerase chain reaction (qPCR) method.

RESULTS

The results showed that a total of 42 flavonoids are provisionally annotated in Tibetan tea using KGMN strategies. Tibetan tea significantly reduced body weight gain and increased T-AOC and SOD activities in mice compared with the H group. Based on the results of transcriptome and qPCR, it was confirmed that Tibetan tea could play a key role in antioxidant and lipid lowering by regulating oxidative stress and lipid metabolism related pathways such as insulin resistance, P53 signaling pathway, insulin signaling pathway, fatty acid elongation and fatty acid metabolism.

CONCLUSIONS

This study was the first to use computational tools to deeply explore the composition of Tibetan tea and revealed its potential antioxidant and hypolipidemic mechanisms, and it provides new insights into the composition and bioactivity of Tibetan tea.

Anti-Obesity Effect of a Tea Mixture Nano-Formulation on Rats Occurs via the Upregulation of AMP-Activated Protein Kinase/Sirtuin-1/Glucose Transporter Type 4 and Peroxisome Proliferator-Activated Receptor Gamma Pathways

White, green, and oolong teas are produced from the tea plant (Camellia sinensis (L.) Kuntze) and are reported to have anti-obesity and hypolipidemic effects. The current study aims to investigate the anti-obesity effects of a tea mixture nano-formulation by targeting the AMPK/Sirt-1/GLUT-4 axis in rats. In vitro lipase and α-amylase inhibition assays were used to determine the active sample, which was then incorporated into a nanoparticle formulation subjected to in vivo anti-obesity testing in rats by measuring the expression level of different genes implicated in adipogenesis and inflammation using qRT-PCR. Moreover, metabolomic analysis was performed for each tea extract using LC/ESI MS/MS coupled to chemometrics in an attempt to find a correlation between the constituents of the extracts and their biological activity. The in vitro pancreatic lipase and α-amylase inhibition assays demonstrated more effective activity in the tea mixture than the standards, orlistat and acarbose, respectively, and each tea alone. Thus, the herbal tea mixture and its nanoparticle formulation were evaluated for their in vivo anti-obesity activity. Intriguingly, the tea mixture significantly decreased the serum levels of glucose and triglycerides and increased the mRNA expression of GLUT-4, P-AMPK, Sirt-1, and PPAR-γ, which induce lipolysis while also decreasing the mRNA expression of TNF-α and ADD1/SREBP-1c, thereby inhibiting the inflammation associated with obesity. Our study suggests that the tea mixture nano-formulation is a promising therapeutic agent in the treatment of obesity and may also be beneficial in other metabolic disorders by targeting the AMPK/Sirt-1/Glut-4 pathway.

The use of cellulose, chitosan and hyaluronic acid in transdermal therapeutic management of obesity: A review

Obesity is a clinical condition with rising popularity and detrimental impacts on human health. According to the World Health Organization, obesity is the sixth most common cause of death worldwide. It is challenging to combat obesity because medications that are successful in the clinical investigation have harmful side effects when administered orally. The conventional approaches for treating obesity primarily entail synthetic compounds and surgical techniques but possess severe adverse effects and recurrences. As a result, a safe and effective strategy to combat obesity must be initiated. Recent studies have shown that biological macromolecules of the carbohydrate class, such as cellulose, hyaluronic acid, and chitosan, can enhance the release and efficacy of medications for obesity but due to their short biological half-lives and poor oral bioavailability, their distribution rate is affected. This helps to comprehend the need for an effective therapeutic approach via a transdermal drug delivery system. This review focuses on the transdermal administration, utilizing cellulose, chitosan, and hyaluronic acid via microneedles, as it offers a promising solution to overcome existing therapy limitations in managing obesity and it also highlights how microneedles can effectively deliver therapeutic substances through the skin's outer layer, bypassing pain receptors and specifically targeting adipose tissue.

Cardiovascular Remodeling Post-Ischemia: Herbs, Diet, and Drug Interventions

Cardiovascular disease (CVD) is a serious health burden with increasing prevalence, and CVD continues to be the principal global source of illness and mortality. For several disorders, including CVD, the use of dietary and medicinal herbs instead of pharmaceutical drugs continues to be an alternate therapy strategy. Despite the prevalent use of synthetic pharmaceutical medications, there is currently an unprecedented push for the use of diet and herbal preparations in contemporary medical systems. This urge is fueled by a number of factors, the two most important being the common perception that they are safe and more cost-effective than modern pharmaceutical medicines. However, there is a lack of research focused on novel treatment targets that combine all these strategies-pharmaceuticals, diet, and herbs. In this review, we looked at the reported effects of pharmaceutical drugs and diet, as well as medicinal herbs, and propose a combination of these approaches to target independent pathways that could synergistically be efficacious in treating cardiovascular disease.

The effect of green tea supplementation on the anthropometric outcomes in overweight and obese women: a time and dose-response meta-analysis of randomized controlled trials

Inconsistencies are evident within the literature regarding the role of Green Tea (GT) supplementation on women living with obesity. To address this, we conducted to determine the impact of GT supplementation on the weight, body mass index (BMI), and waist circumference (WC) in overweight and obese women using time and dose-response meta-analysis of randomized controlled trials (RCTs). This meta-analysis searched electronic Scopus, Web of Science, Embase, and PubMed/Medline databases from inception to December 1st, 2022. Data were reported as weighted mean difference (WMD) with 95% confidence interval (CI). A total of 2061 references were identified, and 15 articles with 16 RCT arms on body weight, 17 RCT arms on BMI, and 7 RCT arms on WC were included in the meta-analysis. GT supplementation significantly decreases body weight (WMD: -1.23 kg, 95% CI: -2.13 to -0.33, p = 0.007), BMI (WMD: -0.47 kg/m2, 95% CI: -0.87 to -0.07, p = 0.020) and WC (WMD: -3.46 cm, 95% CI: -6.75 to -0.16, p = 0.040). In subgroup analyses, GT consumption demonstrated lowered body weight with dosaes ≥1000 mg/day (WMD: -1.38 kg), in the RCTs, which lasted ≥8 wk (WMD: -1.24 kg). The non-linear dose-response assessment detected a negative correlation between the changes in body weight and BMI in green tea consumption of more than 1000 (mg/day). The GT supplementation reduced the weight, BMI, and WC in overweight and obese women. In clinical practice, healthcare professionals can recommend using GT with dosages ≥ 1000mg/day and duration ≥ 8 wk in obese women.

Treatments of heating and ultrasound improve the inhibition of gallocatechin gallate on tyrosinase

BACKGROUND

Gallocatechin gallate (GCG), a catechin of tea polyphenols, possesses inhibitory ability against tyrosinase, but few studies have reported how common processing methods affect it. In this research, the influence of heating and ultrasound treatments on the inhibition of GCG against tyrosinase was explored by ultraviolet-visible absorption, fluorescence spectroscopy, high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry.

RESULTS

Both heating and ultrasound treatments of GCG alone improved GCG's inhibitory ability against tyrosinase compared with the untreated, and a combination of heating and ultrasound treatment (100 °C, 20 min + 630 W, 20 min) further decreased the relative tyrosinase activity to 26.8%. The treated GCG exhibited a stronger fluorescence quenching effect on tyrosinase, but did not have any influence on the static quenching mechanism. Compared to the untreated GCG, the binding constants of treated GCG by heating, ultrasound and their combination with tyrosinase significantly increased, but the number of binding sites was still approximately one and the main driving force of the treated GCG was still hydrophobic interaction. After treatments of heating, ultrasound and their combination, the composition of GCG solutions was changed.

CONCLUSION

The enhanced inhibition of treated GCG on tyrosinase may be due to partial conversion of GCG into epigallocatechin-3-gallate (EGCG) and gallic acid (GA), which may cooperate with GCG to better inhibit the enzyme activity. This study has provided some valuable information for the application of catechins against tyrosinase in food processing and cosmetic industry. © 2022 Society of Chemical Industry.

Effects of Ethanolic and Aqueous Extracts of Garcinia gardneriana Leaves in an In Vivo Experimental Model Induced by a Hyperlipidic Diet

The study of medicinal plants, such as the genus Garcinia (Clusiaceae), in the treatment of non-communicable chronic diseases has aroused the interest of researchers. However, there are no studies in the literature that have investigated the effects of Garcinia gardneriana in experimental models of obesity for possible metabolic alterations. Swiss mice receiving a high-fat diet were supplemented with aqueous or ethanolic extract of G. gardneriana at doses of 200 or 400 mg/kg/day. It was found that there was a reduction in food consumption in experimental groups compared with the control groups, and the group supplemented with aqueous extract at a dose of 200 mg/kg/daydisplayed a reduction in weight. The results showed an increase in the values of high density lipoprotein (HDL-c), total cholesterol, triglycerides and fasting blood glucose. G. gardneriana did not protect against insulin resistance, and caused in an increase in monocyte chemoattractant protein-1 (MCP-1) concentrations and a reduction in interleukin 10 (IL-10). In addition, hepatic steatosis and microvesicular steatosis were indicated. It was revealed that, under the experimental conditions in the study, G. gardneriana did not prevent weight gain or comorbidities; that is, a different behavior was obtained from that described in the literature with regard to the medicinal potential of the Garcinia species, which is probably related to the phytochemical properties.

Insights on Dietary Polyphenols as Agents against Metabolic Disorders: Obesity as a Target Disease

Obesity is a condition that leads to increased health problems associated with metabolic disorders. Synthetic drugs are available for obesity treatment, but some of these compounds have demonstrated considerable side effects that limit their use. Polyphenols are vital phytonutrients of plant origin that can be incorporated as functional food ingredients. This review presents recent developments in dietary polyphenols as anti-obesity agents. Evidence supporting the potential application of food-derived polyphenols as agents against obesity has been summarized. Literature evidence supports the effectiveness of plant polyphenols against obesity. The anti-obesity mechanisms of polyphenols have been explained by their potential to inhibit obesity-related digestive enzymes, modulate neurohormones/peptides involved in food intake, and their ability to improve the growth of beneficial gut microbes while inhibiting the proliferation of pathogenic ones. Metabolism of polyphenols by gut microbes produces different metabolites with enhanced biological properties. Thus, research demonstrates that dietary polyphenols can offer a novel path to developing functional foods for treating obesity. Upcoming investigations need to explore novel techniques, such as nanocarriers, to improve the content of polyphenols in foods and their delivery and bioavailability at the target sites in the body.

The effects of green tea supplementation on cardiovascular risk factors: A systematic review and meta-analysis

Purpose

A bulk of observational studies have revealed the protective role of green tea supplementation in cardiovascular diseases. The current systematic review and meta-analysis study aimed to establish the effects of green tea supplementation on cardiovascular risk factors including lipid profile, blood pressure, glycemic control markers and CRP.

Methods

A systematic literature search of randomized clinical trials (RCTs) that investigated the effects of green tea supplementation and cardiovascular risk factors was undertaken in online databases including PubMed/Medline, Scopus, Web of Science, and Embase using a combination of green tea and cardiovascular risk factors search terms. Meta-analyses were carried out using a random-effects model. The I2 index was used to assess the heterogeneity of RCTs.

Results

Among the initial 11,286 studies that were identified from electronic databases search, 55 eligible RCTs with 63 effect sizes were eligible. Results from the random effects meta-analysis showed that GTE supplementation significantly reduced TC (WMD = -7.62; 95% CI: -10.51, -4.73; P = < 0.001), LDL-C (WMD = -5.80; 95% CI: -8.30, -3.30; P = < 0.001), FBS (WMD = -1.67; 95% CI: -2.58, -0.75; P = < 0.001), HbA1c (WMD = -0.15; 95% CI: -0.26, -0.04; P = 0.008), DBP (WMD = -0.87; 95% CI: -1.45, -0.29; P = 0.003), while increasing HDL-C (WMD = 1.85; 95% CI: 0.87, 2.84; P = 0.010). Subgroup analyses based on the duration of supplementation (≥ 12 vs. < 12 weeks), dose of green tea extract (GTE) (≥1,000 vs. < 1,000 mg/d), sex (male, female, and both), baseline serum levels of lipid profile, and glycemic control factors demonstrated different results for some risk factors.

Conclusion

The current study suggests improvements in the lipid and glycemic profiles following green tea supplementation. These findings support previous evidence showing the health benefits of green tea supplementation on cardiometabolic risk factors.

Bioaccessibility and Bioavailability of (-)-Epigallocatechin Gallate in the Bread Matrix with Glycemic Reduction

Bread has a high glycemic index (GI) and rich contents of quickly digestible carbohydrates, which is associated with insulin resistance and the risk of chronic diseases. (-)-Epigallocatechin Gallate (EGCG) is the primary catechin component that inhibits starch hydrolases, while the low release and absorption rates limit its utilization. In this study, EGCG was added to the bread matrix for fortification to reduce its glycemic index compared to white bread. EGCG fortification at 4% decreased the starch digestion rate of baked bread by 24.43% compared to unfortified bread and by 14.31% compared to white bread, with an identical amount of EGCG outside the matrix. Moreover, the predicted GI (pGI) was reduced by 13.17% compared to white bread. Further, 4% EGCG-matched bread enhanced the bioaccessibility and bioavailability of EGCG by 40.38% and 47.11%, respectively, compared to the control. The results of molecular docking demonstrated that EGCG had a higher binding affinity with α-amylase than with α-glucosidase, indicating that EGCG may effectively inhibit the accumulation of carbs during starch digestion. Thus, EGCG can be used as a functional ingredient in bread to reduce its glycemic potential, and the bread matrix can be used as a carrier for EGCG delivery to enhance its bioaccessibility and bioavailability.

Epigallocatechin Gallate and Glutathione Attenuate Aflatoxin B1-Induced Acute Liver Injury in Ducklings via Mitochondria-Mediated Apoptosis and the Nrf2 Signalling Pathway

Aflatoxin B1 (AFB1) exists widely in feed and food with severe hazards, posing a serious threat to human and animal health. Epigallocatechin gallate (EGCG) and glutathione (GSH) have been reported as having anti-oxidative and other functions. The present study aimed to investigate the detoxification effect of EGCG and GSH alone or in combination on AFB1 exposure in ducklings. Fifty one-day-old male ducklings were randomly assigned into five experimental groups (n = 10): 1. Control (CTR); 2. 0.3 mg/kg BW AFB1 (AFB1); 3. 0.3 mg/kg BW AFB1 + 100 mg/kg BW EGCG (AFB1 + EGCG); 4. 0.3 mg/kg BW AFB1 + 30 mg/kg BW GSH (AFB1 + GSH); 5. 0.3 mg/kg BW AFB1 + 100 mg/kg BW EGCG + 30 mg/kg BW GSH (AFB1 + EGCG + GSH). The experiment lasted for seven days. Compared with the CTR group, AFB1 reduced growth performance, total serum protein and albumin content, increased serum enzyme activity (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and γ-glutamyl transpeptidase), and caused pathological damage to the ducklings' livers. AFB1 exposure increased malondialdehyde content and decreased superoxide dismutase, total antioxidant capacity, catalase, glutathione peroxidase activities, and glutathione content in the liver. EGCG and GSH alone or in combination mitigated these adverse effects. Meanwhile, EGCG and GSH attenuate apoptosis of hepatocytes, and regulated AFB1-induced changes in the abundance of genes contained in the Keap1/Nrf2 signalling and apoptotic pathways. Collectively, these results suggest that EGCG and GSH alleviate the hepatocyte injury induced by AFB1 by inhibiting oxidative stress and attenuating excessive mitochondria-mediated apoptosis.

A 60-Day Green Tea Extract Supplementation Counteracts the Dysfunction of Adipose Tissue in Overweight Post-Menopausal and Class I Obese Women

Menopause is characterized by weight gain and increased visceral fat, which acts as an endocrine organ secreting proinflammatory adipocytokines, with consequent increased risk of metabolic disorders. The aim of this double-blind, placebo-controlled randomized trial was to evaluate the effects of a 60-day dietary supplementation using Camellia sinensis leaf extract on adipose tissue dysfunction in overweight or class I obese post-menopausal, sedentary women. Primary endpoints were the respiratory quotient (RQ), the percentage of carbohydrates (%CHO), the percentage of fat oxidation (%FAT), and the resting energy expenditure (REE) measured by indirect calorimetry. Secondary endpoints included body composition, by dual x-ray absorptiometry (DXA), glucose profile, lipid profile, inflammatory state, liver and kidney function, hormonal status regarding satiety, and status of catecholamines. Twenty-eight women were randomized into two groups: 14 (BMI 31.1 ± 3.5) were supplemented and 14 (BMI 31.9 ± 2.2) received placebo. In regards to the between-group differences over time (β), a statistically significant difference between the supplemented and placebo group was observed for: RQ (β = -0.04, p = 0.009), % fat oxidation (β = 11.04, p = 0.0006), insulin (β = -1.74, p = 0.009), HOMA (β = -0.31, p = 0.02), waist circumference (β = -1.07, p = 0.007), REE (β = 83.21, p = 0.009), and CRP (β = -0.14, p = 0.02). These results demonstrate that a 60-day green tea extract supplementation counteracts the dysfunction of adipose tissue in overweight post-menopausal and class I obese women.

Targeting Nanotechnology and Nutraceuticals in Obesity: An Updated Approach

HYPOTHESIS

This review article represents a brief layout of the risk factors and pathophysiology responsible for obesity, customary treatment strategies, and nanotechnology-based nutraceutical for the therapeutics of obesity.

EXPERIMENTS

An exhaustive search of the literature was done for this purpose, using Google Scholar, PubMed, and ScienceDirect databases. A literature study was conducted using publications published in peer-reviewed journals between 2000 and 2022.

FINDINGS

This was revealed that risk factors responsible for obesity were genetic abnormalities and environmental and socio-economic factors. Several research articles published between 2000 and 2022 were based on phytoconstituents-based nanoformulation for obesity therapeutics and, therefore, have been systematically compiled in this review. Various nutraceuticals like Garcinia cambogia, quercetin, resveratrol, capsaicin, Capsicum, Curcuma longa, Camella Sinensis, Zingiber officinalis, Citrus aurantium, Aegle marmelos, Coffea canephora, Asparagus officinalis, Gardenia jasminoides, Catha edulis, Clusia nemroisa, Rosmarinus officinalis, Cirsium setidens, Betula platyphylla, Tripterygium wilfordi possessing anti-obesity actions are discussed in this review along with their patents, clinical trials as well as their nanoformulation available.

CONCLUSION

This review illustrates that nanotechnology has a great propensity to impart a promising role in delivering phytochemicals and nutraceuticals in managing obesity conditions and other related disorders.

Consumer Choices and Habits Related to Tea Consumption by Poles

Tea is one of the most consumed beverages in the world. In the literature, much attention is paid to the influence of tea and its components on human health and consumer purchasing behavior. The aim of the study was to analyze the habits of Polish consumers regarding tea consumption, brewing methods, and their choices related to tea, to describe the characteristics of tea consumers, and present their segmentation based on consumer choices and habits regarding tea consumption. The study was performed using the computer-assisted web interviewing (CAWI) method on a group of 1700 adult consumers of tea. Information about consumer choices and habits related to tea consumption was collected, including brewing method, place of tea consumption, and factors determining tea choices. Using cluster analysis, six groups of tea consumers were identified. These are “Occasional tea gourmets”, “Yerba mate drinkers”, “Tea gourmets”, “Occasional consumers”, “Undemanding tea consumers,” and “Occasional strong tea consumers”. In summary, it can be said that Poles are not tea gourmets; they prefer black tea, in bags, brewed in cups or glasses for up to 3 min, and usually drink teas without any additives, at home, several times a week, during breakfast and between meals. The most popular brand among the respondents was Lipton. Consumers have little knowledge of the health benefits of tea.

Polyphenols as Plant-Based Nutraceuticals: Health Effects, Encapsulation, Nano-Delivery, and Application

Plant polyphenols have attracted considerable attention because of their key roles in preventing many diseases, including high blood sugar, high cholesterol, and cancer. A variety of functional foods have been designed and developed with plant polyphenols as the main active ingredients. Polyphenols mainly come from vegetables and fruits and can generally be divided according to their structure into flavonoids, astragalus, phenolic acids, and lignans. Polyphenols are a group of plant-derived functional food ingredients with different molecular structures and various biological activities including antioxidant, anti-inflammatory, and anticancer properties. However, many polyphenolic compounds have low oral bioavailability, which limits the application of polyphenols in nutraceuticals. Fortunately, green bio-based nanocarriers are well suited for encapsulating, protecting, and delivering polyphenols, thereby improving their bioavailability. In this paper, the health benefits of plant polyphenols in the prevention of various diseases are summarized, with a review of the research progress into bio-based nanocarriers for the improvement of the oral bioavailability of polyphenols. Polyphenols have great potential for application as key formulations in health and nutrition products. In the future, the development of food-grade delivery carriers for the encapsulation and delivery of polyphenolic compounds could well solve the limitations of poor water solubility and low bioavailability of polyphenols for practical applications.

Effect of Green Tea on Weight Gain and Semen Quality of Rabbit Males

The goal of the current study was to evaluate the action of the green tea plant (Camellia sinensis, L) on male rabbit reproduction and some non-reproductive indexes. Male rabbits were fed either a standard diet (control group) or a diet enriched with green tea powder (experimental groups; E): 5 g (E1) or 20 g (E2) per 100 kg of the milled complete feed mixture. Weight gain, sperm concentration, total and progressive motility, as well as haematological, and biochemical parameters and changes in testicular tissue histomorphology were evaluated. Feeding with green tea, at both tested concentrations, decreased weight gain per week and the total average weight gain compared to the control group (p < 0.05). Furthermore, green tea decreased sperm concentration, motility and progressive motility in the group fed with a lower dose (5 g) of green tea powder (p < 0.05), whilst a higher dose (20 g) was neutral. Some haematological and biochemical indexes, like medium-size cell count (MID), mean corpuscular haemoglobin concentration (MCHC), platelet percentage (PCT), levels of phosphorus (P) and total proteins (TP) were decreased in one or both experimental groups (p < 0.05), whilst the triglyceride level (TG) was increased in the E2 group (p < 0.05). The thicknesses of the testicular seminiferous tubules and epithelial layer were not affected by any concentration of green tea powder (p > 0.05). These observations suggest that green tea in the diet may have an adverse effect on rabbit growth and sperm quality, but their effect may be potentially dose-dependent.

Encapsulation of Catechin into β-Glucan Matrix Using Wet Milling and Ultrasonication as a Coupled Approach: Characterization and Bioactivity Retention

In this study, the nanoencapsulation of catechin into the β-glucan matrix from oats [O-Glu (C)] and barley [B-Glu (C)] was performed using the coupled approach of ultrasonication and wet milling. The nanoencapsulated catechin was characterised by particle size distribution, surface charge, SEM, and FTIR. The particle size was found to be 200 nm and 500 nm while zeta potential was found −27.13 and −24 mV for O-Glu (C) and B-Glu (C), respectively. The encapsulation efficiency of O-Glu (C) and B-Glu (C) was found to be 86.5% and 88.2%. FTIR and SEM revealed successful entrapment of catechin in β-glucan. The encapsulated capsules showed sustainable release during simulated gastrointestinal conditions. Moreover, both O-Glu (C) and B-Glu (C) showed that biological activity such as lipase inhibition activity and antioxidant assay were retained after in vitro digestion. It was concluded that O-Glu (C) and B-Glu (C) can be used as functional ingredients effectively in food as well as in the pharmaceutical field.

Effects of Keemun and Dianhong Black Tea in Alleviating Excess Lipid Accumulation in the Liver of Obese Mice: A Comparative Study

Schematic diagram of the effects of two black teas in alleviating excess hepatic lipid accumulation.

Tea and its phytochemicals: Hidden health benefits & modulation of signaling cascade by phytochemicals

Tea, one of the most widely consumed beverages, is prepared from the leaves of the Camellia sinensis. The promising health recompenses of tea have been linked to its different phenolic components, which have diverse biological characteristics. Tea also contains several flavonoids, alkaloids, phenolic, theanine, etc., which are associated with anti-oxidant characteristics and a variety of health benefits. It can also lower the pervasiveness of neurological disorders as well as prevent different types of cancer, metabolic syndromes, cardiovascular diseases, urinary stone, obesity, type 2 diabetes. Keeping in mind that tea helps to improve health and prevents many diseases, its consumption has been regarded as a "health-promoting habit" and current medical investigators have established the scientific basis for this concept over time. The current review provides new updated information and perspectives on the tea phytochemicals and their overall health benefits based on molecular processes, experimental studies, and clinical trials.

Tea polyphenols-loaded nanocarriers: preparation technology and biological function

Tea polyphenols (TP) have various biological functions including anti-oxidant, anti-bacterial, anti-apoptotic, anti-inflammatory and bioengineered repair properties. However, TP exhibit poor stability and bioavailability in the gastrointestinal tract. Nanoencapsulation techniques can be used to protect TP and to uphold their original characteristics during processing, storage and digestion, improve their physiochemical properties and enhance their health promoting effects. Nano-embedded TP show higher antioxidant, antibacterial and anticancer properties than TP, allowing TP to play a better role in bioengineering restoration after embedding. In this review, recent advances in nanoencapsulation of TP with biopolymeric nanocarriers (polysaccharides and proteins), lipid-based nanocarriers and innovative developments in preparation strategies were mainly discussed. Additionally, the strengthening biological functions of stability and bioavailability, antioxidant, antibacterial, anticancer activities and bioengineering repair properties activities after the nano-embedding of TP have been considered. Finally, further studies could be conducted for exploring the application of nanoencapsulated systems in food for industrial applications.

Association between Green Tea Consumption and Abdominal Obesity Risk in Middle-Aged Korean Population: Findings from the Korean Genome and Epidemiology Study

The prevalence of general and abdominal obesity is increasing with rapid economic growth and the westernization of dietary habits in Korea, especially in the middle-aged population. Data were obtained from the Korean Genome and Epidemiology Study (KoGES), which recruited 10,030 participants between the ages of 40 and 69 years. Information on green tea consumption was obtained from the food frequency questionnaire and categorized as none, <1 cup, between 1 and <4 cups, and ≥4 cups. Multivariable logistic regression models were used to estimate the ORs and 95% CIs to examine any possible associations between green tea consumption and the risk of abdominal obesity after controlling for potential confounders. High consumption of green tea was associated with a 44% lower odds ratio for abdominal obesity (none vs. ≥4 cups/week: OR, 0.56; 95% CI 0.41-0.78; p for trend = 0.001). When stratified by sex, an inverse association between green tea consumption and abdominal obesity was observed only in women (none vs. ≥4 cups/week: OR, 0.71; 95% CI 0.57−0.88; p for trend = 0.004). No significant association was found among men. Our findings indicate that green tea consumption has beneficial effects in the prevention of abdominal obesity in middle-aged Korean women.

Increased dosage and treatment time of Epigallocatechin-3-gallate (EGCG) negatively affects skeletal parameters in normal mice and Down syndrome mouse models

Bone abnormalities affect all individuals with Down syndrome (DS) and are linked to abnormal expression of DYRK1A, a gene found in three copies in people with DS and Ts65Dn DS model mice. Previous work in Ts65Dn male mice demonstrated that both genetic normalization of Dyrk1a and treatment with ~9 mg/kg/day Epigallocatechin-3-gallate (EGCG), the main polyphenol found in green tea and putative DYRK1A inhibitor, improved some skeletal deficits. Because EGCG treatment improved mostly trabecular skeletal deficits, we hypothesized that increasing EGCG treatment dosage and length of administration would positively affect both trabecular and cortical bone in Ts65Dn mice. Treatment of individuals with DS with green tea extract (GTE) containing EGCG also showed some weight loss in individuals with DS, and we hypothesized that weights would be affected in Ts65Dn mice after EGCG treatment. Treatment with ~20 mg/kg/day EGCG for seven weeks showed no improvements in male Ts65Dn trabecular bone and only limited improvements in cortical measures. Comparing skeletal analyses after ~20mg/kg/day EGCG treatment with previously published treatments with ~9, 50, and 200 mg/kg/day EGCG showed that increased dosage and treatment time increased cortical structural deficits leading to weaker appendicular bones in male mice. Weight was not affected by treatment in mice, except for those given a high dose of EGCG by oral gavage. These data indicate that high doses of EGCG, similar to those reported in some treatment studies of DS and other disorders, may impair long bone structure and strength. Skeletal phenotypes should be monitored when high doses of EGCG are administered therapeutically.

Flavonoid-Amyloid Fibril Hybrid Hydrogels for Obesity Control via Construction of Gut Microbiota

Innovative precise clinical approaches to protect humans from the alarming global growth of epidemics of chronic diseases, such as metabolic syndrome (MetS), are urgently needed. Here, we introduce protein hydrogels...

An Overview on How Exercise with Green Tea Consumption Can Prevent the Production of Reactive Oxygen Species and Improve Sports Performance

Free radicals are reactive products that have multiple effects on the human body. Endogenous and exogenous antioxidants manage the overproduction of free radicals. However, an imbalance between free radicals and antioxidant factors causes oxidative stress. Exercise and physical activity are factors that increase oxidative stress and disrupts the body’s homeostasis. Intensity and duration of training, training characteristics, and fitness level can have positive or negative effects on oxidative stress. Green tea consumption is recommended for the prevention of a variety of diseases, health maintenance, and weight loss. The effectiveness of green tea is primarily due to the presence of catechins and polyphenols, specifically (–)-epigallocatechin-3-gallate, which has antioxidant and anti-inflammatory properties based on clinical and animal studies. This review investigates the effect of green tea exercise and their interactive effects on free radicals and sports improvement.

Comparative study of the anti-obesity and gut microbiota modulation effects of green tea phenolics and their oxidation products in high-fat-induced obese mice

Green and black teas are regarded to possess therapeutic potential for the treatment of obesity, however it is not clear which tea performs better in body weight control. In this study, aiming to eliminate cultivar variation, green tea phenolics (GTP) were oxidized by tyrosinase to obtain oxidized tea phenolics (OTP). Thereafter, their anti-obesity effect on high-fat diet induced obese mice were compared. The results showed that despite their distinctive phenolic profiles, GTP and OTP exerted similar anti-obesity properties after 12 weeks of dietary intervention. Furthermore, cecal microbiota profiling exhibited comparable modulatory effects of GTP and OTP on multiple bacterial taxa, including Parabacteroides distasonis, Bifidobacterium, Prevotella, and Akkermansia muciniphila, which were strongly associated with obesity related indexes. Putative bacterial function profiling implicated that both GTP and OTP might regulate the lipid metabolism similarly. Collectively, the oxidation of GTP did not influence the anti-obesity and gut microbiota modulatory effects to any large extent.

Lipid-lowering nutraceuticals update on scientific evidence

: Cardiovascular diseases (CVDs) are the main cause of mortality worldwide. Risk factors of CVD can be classified into modifiable (smoking, hypertension, diabetes, hypercholesterolemia) through lifestyle changes or taking drug therapy and not modifiable (age, ethnicity, sex and family history). Elevated total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) levels have a lead role in the development of coronary heart disease (CHD), while high levels of high-density lipoprotein-cholesterol (HDL-C) seem to have a protective role.The current treatment for dyslipidemia consists of lifestyle modification or drug therapy even if not pharmacological treatment should be always considered in addition to lipid-lowering medications.The use of lipid-lowering nutraceuticals alone or in association with drug therapy may be considered when the atherogenic cholesterol goal was not achieved.These substances can be classified according to their mechanisms of action into natural inhibitors of intestinal cholesterol absorption, inhibitors of hepatic cholesterol synthesis and enhancers of the excretion of LDL-C. Nevertheless, many of them are characterized by mixed or unclear mechanisms of action.The use of these nutraceuticals is suggested in individuals with borderline lipid profile levels or with drug intolerance, but cannot replace standard lipid-lowering treatment in patients at high, or very high CVD risk.Nutraceuticals can also have vascular effects, including improvement in endothelial dysfunction and arterial stiffness, as well as antioxidative properties. Moreover, epidemiological and clinical studies reported that in patients intolerant of statins, many nutraceuticals with demonstrated hypolipidemic effect are well tolerated.

The Effect of Pluchea indica (L.) Less. Tea on Blood Glucose and Lipid Profile in People with Prediabetes: A Randomized Clinical Trial

Objective: Diabetes mellitus and dyslipidemia are currently increasing dramatically, and conventional medicine in the treatment of them has limited efficacies and serious adverse effects. Pluchea indica (L.) Less. tea (PIT) is widely consumed as a health-promoting drink in Southeast Asia. This study aimed to investigate whether P. indica tea has antidyslipidemic and antihyperglycemic effects and toxicity in humans. Design: A randomized clinical trial. Setting/Location: Nakhonratchasima, Thailand. Participants: Forty-five participants with prediabetes. Interventions: Participants were randomized to receive placebo tea, 1.5 g of PIT, and 1.5 g Camellia sinensis tea (green tea, CST) once daily for 12 weeks. Outcome Measurements: The oral glucose tolerance test (OGTT), total cholesterol, triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), blood urea nitrogen (BUN), creatinine, alanine transaminase (ALT), alkaline phosphatase (ALP), and complete blood count (CBC) before and after treatment were investigated. Results: The results showed that PIT significantly ameliorated hyperglycemia and significantly lower serum TG (109.22 ± 5.21 mg/dL) and LDL-C (122.20 ± 3.67 mg/dL) than placebo (145.56 ± 8.18 and 142.07 ± 8.58 mg/dL, respectively) (p < 0.05). Moreover, PIT exhibited serum TG (109.22 ± 5.21 mg/dL) significantly lower than CST (124.38 ± 4.70 mg/dL) (p < 0.05). In addition, the serum HDL-C of PIT (57.56 ± 3.05 mg/dL) was significantly higher than the placebo (46.44 ± 2.47 mg/dL) (p < 0.05). Furthermore, the toxicity testing showed that no significant difference in BUN, creatinine, ALT, ALP, and CBC of PIT-treated group compared with the placebo (p > 0.05). Conclusions: These results suggest that PIT may ameliorate hyperglycemia and dyslipidemia in prediabetes people. It may not be toxic to the kidney, liver, and blood. So, PIT has the potential to develop to be a health-promoting tea or herbal medicine for hyperglycemia and dyslipidemia prevention.

Providing food to patients in primary care to induce weight loss: a systematic literature review

PURPOSE

Primary care is the ideal setting to promote weight management, warranting innovative ways to support patients. This systematic review aimed to determine whether providing food to patients in primary care can help to reduce body weight.

METHODS

Four databases were searched for studies that aimed to elicit weight loss by directly providing foodstuffs and/or supplements to patients in primary care settings. Interventions with adults of any gender or race were included. Interventions that involved other components such as exercise classes or education sessions were excluded. The methodological quality of each study was appraised using the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies.

RESULTS

Four heterogeneous studies met the eligibility criteria, representing 476 adults. Two studies used meal-replacement products but differed in length and intensity, another study provided green tea and vitamin E supplementation, and the final study provided vouchers for use at a farmers' market hosted at a primary care clinic. Interventions ranged in length from 4 to 13 weeks. Three of the four studies observed weight loss in some form and all studies observed at least one other improvement in a health outcome such as waist circumference, blood pressure or fasting insulin levels.

CONCLUSIONS

A small yet notable body of literature supports the concept of providing food to patients in primary care settings to support weight loss. Further, high-quality research is needed on the efficacy and cost-effectiveness of this approach to ultimately inform policy initiatives for primary care.

Effect of Acute and Chronic Dietary Supplementation with Green Tea Catechins on Resting Metabolic Rate, Energy Expenditure and Respiratory Quotient: A Systematic Review

The consumption of green tea catechins (GTC) is associated with modulations of fat metabolism and consequent weight loss. The aim of this systematic review was to investigate the effect of GTC on resting metabolic rate (RMR), energy expenditure (EE), and respiratory quotient (RQ). Eligible studies considered both the chronic and acute intake of GTC-based supplements, with epigallocatechin gallate (EGCG) doses ranging between 100–800 mg. Findings from 15 studies (n = 499 participants) lasting 8–12 weeks (for chronic consumption) or 1–3 days (for acute intake) are summarized. This review reveals the positive effects of GTC supplementation on RQ values (272 subjects). Regarding the effects of acute and chronic GTC supplementation on RMR (244 subjects) and EE (255 subjects), the results did not allow for a definitive conclusion, even though they were promising, because some reported a positive improvement (two studies revealed an increase in RMR: one demonstrated an RMR increase of 43.82 kcal/day and another demonstrated an increase of 260.8 kcal/day, mainly when subjects were also engaged in resistance training exercise). Considering GTC daily dose supplementation, studies in which modifications of energetic parameters occurred, in particular RQ reduction, considered GTC low doses (100–300 mg). GTC may be useful for improving metabolic profiles. Further investigations are needed to better define adequate doses of supplementation.

Natural Bioactive Compounds Useful in Clinical Management of Metabolic Syndrome

Metabolic syndrome (MetS) is a clinical manifestation characterized by a plethora of comorbidities, including hyperglycemia, abdominal obesity, arterial hypertension, and dyslipidemia. All MetS comorbidities participate to induce a low-grade inflammation state and oxidative stress, typical of this syndrome. MetS is related to an increased risk of cardiovascular diseases and early death, with an important impact on health-care costs. For its clinic management a poly-pharmaceutical therapy is often required, but this can cause side effects and reduce the patient's compliance. For this reason, finding a valid and alternative therapeutic strategy, natural and free of side effects, could represent a useful tool in the fight the MetS. In this context, the use of functional foods, and the assumption of natural bioactive compounds (NBCs), could exert beneficial effects on body weight, blood pressure and glucose metabolism control, on endothelial damage, on the improvement of lipid profile, on the inflammatory state, and on oxidative stress. This review focuses on the possible beneficial role of NBCs in the prevention and in the clinical management of MetS and its comorbidities.

Epigallocatechin Gallate During Dietary Restriction - Potential Mechanisms of Enhanced Liver Injury

Green tea extract (GTE) is popular in weight loss, and epigallocatechin gallate (EGCG) is considered as the main active component. However, GTE is the primary cause of herbal and dietary supplement-induced liver injury in the United States. Whether there is a greater risk of liver injury when EGCG is consumed during dieting for weight loss has not been previously reported. This study found for the first time that EGCG could induce enhanced lipid metabolism pathways, suggesting that EGCG had the so-called “fat burning” effect, although EGCG did not cause liver injury at doses of 400 or 800 mg/kg in normal mice. Intriguingly, we found that EGCG caused dose-dependent hepatotoxicity on mice under dietary restriction, suggesting the potential combination effects of dietary restriction and EGCG. The combination effect between EGCG and dietary restriction led to overactivation of linoleic acid and arachidonic acid oxidation pathways, significantly increasing the accumulation of pro-inflammatory lipid metabolites and thus mediating liver injury. We also found that the disruption of Lands’ cycle and sphingomyelin-ceramides cycle and the high expression of taurine-conjugated bile acids were important metabolomic characteristics in EGCG-induced liver injury under dietary restriction. This original discovery suggests that people should not go on a diet while consuming EGCG for weight loss; otherwise the risk of liver injury will be significantly increased. This discovery provides new evidence for understanding the “drug-host” interaction hypothesis of drug hepatotoxicity and provides experimental reference for clinical safe use of green tea-related dietary supplements.

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.

Mechanisms of action for the anti-obesogenic activities of phytochemicals

The prevalence of obesity is increasing rapidly globally and has recently reached pandemic proportions. It is a multifactorial disorder linked to a number of non-communicable diseases such as type-2 diabetes, cardiovascular disease, and cancer. Over-nutrition and a sedentary lifestyle are considered the most significant causes of obesity; a healthy lifestyle and behavioural interventions are the most powerful ways to achieve successful weight loss, but to maintain this in the long term can prove difficult for many individuals, without medical intervention. Various pharmacological anti-obesogenic drugs have been tested and marketed in the past and have been moderately successful in the management of obesity, but their adverse effects on human health often outweigh the benefits. Natural products from plants, either in the form of crude extracts or purified phytochemicals, have been shown to have anti-obesogenic properties and are generally considered as nontoxic and cost-effective compared to synthetic alternatives. These plant products combat obesity by targeting the various pathways and/or regulatory functions intricately linked to obesity. Their mechanisms of action include inhibition of pancreatic lipase activities, an increase in energy expenditure, appetite regulation, lipolytic effects, and inhibition of white adipose tissue development. In this review, we discuss the distinct anti-obesogenic properties of recently reported plant extracts and specific bioactive compounds, along with their molecular mechanisms of action. This review will provide a common platform for understanding the different causes of obesity and the possible approaches to using plant products in tackling this worldwide health issue.