Therapeutic effect of high-dose green tea extract on weight reduction: A randomized, double-blind, placebo-controlled clinical trial

Epigallocatechin gallate alleviates non-alcoholic fatty liver disease through the inhibition of the expression and activity of Dipeptide kinase 4

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has emerged as the most prevalent glocal cause of chronic hepatic disease, with incidence rates that continue to rise steadily. Treatment options for affected patients are currently limited to dietary changes and exercise interventions, with no drugs having been licensed for the treatment of this disease. There is thus a pressing need for the development of novel therapeutic strategies. Work from our group suggests that the primary bioactive ingredient in green tea, epigallocatechin gallate (EGCG), may help reduce liver fat content and protect against hepatic injury through the inhibition of dipeptidyl peptidase 4 (DPP4) expression and activity. The study investigated the potential pathways by which EGCG may improve NAFLD, identified the sites of interaction between EGCG and DPP4, and proposed novel clinical treatment strategies.

METHODS

A clinical randomized controlled trial was conducted to investigate the potential efficacy of EGCG in NAFLD patients. The study compared relevant indices before and after EGCG administration. Animal models of NAFLD were constructed using male C57BL/6J mice fed a high-fat diet to observe the ameliorative effects of EGCG on the livers of the model mice and to investigate the potential pathways by which EGCG alleviates NAFLD. The interaction mechanism between EGCG and DPP4 was investigated using oleic acid and palmitic acid-treated HepG2 cell lines. Plasmids in which different sites had been disrupted were used to identify the effective interaction sites.

RESULTS

ECGC was found to suppress the accumulation of lipids, inhibit inflammation, remediate dysregulated lipid metabolism, and improve the pathogenesis of NAFLD via the inhibition of the expression and activity of DPP4.

CONCLUSIONS

The study results indicate that EGCG has a positive impact on improving NAFLD. These results highlight promising new opportunities to safely and effectively treat NAFLD in the clinic.

STUDY ID NUMBER

ChiCTR2300076741; https://www.chictr.org.cn/.

Effects of green tea on lipid profile in overweight and obese women

The effect of green tea administration on serum lipids' concentrations remains unclear as various investigations, which have explored this topic, have produced conflicting results. Gender might be one of the factors influencing the impact of green tea on the lipid profile. Hence, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effect of green tea intake on the lipid profile in overweight and obese women. We searched five databases (Web of Science, SCOPUS, Embase, PubMed/Medline, and Google Scholar) using a combination of MeSH and non-MeSH terms. Results were expressed as weighted mean differences (WMDs) and 95% confidence intervals (CIs) and synthesized with a random-effects model. In total, 15 eligible RCTs with 16 arms (1818 participants) were included in the meta-analysis. The combined effect size revealed a significant reduction in total cholesterol (TC) (WMD: -4.45 mg/dl, 95% CI: -6.63, -2.27, P<0.001) and low-density lipoprotein cholesterol (LDL-C) (WMD: -4.49 mg/dl, 95% CI: -7.50 to -1.47, P=0.003) concentrations following green tea supplementation in overweight and/or obese women. In addition, a more pronounced reduction of triglyceride (TG) levels occurred when the baseline TG value was ≥150 mg/dL (WMD: -24.45 mg/dL, 95% CI: -40.63 to -8.26, P=0.003). Moreover, a significant decrease in TG concentrations occurred in RCTs conducted on overweight subjects (BMI: 25-29.99 kg/m2) (WMD: -5.88 mg/dl, 95% CI: -10.76 to -0.99, P=0.01). In the subgroup analyses based on the study population, a notable increase in high-density lipoprotein cholesterol (HDL-C) values was observed in obese individuals (>30 kg/m2) (WMD: 2.63 mg/dl, 95% CI: 0.10 to 5.16, P=0.041). Consumption of green tea causes a reduction in LDL-C and TC concentrations in overweight and obese women. The decline in TG levels was notable particularly in overweight patients with hypertriglyceridemia at baseline. In addition, a significant increase in HDL-C was detected in obese subjects following intake of green tea.

The associations between dietary flavonoid intake and hyperlipidemia: data from the national health and nutrition examination survey 2007-2010 and 2017-2018

Background

Hyperlipidemia is a worldwide health problem and a significant risk factor for cardiovascular diseases; therefore, it imposes a heavy burden on society and healthcare. It has been reported that flavonoids can increase energy expenditure and fat oxidation, be anti-inflammatory, and reduce lipid factor levels, which may reduce the risk of hyperlipidemia. However, the relationship between the prevalence of hyperlipidemia and dietary flavonoid intake in the population remains unclear.

Methods

This study included 8,940 adults from the 2007-2010 and 2017-2018 National Health and Nutrition Examination Surveys (NHANES). The relationship between dietary flavonoid intake and the prevalence of hyperlipidemia was analyzed using weighted logistic regression and weighted restricted cubic spline.

Results

We found an inverse relationship between subtotal catechins intake and hyperlipidemia prevalence in the third quartile [0.74 (0.56, 0.98), p = 0.04] compared with the first quartile. The prevalence of hyperlipidemia and total flavan-3-ol intake in the third quartile were inversely correlated [0.76 (0.59, 0.98), p = 0.03]. Total anthocyanin intake was inversely related to the prevalence of hyperlipidemia in the third quartile [0.77 (0.62, 0.95), p = 0.02] and the fourth quartile [0.77 (0.60, 0.98), p = 0.04]. The prevalence of hyperlipidemia was negatively correlated with total flavonols intake in the fourth quartile [0.75 (0.60, 0.94), p = 0.02]. Using restricted cubic splines analysis, we found that subtotal catechins intake and total flavan-3-ol intake had a nonlinear relationship with the prevalence of hyperlipidemia.

Conclusion

Our study may provide preliminary research evidence for personalizing improved dietary habits to reduce the prevalence of hyperlipidemia.

The effects of green tea extract supplementation on body composition, obesity-related hormones and oxidative stress markers: a grade-assessed systematic review and dose-response meta-analysis of randomised controlled trials

Research indicates that green tea extract (GTE) supplementation is beneficial for a range of conditions, including several forms of cancer, CVD and liver diseases; nevertheless, the existing evidence addressing its effects on body composition, oxidative stress and obesity-related hormones is inconclusive. This systematic review and meta-analysis aimed to investigate the effects of GTE supplementation on body composition (body mass (BM), body fat percentage (BFP), fat mass (FM), BMI, waist circumference (WC)), obesity-related hormones (leptin, adiponectin and ghrelin) and oxidative stress (malondialdehyde (MDA) and total antioxidant capacity (TAC)) markers. We searched proper databases, including PubMed/Medline, Scopus and Web of Science, up to July 2022 to recognise published randomised controlled trials (RCT) that investigated the effects of GTE supplementation on the markers mentioned above. A random effects model was used to carry out a meta-analysis. The heterogeneity among the studies was assessed using the I2 index. Among the initial 11 286 studies identified from an electronic database search, fifty-nine studies involving 3802 participants were eligible to be included in this meta-analysis. Pooled effect sizes indicated that BM, BFP, BMI and MDA significantly reduced following GTE supplementation. In addition, GTE supplementation increased adiponectin and TAC, with no effects on FM, leptin and ghrelin. Certainty of evidence across outcomes ranged from low to high. Our results suggest that GTE supplementation can attenuate oxidative stress, BM, BMI and BFP, which are thought to negatively affect human health. Moreover, GTE as a nutraceutical dietary supplement can increase TAC and adiponectin.

Epigenetics in obesity: Mechanisms and advances in therapies based on natural products

Obesity is a major risk factor for morbidity and mortality because it has a close relationship to metabolic illnesses, such as diabetes, cardiovascular diseases, and some types of cancer. With no drugs available, the mainstay of obesity management remains lifestyle changes with exercise and dietary modifications. In light of the tremendous disease burden and unmet therapeutics, fresh perspectives on pathophysiology and drug discovery are needed. The development of epigenetics provides a compelling justification for how environmental, lifestyle, and other risk factors contribute to the pathogenesis of obesity. Furthermore, epigenetic dysregulations can be restored, and it has been reported that certain natural products obtained from plants, such as tea polyphenols, ellagic acid, urolithins, curcumin, genistein, isothiocyanates, and citrus isoflavonoids, were shown to inhibit weight gain. These substances have great antioxidant potential and are of great interest because they can also modify epigenetic mechanisms. Therefore, understanding epigenetic modifications to target the primary cause of obesity and the epigenetic mechanisms of anti-obesity effects with certain phytochemicals can prove rational strategies to prevent the disease and develop novel therapeutic interventions. Thus, the current review aimed to summarize the epigenetic mechanisms and advances in therapies for obesity based on natural products to provide evidence for the development of several potential anti-obesity drug targets.

Natural compounds as obesity pharmacotherapies

Obesity has become a serious global public health problem, affecting over 988 million people worldwide. Nevertheless, current pharmacotherapies have proven inadequate. Natural compounds have garnered significant attention due to their potential antiobesity effects. Over the past three decades, ca. 50 natural compounds have been evaluated for the preventive and/or therapeutic effects on obesity in animals and humans. However, variations in the antiobesity efficacies among these natural compounds have been substantial, owing to differences in experimental designs, including variations in animal models, dosages, treatment durations, and administration methods. The feasibility of employing these natural compounds as pharmacotherapies for obesity remained uncertain. In this review, we systematically summarized the antiobesity efficacy and mechanisms of action of each natural compound in animal models. This comprehensive review furnishes valuable insights for the development of antiobesity medications based on natural compounds.

The effect of green tea (Camellia sinensis) on lipid profiles and renal function in people with type 2 diabetes and nephropathy: a randomized controlled clinical trial

Introduction

Diabetic nephropathy is one of the most important microvascular complications of diabetes. Despite the modern treatments, herbs or medicinal plants have gained wide attention. One of these herbs is green tea (Camellia sinensis), which may have an impact on renal function, lipid profiles, and HbA1c. However, the evidence for this is unclear and limited. The present study aimed to evaluate the effect of different doses of green tea on these parameters in type 2 diabetes patients (T2DM) with nephropathy.

Methods

Sixty-six individuals with T2DM nephropathy (aged 30-70 years) were randomly assigned to receive three cups of green tea/day (n = 22), two cups of green tea/day (n = 22), and the control group (n = 22) for 12 weeks. Lipid profiles, glycated hemoglobin A1c (HbA1c), and renal markers were measured before and after intervention. Data were analyzed using SPSS software version 23. One-way analysis of variance (ANOVA), least significant difference (LSD) post hoc, and analysis of covariance were used to compare quantitative variables.

Results

In total, 64 participants completed the study. Consuming three cups of infusion green tea per day (7.5 gr) led to a significant reduction in serum levels of total cholesterol (p = 0.009) and HbA1c (p = 0.006) and increased in high-density lipoprotein cholesterol (HDL-C) (p = 0.02) compared with the control group who did not drink green tea. However, no significant differences were observed for other variables.

Conclusion

In general, it was found that drinking three cups of green tea infusion (7.5 gr) per day produced beneficial effects on some lipid profiles and HbA1c without any adverse effects on renal function in patients with T2DM nephropathy. More studies are needed to fully elucidate these findings.

Clinical trial registration

Iranian Registry of Clinical Trials (www.irct.ir) under registry number: IRCT2014020114538N2.

(-)-Epigallocatechin-3-Gallate Reduces Perfluorodecanoic Acid-Exacerbated Adiposity and Hepatic Lipid Accumulation in High-Fat Diet-Fed Male C57BL/6J Mice

Perfluorodecanoic acid (PFDA), an enduring and harmful organic pollutant, is widely employed in diverse food-related sectors. Our previous studies have provided evidence that PFDA has the potential to facilitate obesity and hepatic fat accumulation induced by high-fat diet (HFD) intake. Epigallocatechin-3-gallate (EGCG), a polyphenol found in green tea, has been suggested to possess potential preventive effects against metabolic abnormalities and fatty liver. The purpose of this research was to investigate the effects of EGCG on PFDA-exacerbated adiposity and hepatic lipid accumulation in HFD-fed mice. The results showed that EGCG reduced body weight gain; tissue and organ weights; blood glucose, serum insulin, HOMA-IR, leptin, and lipid parameters; serum inflammatory cytokines (IL-1β, IL-18, IL-6, and TNF-α); and hepatic lipid accumulation in PFDA-exposed mice fed an HFD. Further work showed that EGCG improved liver function and glucose homeostasis in mice fed an HFD and co-exposed to PFDA. The elevated hepatic mRNA levels of SREBP-1 and associated lipogenic genes, NLRP3, and caspase-1 in PFDA-exposed mice fed an HFD were significantly decreased by EGCG. Our work provides evidence for the potential anti-obesity effect of EGCG on co-exposure to HFD and PFDA and may call for further research on the bioactivity of EGCG to attenuate the endocrine disruption effects of long-term exposure to pollutants.

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.

A Comprehensive Review of Phytonutrients as a Dietary Therapy for Obesity

Obesity is a complex medical condition mainly caused by eating habits, genetics, lifestyle, and medicine. The present study deals with traditional diets like the Mediterranean diet, Nordic diet, African Heritage diet, Asian diet, and DASH, as these are considered to be sustainable diets for curing obesity. However, the bioavailability of phytonutrients consumed in the diet may vary, depending on several factors such as digestion and absorption of phytonutrients, interaction with other substances, cooking processes, and individual differences. Hence, several phytochemicals, like polyphenols, alkaloids, saponins, terpenoids, etc., have been investigated to assess their efficiencies and safety in the prevention and treatment of obesity. These phytochemicals have anti-obesity effects, mediated via modulation of many pathways, such as decreased lipogenesis, lipid absorption, accelerated lipolysis, energy intake, expenditure, and preadipocyte differentiation and proliferation. Owing to these anti-obesity effects, new food formulations incorporating these phytonutrients were introduced that can be beneficial in reducing the prevalence of obesity and promoting public health.

Could Natural Products Help in the Control of Obesity? Current Insights and Future Perspectives

Obesity is a global issue faced by many individuals worldwide. However, no drug has a pronounced effect with few side effects. Green tea, a well-known natural product, shows preventive effects against obesity by decreasing lipogenesis and increasing fat oxidation and antioxidant capacity. In contrast, other natural products are known to contribute to obesity. Relevant articles published on the therapeutic effect of natural products on obesity were retrieved from PubMed, Web of Science, and Scopus. The search was conducted by entering keywords such as "obesity", "natural product", and "clinical trial". The natural products were classified as single compounds, foods, teas, fruits, herbal medicines-single extract, herbal medicines-decoction, and herbal medicines-external preparation. Then, the mechanisms of these medicines were organized into lipid metabolism, anti-inflammation, antioxidation, appetite loss, and thermogenesis. This review aimed to assess the efficacy and mechanisms of effective natural products in managing obesity. Several clinical studies reported that natural products showed antiobesity effects, including Coffea arabica (coffee), Camellia sinensis (green tea), Caulerpa racemosa (green algae), Allium sativum (garlic), combined Ephedra intermedia Schrenk, Thea sinensis L., and Atractylodes lancea DC extract (known as Gambisan), Ephedra sinica Stapf, Angelica Gigantis Radix, Atractylodis Rhizoma Alba, Coicis semen, Cinnamomi cortex, Paeoniae radix alba, and Glycyrrhiza uralensis (known as Euiiyin-tang formula). Further studies are expected to refine the pharmacological effects of natural products for clinical use.

Recent Advances in Nutraceuticals for the Treatment of Sarcopenic Obesity

Sarcopenic obesity, low muscle mass, and high body fat are growing health concerns in the aging population. This review highlights the need for standardized criteria and explores nutraceuticals as potential therapeutic agents. Sarcopenic obesity is associated with insulin resistance, inflammation, hormonal changes, and reduced physical activity. These factors lead to impaired muscle activity, intramuscular fat accumulation, and reduced protein synthesis, resulting in muscle catabolism and increased fat mass. Myostatin and irisin are myokines that regulate muscle synthesis and energy expenditure, respectively. Nutritional supplementation with vitamin D and calcium is recommended for increasing muscle mass and reducing body fat content. Testosterone therapy decreases fat mass and improves muscle strength. Vitamin K, specifically menaquinone-4 (MK-4), improves mitochondrial function and reduces muscle damage. Irisin is a hormone secreted during exercise that enhances oxidative metabolism, prevents insulin resistance and obesity, and improves bone quality. Low-glycemic-index diets and green cardamom are potential methods for managing sarcopenic obesity. In conclusion, along with exercise and dietary support, nutraceuticals, such as vitamin D, calcium, vitamin K, and natural agonists of irisin or testosterone, can serve as promising future therapeutic alternatives.

Phytochemicals for the treatment of metabolic diseases: Evidence from clinical studies

With the continuous improvement of people's living standard, the incidence of metabolic diseases is gradually increasing in recent years. There is growing interest in finding drugs to treat metabolic diseases from natural compounds due to their good efficacy and limited side effects. Over the past few decades, many phytochemicals derived from natural plants, such as berberine, curcumin, quercetin, resveratrol, rutin, and hesperidin, have been shown to have good pharmacological activity against metabolic diseases in preclinical studies. More importantly, clinical trials using these phytochemicals to treat metabolic diseases have been increasing. This review comprehensively summarizes the clinical progress of phytochemicals derived from natural plants in the treatment of several metabolic diseases, including type 2 diabetes mellitus (T2DM), obesity and non-alcoholic fatty liver disease (NAFLD). Accumulating clinical evidence shows that a total of 18 phytochemicals have good therapeutic effects on the three metabolic diseases by lowering blood glucose and lipid levels, reducing insulin resistance, enhancing insulin sensitivity, increasing energy expenditure, improving liver function, and relieving inflammation and oxidative stress. The information will help us better understand the medicinal value of these phytochemicals and promote their clinical application in the treatment of metabolic diseases.

The association between circulatory, local pancreatic PCSK9 and type 2 diabetes mellitus: The effects of antidiabetic drugs on PCSK9

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a potent modulator of cholesterol metabolism and plays a crucial role in the normal functioning of pancreatic islets and the progression of diabetes. Islet autocrine PCSK9 deficiency can lead to the enrichment of low-density lipoprotein (LDL) receptor (LDLR) and excessive LDL cholesterol (LDL-C) uptake, subsequently impairing the insulin secretion in β-cells. Circulatory PCSK9 levels are primarily attributed to hepatocyte secretion. Notably, anti-PCSK9 strategies proposed for individuals with hypercholesterolemia chiefly target liver-derived PCSK9; however, these anti-PCSK9 strategies have been associated with the risk of new-onset diabetes mellitus (NODM). In the current review, we highlight a new direction in PCSK9 inhibition therapy strategies: screening candidates for anti-PCSK9 from the drugs used in type 2 diabetes mellitus (T2DM) treatment. We explored the association between circulating, local pancreatic PCSK9 and T2DM, as well as the relationship between PCSK9 monoclonal antibodies and NODM. We discussed the emergence of artificial and natural drugs in recent years, exhibiting dual benefits of antidiabetic activity and PCSK9 reduction, confirming that the diverse effects of these drugs may potentially impact the progression of diabetes and associated disorders, thereby introducing novel avenues and methodologies to enhance disease prognosis.

Targeting Metabolic Syndrome in Hidradenitis Suppurativa by Phytochemicals as a Potential Complementary Therapeutic Strategy

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by the appearance of painful inflamed nodules, abscesses, and pus-draining sinus tracts in the intertriginous skin of the groins, buttocks, and perianal and axillary regions. Despite its high prevalence of ~0.4-1%, therapeutic options for HS are still limited. Over the past 10 years, it has become clear that HS is a systemic disease, associated with various comorbidities, including metabolic syndrome (MetS) and its sequelae. Accordingly, the life expectancy of HS patients is significantly reduced. MetS, in particular, obesity, can support sustained inflammation and thereby exacerbate skin manifestations and the chronification of HS. However, MetS actually lacks necessary attention in HS therapy, underlining the high medical need for novel therapeutic options. This review directs attention towards the relevance of MetS in HS and evaluates the potential of phytomedical drug candidates to alleviate its components. It starts by describing key facts about HS, the specifics of metabolic alterations in HS patients, and mechanisms by which obesity may exacerbate HS skin alterations. Then, the results from the preclinical studies with phytochemicals on MetS parameters are evaluated and the outcomes of respective randomized controlled clinical trials in healthy people and patients without HS are presented.

Exploring the Effects of Short-Term Daily Intake of Nitraria retusa Tea on Lipid Profile: A Pre-Post, Uncontrolled Pilot Study in Both Healthy and Overweight/Obese Adults

In the present study, we aimed to explore the feasibility, compliance, and potential benefits of Nitraria retusa extract (NRE) intervention in both healthy (BMI ≤ 24.9 Kg/m2) and overweight/obese adults (BMI > 25 Kg/m2). A total of 98 participants, including 37 healthy individuals and 61 overweight/obese adults, were randomly assigned to either a low-dose (500 mg/day) or a high-dose (2000 mg/day) NRE intervention group. Plasma lipid biomarkers, liver and kidney functions, general hematology, and blood glucose levels were measured at the baseline and 10 days after intervention. While the lipid profile of the healthy participants did not show any statistically significant changes, the obese participants in the high-dose group experienced a significant decrease in triglyceride levels (within-group difference p value = 0.004) and an increase in HDL levels (within-group p value < 0.001). No significant differences were observed in other parameters, indicating that NRE at the given doses was safe. Furthermore, the study had impressive compliance and acceptability, with over 90% of participants completing the intervention and diligently following the study protocol. This pilot study represents the first investigation into the feasibility, acceptability, and potential benefits of NRE intervention on lipid profiles in human volunteers.

Epigallocatechin-3-Gallate Therapeutic Potential in Cancer: Mechanism of Action and Clinical Implications

Cellular signaling pathways involved in the maintenance of the equilibrium between cell proliferation and apoptosis have emerged as rational targets that can be exploited in the prevention and treatment of cancer. Epigallocatechin-3-gallate (EGCG) is the most abundant phenolic compound found in green tea. It has been shown to regulate multiple crucial cellular signaling pathways, including those mediated by EGFR, JAK-STAT, MAPKs, NF-κB, PI3K-AKT-mTOR, and others. Deregulation of the abovementioned pathways is involved in the pathophysiology of cancer. It has been demonstrated that EGCG may exert anti-proliferative, anti-inflammatory, and apoptosis-inducing effects or induce epigenetic changes. Furthermore, preclinical and clinical studies suggest that EGCG may be used in the treatment of numerous disorders, including cancer. This review aims to summarize the existing knowledge regarding the biological properties of EGCG, especially in the context of cancer treatment and prophylaxis.

Therapeutic Activity of Green Tea Epigallocatechin-3-Gallate on Metabolic Diseases and Non-Alcoholic Fatty Liver Diseases: The Current Updates

Green tea polyphenols have numerous functions including antioxidation and modulation of various cellular proteins and are thus beneficial against metabolic diseases including obesity, type 2 diabetes, cardiovascular and non-alcoholic fatty liver diseases, and their comorbidities. Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea and is attributed to antioxidant and free radical scavenging activities, and the likelihood of targeting multiple metabolic pathways. It has been shown to exhibit anti-obesity, anti-inflammatory, anti-diabetic, anti-arteriosclerotic, and weight-reducing effects in humans. Worldwide, the incidences of metabolic diseases have been escalating across all age groups in modern society. Therefore, EGCG is being increasingly investigated to address the problems. This review presents the current updates on the effects of EGCG on metabolic diseases, and highlights evidence related to its safety. Collectively, this review brings more evidence for therapeutic application and further studies on EGCG and its derivatives to alleviate metabolic diseases and non-alcoholic fatty liver diseases.

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.

The therapeutic role and potential mechanism of EGCG in obesity-related precocious puberty as determined by integrated metabolomics and network pharmacology

Objective

(-)-Epigallocatechin-3-gallate (EGCG) has preventive effects on obesity-related precocious puberty, but its underlying mechanism remains unclear. The aim of this study was to integrate metabolomics and network pharmacology to reveal the mechanism of EGCG in the prevention of obesity-related precocious puberty.

Materials and methods

A high-performance liquid chromatography-electrospray ionization ion-trap tandem mass spectrometry (LC-ESI-MS/MS) was used to analyze the impact of EGCG on serum metabolomics and associated metabolic pathways in a randomized controlled trial. Twelve weeks of EGCG capsules were given to obese girls in this trail. Additionally, the targets and pathways of EGCG in preventing obesity-related precocious puberty network pharmacology were predicted using network pharmacology. Finally, the mechanism of EGCG prevention of obesity-related precocious puberty was elucidated through integrated metabolomics and network pharmacology.

Results

Serum metabolomics screened 234 endogenous differential metabolites, and network pharmacology identified a total of 153 common targets. These metabolites and targets mainly enrichment pathways involving endocrine-related pathways (estrogen signaling pathway, insulin resistance, and insulin secretion), and signal transduction (PI3K-Akt, MAPK, and Jak-STAT signaling pathways). The integrated metabolomics and network pharmacology indicated that AKT1, EGFR, ESR1, STAT3, IGF1, and MAPK1 may be key targets for EGCG in preventing obesity-related precocious puberty.

Conclusion

EGCG may contribute to preventing obesity-related precocious puberty through targets such as AKT1, EGFR, ESR1, STAT3, IGF1, and MAPK1 and multiple signaling pathways, including the estrogen, PI3K-Akt, MAPK, and Jak-STAT pathways. This study provided a theoretical foundation for future research.

New Insights into Herb-Induced Liver Injury

Significance: Herbs are widely used worldwide. However, inappropriate use of some of the herbs can lead to herb-induced liver injury (HILI). Intriguingly, HILI incidents are on the rise, and our understanding of the underlying etiologies is in progress, and hence, an update on the current status of incidents as well as our understanding on the etiologies of HILI is appropriate. Recent Advances: HILI reports due to the use of some herbs that are traditionally considered to be safe are also on the rise. Furthermore, HILI due to the use of certain herbs in combination with other herbs (herb-herb interaction [HHI]) or non-herb components (herb-drug interaction [HDI]) has also been reported, suggesting a potentially important new type of inappropriate use of herbs. Critical Issues: Updated overviews focus on the epidemiology, etiology, phenotypes, and risk factors of HILI, as well as HDI and HHI, and analysis on several types of newly reported "toxic" effects of herbs based on types of hepatotoxicity and the HILI mechanisms. Future Directions: HILI will continue to be a significant public health challenge in the near future. In the light of the lack of broadly available guidelines and regulations for proper and safe uses of herbs worldwide, raising the public awareness of HILI will remain one of the most effective measures. In particular, it should include a better understanding of the contributing factors; a more detail subclassification and description of HILI, better characterization of the components/substances that could induce HILI; and development of HILI diagnosis based on the Roussel Uclaf Causality Assessment Method (RUCAM). Antioxid. Redox Signal. 38, 1138-1149.

Suppression of the Excitability of Rat Nociceptive Secondary Sensory Neurons following Local Administration of the Phytochemical, (-)-Epigallocatechin-3-gallate

The phytochemical, polyphenolic compound, (-)-epigallocatechin-3-gallate (EGCG), is the main catechin found in green tea. Although a modulatory effect of EGCG on voltage-gated sodium and potassium channels has been reported in excitable tissues, the in vivo effect of EGCG on the excitability of nociceptive sensory neurons remains to be determined. Our aim was to investigate whether local administration of EGCG to rats attenuates the excitability of nociceptive spinal trigeminal nucleus caudalis (SpVc) neurons in response to mechanical stimulation in vivo. Extracellular single unit recordings were made from SpVc neurons in response to orofacial mechanical stimulation of anesthetized rats. The mean firing frequency of SpVc wide-dynamic range neurons following both non-noxious and noxious mechanical stimuli was significantly inhibited by EGCG in a dose-dependent and reversible manner. The mean magnitude of inhibition by EGCG on SpVc neuronal discharge frequency was similar to that of the local anesthetic, 1% lidocaine. Local injection of half-dose of lidocaine replaced the half-dose of EGCG. These results suggest that local injection of EGCG suppresses the excitability of nociceptive SpVc neurons, possibly via the inhibition of voltage-gated sodium channels and opening of voltage-gated potassium channels in the trigeminal ganglion. Therefore, administration of EGCG as a local anesthetic may provide relief from trigeminal nociceptive pain without side effects.

Catechins and Proanthocyanidins Involvement in Metabolic Syndrome

Recent studies on natural antioxidant compounds have highlighted their potentiality against various pathological conditions. The present review aims to selectively evaluate the benefits of catechins and their polymeric structure on metabolic syndrome, a common disorder characterized by a cluster of three main risk factors: obesity, hypertension, and hyperglycemia. Patients with metabolic syndrome suffer chronic low inflammation state and oxidative stress both conditions effectively countered by flavanols and their polymers. The mechanism behind the activity of these molecules has been highlighted and correlated with the characteristic features present on their basic flavonoidic skelethon, as well as the efficient doses needed to perform their activity in both in vitro and in vivo studies. The amount of evidence provided in this review offers a starting point for flavanol dietary supplementation as a potential strategy to counteract several metabolic targets associated with metabolic syndrome and suggests a key role of albumin as flavanol-delivery system to the different target of action inside the organism.

Influence of Polyphenols on Adipose Tissue: Sirtuins as Pivotal Players in the Browning Process

Adipose tissue (AT) can be classified into two different types: (i) white adipose tissue (WAT), which represents the largest amount of total AT, and has the main function of storing fatty acids for energy needs and (ii) brown adipose tissue (BAT), rich in mitochondria and specialized in thermogenesis. Many exogenous stimuli, e.g., cold, exercise or pharmacological/nutraceutical tools, promote the phenotypic change of WAT to a beige phenotype (BeAT), with intermediate characteristics between BAT and WAT; this process is called "browning". The modulation of AT differentiation towards WAT or BAT, and the phenotypic switch to BeAT, seem to be crucial steps to limit weight gain. Polyphenols are emerging as compounds able to induce browning and thermogenesis processes, potentially via activation of sirtuins. SIRT1 (the most investigated sirtuin) activates a factor involved in mitochondrial biogenesis, peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), which, through peroxisome proliferator-activated receptor γ (PPAR-γ) modulation, induces typical genes of BAT and inhibits genes of WAT during the transdifferentiation process in white adipocytes. This review article aims to summarize the current evidence, from pre-clinical studies to clinical trials, on the ability of polyphenols to promote the browning process, with a specific focus on the potential role of sirtuins in the pharmacological/nutraceutical effects of natural compounds.

Preventive effect of Ya'an Tibetan tea on obesity in rats fed with a hypercaloric high-fat diet revealed by gut microbiology and metabolomics studies

Ya'an Tibetan Tea (YATT) is a classic dark tea variety fermented with a unique geographical environment and traditional craftsmanship. Previous research indicates that it is beneficial for obesity and related metabolic disorders, but no systematic research currently reveals its precise mechanisms. This work investigated the preventive effect of YATT on obesity and the corresponding potential mechanisms by performing 16S rRNA gene sequencing and metabolomics studies. Our results demonstrated that YATT could significantly improve the body weight and fat deposition in hypercaloric high-fat diet (HFD)-induced obese rats, enhance antioxidant enzymes activity and reduce inflammation, and reverse the liver damage caused by an HFD. Moreover, 16S rRNA analysis showed that YATT could improve the intestinal microbial disorders caused by the HFD by significantly reversing the increase in Firmicutes/Bacteroidetes（F/B）ratio and the relative abundance of flora associated with the HFD, such as unclassified_Lachnospiraceae and Romboutsia flora. In addition, metabolomic analysis of cecum contents identified 121 differential metabolites, of which 19 were common to all experimental rats fed with and without a high-fat diet. Strikingly, 17 of the most prevalent 19 differential metabolites, including Theobromine, L-Valine, and Diisobutyl phthalate, were considerably reversed by YATT. Enrichment analysis of the metabolic pathways of these differential metabolites indicated that Caffeine metabolism, Phenylalanine metabolism, and Lysine degradation are the potential metabolic pathways responsible for the obesity prevention effect of YATT. Collectively, this work revealed that YATT has good potential for obesity prevention and the improvement of intestinal microbial communities, potentially due to the YATT-induced alterations in the metabolic pathways and functional metabolite levels of caffeine and amino acids. These results inform the material basis of YATT for obesity prevention and its mechanisms and provide essential insights for developing YATT as a healthy beverage for obesity prevention.

A comprehensive review on clinically proven medicinal plants in the treatment of overweight and obesity, with mechanistic insights

Background and objectives

Obesity has become a global health issue, more precisely, a pandemic throughout the present world due to its high prevalence in the recent era. Increased risk of morbidity and mortality in obese patients can be attributed to its association with the development of different life-threatening conditions. Plants are considered one of the most important sources of bioactive molecules which are used against a wide range of health disorders. This systematic review explores the efficacy as well as the safety profile of commonly used medicinal plants in the management of obesity that may help people to maintain a healthy weight.

Methods

This review is based on comprehensive literature searches from PubMed, Science Direct, Scopus, and Google Scholar databases using the keywords- "plants in obesity", "plants used in weight reduction" or keywords that are similar to those. Medicinal plants which have been clinically proven for their anti-obesity effect have only been selected for this study and attempts to investigate beneficial effects and adverse effects along with their mechanism of action have also been taken in this review.

Results

A significant reduction of weight in both human and other animals are exhibited by the extracts of Phaseolus vulgaris, green coffee, Yerba Mate, green tea, Gynostemma pentaphyllum, and the combination of Cissus quadrangularis/Irvingia gabonensis. All of those plant extracts seemed to work on different physiological pathways and none of those extracts showed any notable adverse effects in human or animal models.

Conclusion

Our review suggests that the discussed medicinal plants are effective in reducing the weight of obese patients without causing notable adverse reactions. Although further study is necessary to confirm their exact molecular mechanism and safety in human use.

Research progress on the lipid-lowering and weight loss effects of tea and the mechanism of its functional components

Obesity caused by poor eating habits has become a great challenge faced by public health organizations worldwide. Optimizing dietary intake and ingesting special foods containing biologically active substances (such as polyphenols, alkaloids, and terpenes) is a safe and effective dietary intervention to prevent the occurrence and development of obesity. Tea contains several active dietary factors, and daily tea consumption has been shown to have various health benefits, especially in regulating human metabolic diseases. Here, we reviewed recent advances in research on tea and its functional components in improving obesity-related metabolic dysfunction, and gut microbiota homeostasis and related clinical research. Furthermore, the potential mechanisms by which the functional components of tea could promote lipid-lowering and weight-loss effects by regulating fat synthesis/metabolism, glucose metabolism, gut microbial homeostasis, and liver function were summarized. The research results showing a "positive effect" or "no effect" objectively evaluates the lipid-lowering and weight-loss effects of the functional components of tea. This review provides a new scientific basis for further research on the functional ingredients of tea for lipid lowering and weight loss and the development of lipid-lowering and weight-loss functional foods and beverages derived from tea.

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.

Biometabolites of Citrus unshiu Peel Enhance Intestinal Permeability and Alter Gut Commensal Bacteria

Flavanones in Citrus unshiu peel (CUP) have been used as therapeutic agents to reduce intestinal inflammation; however, the anti-inflammatory effects of their biometabolites remain ambiguous. Here, we identified aglycone-type flavanones, such as hesperetin and naringenin, which were more abundant in the bioconversion of the CUP than in the ethanol extracts of the CUP. We found that the bioconversion of the CUP induced the canonical nuclear factor-κB pathway via degradation of IκB in Caco-2 cells. To check the immune suppressive capacity of the aglycones of the CUP in vivo, we orally administered the bioconversion of the CUP (500 mg/kg) to mice for two weeks prior to the 3% dextran sulfate sodium treatment. The CUP-pretreated group showed improved body weight loss, colon length shortage, and intestinal inflammation than the control mice. We also found a significant decrease in the population of lamina propria Th17 cells in the CUP-pretreated group following dextran sodium sulfate (DSS) treatment and an increase in mRNA levels of occludin in CUP-treated Caco-2 cells. Pyrosequencing analysis revealed a decreased abundance of Alistipes putredinis and an increased abundance of Muribaculum intestinale in the feces of the CUP-pretreated mice compared to those of the control mice. Overall, these findings suggest that the pre-administration of CUP biometabolites may inhibit the development of murine colitis by modulating intestinal permeability and the gut microbiome.

Therapeutic Effects of Green Tea Polyphenol (‒)-Epigallocatechin-3-Gallate (EGCG) in Relation to Molecular Pathways Controlling Inflammation, Oxidative Stress, and Apoptosis

(‒)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea. Thanks to multiple interactions with cell surface receptors, intracellular signaling pathways, and nuclear transcription factors, EGCG possesses a wide variety of anti-inflammatory, antioxidant, antifibrotic, anti-remodelation, and tissue-protective properties which may be useful in the treatment of various diseases, particularly in cancer, and neurological, cardiovascular, respiratory, and metabolic disorders. This article reviews current information on the biological effects of EGCG in the above-mentioned disorders in relation to molecular pathways controlling inflammation, oxidative stress, and cell apoptosis.

Tea Plant (Camellia sinensis): A Current Update on Use in Diabetes, Obesity, and Cardiovascular Disease

The tea plant (C. sinensis) has traditionally been consumed worldwide as "tea" for its many health benefits, with the potential for the prevention and therapy of various conditions. Regardless of its long history, the use of tea plants in modern times seems not to have changed much, as the beverage remains the most popular form. This review aimed to compile scientific information about the role and action of tea plants, as well as their status concerning clinical applications, based on the currently available evidence, with a focus on metabolic syndrome, mainly covering obesity, diabetes, and cardiovascular disease. It has been recognized that these diseases pose a significant threat to public health, and the development of effective treatment and prevention strategies is necessary but still challenging. In this article, the potential benefits of tea plants and their derived bioactive components (such as epigallocatechin-3-gallate) as anti-obesity, anti-diabetic, and anti-cardiovascular agents are clearly shown and emphasized, along with their mechanisms of action. However, according to the status of the clinical translation of tea plants, particularly in drug development, more substantial efforts in well-designed, randomized, controlled trials are required to expand their applications in treating the three major metabolic disorders and avoiding the toxicity caused by overconsumption.

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.

Impact of the herbal medicine, Ephedra sinica stapf, on gut microbiota and body weight in a diet-induced obesity model

Obesity is a chronic metabolic disease caused by excessive body fat and has become a global public health problem. Evidence suggests that obesity and obesity-induced metabolic disorders are closely related to gut microbiota. Bupropion (BP), an antidepressant medicine, and Ephedra sinica Stapf [Ephedraceae; Ephedrae Herba], a herbal medicine, are sympathetic stimulants and have weight loss effects. However, to our best knowledge, no studies have simultaneously assessed the effects of drugs and herbal medicines on obesity and gut microbiota. This study aimed to determine the effects of BP and ES on weight loss and re-modulation of host gut microbiota. To test this hypothesis, we fed C57BL/6J mice with a high-fat diet supplemented with bupropion (BP; 30 mg/kg/day) and Ephedra sinica Stapf extract (ES; 150 mg/kg/day) via oral gavage for eight weeks. Further, we evaluated the effects of BP and ES on body weight and fat accumulation. In addition, we evaluated the effects of BP and ES on gut microbiota using 16S rRNA amplicon sequencing. Our results showed that weight loss was confirmed in both BP and ES; however, it was more pronounced in ES. ES changed the overall composition of the gut microbiota by restoring the relative abundance of Oscillospiraceae, Lachnospiraceae, and the Firmicutes/Bacteroidetes ratio, an indicator of gut microbiota dysbiosis. Nine amplicon sequence variants (ASVs) of the gut microbiome were significantly recovered by BP and ES treatment, of which eight ASVs correlated with body weight and fat accumulation. Additionally, three ASVs were significantly recovered by ES treatment alone. In conclusion, the anti-obesity effects of BP and ES, especially fat accumulation, are related to the regulation of gut microbiota. Moreover, ES had a greater influence on the gut microbiota than BP.

Effects of sodium-glucose co-transporter-2 inhibitors on anthropometric indices and metabolic markers in overweight/obese individuals without diabetes: a systematic review and meta-analysis

AIMS

To identify the impact of sodium-glucose co-transporter-2 (SGLT2) inhibitors on anthropometric indices and metabolic markers in individuals without diabetes who are overweight/obese.

MATERIALS AND METHODS

Clinical trials investigating the safety and efficacy of SGLT2 inhibitors in overweight or obese adults were sought in PubMed, Scopus, Google Scholar, and EMBASE databases. The overall intervention effect was estimated using a random-effect meta-analysis. Jadad scale was used to assess the risk of bias. The heterogeneity of the studies was assessed using the Cochran's test (Q test) and I² Index. Analyses of meta-regression were carried out to identify possible sources of heterogeneity among the trials. The analyses were all conducted using Stata, and p < .05 was set as the statistically significant level.

RESULTS

Of the five clinical trials that were included in the meta-analysis, five, four, three, and two clinical trials met the eligibility criteria for evaluating the efficacy of SGLT2 inhibitors on the weight, waist circumference (WC) and blood pressure, body mass index (BMI), and lipid and glucose profile, respectively. According to the results, SGLT2 inhibitors lowered BMI (WMD = -0.47 [95% CI: -0.63, -0.31]; p < .001), and WC (WMD = -3.25 [95% CI: -6.36, -0.14]; p = .04), but had no significant influence on blood pressure, lipid, and glucose profile of overweight/obese patients compared to the control groups.

CONCLUSION

The SGLT2 inhibitors appear to ameliorate some anthropometric and metabolic markers. There is, however, a limited number of studies, and further research is required for a firm conclusion.

REGISTRATION CODE IN PROSPERO

CRD42022306415.

Dietary supplements for obesity

Obesity and associated complications including diabetes, cardiometabolic dysfunction, disability, malignancy and premature mortality are considered epidemic. Research on obesity is therefore of worldwide importance. The development of obesity is a multifactorial phenomenon with contributions from biological, behavioral, genetic and environmental factors. Obesity and its associated issues require various lifestyle modifications and treatment options such medication, exercise, diet, surgery, pharmacological therapy and dietary supplements. Dietary supplements are considered an attractive alternative to traditional therapy due to their low toxicity profile and their accessibility to the general population. Dietary supplements may include one or more dietary ingredients. In this narrative review, we analyze the effects on obesity and obesity-related issues of various natural components. For example, there are a myriad of supplements that have been used as dietary supplements for weight loss such as minerals, vitamins, amino acids, metabolites, herbs, and plant extracts. This narrative review aims to present the benefits and side-effects of several ingredients of dietary supplements for weight loss and treatment of obesity. In particular, the mechanism of action, results of clinical trials, and possible side effects will be presented for the following ingredients: β-Glucans, bitter orange, calcium, vitamin D, chitosan, chromium, cocoa, coleus forskohlii, conjugate linoleic acid, ephedra sinica, fucoxanthin, garcinia cambogia, glucomannan, green coffee, green tea, guar gum, raspberry, hoodia gordonii, irvingia gabonensis, phenylpropylamine, pyruvate, white kidney bean.

Effect of flavonoid intake on circulating levels of adiponectin and leptin: A systematic review and meta-analysis of randomized controlled clinical trials

This meta-analysis of randomized controlled trials (RCTs) was conducted to explore the effects of flavonoid intake on adiponectin and leptin levels. The PubMed, EMBASE, and Cochrane Library databases were searched on March 1, 2021. Random-effects, subgroup, sensitivity, and meta-regression analyses were conducted on 40 publications. Flavonoid intake significantly increased circulating adiponectin (0.54 μg/ml, 95% CI [0.20, 0.88], p = .002; I²  = 86.4%) and significantly reduced leptin levels (weighted mean difference: -0.79 ng/ml, 95% CI [-1.33, -0.25], p = .004; I²  = 87.7%). Subgroup analysis demonstrated that flavonoid intervention produced a significant elevation in adiponectin levels only in studies that lasted more than 12 weeks, conducted in Asian regions, were parallel-designed, involved obese or overweight participants and participants with type 2 diabetes mellitus (T2DM) or cardiovascular diseases, used tea catechins, and used a dietary supplement intervention. A significantly negative effect on leptin levels was observed in studies conducted in Asian countries, with healthy participants and participants with T2DM, used whole food interventions, and involved participants with lower baseline leptin levels. In conclusion, flavonoid intake significantly increased circulating adiponectin and decreased leptin levels; however, study heterogeneity was very high. Future well-designed trials are required to address heterogeneous study designs and clarify the efficacy of plants in regulating adiponectin and leptin levels.

Green Tea Catechins: Nature’s Way of Preventing and Treating Cancer

Green tea’s (Camellia sinensis) anticancer and anti-inflammatory effects are well-known. Catechins are the most effective antioxidants among the physiologically active compounds found in Camellia sinesis. Recent research demonstrates that the number of hydroxyl groups and the presence of specific structural groups have a substantial impact on the antioxidant activity of catechins. Unfermented green tea is the finest source of these chemicals. Catechins have the ability to effectively neutralize reactive oxygen species. The catechin derivatives of green tea include epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG). EGCG has the greatest anti-inflammatory and anticancer potential. Notably, catechins in green tea have been explored for their ability to prevent a variety of cancers. Literature evidence, based on epidemiological and laboratory studies, indicates that green tea catechins have certain properties that can serve as the basis for their consideration as lead molecules in the synthesis of novel anticancer drugs and for further exploration of their role as pharmacologically active natural adjuvants to standard chemotherapeutics. The various sections of the article will focus on how catechins affect the survival, proliferation, invasion, angiogenesis, and metastasis of tumors by modulating cellular pathways.

Compound green tea (CGT) regulates lipid metabolism in high-fat diet induced mice

This work aims to study the effect of compound green tea (CGT) on liver lipid metabolism in mice based on metabolomics of liquid chromatography-mass spectrometry (LC-MS), and preliminarily identify potential biomarkers and pathways of action by using a metabonomic network database to explore the lipid-lowering effect of CGT. In this study, forty mice were randomly divided into four groups: compound tea treatment group (DH), high-fat model control group (NK), normal control group (CK) and positive drug group (YK). After a month of different interventions, the mice were weighed and the blood lipid indexes were detected. In addition, differential liver metabolites were monitored by using LC-MS. The results showed that CGT and positive drug treatment were able to decrease body weight, liver coefficient, TC, TG and LDL levels of obese mice, while increasing HDL levels. Among the 110 compounds obtained, 54 metabolites were significantly altered in the four comparisons. More importantly, 15 remarkably downregulated metabolites involved in Lysopc 16:1, Lysopc 18:1, and Lysopc 18:2 were found in the DH group when the mice were treated with CGT; meanwhile, the positive drug Xuezhikang was able to significantly downregulate 14 compounds, including (±)18-HEPE, and 6 keto-PGF1α, compared with the NK group. Besides, KEGG enrichment analysis also revealed the important metabolic pathways, such as linoleic acid metabolism, Biosynthesis of unsaturated fatty acids, and α-linolenic acid metabolism, were related to fatty acid metabolism. These results suggested that CGT could regulate the lipid metabolism in the liver of hyperlipidemia mice, and may regulate 54 potential biomarkers in mice through a related metabolic pathway to make them return to a normal state and improve the disorder of lipid metabolism.

Supplementation with Two New Standardized Tea Extracts Prevents the Development of Hypertension in Mice with Metabolic Syndrome

Hypertension is considered to be both a cardiovascular disease and a risk factor for other cardiovascular diseases, such as coronary ischemia or stroke. In many cases, hypertension occurs in the context of metabolic syndrome (MetS), a condition in which other circumstances such as abdominal obesity, dyslipidemia, and insulin resistance are also present. The high incidence of MetS makes necessary the search for new strategies, ideally of natural origin and with fewer side effects than conventional pharmacological treatments. Among them, the tea plant is a good candidate, as it contains several bioactive compounds such as caffeine, volatile terpenes, organic acids, and polyphenols with positive biological effects. The aim of this study was to assess whether two new standardized tea extracts, one of white tea (WTE) and the other of black and green tea (CTE), exert beneficial effects on the cardiovascular alterations associated with MetS. For this purpose, male C57/BL6J mice were fed a standard diet (Controls), a diet high in fats and sugars (HFHS), HFHS supplemented with 1.6% WTE, or HFHS supplemented with 1.6% CTE for 20 weeks. The chromatography results showed that CTE is more concentrated on gallic acid, xanthines and flavan-3-ols than WTE. In vivo, supplementation with WTE and CTE prevented the development of MetS-associated hypertension through improved endothelial function. This improvement was associated with a lower expression of proinflammatory and prooxidant markers, and—in the case of CTE supplementation—also with a higher expression of antioxidant enzymes in arterial tissue. In conclusion, supplementation with WTE and CTE prevents the development of hypertension in obese mice; as such, they could be an interesting strategy to prevent the cardiovascular disorders associated with MetS.

Epigallocatechin gallate as a nutraceutical to potentially target the metabolic syndrome: novel insights into therapeutic effects beyond its antioxidant and anti-inflammatory properties

Epigallocatechin gallate (EGCG) is one of the most abundant and powerful flavonoids contained in green tea. Because of the global increase in green tea consumption, there has been a general interest in understanding its health benefits, including its bioactive compounds like EGCG. Indeed, preclinical evidence already indicates that EGCG demonstrated a strong antioxidant and anti-inflammatory properties that could be essential in protecting against metabolic syndrome. The current review explores clinical evidence reporting on the beneficial effects of EGCG supplementation in obese subjects or patients with diverse metabolic complications that include type 2 diabetes and cardiovascular disease. The discussion incorporates the impact of different formulations of EGCG, as well as the effective doses and treatment duration. Importantly, besides highlighting the potential use of EGCG as a nutraceutical, the current review also discusses crucial evidence related to its pharmaceutical development as an agent to hinder metabolic diseases, including its bioavailability and metabolism profile, as well as its well-known biological properties.

Antioxidative, Anti-Inflammatory, Anti-Obesogenic, and Antidiabetic Properties of Tea Polyphenols-The Positive Impact of Regular Tea Consumption as an Element of Prophylaxis and Pharmacotherapy Support in Endometrial Cancer

Endometrial cancer (EC) is second only to cervical carcinoma among the most commonly diagnosed malignant tumours of the female reproductive system. The available literature provides evidence for the involvement of 32 genes in the hereditary incidence of EC. The physiological markers of EC and coexisting diet-dependent maladies include antioxidative system disorders but also progressing inflammation; hence, the main forms of prophylaxis and pharmacotherapy ought to include a diet rich in substances aiding the organism’s response to this type of disorder, with a particular focus on ones suitable for lifelong consumption. Tea polyphenols satisfy those requirements due to their proven antioxidative, anti-inflammatory, anti-obesogenic, and antidiabetic properties. Practitioners ought to consider promoting tea consumption among individuals genetically predisposed for EC, particularly given its low cost, accessibility, confirmed health benefits, and above all, suitability for long-term consumption regardless of the patient’s age. The aim of this paper is to analyse the potential usability of tea as an element of prophylaxis and pharmacotherapy support in EC patients. The analysis is based on information available from worldwide literature published in the last 15 years.

The transported active mulberry leaf phenolics inhibited adipogenesis through PPAR-γ and Leptin signaling pathway

The effective components of mulberry leaf polyphenols (MLPs) should be absorbed and transported by the intestinal cells before regulating lipid metabolism. The Caco-2 intestinal epithelial cell and 3 T3-L1 adipocytes were coupled to screen the effective components of MLPs that are being absorbed and transported by intestinal cells. The regulation and molecular mechanism by which the effective components affect adipogenesis were analyzed in this study. Among the 12 main components identified, five main compounds were well absorbed with Papp in the order of benzoic acid > chlorogenic acid > astragaloside > hyperoside > rutin. Chlorogenic acid and benzoic acid were mainly absorbed through passive diffusion, while rutin, astragaloside, and hyperoside were mainly by active transport, of which chlorogenic and rutin absorption were mediated by the efflux protein, P-glycoprotein (P-pg). Based on the transport volume of 2 mg/ml MLPs within 2 h, 25% of the maximum transported MLPs (TMLPs) was a safe concentration for 3 T3-L1 preadipocytes. Except for astragaloside, the other four components showed a significant inhibitory effect on lipid droplets, TG and TC, and chlorogenic acid and benzoic acid had the strongest effect. Additionally, we observed a synergistic effect as TMLPs were the most effective. We hypothesized that TMLPs, chlorogenic acid and benzoic acid suppressed adipogenesis and regulated lipid metabolism by inhibiting PPAR-γ, C/EBP-α, and FAS mRNA while promoting ADIPO and Leptin mRNA expression. PRACTICAL APPLICATIONS: The absorption and adipogenesis inhibition effect of mulberry leaf phenolics were evaluated in this study. The results provided guideline for the development of functional foods in regulating lipid metabolism.

Effects of Tea Treatments against High-Fat Diet-Induced Disorder by Regulating Lipid Metabolism and the Gut Microbiota

High-fat diet (HFD) may induce changes of metabolism and gut microbiota changes, and these changes are susceptible to diet adjustments such as tea treatment. However, the treatment effects may vary among different types of tea. In this study, we evaluated the effects of six types of tea on glucose and lipid metabolism and gut microbiota in HFD mice. We established HFD mouse model by 12 weeks feed with 60% fat diet, then treated with teas for six weeks. Here, we showed that treatment with different types of tea can inhibit weight gain and insulin resistance though different ways. Green tea regulated lipid metabolism by regulating the expression of adenosine 5′-monophosphate-activated protein kinase (AMPK) and carnitine palmitoyltransferase-I (CPT-1). The effect of dark tea and white tea in reducing liver weight seemed to be related to activities of acetyl-CoA carboxylase (ACC). Yellow tea exhibited the best anti-inflammatory and antioxidant effects and effects of recovering the disorder of model mouse microbiota. The decrease in blood sugar and the upregulation of gluconeogenesis-related enzymes seemed to be related to the decrement of unclassified Lachnospiraceae. These different effects may result from the unique chemical compositions contained by different types of tea, which can regulate different lipid and glucose metabolism-related proteins. Despite variations in its compositions and metabolic reactions, tea is a potent antiobesity and hypoglycemic agent.

Dietary Supplements for Weight Management: A Narrative Review of Safety and Metabolic Health Benefits

Dietary supplements for weight management include myriad ingredients with thermogenic, lipotropic, satiety, and other metabolic effects. Recently, the safety of this product category has been questioned. In this review, we summarize the safety evidence as well as relevant clinical findings on weight management and metabolic effects of six representative dietary supplement ingredients: caffeine, green tea extract (GTE), green coffee bean extract (GCBE), choline, glucomannan, and capsaicinoids and capsinoids. Of these, caffeine, GTE (specifically epigallocatechin gallate [EGCG]), and choline have recommended intake limits, which appear not to be exceeded when used according to manufacturers’ instructions. Serious adverse events from supplements with these ingredients are rare and typically involve unusually high intakes. As with any dietary component, the potential for gastrointestinal intolerance, as well as possible interactions with concomitant medications/supplements exist, and the health status of the consumer should be considered when consuming these components. Most of the ingredients reviewed also improved markers of metabolic health, such as glucose, lipids, and blood pressure, although the data are limited for some. In summary, weight management supplements containing caffeine, GTE, GCBE, choline, glucomannan, and capsaicinoids and capsinoids are generally safe when taken as directed and demonstrate metabolic health benefits for overweight and obese people.

Mechanisms Underlying the Interaction Between Chronic Neurological Disorders and Microbial Metabolites via Tea Polyphenols Therapeutics

The number of hydroxyl groups and existence of characteristic structural groups in tea polyphenols (TP) make them have antioxidant activity, which gives TP anti-inflammatory effects, toward protecting the intestinal flora and brain neurons. Host-associated microbial metabolites are emerging as dominant modifiers of the central nervous system. As yet, the investigations on host-microbiota crosstalking remain challenging, studies focusing on metabolites such as serotonin, short-chain fatty acids, and others have pinpointed multiple actionable signaling pathways relevant to host health. However, there are still complexities and apparent limitations inherent in transforming complex human diseases to corresponding animal models. Here, we choose to discuss several intestinal metabolites with research value, as crucial areas for assessing TP-mediated chronic brain diseases interactions with microbial.

Effects of Antioxidant Intake on Fetal Development and Maternal/Neonatal Health during Pregnancy

During pregnancy, cycles of hypoxia and oxidative stress play a key role in the proper development of the fetus. Hypoxia during the first weeks is crucial for placental development, while the increase in oxygen due to the influx of maternal blood stimulates endothelial growth and angiogenesis. However, an imbalance in the number of oxidative molecules due to endogenous or exogenous factors can overwhelm defense systems and lead to excessive production of reactive oxygen species (ROS). Many pregnancy complications, generated by systemic inflammation and placental vasoconstriction, such as preeclampsia (PE), fetal growth restriction (FGR) and preterm birth (PTB), are related to this increase of ROS. Antioxidants may be a promising tool in this population. However, clinical evidence on their use, especially those of natural origin, is scarce and controversial. Following PRISMA methodology, the current review addresses the use of natural antioxidants, such as epigallocatechin gallate (EGCG), melatonin and resveratrol (RESV), as well as other classical antioxidants (vitamin C and E) during the prenatal period as treatment of the above-mentioned complications. We review the effect of antioxidant supplementation on breast milk in lactating mothers.