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

Mechanism of Green Tea Peptides in Lowering Blood Pressure and Alleviating Renal Injury Induced by Hypertension Through the Ang II/TGF-β1/SMAD Signaling Pathway

Background/Objectives: The kidney plays a crucial role in regulating normal blood pressure and is one of the major organs affected by hypertension. The present study aimed to investigate the hypotensive and renoprotective effects of four specific green tea peptides extracted from green tea dregs on spontaneously hypertensive rats (SHRs) and to investigate the underlying mechanisms. Methods: Four specific green tea peptides (40 mg/kg) were gavaged to SHRs for 4 weeks, and blood pressure, renal function, renal pathological changes, renal tissue fibrosis indexes, and inflammation indexes were examined in SHRs to analyze the role of the four green tea peptides in alleviating hypertension and its renal injury. Results: The results showed that the four TPs significantly reduced systolic and diastolic blood pressure (20-24% and 18-28%) in SHR compared to the model group. Meanwhile, gene levels and protein expression of renal fibrosis-related targets such as phospho-Smad2/3 (p-Smad2/3) (26-47%), Sma- and Mad-related proteins 2/3 (Smad2/3) (19-38%), transforming growth factor-β1 (TGF-β1) (36-63%), and alpha-smooth muscle actin (alpha-SMA) (58-86%) were also significantly reduced. In addition, the reduced expression levels of medullary differentiation factor 88 (MyD88) (14-36%), inducible nitric oxide synthase (iNOS) (58-73%), and nuclear factor-κB p65 (NF-kB p65) (35-78%) in kidneys also confirmed that TPs attenuated renal inflammation in SHR. Therefore, green tea peptides could attenuate the fibrosis and inflammatory responses occurring in hypertensive kidneys by inhibiting the Ang II/TGF-β1/SMAD signaling pathway and MyD88/NF-κB p65/iNOS signaling pathway. Conclusions: The results showed that green tea peptides may be effective candidates for lowering blood pressure and attenuating kidney injury.

Green tea fermented by Ganoderma lucidum presented anti-obesity properties via enhanced thermogenesis in vitro and on C57BL/6J mice

High-fat diets contribute to obesity and metabolic disorders. Ganoderma lucidum is renowned for its abundant bioactive compounds and diverse pharmacological effects. Green tea fermented by G. lucidum (TFG) has been shown to enhance lipid-lowering activity in vitro significantly. Using UPLC-MS/MS and GC-MS/MS, we identified 78 active lipid-lowering compounds in TFG. We explored their potential targets and pathways through network pharmacology, validated by in vivo experiments. In a 4-week trial, 70 mice were randomly assigned to 7 groups: ND (normal diet), HFD (high-fat diet), PC-HFD (HFD with orlistat), NFT1 (HFD with 200 mg/kg/day non-fermented tea), NFT2 (HFD with 400 mg/kg/day NFT), TFG1 (HFD with 200 mg/kg/day TFG), and TFG2 (HFD with 400 mg/kg/day TFG). TFG treatment significantly reduced body weight, hepatic lipid droplets, and epididymal adipocyte size in mice compared to the HFD group. TFG also increased the abundance of lipid-lowering bacteria, such as Lactococcus and Lachnospirales. Liver transcriptomic and fecal metabolomic analyses revealed that TFG reduced triglyceride (TG), diglyceride (DG), monoglyceride (MG), and free fatty acid (FFA) levels and differentially regulated key genes (Dpf3, Atp5k, ND3) involved in the thermogenesis pathway. RT-PCR confirmed that TFG upregulated the mRNA expressions of AMPK, UCP1, PGC1α, and PPARγ in dorsal fat. In conclusion, TFG enhances thermogenesis via the AMPK-PGC1α pathway and increases the abundance of lipid-lowering bacteria, thereby reducing fat accumulation in mice. These findings offer insights into TFG's anti-obesity mechanisms, providing a scientific basis for developing new weight loss methods or products.

Effects of Dietary Tea Polyphenols on the Growth, Antioxidant Status, Immune Function, and Intestinal Microbiota of Largemouth Bass (Micropterus salmoides)

This research aimed to explore the impact of tea polyphenol (TP) supplementation on the development, antioxidant properties, immune responses, and gut wellness in largemouth bass (Micropterus salmoides, LMB). Four diets with varying levels of TPs (0.00%, 0.02%, 0.04%, and 0.08%) were devised to feed LMB with an initial weight of 4.3 ± 0.02 g for 56 days, among which the intermittent feeding (IF) group was fed a diet supplemented with TP8 for 7 days, followed by a basal diet for another 7 days, and this was repeated until the end (56th day). The results demonstrated that supplementation with 0.04% or 0.08% TPs in the diet could reduce the crude lipid content and increase the crude protein content of LMB (p < 0.05). The levels of total cholesterol (CHO) and low-density lipoprotein (LDL) in the serum significantly decreased with the addition of 0.08% dietary TPs to the diet (p < 0.05). Dietary TPs can stimulate the activities of antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) and enhance the antioxidant capacity of LMB (p < 0.05). The activities of immune enzymes such as acid phosphatase (ACP) were increased to improve the immune response via the addition of TPs (p < 0.05). Supplementation with 0.02% and 0.04% TPs reduced liver fatty infiltration and alleviated hepatocyte damage. Compared with the control diet, dietary TPs significantly increased villus height (VH), villus width (VW), and lipase (LPS) activity in the intestine (p < 0.05), and supplementation with 0.04% TPs significantly increased muscular layer thickness (MT) (p < 0.05). With the increase in dietary TPs, distinct differences were observed in the intestinal microbial composition and the relative abundance of potential pathogens, especially Clostridiaceae, which decreased, along with the enrichment of pathways related to metabolism, including amino acid metabolism, carbohydrate metabolism, and lipid metabolism. Additionally, intermittent feeding could alleviate the adverse effects caused by a high dosage. In conclusion, dietary TPs of LMB could enhance antioxidant capacity and immunity and improve intestinal health, and intermittent feeding could mitigate the adverse effects caused by a high dosage.

Pancreatic lipase immobilization on cellulose filter paper for inhibitors screening and network pharmacology study of anti-obesity mechanism

The discovery of pancreatic lipase (PL) inhibitors is an essential route to develop new anti-obesity drugs. In this experiment, chitosan was used to add amino groups to cellulose filter paper (CFP) and then glutaraldehyde was used to covalently combine PL with amino-modified CFP through the Schiff base reaction. Under optimal immobilization conditions, CFP immobilized PL has a wide range of pH and temperature tolerance, as well as excellent reproducibility, reusability and storage stability. Subsequently, 26 natural products (NPs) were screened by immobilized PL with black tea extract having the highest inhibition rate. Three compounds with binding effects on PL (epigallocatechin gallate, theaflavin-3-gallate and theaflavin-3,3'-digallate) were captured. Molecular docking proved that these three compounds have a strong binding affinity for PL. Fluorescence spectra further revealed that theaflavin-3,3'-digallate could statically quench the intrinsic fluorescence of pancreatic lipase. The molecular docking and thermodynamic parameters indicated that electrostatic interaction was considered as the main interaction force between PL and theaflavin-3,3'-digallate. Finally, the potential anti-obesity targets and pathways of the three compounds were discussed through network pharmacology. This study not only proposes a simple and efficient method for screening PL inhibitors, but also sheds light on the anti-obesity mechanism of active compounds in black tea.

Effect of White Tea on Leptin and Asprosin Levels in Rats Feeding a High-Fat Diet

BACKGROUND

Currently, obesity affects over 600 million individuals and is responsible for numerous severe health conditions, particularly diabetes and metabolic syndrome. The objective of our study was to examine the impact of white tea, known for its potent antioxidant properties, on the reduction in body weight as well as the levels of leptin and asprosin.

METHODS

A total of 72 male Sprague-Dawley rats were randomly assigned to 9 groups, with each group consisting of 8 rats. The groups were partitioned into two in order to examine the preventative and therapeutic effects of white tea on obesity. During this study, the case groups were administered white tea together with a high-fat diet, whereas the positive control group was administered orlistat along with a high-fat diet through oral gavage. After the experiment concluded, the levels of leptin, asprosin, and insulin hormones were evaluated in serum samples collected from rats using the ELISA method.

RESULTS

The findings demonstrated that the administration of white tea led to a significant decrease in body weight, serum leptin, and asprosin levels, as well as oxidative stress indicators, in rats that were fed a high-fat diet.

CONCLUSIONS

Utilizing natural chemicals, such as white tea, which possess minimal side effects and have powerful antioxidant activity, can mitigate the detrimental consequences associated with obesity.

Global hotspots and trends in tea anti-obesity research: a bibliometric analysis from 2004 to 2024

Background

The prevalence of obesity and its related ailments is on the rise, posing a substantial challenge to public health. Tea, widely enjoyed for its flavors, has shown notable potential in mitigating obesity. Yet, there remains a lack of exhaustive bibliometric studies in this domain.

Methods

We retrieved and analyzed multidimensional data concerning tea and obesity studies from January 2004 to June 2024, using the Web of Science Core Collection database. This bibliometric investigation utilized tools such as Bibliometrix, CiteSpace, and VOSviewer to gather and analyze data concerning geographical distribution, leading institutions, prolific authors, impactful journals, citation patterns, and prevalent keywords.

Results

There has been a significant surge in publications relevant to this field within the last two decades. Notably, China, Hunan Agricultural University, and the journal Food and Function have emerged as leading contributors in terms of country, institution, and publication medium, respectively. Zhonghua Liu of Hunan Agricultural University has the distinction of most publications, whereas Joshua D. Lambert of The State University of New Jersey is the most cited author. Analyses of co-citations and frequently used keywords have identified critical focus areas within tea anti-obesity research. Current studies are primarily aimed at understanding the roles of tea components in regulating gut microbiota, boosting fat oxidation, and increasing metabolic rate. The research trajectory has progressed from preliminary mechanism studies and clinical trials to more sophisticated investigations into the mechanisms, particularly focusing on tea's regulatory effects on gut microbiota.

Conclusion

This study offers an intricate overview of the prevailing conditions, principal focus areas, and developmental trends in the research of tea's role against obesity. It delivers a comprehensive summary and discourse on the recent progress in this field, emphasizing the study's core findings and pivotal insights. Highlighting tea's efficacy in obesity prevention and treatment, this study also points out the critical need for continued research in this area.

Blood circulation effect of fermented citrus bioconversion product (FCBP) in EA.hy926 endothelial cells and high-fat diet-fed mouse model

Background

The escalating global burden of cardiovascular diseases, largely driven by unhealthy lifestyle choices and dietary patterns, has intensified the search for effective and safe interventions. With current treatments often marred by significant side effects, the exploration of natural compounds such as flavonoids presents a compelling alternative.

Objective

This study investigated the effects of fermented citrus bioconversion product (FCBP), a fermented citrus bioflavonoid, on various markers of cardiovascular health in the context of a high-fat diet.

Design

In vivo, a high-fat diet-induced mouse model was used to assess the effects of FCBP on body weight, serum nitric oxide (NO) levels, activated partial thromboplastin time (aPTT), phosphatidylserine (PS) exposure on red blood cells, and the expression of inflammatory markers Intercellular Adhesion Molecule (ICAM)-1 and Vascular Cell Adhesion Molecule (VCAM)-1 in the thoracic aorta. In vitro, EA.hy926 endothelial cells were used to evaluate the compound's effects on cell viability, NO production, endothelial nitric oxide synthase (eNOS) expression, and cell adhesion molecule (CAM) levels to further understand the mechanisms behind the in vivo findings.

Results

In vivo, FCBP supplementation led to a dose-dependent reduction in weight gain, a significant decrease in serum NO levels at 10 mg/kg, and reduced ICAM-1 and VCAM-1 expressions in the thoracic aorta, indicating anti-inflammatory properties. PS exposure on red blood cells was also reduced, suggesting decreased procoagulant activity, while aPTT remained unchanged. In vitro, FCBP was non-cytotoxic to endothelial cells, showed a trend toward increased NO production and eNOS expression, and reduced the expression of ICAM-1 and VCAM-1, supporting its potential anti-inflammatory effects.

Conclusions

FCBP demonstrates potential as a bioactive compound for managing cardiovascular health by reducing inflammation, mitigating weight gain, and influencing blood circulation-related parameters under high-fat diet conditions. Further studies, including diverse models and human trials, are warranted to elucidate its mechanisms and compare its efficacy with established cardiovascular therapeutics.

Multilocus Distance-Regulated Sensor Array for Recognition of Polyphenols via Machine Learning and Indicator Displacement Assay

Developing new strategies to construct sensor arrays that can effectively distinguish multiple natural components with similar structures in mixtures is an exceptionally challenging task. Here, we propose a new multilocus distance-modulated indicator displacement assay (IDA) strategy for constructing a sensor array, incorporating machine learning optimization to identify polyphenols. An 8-element array, comprising two fluorophores and their six dynamic covalent complexes (C1-C6) formed by pairing two fluorophores with three distinct distance-regulated quenchers, has been constructed. Polyphenols with diverse spatial arrangements and combinatorial forms compete with the fluorophores by forming pseudocycles with quenchers within the complexes, leading to varying degrees of fluorescence recovery. The array accurately and effectively distinguished four tea polyphenols and 16 tea varieties, thereby demonstrating the broad applicability of the multilocus distance-modulated IDA array in detecting polyhydroxy foods and natural medicines.

Fu Brick Tea as a Staple Food Supplement Attenuates High Fat Diet Induced Obesity in Mice

Fu brick tea (FBT), a product of microbial fermentation from primary dark tea, also known as raw material tea (RMT), has been extensively studied for its functional properties. However, its potential as a staple food supplement for weight loss remains poorly understood. This study compared the weight loss effects of orlistat, traditional plain noodles (NN), and noodles supplemented with varying amounts of RMT (RMTN) and FBT (FBTN), with the aim to elucidate their lipid-reducing effects and underlying mechanisms. Experimental trials on high fat diet fed mice revealed significant weight loss, lipid-lowering, and hypoglycemic effects upon supplementation with orlistat, RMTN, and FBTN. Moreover, supplementation with orlistat, RMTN, and FBTN effectively restored serum and liver-related index levels, mitigating high-fat diet-induced dyslipidemia. Additionally, these supplements ameliorated liver and kidney damage by inhibiting oxidative stress and inflammatory responses. Furthermore, orlistat, RMTN, and FBTN exert their anti-obesity effects primarily by modulating genes associated with lipid metabolism and inflammatory responses and through regulation of the composition and structure of the gut microbiota. Importantly, FBTN demonstrated a significantly stronger lipid-lowering effect compared to RMTN, particularly at higher tea addition ratios. In contrast, NN supplementation exhibited minimal to no weight loss effects. Based on these findings, it could be inferred that FBT holds promise as a staple food supplement to ameliorate high-fat diet-induced obesity and its associated health conditions.

Accurate Classification of Chunmee Tea Grade Using NIR Spectroscopy and Fuzzy Maximum Uncertainty Linear Discriminant Analysis

The grade of tea is closely related to tea quality, so the identification of tea grade is an important task. In order to improve the identification capability of the tea grade system, a fuzzy maximum uncertainty linear discriminant analysis (FMLDA) methodology was proposed based on maximum uncertainty linear discriminant analysis (MLDA). Based on FMLDA, a tea grade recognition system was established for the grade recognition of Chunmee tea. The process of this system is as follows: firstly, the near-infrared (NIR) spectra of Chunmee tea were collected using a Fourier transform NIR spectrometer. Next, the spectra were preprocessed using standard normal variables (SNV). Then, direct linear discriminant analysis (DLDA), maximum uncertainty linear discriminant analysis (MLDA), and FMLDA were used for feature extraction of the spectra, respectively. Finally, the k-nearest neighbor (KNN) classifier was applied to classify the spectra. The k in KNN and the fuzzy coefficient, m, were discussed in the experiment. The experimental results showed that when k = 1 and m = 2.7 or 2.8, the accuracy of the FMLDA could reach 98.15%, which was better than the other two feature extraction methods. Therefore, FMLDA combined with NIR technology is an effective method in the identification of tea grade.