Tea's anti-obesity properties, cardiometabolic health-promoting potentials, bioactive compounds, and adverse effects: A review focusing on white and green teas

Anti-obesity and other health benefits of bioprocessed black rice bran in combination with green tea extract in 3T3-L1 preadipocyte cells and in mice on a high-fat diet

Black rice bran, a waste product from the commercial milling of black rice that removes the bran and germ leaving the starchy endosperm, contains bioactive anthocyanin, phenolic, and phytosteroid compounds that may have health benefits. This study determined the effect of a polysaccharide-rich bioprocessed (fermented) black rice bran and a green tea extract individually and in combination on weight loss in orally fed mice on a high-fat diet and on concurrent changes in blood glucose and insulin as well as in cholesterol, triglyceride, and high-density and low-density lipoproteins (HDL and LDL). At the end of the eight-week feeding study, the combination diet resulted in a 67% lower weight gain than mice on a high-fat diet alone, a greater effect than that of bioprocessed black rice bran or green tea extract individually. The weight loss caused by the combination diet seems to be the result of decreased dietary efficiency. The observed trends in the glucose and insulin data suggest that the combined diet also has anti-diabetic properties, and the corresponding trends in the levels of the serum lipoproteins suggest that the combined diet might also protect against heart disease. Effects on the content, structure, and function of white adipose and liver tissues and on obesity-related biomarkers support the trends in the weight loss data. Based on the observed beneficial effects in 3T3-L1 pre-adipocyte cells and mice, we suggest the need to investigate if the new multifunctional combination food product can also protect against obesity and chronic diseases in humans. Mechanistic aspects that govern the anti-obesity effects and suggestions for future research are discussed.

Polyphenols as Immunomodulators and Epigenetic Modulators: An Analysis of Their Role in the Treatment and Prevention of Breast Cancer

Breast cancer poses a substantial health challenge for women globally. Recently, there has been a notable increase in scholarly attention regarding polyphenols, primarily attributed to not only the adverse effects associated with conventional treatments but also their immune-preventive impacts. Polyphenols, nature-derived substances present in vegetation, including fruits and vegetables, have received considerable attention in various fields of science due to their probable wellness merits, particularly in the treatment and hindrance of cancer. This review focuses on the immunomodulatory effects of polyphenols in breast cancer, emphasizing their capacity to influence the reaction of adaptive and innate immune cells within the tumor-associated environment. Polyphenols are implicated in the modulation of inflammation, the enhancement of antioxidant defenses, the promotion of epigenetic modifications, and the support of immune functions. Additionally, these compounds have been shown to influence the activity of critical immune cells, including macrophages and T cells. By targeting pathways involved in immune evasion, polyphenols may augment the capacity of the defensive system to detect and eliminate tumors. The findings suggest that incorporating polyphenol-rich foods into the diet could offer a promising, collaborative (integrative) approach to classical breast cancer remedial procedures by regulating how the defense mechanism interacts with the disease.

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.

Dietary plants for oral cancer prevention and therapy: A review of preclinical and clinical studies

Oral cancer is a disease with high mortality and rising incidence worldwide. Although fragmentary literature on the anti-oral cancer effects of plant products has been published, a comprehensive analysis is lacking. In this work, a critical and comprehensive evaluation of oral cancer preventative or therapeutic effects of dietary plants was conducted. An exhaustive analysis of available data supports that numerous dietary plants exert anticancer effects, including suppression of cell proliferation, viability, autophagy, angiogenesis, invasion, and metastasis while promoting cell cycle arrest and apoptosis. Plant extracts and products target several cellular mechanisms, such as the reversal of epithelial-to-mesenchymal transition and the promotion of oxidative stress and mitochondrial membrane dysfunction by modulation of various signaling pathways. These agents were also found to regulate cellular growth signaling pathways by action on extracellular signal-regulated kinase and mitogen-activated protein kinase, inflammation via modulation of cyclooxygenase (COX)-1, COX-2, and nuclear factor-κB p65, and metastasis through influence of cadherins and matrix metalloproteinases. In vivo studies support these findings and demonstrate a decrease in tumor burden, incidence, and hyperplastic and dysplastic changes. Clinical studies also showed decreased oral cancer risk. However, high-quality studies should be conducted to establish the clinical efficacy of these plants. Overall, our study supports the use of dietary plants, especially garlic, green tea, longan, peppermint, purple carrot, saffron, tomato, and turmeric, for oral cancer prevention and intervention. However, further research is required before clinical application of this strategy.

Synergistic Effect of β-Cryptoxanthin and Epigallocatechin Gallate on Obesity Reduction

Chronic obesity is an alarmingly growing global public health concern, posing substantial challenges for the prevention of chronic diseases, including hyperinsulinemia, type 2 diabetes, hyperlipidemia, hypertension, and coronary artery disease, and there is an urgent need for early mitigation strategies. We previously reported the obesity-reducing effects of green tea and β-cryptoxanthin intake. However, since tea has a complex mixture of compounds, it remained unclear which component contributed the most to this effect. Using high-performance liquid chromatography, we analyzed the components of tea in this study to determine if consumption of any combination of these compounds with β-cryptoxanthin had an obesity-reducing effect. Consuming epigallocatechin gallate (EGCG), a component of green tea, and β-cryptoxanthin for 4 weeks led to a decrease in body weight. Moreover, the weight and size of the white adipose tissues were significantly reduced, and blood biochemistry test results were comparable to normal values, with particular improvement in liver function. This indicated that intake of EGCG and β-cryptoxanthin reduces obesity in both subcutaneous and visceral fat. These findings suggest that simultaneous intake of EGCG and β-cryptoxanthin not only reduces obesity but also has a systemic beneficial effect on the body's normal physiological function.

The health benefits of dietary polyphenols on pediatric intestinal diseases: Mechanism of action, clinical evidence and future research progress

Pediatric intestinal development is immature, vulnerable to external influences and produce a variety of intestinal diseases. At present, breakthroughs have been made in the treatment of pediatric intestinal diseases, but there are still many challenges, such as toxic side effects, drug resistance, and the lack of more effective treatments and specific drugs. In recent years, dietary polyphenols derived from plants have become a research hotspot in the treatment of pediatric intestinal diseases due to their outstanding pharmacological activities such, as anti-inflammatory, antibacterial, antioxidant and regulation of intestinal flora. This article reviewed the mechanism of action and clinical evidence of dietary polyphenols in the treatment of pediatric intestinal diseases, and discussed the influence of physiological characteristics of children on the efficacy of polyphenols, and finally prospected the new dosage forms of polyphenols in pediatrics.

Effects of Herbal Tea (Non-Camellia sinensis) on Glucose Homeostasis and Serum Lipids in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

CONTEXT

Hyperglycemia and hyperlipidemia increase the risk for diabetes and its complications, atherosclerosis, heart failure, and stroke. Identification of safe and cost-effective means to reduce risk factors is needed. Herbal teas may be a vehicle to deliver antioxidants and polyphenols for prevention of complications.

OBJECTIVE

This systematic review and meta-analysis were conducted to evaluate and summarize the impact of herbal tea (non-Camellia sinensis) on glucose homeostasis and serum lipids in individuals with type 2 diabetes (T2D).

DATA SOURCES

PubMed, FSTA, Web of Science, CINAHL, MEDLINE, and Cochrane Library databases were searched from inception through February 2023 using relevant keyword proxy terms for diabetes, serum lipids, and "non-Camellia sinensis" or "tea."

DATA EXTRACTION

Data from 14 randomized controlled trials, totaling 551 participants, were included in the meta-analysis of glycemic and serum lipid profile end points.

RESULTS

Meta-analysis suggested a significant association between drinking herbal tea (prepared with 2-20 g d-1 plant ingredients) and reduction in fasting blood glucose (FBG) (P = .0034) and glycated hemoglobin (HbA1c; P = .045). In subgroup analysis based on studies using water or placebo as the control, significant reductions were found in serum total cholesterol (TC; P = .024), low-density lipoprotein cholesterol (LDL-C; P = .037), and triglyceride (TG; P = .043) levels with a medium effect size. Meta-regression analysis suggested that study characteristics, including the ratio of male participants, trial duration, and region, were significant sources of FBG and HbA1c effect size heterogeneity; type of control intervention was a significant source of TC and LDL-C effect size heterogeneity.

CONCLUSIONS

Herbal tea consumption significantly affected glycemic profiles in individuals with T2D, lowering FBG levels and HbA1c. Significance was seen in improved lipid profiles (TC, TG, and LDL-C levels) through herbal tea treatments when water or placebo was the control. This suggests water or placebo may be a more suitable control when examining antidiabetic properties of beverages. Additional research is needed to corroborate these findings, given the limited number of studies.

EGCG Suppresses Adipogenesis and Promotes Browning of 3T3-L1 Cells by Inhibiting Notch1 Expression

BACKGROUND

With the changes in lifestyle and diet structure, the incidence of obesity has increased year by year, and obesity is one of the inducements of many chronic metabolic diseases. Epigallocatechin gallate (EGCG), which is the most abundant component of tea polyphenols, has been used for many years to improve obesity and its complications. Though it has been reported that EGCG can improve obesity through many molecular mechanisms, EGCG may have many mechanisms yet to be explored. In this study, we explored other possible mechanisms through molecular docking and in vitro experiments.

METHODS

AutoDock Vina was selected for conducting the molecular docking analysis to elucidate the interaction between EGCG and Notch1, while molecular dynamics simulations were employed to validate this interaction. Then, the new regulation mechanism of EGCG on obesity was verified with in vitro experiments, including a Western blot experiment, immunofluorescence experiment, oil red O staining, and other experiments in 3T3-L1 adipocytes.

RESULTS

The molecular docking results showed that EGCG could bind to Notch1 protein through hydrogen bonding. In vitro cell experiments demonstrated that EGCG can significantly reduce the sizes of lipid droplets of 3T3-L1 adipocytes and promote UCP-1 expression by inhibiting the expression of Notch1 in 3T3-L1 adipocytes, thus promoting mitochondrial biogenesis.

CONCLUSIONS

In this study, molecular docking and in vitro cell experiments were used to explore the possible mechanism of EGCG to improve obesity by inhibiting Notch1.

First ATR-FTIR Characterization of Black, Green and White Teas (Camellia sinensis) from European Tea Gardens: A PCA Analysis to Differentiate Leaves from the In-Cup Infusion

ATR-FTIR (Attenuated Total Reflectance Fourier Transform InfraRed) spectroscopy, combined with chemometric, represents a rapid and reliable approach to obtain information about the macromolecular composition of food and plant materials. With a single measurement, the chemical fingerprint of the analyzed sample is rapidly obtained. Hence, this technique was used for investigating 13 differently processed tea leaves (green, black and white) all grown and processed in European tea gardens, and their vacuum-dried tea brews, prepared using both hot and cold water, to observe how the components differ from tea leaf to the in-cup infusion. Spectra were collected in the 1800-600 cm-1 region and were submitted to Principal Component Analysis (PCA). The comparison of the spectral profiles of leaves and hot and cold infusions of tea from the same country, emphasizes how they differ in relation to the different spectral regions. Differences were also noted among the different countries. Furthermore, the changes observed (e.g., at ~1340 cm-1) due to catechin content, confirm the antioxidant properties of these teas. Overall, this experimental approach could be relevant for rapid analysis of various tea types and could pave the way for the industrial discrimination of teas and of their health properties without the need of time-consuming, lab chemical assays.