Application of BRAFO-tiered approach for health benefit-risk assessment of dark tea consumption in China

Improvement of chronic metabolic inflammation and regulation of gut homeostasis: Tea as a potential therapy

Chronic metabolic inflammation is a common mechanism linked to the development of metabolic disorders such as obesity, diabetes, and cardiovascular disease (CVD). Chronic metabolic inflammation often related to alterations in gut homeostasis, and pathological processes involve the activation of endotoxin receptors, metabolic reprogramming, mitochondrial dysfunction, and disruption of intestinal nuclear receptor activity. Recent investigations into homeostasis and chronic metabolic inflammation have revealed a novel mechanism which is characterized by a timing interaction involving multiple components and targets. This article explores the positive impact of tea consumption on metabolic health of populations, with a special focus on the improvement of inflammatory indicators and the regulation of gut microbiota. Studies showed that tea consumption is related to the enrichment of gut microbiota. The relative proportion of Firmicutes/Bacteroidetes (F/B) is altered, while the abundance of Lactobacillus, Bifidobacterium, and A. muciniphila increased significantly in most of the studies. Thus, tea consumption could provide potential protection from the development of chronic diseases by improving gut homeostasis and reducing chronic metabolic inflammation. The direct impact of tea on intestinal homeostasis primarily targets lipopolysaccharide (LPS)-related pathways. This includes reducing the synthesis of intestinal LPS, inhibiting LPS translocation, and preventing the binding of LPS to TLR4 receptors to block downstream inflammatory pathways. The TLR4/MyD88/NF-κB p65 pathway is crucial for anti-metaflammatory responses. The antioxidant properties of tea are linked to enhancing mitochondrial function and mitigating mitochondria-related inflammation by eliminating free radicals, inhibiting NLRP3 inflammasomes, and modulating Nrf2/ARE activity. Tea also contributes to safeguarding the intestinal barrier through various mechanisms, such as promoting the synthesis of short-chain fatty acids in the intestine, activating intestinal aryl hydrocarbon receptor (AhR) and farnesoid X receptor (FXR), and improving enteritis. Functional components that improve chronic metabolic inflammation include tea polyphenols, tea pigments, TPS, etc. Tea metabolites such as 4-Hydroxyphenylacetic acid and 3,4-Dihydroxyflavan derivatives, etc., also contribute to anti-chronic metabolic inflammation effects of tea consumption. The raw materials and processing technologies affect the functional component compositions of tea; therefore, consuming different types of tea may result in varying action characteristics and mechanisms. However, there is currently limited elaboration on this aspect. Future research should conduct in-depth studies on the mechanism of tea and its functional components in improving chronic metabolic inflammation. Researchers should pay attention to whether there are interactions between tea and other foods or drugs, explore safe and effective usage and dosage, and investigate whether there are individual differences in the tea-drinking population leading to different effects of tea intervention. Ultimately, the application of tea drinking could be a universal therapy for regulating intestinal homeostasis, anti-chronic metabolic inflammatory responses, and promoting metabolic health.

The role of tea in managing cardiovascular risk factors: potential benefits, mechanisms, and interventional strategies

Traditional major cardiovascular disease (CVD) risk factors include dyslipidemia, hypertension, smoking, diabetes, and obesity. Tea is rich in various bioactive substances such as tea polyphenols, theaflavins, and tea polysaccharides. Due to the regulatory effects on multiple pathways and its anti-inflammatory and antioxidant properties, these active substances have shown significant efficacy in regulating dyslipidemia, hypertension, diabetes, obesity, and cardiac autonomic function. Additionally, tea possesses anti-inflammatory and antithrombotic properties, making it a promising dietary supplement for nutritional interventions in the primary and secondary prevention of CVDs. However, the complex composition of tea, although shown to have certain effects in vivo, does not fully elucidate the specific mechanisms of action. Moreover, the varying application methods across different studies lead to differences in intervention effects and dose-response relationships, sometimes resulting in contradictory findings. This article reviews the potential benefits, mechanisms of action, and application methods of tea for cardiovascular risk factors, elucidating its potential as a nutritional intervention.

Chemical Basis and Molecular Mechanism of Aged Qingzhuan Tea Alleviating DSS-Induced Colitis

SCOPE

Inflammatory bowel disease (IBD) poses a serious threat to human health. Qingzhuan tea (QZT), especially aged QZT, was concerned to have a potential effect on the prevention of colitis. In this study, we aim to assess the feasibility of different aged QZT on the alleviation of colitis induced by DSS.

METHODS AND RESULTS

A comprehensive investigation into the efficacy of QZT of different aging years was conducted by establishing the animal model of colitis and the cellular inflammation model. The results demonstrated that QZT aged 0-20 years could significantly alleviate the symptoms of colitis. Notably, QZT aged for 5 years (A5) and 10 years (A10) was particularly effective in downregulating the levels of proinflammatory cytokines, via suppressing the activation of the NF-κB p65 pathway and upregulating the expression of the Nrf2/ARE pathway. The additional upregulation of gut microbiota including Allobaculum and Lactobacillus and superior alleviation on mitochondrial damage may be the mechanisms for A10 to show the better activity than A0 on alleviating colitis.

CONCLUSION

Our study highlights the potential of QZT, especially A5 and A10, and provides valuable insights for the development of functional foods targeting colitis.

A review of endocrine disrupting chemicals migration from food contact materials into beverages

A significant and pressing issue revolves around the potential human exposure to endocrine disrupting chemicals (EDCs), which pose a substantial risk primarily through contaminated beverages. However, a comprehensive review for comparison of the migration rates of EDCs into these matrixes is currently lacking. This study reviews the beverages contamination with EDCs, including phthalates (PAEs), bisphenol A (BPA), hormone-like compounds, elements, and other organic EDCs. Also, the EDCs migration into milk and other dairy products, coffee, tea, and cold beverages related to their release from contact materials, preparation components, and storage conditions are briefly summarized. The data illustrates that besides the contamination of raw materials, the presence of EDCs associated with the type of food contact materials (FCMs)and their migration rate is increased with acidity, temperature, and storage time. The highest concentration of PAEs was detected from plastic and synthetic polymer films, while BPA strongly leaches from epoxy resins and canned metal. Furthermore, the presence of elements with endocrine disrupting characteristics was confirmed in cold beverages, soft drinks, hot drink and milk. Moreover, hormone-like compounds have been found to be released from coffee preparation components. Despite the few data about the migration rate of other EDCs including UV-stabilizers, surfactants, and antibacterial compounds into beverages, their presence was reported into milk, coffee, and different beverages, especially in packed samples. Studies on the EDCs leaching have primarily focused on PAEs and BPA, while other compounds require further investigation. Regardless, the possible risk that EDCs pose to humans through beverage consumption cannot be overlooked.

Possible Mechanisms of Dark Tea in Cancer Prevention and Management: A Comprehensive Review

Tea is one of the most popular drinks in the world. Dark tea is a kind of post-fermented tea with unique sensory characteristics that is produced by the special fermentation of microorganisms. It contains many bioactive substances, such as tea polyphenols, theabrownin, tea polysaccharides, etc., which have been reported to be beneficial to human health. This paper reviewed the latest research on dark tea's potential in preventing and managing cancer, and the mechanisms mainly involved anti-oxidation, anti-inflammation, inhibiting cancer cell proliferation, inducing cancer cell apoptosis, inhibiting tumor metastasis, and regulating intestinal flora. The purpose of this review is to accumulate evidence on the anti-cancer effects of dark tea, the corresponding mechanisms and limitations of dark tea for cancer prevention and management, the future prospects, and demanding questions about dark tea's possible contributions as an anti-cancer adjuvant.

The New Insight into the Effects of Different Fixing Technology on Flavor and Bioactivities of Orange Dark Tea

Peach leaf orange dark tea (ODT) is a fruity tea made by removing the pulp from peach leaf orange and placing dry Qingzhuan tea into the husk, followed by fixing them together and drying. Since the quality of traditional outdoor sunlight fixing (SL) is affected by weather instability, this study explored the feasibility of two new fixing methods, including hot air fixing (HA) and steam fixing (ST). Results showed that fixing method had a great impact on ODT shape, aroma, and taste. Compared with SL and ST, HA endowed ODT with higher fruit aroma, mellow taste, better coordination, and higher sensory evaluation score. Physical-chemical composition analysis showed that SL-fixed orange peel was higher than HA- or ST-fixed peel in the content of polyphenols, flavonoids, soluble protein, hesperidin and limonin, while HA has a higher content of volatile substances and contains more alcohols, aldehydes and ketones, and acid and esters than ST and SL. Activity analysis showed that HA was superior to ST or SL in comprehensive antioxidant activity and inhibitory activity against α-glucosidase. Comprehensive results demonstrated that HA has better performance in improving ODT quality and can replace the traditional SL method in production.

New Perspectives on Sleep Regulation by Tea: Harmonizing Pathological Sleep and Energy Balance under Stress

Sleep, a conservative evolutionary behavior of organisms to adapt to changes in the external environment, is divided into natural sleep, in a healthy state, and sickness sleep, which occurs in stressful environments or during illness. Sickness sleep plays an important role in maintaining energy homeostasis under an injury and promoting physical recovery. Tea, a popular phytochemical-rich beverage, has multiple health benefits, including lowering stress and regulating energy metabolism and natural sleep. However, the role of tea in regulating sickness sleep has received little attention. The mechanism underlying tea regulation of sickness sleep and its association with the maintenance of energy homeostasis in injured organisms remains to be elucidated. This review examines the current research on the effect of tea on sleep regulation, focusing on the function of tea in modulating energy homeostasis through sickness sleep, energy metabolism, and damage repair in model organisms. The potential mechanisms underlying tea in regulating sickness sleep are further suggested. Based on the biohomology of sleep regulation, this review provides novel insights into the role of tea in sleep regulation and a new perspective on the potential role of tea in restoring homeostasis from diseases.

Sichuan dark tea improves lipid metabolism and prevents aortic lipid deposition in diet-induced atherosclerosis model rats

Background and aims

Sichuan dark tea (ST), Zangcha, is a traditional fermented Chinese tea found in Sichuan and Tibet and claimed for beneficial effects against lifestyle-related metabolic disorders. We examined the effects of ST on lipid metabolism and atherosclerosis.

Methods and results

Sichuan dark tea was given to fat-rich diet-induced atherosclerosis model rats in comparison with dark-fermented Chinese Pu-erh tea (PT) and Japanese green tea (GT). After 8 weeks of feeding, ST and PT induced an increase in high-density lipoprotein (HDL)-cholesterol and a decrease in glucose, and ST decreased triglyceride in plasma. ST also induced low pH in the cecum. There was no significant change in their body weight among the fat-feeding groups but a decrease was found in the visceral fat and liver weight in the ST group. Accordingly, ST reduced lipid deposition in the aorta in comparison with PT and GT. ST increased mRNA of LXRα, PPARα, PPARγ, and ABCA1 in the rat liver. The extract of ST stimulated the AMPK pathway to increase the expression of ABCA1 in J774 cells and increased expression of lipoprotein lipase and hormone-sensitive lipase in 3T3L1 cells, consistent with its anti-atherogenic effects in rats. High-performance liquid chromatography analysis showed unique spectra of original specific compounds of caffeine and catechins in each tea extract, but none of them was likely responsible for these effects.

Conclusion

Sichuan dark tea increases plasma HDL and reduces plasma triglyceride to decrease atherosclerosis through AMPK activation. Further study is required to identify specific components for the effects of this tea preparation.