Influencing Factors on the Physicochemical Characteristics of Tea Polysaccharides

Physicochemical evaluation, structural characterization, in vitro and in vivo bioactivities of water-soluble polysaccharides from Luobuma (Apocynum L.) tea

Luobuma tea is made from the leaves of Apocynum hendersonii (Bt) and A. venetum (Ht) and has been used for a very long time in China and Japan as herbal tea. This study isolated water-soluble polysaccharides from the two species` teas. Physicochemical properties, structural properties, in vitro and in vivo antioxidant and immunomodulatory activities were determined for the first time. The results showed that the Bt and Ht polysaccharides with molecular weights of 31.21 and 49.11 kDa, respectively, composed of arabinose, galactose, rhamnose, glucose, xylose, fucose, and mannose. A dose-dependent nitric oxide production and interleukin-6 inhibitory effects were obtained. Also, they suppressed the expression of cyclooxygenase-2, tumor necrosis factor-α and interleukin-6 mRNA in LPS-induced RAW 264.7 macrophages. Likewise, Bt and Ht have significantly reduced edema in the paws of mice after carrageenan injection. These results suggested that the Luobuma teas polysaccharides can be explored as potential antioxidants and anti-inflammatory agents.

Fu brick tea polysaccharides: A state-of-the-art mini-review on extraction, purification, characteristics, bioactivities and applications

Fu brick tea (FBT), a post-fermented dark tea, is highly esteemed for its abundant nutritional and medicinal values. Fu brick polysaccharides (FBTPs) are acidic heteropolysaccharides primarily composed of galactose and galacturonic acid, which are crucial components of FBT. FBTPs exhibit multiple bioactivities, including immunomodulatory, antioxidant, anti-inflammatory, regulatory effects on intestinal microbiota, anti-obesity, among others. Owing to their significant marketing potential and promising development prospects, FBTPs have attracted considerable attention from researchers worldwide. However, the specific mechanisms and underlying structure-function relationships of FBTPs are not well understood. Consequently, this review aims to provide comprehensive and cutting-edge information on the extraction, purification, structural characteristics, and biological activities of FBTPs, with an emphasis on exploring how their structural characteristics influence biological activities and therapeutic potential. We found that different materials and extraction techniques could result in differences in the structure-activity relationship of FBTPs. Furthermore, monosaccharide composition and molecular weight could also significantly impact the bioactivities of FBTPs, such as lipid-lowering effects and immunomodulatory activity. This review would further facilitate the applications of FBTPs as therapeutic agents and functional foods, thereby laying a solid foundation for their further development and utilization.

Biological potential and mechanisms of Tea's bioactive compounds: An Updated review

BACKGROUND

Tea (Camellia sinensis) has a rich history and is widely consumed across many countries, and is categorized into green tea, white tea, oolong tea, yellow tea, black tea, and dark tea based on the level of fermentation. Based on a review of previous literature, the commonly recognized bioactive substances in tea include tea polyphenols, amino acids, polysaccharides, alkaloids, terpenoids, macro minerals, trace elements, and vitamins, which have been known to have various potential health benefits, such as anticancer, antioxidant, anti-inflammatory, anti-diabetes, and anti-obesity properties, cardiovascular protection, immune regulation, and control of the intestinal microbiota. Most studies have only pointed out the characteristics of tea's bioactivities, so a comprehensive summary of the pharmacological characteristics and mechanisms of tea's bioactivities and their use risks are vital.

AIM OF REVIEW

This paper aims to summarize tea's bioactive substances of tea and their pharmacological characteristics and mechanisms, providing a scientific basis for the application of bioactive substances in tea and outlining future research directions for the study of bioactive substances in tea.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review summarizes the main biologically active substances, pharmacological effects, and mechanisms and discusses the potential risks. It may help researchers grasp more comprehensive progress in the study of tea bioactive substances to further promote the application of tea as a natural bioactive substance in the medical field.

Extraction methods, chemical compositions, molecular structure, health functions, and potential applications of tea polysaccharides as a promising biomaterial: a review

Tea polysaccharides (TPS) have attracted much attention due to their multiple biological activities, excellent biocompatibility and good biodegradability, creating a wide range of potential applications in the food and pharmaceutical industries. However, the high molecular weight and complexity of TPS components have restricted its purification and bioactivity, limiting its potential applications. In this review, the effects of various extraction methods, tea processing, and degree of fermentation on the composition and structure of TPS were thoroughly investigated to overcome this dilemma. Through a comprehensive analysis of in vivo and in vitro studies, the health benefits of TPS are discussed in detail, including antioxidant, anti-obesity, modulation of gut microbial communities, and anticancer bioactivities. Typical structural characterization techniques of TPS are also summarized, and interactions with common food components are discussed in depth, providing a deeper perspective on the overall knowledge of TPS. Finally, this review offers an extensive overview of the wide range of applications of TPS, including its strong emulsifying properties and bio-accessibility, in various fields such as food nutrition, drug delivery, encapsulation films, and emulsifiers. This review aims to provide a theoretical basis for the profound development of TPS for productive utilization.

Interplay between traditional Chinese medicine polysaccharides and gut microbiota: The elusive "polysaccharides-bond-bacteria-enzyme" equation

Polysaccharides are one of the most important components of traditional Chinese medicine (TCM) and have been extensively studied for their immunomodulatory properties. The functions and effects of TCM polysaccharides are closely related to the gut microbiota, making the study of their interaction a hot topic in the field of TCM metabolism. This review follows two main inquiries: first, how the gut microbiota breaks down TCM polysaccharides to produce bioactive metabolites; and second, how TCM polysaccharides reshape the gut microbiota as a carbon source. Understanding the interaction mechanism involves a challenging equation of the structural association of TCM polysaccharides with the metabolic activities of the microbiota. This review has meticulously searched, partially organized literature spanning the past decade, that delves into the interaction mechanism between TCM polysaccharides and gut microbiota. It also gives an overview of the complex factors of the elusive "polysaccharides-bond-bacteria-enzyme" equation: the complexity of polysaccharide structures, the diversity of glycosidic bond types, the communal nature of metabolizing microbiota, the enzymes involved in functional degradation by microbiota, and the hierarchical roles of polysaccharide utilization locus and gram-positive PULs. Finally, this review aims to facilitate discussion among peers in the field of TCM microbiota and offers prospects for research in related fields, paving the way for pharmacological studies on TCM polysaccharides and gut microbiota therapeutics, and providing a reference point for further clinical research.

Impact of internal metal ions in tea polysaccharides on antioxidant potential and suppression of cancer cell growth

Four kinds of tea polysaccharides (MBTPS, MGTPS, ZBTPS, ZGTPS) were extracted from Maofeng black tea, Maofeng green tea,Ziyan black tea and Ziyan green tea, and then four tea polysaccharides (RMBTPS, RMGTPS, RZBTPS, RZGTPS) after metal removal were prepared. The physicochemical properties, antioxidant activity and inhibitory activity on cancer cell proliferation of the above polysaccharides were studied. The composition analysis shows that these tea polysaccharides were glycoproteins complexes, composed of a variety of monosaccharides, and the removal of metal ions did not lead to fundamental changes in the composition of polysaccharides. In vitro activity, after removing metal ions, the ABTS free radicals scavenging ability and reducing power of tea polysaccharides were decreased, and the inhibitory effect on proliferation of H22 cells weakened. There was a great correlation between metal elements Al and Ni and biological activity. The results showed that the metal ions in tea polysaccharides, especially Al and Ni, had positive effects on biological activity.

Interactions between intestinal microbial fermentation products of Pleurotus eryngii polysaccharide with gut mucus

Recently, Pleurotus eryngii (P. eryngii) polysaccharide (PEP) has received a lot of attention from many researchers as the primary active substance. The PEP influences the gut microbiota in several ways, including the interaction of fermentation products with the intestinal mucus layer (IML) and intestinal epithelial cells. Herein, we characterized interactions between the IML and PEP after degradation by the gut microbes. Our results showed that fermented P. eryngii polysaccharide (FPEP) can interact with intestinal mucus (IM), and this interaction can reduce the degree of molecular aggregation of polysaccharides. At the same time, the fermentation time of FPEP also affects the interaction between the two. SEM showed that the FPEP solution tended to aggregate into larger particles, while with the addition of IM, the FPEP molecules were dispersed. Particle size measurements unveil substantial differences in the fermented polysaccharides' particle size between the group with supplementary IM (0 hours of fermentation: 485.1 ± 11.3 nm) and the group without IM (0 hours of fermentation: 989.33 ± 21.3 nm). Remarkably, within the group with added IM, the particle size reached its maximum at 24 hours of fermentation (585.87 ± 42.83 nm). Additionally, turbidity assessments demonstrate that, during the 12-hour interaction period, the 24-hour fermented polysaccharides consistently exhibit the highest OD values, ranging between 0.57 and 0.61. This work investigates the interaction between FPEP and IM, predicting the adhesion of polysaccharides to IM. Meanwhile, this provides a theoretical basis for further studies on the absorption and transport pathways of PEP and provides a novel research viewpoint on intestinal digestion and absorption.

Recent insights into the physicochemical properties, bioactivities and their relationship of tea polysaccharides

Tea polysaccharides (TPS) is receiving global concern in past years due to their therapeutic effects in many diseases such as obesity and diabetes. Many publications imply that the unique physicochemical properties and bioactivities of TPS are prerequisites for its use as a biofilm, drug carrier and emulsifier. Despite numerous healthy benefits, studies on the in-deep structure-activity relationship of TPS still not well explored and explained yet. The main reasons for the research limitation are attributed mainly to the unbreakable advanced structural research technology and the formation of TPS conjugates. The present review also summarizes some similar parameters in primary structure of TPS with better bioactivities, discusses the relationships between their physicochemical properties and bioactivities, and suggests that function-specific TPS would be obtained in the future if the links between preparation methods, physicochemical properties and bioactivities of TPS could be well understood and established.

Chain conformation, mucoadhesive properties of fucoidan in the gastrointestinal tract and its effects on the gut microbiota

Fucoidans are valuable marine polysaccharides with various bioactivities and physicochemical properties. However, its digestive properties, mucoadhesive properties, and bioactivity in the gastrointestinal tract are still unclear. In this study, simulated digestion, fecal fermentation in vitro, and rheology models were utilized to investigate the chain conformation, influence on gut microbiota, and mucin adhesive properties of fucoidan from the sea cucumber Thelenota ananas (Ta-FUC). The results showed that Ta-FUC was nondigestible with a temporary decrease in molecular weight in gastric conditions, accompanied by the chain conformation becoming more flexible. Moreover, Ta-FUC exhibited strong mucin adhesive function in the simulated intestinal environment, with supramolecular disulfide, hydrogen, and hydrophobic interactions in order of intensity. During fermentation, Ta-FUC was degraded by the intestinal flora to produce various short-chain fatty acids and promoted the relative abundance of Bacteroidota and Firmicutes, reducing the proportion of Proteobacteria. Therefore, these results indicate that Ta-FUC could be a potential prebiotic and ingredient for developing targeted delivery systems in the functional food and pharmaceutical industries.

Antioxidant and hypoglycemic activity of tea polysaccharides with different degrees of fermentation

Four polysaccharides (GTPS, OTPS, BTPS and DTPS) were extracted from green tea, oolong tea, black tea and dark tea respectively. The physical and chemical properties, antioxidant and hypoglycemic activities were studied. Structural analysis showed that these tea polysaccharides were glycoprotein complexes, and there were significant differences in microstructure, protein, total sugar and uronic acid content. They were all composed of multiple monosaccharides and different molar ratios. In terms of antioxidant activity, completely fermented BTPS and DTPS had higher activity. Regarding to hypoglycemic effects, BTPS showed higher α-glucosidase inhibitory activity in vitro. And in the treatment of type 2 diabetes mice, Oral BTPS significantly controlled the levels of blood glucose, TG, TC, LDL-C, Cr, UREA, ALT and AST in diabetic mice, and improved insulin resistance. Histopathological observation further confirmed that BTPS can alleviate liver injury caused by hyperglycemia and hyperlipidemia. Data showed that BTPS significantly improved hyperglycemia and liver function in diabetic mice.

A Review on the Extraction, Bioactivity, and Application of Tea Polysaccharides

Tea is a non-alcoholic drink containing various active ingredients, including tea polysaccharides (TPSs). TPSs have various biological activities, such as antioxidant, anti-tumor, hypoglycemic, and anti-cancer activities. However, TPSs have a complex composition, which significantly limits the extraction and isolation methods, thus limiting their application. This paper provides insight into the composition, methodological techniques for isolation and extraction of the components, biological activities, and functions of TPSs, as well as their application prospects.

Advances in the Utilization of Tea Polysaccharides: Preparation, Physicochemical Properties, and Health Benefits

Tea polysaccharide (TPS) is the second most abundant ingredient in tea following tea polyphenols. As a complex polysaccharide, TPS has a complex chemical structure and a variety of bioactivities, such as anti-oxidation, hypoglycemia, hypolipidemic, immune regulation, and anti-tumor. Additionally, it shows excellent development and application prospects in food, cosmetics, and medical and health care products. However, numerous studies have shown that the bioactivity of TPS is closely related to its sources, processing methods, and extraction methods. Therefore, the authors of this paper reviewed the relevant recent research and conducted a comprehensive and systematic review of the extraction methods, physicochemical properties, and bioactivities of TPS to strengthen the understanding and exploration of the bioactivities of TPS. This review provides a reference for preparing and developing functional TPS products.

Population structure analysis to explore genetic diversity and geographical distribution characteristics of cultivated-type tea plant in Guizhou Plateau

BACKGROUND

Tea plants originated in southwestern China. Guizhou Plateau is an original center of tea plants, and is rich in germplasm resources. However, the genetic diversity, population structure and distribution characteristics of cultivated-type tea plants in the region are unknown. In this study, we explored the genetic diversity and geographical distribution of cultivated-type tea accessions in Guizhou Plateau.

RESULTS

We used 112,072 high-quality genotyping-by-sequencing to analyze the genetic diversity, principal components, phylogeny, population structure, and linkage disequilibrium, and develop a core collection of 253 cultivated-type tea plant accessions from Guizhou Plateau. The results showed Genetic diversity of the cultivated-type tea accessions of the Pearl River Basin was significantly higher than that of the cultivated-type tea accessions of the Yangtze River Basin. Three inferred pure groups (CG-1, CG-2 and CG-3) and one inferred admixture group (CG-4), were identified by a population structure analysis, and verified by principal component and phylogenetic analyses. The highest genetic distance and differentiation coefficients were determined for CG-2 vs CG-3. The lower genetic distance and differentiation coefficients were determined for CG-4 vs CG-2 and CG-4 vs CG-3, respectively. We developed a core set and a primary set. The primary and core sets contained 77.0 and 33.6% of all individuals in the initial set, respectively. The primary set may serve as the primary population in genome-wide association studies, while the core collection may serve as the core population in multiple treatment setting studies.

CONCLUSIONS

The present study demonstrated the genetic diversity and geographical distribution characteristics of cultivated-type tea plants in Guizhou Plateau. Significant differences in genetic diversity and evolutionary direction were detected between the ancient landraces of the Pearl River Basin and the those of the Yangtze River Basin. Major rivers and ancient hubs were largely responsible for the genetic exchange between the Pearl River Basin and the Yangtze River Basin ancient landraces as well as the formation of the ancient hubs evolutionary group. Genetic diversity, population structure and core collection elucidated by this study will facilitate further genetic studies, germplasm protection, and breeding of tea plants.