Oolong tea polysaccharide and polyphenols prevent obesity development in Sprague-Dawley rats

A review: Polysaccharides targeting mitochondria to improve obesity

Polysaccharides are one of the most important and widely used bioactive components of natural products, which can be used to treat metabolic diseases. Natural polysaccharides (NPs) have been the subject of much study and research in the field of treating obesity in recent years. Studies in the past have demonstrated that mitochondria are important for the initiation, progression, and management of obesity. Additionally, NPs have the ability to improve mitochondrial dysfunction via a variety of mechanisms. This review summarized the relationship between the structure of NPs and their anti-obesity activity, focusing on the anti-obesity effects of these compounds at the mitochondrial level. We discussed the association between the structure and anti-obesity action of NPs, including molecular weight, monosaccharide composition, glycosidic linkage, conformation and extraction methods. Furthermore, NPs can demonstrate a range of functions in adipose tissue, including but not limited to improving the mitochondrial oxidative respiratory chain, inhibiting oxidative stress, and maintaining mitochondrial mass homeostasis. The purpose of this work is to acquire a thorough understanding of the function that mitochondria play in the anti-obesity effects of NPs and to offer fresh insights for the investigation of how NPs prevent obesity and the creation of natural anti-obesity medications.

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.

Prunus persica (L.) Batsch blossom soluble dietary fiber synergia polyphenol improving loperamide-induced constipation in mice via regulating stem cell factor/C-kit, NF-κB signaling pathway and gut microbiota

This study aimed to investigate the ameliorating effects of peach blossom soluble dietary fiber (PBSDF) and polyphenol (PBP) combinations on loperamide (Lop)-induced constipation in mice, together with the possible mechanism of action. The results demonstrated that the combined use of PBSDF and PBP could synergistically accelerate the gastrointestinal transit rate and gastric emptying rate, shorten first red fecal defecation time, accelerate the frequency of defecation, regulate the abnormal secretion of gastrointestinal neurotransmitters and pro-inflammatory cytokines, and down-regulate the expressions of AQP3 and AQP8. Western blotting and RT-qPCR analysis confirmed that PBSDF + PBP up-regulated the protein and mRNA expressions of SCF and C-kit in SCF/C-kit signaling pathway, and down-regulated pro-inflammatory mediator expressions in NF-κB signaling pathway. 16S rRNA sequencing showed that the diversity of gut microbiota and the relative abundance of specific strains, including Akkermansia, Bacteroides, Ruminococcus, Lachnospiraceae_NK4A136_group, and Turicibacter, rehabilitated after PBSDF + PBP intervention. These findings suggested that the combination of a certain dose of PBSDF and PBP had a synergistic effect on attenuating Lop-induced constipation, and the synergistic mechanism in improving constipation might associated with the regulating NF-κB and SCF/C-kit signaling pathway, and modulating the specific gut strains on constipation-related systemic types. The present study provided a novel strategy via dietary fiber and polyphenol interactions for the treatment of constipation.

Interactive Effects of Arabinoxylan Oligosaccharides and Green Tea Polyphenols on Obesity Management and Gut Microbiota Modulation in High-Fat Diet-Fed Mice

Dietary fiber and polyphenols have been shown to possess antiobesity properties. However, their combined effects need further investigation. This study investigated the individual and combined effects of arabinoxylan oligosaccharides (AXOS) from rice bran and green tea polyphenols (GTP) in high-fat diet-induced obese mice. We found that the combination of AXOS and GTP (A + G) significantly reduced overall fat mass and improved lipid profiles, although the effects were not synergistic. AXOS and GTP regulated lipid metabolism in different tissues and exhibited counteractive effects on gut microbiota. AXOS decreased α diversity and promoted Bifidobacterium, with GTP counteracting these effects. In vitro fermentation confirmed that GTP counteracted AXOS-induced microbiota changes in a dose-dependent manner. This study highlights the potential of tailored combinations of dietary fiber and polyphenols to treat obesity while considering their complex microbial interplay.

Ultrasonic-Assisted Extraction and Gastrointestinal Digestion Characteristics of Polysaccharides Extracted from Mallotus oblongfolius

The polysaccharides were extracted from the leaves of Mallotus oblongifolius (MO) using an ultrasonic-assisted extraction method in this study. The main variables affecting the yield of polysaccharides extracted from Mallotus appallatus (MOPS) were identified and optimized while concurrently investigating its antioxidant capacity, hypoglycemic activity, and digestive properties. The results indicated that the optimal ultrasound-assisted extraction of MOPS involved an ultrasound power of 200 W, a liquid-to-solid ratio of 25:1 (mL:g), an extraction temperature of 75 °C, and an ultrasound time of 45 min, leading to an extraction yield of (7.36 ± 0.45)% (m/m). The MOPS extract exhibited significant scavenging activity against DPPH and ABTS radicals with IC50 values of (25.65 ± 0.53) μg/mL and (100.38 ± 0.38) μg/mL, respectively. Furthermore, it effectively inhibited the enzymatic activities of α-glucosidase and α-amylase with IC50 values of (2.27 ± 0.07) mg/mL and (0.57 ± 0.04) mg/mL, respectively. The content of MOPS remained relatively stable in the stomach and small intestine; however, their ability to scavenge DPPH radicals and ABTS radicals and exhibit reducing power was attenuated, and the inhibition of α-amylase and α-glucosidase activity was diminished. In conclusion, the ultrasonic extraction of MOPS showed feasibility and revealed antioxidant and hypoglycemic effects. However, the activities were significantly reduced after gastric and small intestinal digestion despite no significant change in the MOPS content.

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.

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.

Nobiletin resolves left ventricular and renal changes in 2K-1C hypertensive rats

This study investigated the effects of nobiletin on cardiorenal changes and the underlying mechanisms involved in two-kidney, one-clip (2K-1C) hypertension. 2K-1C rats were treated with nobiletin (15 or 30 mg/kg/day) or losartan (10 mg/kg/day) for 4 weeks (n = 8/group). Nobiletin (30 mg/kg) reduced high levels of blood pressure and circulating angiotensin II and angiotensin-converting enzyme activity in 2K-1C rats. Left ventricular (LV) dysfunction and remodelling in 2K-1C rats were alleviated in the nobiletin-treated group (P < 0.05). Nobiletin reduced the upregulation of Ang II type I receptor (AT₁R)/JAK (Janus kinase)/STAT (signal transducer and activator of transcription) protein expression in cardiac tissue of 2K-1C rats (P < 0.05). The reduction in kidney function, and accumulation of renal fibrosis in 2K-1C rats were alleviated by nobiletin (P < 0.05). Overexpression of AT₁R and NADPH oxidase 4 (Nox4) protein in nonclipped kidney tissue was suppressed in the nobiletin-treated group (P < 0.05). The elevations in oxidative stress parameters and the reductions in antioxidant enzymes were attenuated in 2K-1C rats treated with nobiletin (P < 0.05). In summary, nobiletin had renin-angiotensin system inhibitory and antioxidant effects and attenuated LV dysfunction and remodelling via restoration of the AT₁R/JAK/STAT pathway. Nobiletin also resolved renal damage that was related to modulation of the AT₁R/Nox4 cascade in 2K-1C hypertension.

Oolonghomobisflavans from Camellia sinensis increase Caenorhabditis elegans lifespan and healthspan

Tea polyphenols are widely considered as excellent antioxidant agents which can contribute to human health and longevity. However, the identification of the active biomolecules in complex tea extracts that promote health and longevity are not fully known. Here we used the nematode Caenorhabditis elegans to analyze the health benefits and longevity effects of Camellia sinensis oolong tea extracts (QFT, NFT, and CFT) and oolonghomobisflavan A and oolonghomobisflavan B, which are present in oolong tea extracts. Our results showed that oolong tea extracts and oolonghomobisflavans prolong lifespan and improved healthspan by curtailing the age-related decline in muscle activity and the accumulation of age pigment (lipofuscin). We found that the lifespan and healthspan promoting effects of oolong tea extracts and oolonghomobisflavans were positively correlated with the stress resistance via DAF-16/FOXO transcription factor. Furthermore, oolong tea extracts and oolonghomobisflavans displayed protective effects against Aβ- and polyQ-induced neuro/proteotoxicity. Overall, our study provides new evidence to support the health benefits of oolong tea and importantly identify oolonghomobisflavans as potent bioactive molecules that promote health when supplemented with a normal diet. As such, oolonghomobisflavans represent a valuable new class of compounds that promote healthy aging.

Sensory and chemical characteristics of Tieguanyin oolong tea after roasting

Roasting, a critical process for oolong tea, has been applied to Tieguanyin tea to improve flavor attributes. To investigate the effects of the roasting on the flavor of Tieguanyin, the global metabolomics analysis on the non-volatile and volatile components were proceeded. The weakening of bitterness and astringency, caused by roasting, may be attributed to the decreasing of flavonoids glycosides and procyanidins, whereas the enhancing of sweet aftertaste to the increasing of gallic acid. Besides, l-theanine flavan-3-ols adducts (N-ehtyl-2-pyrrolidinone substituted flavan-3-ols) increased dramatically at 130 °C compared with 105 °C, with the reduction of l-theanine and flavan-3-ols. Meanwhile, high temperature hampered the volatiles' diversity and intensity, resulting from the lowering of floral volatiles, i.e., β-ionone, jasmine, and nerolidol, yet the nitrogen-containing heterocyclic compounds increased, e.g., pyrroles and pyrazines. The results can help to comprehensively understand the influences of roasting technology on the flavor and chemistry of oolong tea.

Role of Herbal Teas in Regulating Cellular Homeostasis and Autophagy and Their Implications in Regulating Overall Health

Tea is one of the most popular and widely consumed beverages worldwide, and possesses numerous potential health benefits. Herbal teas are well-known to contain an abundance of polyphenol antioxidants and other ingredients, thereby implicating protection and treatment against various ailments, and maintaining overall health in humans, although their mechanisms of action have not yet been fully identified. Autophagy is a conserved mechanism present in organisms that maintains basal cellular homeostasis and is essential in mediating the pathogenesis of several diseases, including cancer, type II diabetes, obesity, and Alzheimer’s disease. The increasing prevalence of these diseases, which could be attributed to the imbalance in the level of autophagy, presents a considerable challenge in the healthcare industry. Natural medicine stands as an effective, safe, and economical alternative in balancing autophagy and maintaining homeostasis. Tea is a part of the diet for many people, and it could mediate autophagy as well. Here, we aim to provide an updated overview of popular herbal teas’ health-promoting and disease healing properties and in-depth information on their relation to autophagy and its related signaling molecules. The present review sheds more light on the significance of herbal teas in regulating autophagy, thereby improving overall health.

Pu-erh tea ameliorates obesity and modulates gut microbiota in high fat diet fed mice

Obesity is regarded to be associated with fat accumulation, chronic inflammation, and gut microbiota dysbiosis. Raw and ripened pu-erh tea extract (PETe) have the effect of reducing body weight gain and fat accumulation, which are associated with gut microbiota. However, little is known about the difference of raw and ripened PETe on the regulation of gut microbiota. Here, our results suggested that supplementation of raw and ripened PETe displayed similar anti-obesogenic effect in high fat diet (HFD)-induced obesity mice, by attenuating the body weight gain, fat accumulation, oxidative injury, and low-grade inflammation, improving the glucose tolerance, alleviating the metabolic endotoxemia, and regulating the mRNA and protein expression levels of the lipid metabolism-related genes. 16S rRNA sequencing of fecal samples indicated that raw and ripened PETe intervention displayed different regulatory effect on the HFD-induced gut microbiota dysbiosis at different taxonomic levels. The microbial diversity, the relative abundance of Firmicutes and Bacteroidetes as well as F/B ratio were reversed more closer to normal by ripened PETe. Phylotypes of Bacteroidaceae, Ruminococcaceae, Lachnospiraceae, Muribaculaceae, and Rikenellaceae which are negatively correlated with obesity were enhanced notably by the intervention of ripened PETe, while Erysipelotrichaceae and Lactobacillaceae which have positive correlation with obesity were decreased dramatically. In addition, the treatment of ripened PETe had better effect on the increase of benefical Bacteroides, Alistipes, and Akkemansia and decrease of obesity associated Faecalibaculum and Erysipelatoclostridium (p < 0.05). These findings suggested that pu-erh tea especially ripened pu-erh tea could serve as a great candidate for alleviation of obesity in association with the modulation of gut microbiota.

Exploring Phytotherapeutic Alternatives for Obesity, Insulin Resistance and Diabetes Mellitus

At present, the pathologic spectrum of obesity-insulin resistance (IR)-diabetes mellitus (DM) represents not only a pressing matter in public health but also a paramount object of study in biomedical research, as they constitute major risk factors for cardiovascular disease (CVD), and other chronic non-communicable diseases (NCD). Phytotherapy, the use of medicinal herbs (MH) with treatment purposes, offers a wide array of opportunities for innovation in the management of these disorders; mainly as pharmacological research on small molecules accumulates. Several MH has displayed varied mechanisms of action relevant to the pathogenesis of obesity, IR and DM, including immunological and endocrine modulation, reduction of inflammation and oxidative stress (OS), regulation of appetite, thermogenesis and energy homeostasis, sensitisation to insulin function and potentiation of insulin release, among many others. However, the clinical correlates of these molecular phenomena remain relatively uncertain, with only a handful of MH boasting convincing clinical evidence in this regard. This review comprises an exploration of currently available preclinical and clinical research on the role of MH in the management of obesity, IR, and DM.

Cyclocarya paliurus polysaccharide improves metabolic function of gut microbiota by regulating short-chain fatty acids and gut microbiota composition

The purpose of this paper was to investigate the effects of Cyclocarya paliurus polysaccharide (CP) on gut microbiota composition and predict metabolic function in healthy mice. Healthy Kunming mice were continuously gavaged with CP for 20 days, and mouse feces were collected for analysis. The results showed that CP could remarkably increase the short-chain fatty acids (SCFAs; acetic acid, propionic acid, butyric acid, and valeric acid) in the feces of healthy mice in a dose-dependent matter. 16S rRNA showed that 200 mg/kg body weight CP was effective in increasing diversity of the gut microbiota in healthy mice and affected the relative abundance of specific bacteria. Lachnospiraceae, Clostridiales, and Clostridia were identified as the phenotypic biomarkers of the CP-H group compared with the normal control group. In addition, PICRUSt2 showed that starch and sucrose metabolism, amino acid metabolism, glycerolipid metabolism, pantothenate and CoA biosynthesis, biosynthesis of unsaturated fatty acids, and C5-branched dibasic acid metabolism are the primary enriched phenotypic KEGG pathways in the CP-H group. These findings suggested that early CP intervention could enhance the metabolic function of gut microbiota by increasing the release of SCFAs and altering the composition of gut microbiota.

Effects of Oil Tea on Obesity and Dyslipidemia: A Cross-Sectional Study in China

BACKGROUND

Animal experiments have found that oil tea reduces body weight and improves blood lipid levels. However, the effect of oil tea on human health has not been confirmed yet. This study aims to explore the relationship between oil tea consumption and obesity and dyslipidemia.

METHODS

In a cross-sectional population study in Guangxi, China, a semi-quantitative questionnaire was used to investigate the oil tea consumed and food consumption frequency in adults aged 30 years and over. Anthropometric variables and serum biochemical indicators were measured. A total of 2001 adults were divided into five groups based on their non-consumption status and quartile of consumption (groups non-drink oil tea, Q1-Q4).

RESULTS

The risk of abdominal obesity tended to decrease significantly with increasing consumption of oil tea (P for trend< 0.05) in the overall participants (Q3 group, OR = 0.545, 95% CI = 0.336-0.884; Q4 group, OR = 0.520, 95% CI = 0.311-0.871) and in women (Q2 group, OR = 0.502, 95% CI = 0.274-0.920; Q3 group, OR = 0.397, 95% CI = 0.213-0.740; Q4 group, OR = 0.421, 95% CI = 0.228-0.780). Oil tea consumption Q1, Q2, Q3 and Q4 group significantly reduced the risk of abnormal HDL-cholesterol (P < 0.05). Oil tea consumption Q2 group significantly increased the risk of abnormal LDL-cholesterol (OR = 2.600, 95% CI = 1.033-6.546) in women. Oil tea consumption Q1 (OR = 0.081, 95% CI =0.008-0.864) and Q3 (OR = 0.057, 95% CI = 0.004-0.913) groups significantly reduced the risk of abnormal HDL-cholesterol in women.

CONCLUSION

Oil tea consumption may be associated with a low risk of abdominal obesity. High-dose oil tea consumption may be associated with a low risk of abnormal HDL-cholesterol. Prospective studies with large sample sizes would be required to further investigate this association.

Inhibitory effect of oolonghomobisflavan B on osteoclastogenesis by suppressing p38 MAPK activation

Suppression of differentiation and/or function of osteoclasts is considered an effective therapeutic strategy for osteolytic bone diseases such as periodontitis and osteoporosis. Evidence regarding the health benefits of oolong tea consumption is accumulating, and tea polyphenols have various pharmacological properties such as anti-cancer and anti-diabetes effects. In this study, we investigated the effect of oolonghomobisflavan B (OFB), a polyphenolic compound in oolong tea, on osteoclast differentiation. OFB suppressed receptor activator of nuclear factor-κB (RANKL)-induced formation of tartate-resistant acid phosphatase-positive multinuclear cells without cytotoxicity. OFB also significantly attenuated p38 phosphorylation, which is essential for RANKL-induced osteoclastogenesis, and inhibited the expressions of nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) and osteoclast-specific target genes, including dendritic cell-specific transmembrane protein and cathepsin K. Our findings suggest that OFB exhibits an anti-osteoclastogenic activity by inhibiting RANKL-mediated p38 activation, which is useful for the prevention and treatment of osteolytic bone diseases.

Effect of purity of tea polysaccharides on its antioxidant and hypoglycemic activities

The effects of purity of tea polysaccharides (TPS) on its five antioxidant activities and hypoglycemic activities in vitro were studied. The results showed that the higher the purity of TPS, the lower the antioxidant capacity. The purity of FTPSI is the highest (sugar content 80.72%), but its antioxidant activities were lower than those of Fujian tea polysaccharides (FTPS) and FTPSII. The antioxidant activity of tea polysaccharide is related to its protein and polyphenol content (Pearson r > .90). The protective effect of Zhejiang tea polysaccharides and FTPS on human umbilical vein endothelial cells (HUVEC) was better than that of its purified fractions. The inhibition rates of FTPSII (5 and 2 mg/ml) on α-glucosidase (32.76%) and α-amylase (-11.93%) were higher than those of FTPS and FTPSII. Purification does not change the basic structure of TPS. This study has certain reference value for the study of the antioxidant activities of TPS. Meanwhile, TPS can be used as a potential resource with hypoglycemic function. PRACTICAL APPLICATIONS: A large number of studies have shown that TPS have antioxidant activity. However, several studies considered that the antioxidant activity of TPS mainly comes from the residues of tea polyphenols. Therefore, the in vitro and cell antioxidant activities of TPS were studied in this paper. We believe that both glycoprotein and tea polyphenol are antioxidants of tea, and tea polysaccharide perform preferable effect on hypoglycemic. HUVEC cell model and four in vitro antioxidant test methods were used to study the antioxidant activities of TPS, and two enzyme inhibition activities were used to study the hypoglycemic effect of TPS, in order to provide a theoretical basis for the study of biological activity of TPS.

Oolong tea drinking boosts calcaneus bone mineral density in postmenopausal women: a population-based study in southern China

INTRODUCTION

Observational studies have shown that tea consumption has a potentially beneficial effect on bone health. However, few studies have assessed the effects of types of tea consumed on bone health. We aimed to investigate whether drinking oolong tea is associated with increased calcaneus bone mineral density (BMD) in postmenopausal women.

METHODS

From an epidemiological survey in Shantou, 476 postmenopausal women aged 40 to 88 years were enrolled in the study. All women were questioned about their demographic features, lifestyle, health status, types of tea consumed, habit of tea consumption, and habitual dietary intake by use of a structured questionnaire. Estimated areal BMD was measured by calcaneal quantitative ultrasound (QUS).

RESULTS

As compared with non-tea drinkers, oolong tea drinkers had higher calcaneus BMD (β 34.70 [95% CI 10.38, 59.03]). In addition, calcaneus BMD was significantly increased for those drinking 1-5 cups/day (β 27.43 [95% CI 3.70, 51.16]) but not > 5 cups/day. We observed no linear increase in calcaneus BMD with increasing years of tea consumption and local polynomial regression fitting showed a parabola-shaped association between years of tea consumption and calcaneus BMD. However, symptoms of osteoporosis did not differ by types of tea consumed.

CONCLUSION

Long-term moderate oolong tea consumption may have beneficial effects on bone health in postmenopausal women in Shantou of southern China.