Liubao brick tea activates the PI3K-Akt signaling pathway to lower blood glucose, metabolic disorders and insulin resistance via altering the intestinal flora

Valorization of cell wall polysaccharides extracted from Liubao brick tea residues: chemical, structural, and hypoglycemic properties

BACKGROUND

Tea dregs, typically generated during the production of instant tea or tea beverages, have conventionally been regarded as waste material and routinely discarded. Nevertheless, contemporary research endeavors are concentrating on discovering efficient methods for utilizing the potential of this discarded resource.

RESULTS

In this study, we employed a sequential extraction method using chemical chelating agents to extract and isolate four distinct cell wall polysaccharides, designated as CWTPS-1 through CWTPS-4, from the tea dregs of Liubao brick tea. A comprehensive investigation into their physicochemical, structural, and hypoglycemic properties was conducted. The analysis of chemical composition and physicochemical characteristics revealed that all four CWTPSs were characterized as acidic polysaccharides, albeit with varying chemical compositions and physicochemical attributes. Specifically, the xyloglucan fractions, CWTPS-3 and CWTPS-4, were found to be rich in glucose and xylose, displaying a more uniform molecular weight distribution, greater structural stability, and a more irregular surface compared to the others. Moreover, they exhibited a higher diversity of monosaccharide residues. Importantly, our research unveiled that all four CWTPSs exhibited the capacity to modulate key glucose-regulated and antioxidant enzyme activities within HepG2 cells via the IRS-1-PI3K/AKT signaling pathway, thereby ameliorating cellular insulin resistance. Furthermore, our correlation analysis highlighted significant associations between monosaccharide composition and neutral sugar content with the observed hypoglycemic activity of CWTPSs.

CONCLUSION

This study highlights the potential of utilizing tea dregs as a valuable resource, making a significant contribution to the advancement of the tea industry. Furthermore, CWTPS-4 exhibits promising prospects for further development as a functional food ingredient or additive. © 2024 Society of Chemical Industry.

Network Pharmacology Analysis, Molecular Docking Integrated Experimental Verification Reveal the Mechanism of Gynostemma pentaphyllum in the Treatment of Type II Diabetes by Regulating the IRS1/PI3K/Akt Signaling Pathway

Gynostemma pentaphyllum (Thunb.) Makino (GP), a plant with homology of medicine and food, as a traditional Chinese medicine, possesses promising biological activities in the prevention and treatment of type 2 diabetes mellitus (T2DM). However, the material basis and the mechanism of action of GP in the treatment of T2DM have not been fully elucidated. This study aimed to clarify the active components, potential targets and signaling pathways of GP in treating T2DM. The chemical ingredients of GP were collected by combining UPLC-HRMS analysis and literature research. Network pharmacology revealed that GP had 32 components and 326 potential targets in treating T2DM. The results showed that GP affected T2DM by mediating the insulin resistance signaling pathway, PI3K/Akt signaling pathway and FoxO1 signaling pathway, which had a close relationship with T2DM. Molecular docking results showed that STAT3, PIK3CA, AKT1, EGFR, VEGFA and INSR had high affinity with the active compounds of GP. In vitro, GP extracts obviously increased the glucose uptake and glucose consumption in IR-HepG2 cells. GP extracts increased the levels of PI3K, p-AKT, p-GSK3β and p-FoxO1 and decreased the expression of p-IRS1, p-GS, PEPCK and G6Pase, which indicated that GP could promote glycogen synthesis and inhibit gluconeogenesis by regulating the IRS1/PI3K/Akt signaling pathway. The results demonstrated that GP could improve insulin resistance by promoting glucose uptake and glycogen synthesis and inhibiting gluconeogenesis through regulating the IRS1/PI3K/Akt signaling pathway, which might be a potential alternative therapy for T2DM.

Antidiabetic Potential of Tea and Its Active Compounds: From Molecular Mechanism to Clinical Evidence

Diabetes mellitus (DM) is a chronic endocrine disorder that poses a long-term risk to human health accompanied by serious complications. Common antidiabetic drugs are usually accompanied by side effects such as hepatotoxicity and nephrotoxicity. There is an urgent need for natural dietary alternatives for diabetic treatment. Tea (Camellia sinensis) consumption has been widely investigated to lower the risk of diabetes and its complications through restoring glucose metabolism homeostasis, safeguarding pancreatic β-cells, ameliorating insulin resistance, ameliorating oxidative stresses, inhibiting inflammatory response, and regulating intestinal microbiota. It is indispensable to develop effective strategies to improve the absorption of tea active compounds and exert combinational effects with other natural compounds to broaden its hypoglycemic potential. The advances in clinical trials and population-based investigations are also discussed. This review primarily delves into the antidiabetic potential and underlying mechanisms of tea active compounds, providing a theoretical basis for the practical application of tea and its active compounds against diabetes.

Gut microbiota and metabolic profiles in chronic intermittent hypoxia-induced rats: disease-associated dysbiosis and metabolic disturbances

Aim

Chronic intermittent hypoxia (CIH) is a key characteristic of obstructive sleep apnea (OSA) syndrome, a chronic respiratory disorder. The mechanisms of CIH-induced metabolic disturbance and histopathological damage remain unclear.

Methods

CIH-induced rats underwent daily 8-h CIH, characterized by oxygen levels decreasing from 21% to 8.5% over 4 min, remaining for 2 min, and quickly returning to 21% for 1 min. The control rats received a continuous 21% oxygen supply. The levels of hypersensitive C reactive protein (h-CRP), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8), and nuclear factor kappa-B (NF-κB) were measured by ELISA. Histological analysis of the soft palates was conducted using HE staining. The microbial profiling of fecal samples was carried out by Accu16STM assay. Untargeted metabolomics of serum and soft palate tissue samples were analyzed by UPLC-MS. The protein expression of cAMP-related pathways in the soft palate was determined by Western blot.

Results

After 28 h of CIH induction, a significant increase in pro-inflammatory cytokines was observed in the serum, along with mucosal layer thickening and soft palate tissue hypertrophy. CIH induction altered the diversity and composition of fecal microbiota, specifically reducing beneficial bacteria while increasing harmful bacteria/opportunistic pathogens. Notably, CIH induction led to a significant enrichment of genera such as Dorea, Oscillibacter, Enteractinococcus, Paenibacillus, Globicatella, and Flaviflexus genera. Meanwhile, Additionally, CIH induction had a notable impact on 108 serum marker metabolites. These marker metabolites, primarily involving amino acids, organic acids, and a limited number of flavonoids or sterols, were associated with protein transport, digestion and absorption, amino acid synthesis and metabolism, as well as cancer development. Furthermore, these differential serum metabolites significantly affected 175 differential metabolites in soft palate tissue, mainly related to cancer development, signaling pathways, amino acid metabolism, nucleotide precursor or intermediate metabolism, respiratory processes, and disease. Importantly, CIH induction could significantly affect the expression of the cAMP pathway in soft palate tissue.

Conclusions

Our findings suggest that targeting differential metabolites in serum and soft palate tissue may represent a new approach to clinical intervention and treatment of OSA simulated by the CIH.

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.

Liubao tea extract ameliorates ovalbumin-induced allergic asthma by regulating gut microbiota in mice

Asthma, a chronic airway inflammatory disease, has a complicated pathogenesis and limited therapeutic treatment. Evidence shows that the intestinal microbiota exhibits crucial functional interaction with asthma syndrome. Liubao tea (LBT), a type of postfermented tea in China, positively modulates gut microbiota. However, the potential benefits of LBT extract (LBTE) for allergic asthma are still not understood. Herein, the anti-inflammatory effects of LBTE and its modulation of the gut microbiota of asthmatic mice induced by ovalbumin were explored. The results demonstrate that LBTE significantly inhibited airway hyper-responsiveness and restrained the proliferation of proinflammatory cytokines and inflammatory cells associated with allergic asthma. Additionally, LBTE suppressed inflammatory infiltration, mucus secretion, and excessive goblet cell production by downregulating the gene expression of inflammatory indicators. Interestingly, fecal microbiota transplantation results further implied that the modulation of LBTE on gut microbiota played an essential role in alleviating airway inflammatory symptoms of allergic asthma.

Effect of Galactooligosaccharide on PPARs/PI3K/Akt Pathway and Gut Microbiota in High-Fat and High-Sugar Diet Combined with STZ-Induced GDM Rat Model

Gestational diabetes mellitus (GDM) is a metabolic disorder, characterized by underlying glucose intolerance, diabetes onset or first diagnosis during pregnancy. Galactooligosaccharide (GOS) is essential for consumer protection as food supplementation. However, there is limited understanding of the effects of GOS on GDM. We successfully established a GDM rat model to explore GOS whether participated in PPARs/PI3K/Akt pathway and gut microbiota metabolites to treat for GDM. In this study, compared with the GDM group, GOS administration lowered the levels of TG, LDL-C, and HDL-C in rat serum, as well as improved the pathological changes pancreatic, liver, and kidney tissues. Compared with the GDM group, the protein expressions of PPARα, PPARγ, and PPARβ/δ markedly enhanced in GOS-treated groups (P < 0.01). Moreover, GOS administration upregulated the protein expressions of PPARα, PPARβ, PPARγ, PI3K, Akt, GLUT4, Bax, and Bcl2. GOS administration altered gut microbiota metabolites, including both SCFAs and BAs. Correlation analysis revealed close relationships between gut microbiota and experimental indicators. This study indicated that GOS effectively improved GDM in rats through the modulation of PPARs/PI3K/Akt pathway and gut microbiota. Thus, the GOS could be recommended as a candidate for novel therapy of GDM.

A systemic review on Liubao tea: A time-honored dark tea with distinctive raw materials, process techniques, chemical profiles, and biological activities

Liubao tea (LBT) is a unique microbial-fermented tea that boasts a long consumption history spanning 1500 years. Through a specific post-fermentation process, LBT crafted from local tea cultivars in Liubao town Guangxi acquires four distinct traits, namely, vibrant redness, thickness, aging aroma, and purity. The intricate transformations that occur during post-fermentation involve oxidation, degradation, methylation, glycosylation, and so forth, laying the substance foundation for the distinctive sensory traits. Additionally, LBT contains multitudinous bioactive compounds, such as ellagic acid, catechins, polysaccharides, and theabrownins, which contributes to the diverse modulation abilities on oxidative stress, metabolic syndromes, organic damage, and microbiota flora. However, research on LBT is currently scattered, and there is an urgent need for a systematical recapitulation of the manufacturing process, the dominant microorganisms during fermentation, the dynamic chemical alterations, the sensory traits, and the underlying health benefits. In this review, current research progresses on the peculiar tea varieties, the traditional and modern process technologies, the substance basis of sensory traits, and the latent bioactivities of LBT were comprehensively summarized. Furthermore, the present challenges and deficiencies that hinder the development of LBT, and the possible orientations and future perspectives were thoroughly discussed. By far, the productivity and quality of LBT remain restricted due to the reliance on labor and experience, as well as the incomplete understanding of the intricate interactions and underlying mechanisms involved in processing, organoleptic quality, and bioactivities. Consequently, further research is urgently warranted to address these gaps.

Effects of dietary adjustment of n-3:n-6 fatty-acid ratio to 1:2 on anti-inflammatory and insulin-signaling pathways in ovariectomized mice with high fat diet-induced obesity

Estrogen deficiency increases the secretion of inflammatory mediators and can lead to obesity. Consequently, estrogen deficiency can cause metabolic syndrome, particularly insulin resistance during menopause. Both fish oil and perilla oil contain n-3 fatty acids, which may regulate several inflammatory cytokines. Additionally, adjusting the dietary n-3:n-6 fatty-acid ratio to 1:2 may help treat or prevent chronic diseases. Therefore, we investigated the effect of anti-inflammatory and insulin-signaling pathways, not solely in relation to the (n-3:n-6 fatty-acid ratio at 1:2), but also considering the origin of n-3 fatty acids found in fish oil and perilla oil, in a mouse model of estrogen deficiency induced by ovariectomy and obesity induced by a high-fat diet (HFD). Female C57BL/6J mice were divided into five groups: sham mice on a normal diet; ovariectomized (OVX) mice on a normal diet (OC); OVX mice on a HFD plus lard oil (OL), fish oil (OF), or perilla oil (OP). The dietary n-3:n-6 ratio in the OF and OP groups was adjusted to 1:2. The results showed OF group exhibited significantly lower abdominal adipose tissue weight, fewer liver lipid droplets, and smaller uterine adipocytes, compared with the OL group. Compared with the OL group, the OF and OP groups exhibited higher oral glucose tolerance and lower serum alanine aminotransferase activity, triacylglycerol levels, and total cholesterol levels. Hepatic JAK2, STAT3, and SOCS3 mRNA expression and p-NF-κB p65 and IL-6 levels were significantly lower in the OF and OP groups than in the OL group. Only the OF group exhibited an increase in PI3K and Akt mRNA expression, decrease in GLUT2 mRNA expression, and considerable elevation of p-Akt. Both fish and perilla oil reduced inflammatory signaling markers. However, only fish oil improved insulin signaling (PI3K, Akt, and GLUT2). Our data suggest that fish oil can alleviate insulin signaling through activating the PI3K-Akt-GLUT2 cascade signaling pathway.

Chinese Sumac Fruits (Rhus chinesis Mill.) Alleviate Type 2 Diabetes in C57BL/6 Mice through Repairing Islet Cell Functions, Regulating IRS-1/PI3K/AKT Pathways and Promoting the Entry of Nrf2 into the Nucleus

This research aimed to probe the potential alleviative effects of ethanol extracts of Chinese sumac (Rhus chinesis Mill.) fruits against type 2 diabetes mellitus (T2DM) in C57BL/6 mice induced by high-fat/high-fructose diet (HFFD) and streptozotocin. The results showed that the ethanol extracts could significantly regulate blood glucose levels, glycosylated hemoglobin, blood lipids, insulin, and insulin resistance, while also restoring endogenous oxidative stress. Pathological and immunohistochemical analyses revealed that the extracts partially restored the physiological function of islet cells. Furthermore, Western blotting results suggested that the extracts could regulate the protein expression in IRS-1/PI3K/AKT signaling pathway, and immunofluorescence findings demonstrated their potential to promote the translocation of Nrf2 into the nucleus. This study elucidated a novel finding that ethanol extracts derived from Chinese sumac fruits have the potential to alleviate symptoms of T2DM in mice. Moreover, these findings could offer valuable scientific insights into the potential utilization of R. chinensis fruits as nutritional supplement and/or functional food to prevent or ameliorate diabetes.

Extraction, Physicochemical Properties, Functional Activities and Applications of Inulin Polysaccharide: a Review

Inulin is a naturally soluble dietary fiber that is widely distributed and primarily derived from plants. As a reserve biopolysaccharide in plants, inulin is considered an indigestible carbohydrate of fructan because of its unique β-(2,1)-glycosidic bond structure. Numerous recent animal and human experimental studies have shown that functional inulin possesses multiple bioactivities, including immunomodulatory, antioxidant, antitumor, hepatoprotective, hypoglycemic, and gastrointestinal protective activities. Due to its increasing popularity, people tend to consume foods containing inulin. Moreover, inulin holds promise as a bioactive compound for use in the development of various food products. Therefore, this paper provides a detailed review of the extraction method, physicochemical properties, functional activity, and application development of inulin polysaccharides, to provide a theoretical foundation for further advancements in the fields of preparation and application of functional foods.

Regulation of glucolipid metabolism and gut microbiota by green and black teas in hyperglycemic mice

A high-sugar and -fat diet (HSFD) has become a primary risk factor for diabetes, and dietary intervention shows a substantial effect on the prevention and management of hyperglycemia. In this study, the chemical compositions of the aqueous extracts of stir-fried green tea (GT) and congou black tea (BT) were compared. Moreover, their potential mechanisms and regulatory effects on hepatic glycolipid metabolism and gut microbiota disorders in hyperglycemic mice were further explored. Our results show that GT or BT intervention had a prominent regulatory effect on glycolipid metabolism. Moreover, they could significantly regulate the levels of serum metabolic signatures, the activities of key enzymes in liver glucose metabolism, and the expression of genes or proteins related to glycolipid metabolism via activating the IRS-1-PI3K/AKT-GLUT2 signaling pathway. Significantly, GT or BT administration adjusted the composition and diversity of the gut microbiota, mainly reflecting a significant increase in the abundance of beneficial bacteria (including Allobaculum, Lactobacillus, and Turicibacter) and reducing the abundance of harmful or conditionally pathogenic bacteria (mainly including Clostridiales and Bacteroides). Our results suggest that dietary supplementation with GT or BT could exert a practical anti-diabetic effect. Meanwhile, BT intervention showed a better regulation effect on glycolipid metabolism. This study reveals that GT and BT have excellent potential for developing anti-diabetic food.

Aging-Accelerated Mouse Prone 8 (SAMP8) Mice Experiment and Network Pharmacological Analysis of Aged Liupao Tea Aqueous Extract in Delaying the Decline Changes of the Body

Aging and metabolic disorders feedback and promote each other and are closely related to the occurrence and development of cardiovascular disease, type 2 diabetes, neurodegeneration and other degenerative diseases. Liupao tea is a geographical indication product of Chinese dark tea, with a “red, concentrated, aged and mellow” flavor quality. In this study, the aqueous extract of aged Liupao tea (ALPT) administered by continuous gavage significantly inhibited the increase of visceral fat and damage to the intestinal–liver–microbial axis in high-fat modeling of SAMP8 (P8+HFD) mice. Its potential mechanism is that ALPT significantly inhibited the inflammation and aggregation formation pathway caused by P8+HFD, increased the abundance of short-chain fatty acid producing bacteria Alistipes, Alloprevotella and Bacteroides, and had a calorie restriction effect. The results of the whole target metabolome network pharmacological analysis showed that there were 139 potential active components in the ALPT aqueous extract, and the core targets of their actions were SRC, TP53, AKT1, MAPK3, VEGFA, EP300, EGFR, HSP90AA1, CASP3, etc. These target genes were mainly enriched in cancer, neurodegenerative diseases, glucose and lipid metabolism and other pathways of degenerative changes. Molecular docking further verified the reliability of network pharmacology. The above results indicate that Liupao tea can effectively delay the body’s degenerative changes through various mechanisms and multi-target effects. This study revealed that dark tea such as Liupao tea has significant drinking value in a modern and aging society.

Preparation, Identification and Preliminary Application of the Fenvalerate Monoclonal Antibody in Six Kinds of Dark Tea

Fenvalerate has the advantages of a broad insecticidal spectrum, high efficiency, low toxicity and low cost, and it is widely used in agriculture, especially in tea, resulting in the accumulation of fenvalerate residues in tea and the environment, posing a serious threat to human health. Therefore, the timely monitoring of fenvalerate residue dynamics is vital for ensuring the health of humans and the ecological environment, and it is necessary for establishing a fast, reliable, accurate and on-site method for detecting fenvalerate residues. Based on the methods of immunology, biochemistry and molecular biology, mammalian spleen cells, myeloma cells and mice were used as experimental materials to establish a rapid detection method of an enzyme-linked immunosorbent assay to detect the residues of fenvalerate in dark tea. Three cell lines-1B6, 2A11 and 5G2-that can stably secrete fenvalerate antibodies were obtained by McAb technology, and their sensitivities (IC₅₀) were 36.6 ng/mL, 24.3 ng/mL and 21.7 ng/mL, respectively. The cross-reaction rates of the pyrethroid structural analogs were all below 0.6%. Six dark teas were used to detect the practical application of fenvalerate monoclonal antibodies. The sensitivity IC₅₀ of the anti-fenvalerate McAb in PBS with 30% methanol is 29.12 ng/mL. Furthermore, a latex microsphere immunochromatographic test strip with an LOD of 10.0 ng/mL and an LDR of 18.9-357 ng/mL was preliminarily developed. A specific and sensitive monoclonal antibody for fenvalerate was successfully prepared and applied to detect fenvalerate in dark teas (Pu'er tea, Liupao tea, Fu Brick tea, Qingzhuan tea, Enshi dark tea and selenium-enriched Enshi dark tea). A latex microsphere immunochromatographic test strip was developed for the preparation of rapid detection test strips of fenvalerate.

Hypoglycemic Potential of Carica papaya in Liver Is Mediated through IRS-2/PI3K/SREBP-1c/GLUT2 Signaling in High-Fat-Diet-Induced Type-2 Diabetic Male Rats

Regardless of socioeconomic or demographic background, the prevalence of type 2 diabetes mellitus, which affects more than half a billion people worldwide, has been steadily increasing over time. The health, emotional, sociological, and economic well-being of people would suffer if this number is not successfully handled. The liver is one of the key organs accountable for sustaining metabolic balance. Elevated levels of reactive oxygen species inhibit the recruitment and activation of IRS-1, IRS-2, and PI3K-Akt downstream signaling cascade. These signaling mechanisms reduce hepatic glucose absorption and glycogenesis while increasing hepatic glucose output and glycogenolysis. In our work, an analysis of the molecular mechanism of Carica papaya in mitigating hepatic insulin resistance in vivo and in silico was carried out. The gluconeogenic enzymes, glycolytic enzymes, hepatic glycogen tissue concentration, oxidative stress markers, enzymatic antioxidants, protein expression of IRS-2, PI3K, SREBP-1C, and GLUT-2 were evaluated in the liver tissues of high-fat-diet streptozotocin-induced type 2 diabetic rats using q-RT-PCR as well as immunohistochemistry and histopathology. Upon treatment, C. papaya restored the protein and gene expression in the liver. In the docking analysis, quercetin, kaempferol, caffeic acid, and p-coumaric acid present in the extract were found to have high binding affinities against IRS-2, PI3K, SREBP-1c, and GLUT-2, which may have contributed much to the antidiabetic property of C. papaya. Thus, C. papaya was capable of restoring the altered levels in the hepatic tissues of T2DM rats, reversing hepatic insulin resistance.

Selenium-Enriched and Ordinary Black Teas Regulate the Metabolism of Glucose and Lipid and Intestinal Flora of Hyperglycemic Mice

Black tea is one of the six major tea categories and has a variety of bioactivities. However, little is known about its comprehensive evaluation of hypoglycemic effects and potential mechanisms. In this study, we investigated the in vivo hypoglycemic activity and potential mechanism for aqueous extracts of ordinary black tea (BT) and selenium-enriched black tea (Se-BT) by using an established high-fat diet together with streptozotocin (STZ)-induced hyperglycemic mouse model. Additionally, we also explored their α-glucosidase inhibition activity. The results show that both BT and Se-BT had a favorable glycosidase inhibitory activity. Moreover, the intervention of BT and Se-BT could regulate the mRNA expression and the level of serum parameters related to glucose and lipid metabolisms. Accordingly, they could activate the phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) signaling pathway and alleviate insulin resistance (IR) and hyperglycemia. Moreover, supplementation of BT and Se-BT increased the richness and diversity of intestinal flora and altered the abundance of beneficial and harmful bacteria. Both BT and Se-BT could regulate glucose metabolism, alleviate tissue damage, and restore intestinal flora dysbiosis, suggesting that they could be used as a natural functional food for preventing hyperglycemia.

Antidiabetic effect of sciadonic acid on type 2 diabetic mice through activating the PI3K-AKT signaling pathway and altering intestinal flora

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by hyperglycemia. The aim of this work was to investigate the effect of sciadonic acid (SA) on disorders of glucolipid metabolism and intestinal flora imbalance and to further investigate its potential molecular mechanism of anti-diabetes. The experimental data indicated that SA could alleviate hyperlipidemia, insulin resistance, oxidative stress, the inflammatory response, repair liver function damage, and promote glycogen synthesis caused by T2DM. SA could also activate the PI3K/AKT/GLUT-2 signaling pathway, promote glucose metabolism gene expression, and maintain glucose homeostasis. Furthermore, 16S rRNA analysis revealed that SA could reduce the Firmicutes/Bacteroidota (F/B) ratio; promote norank_f__Muribaculaceae, Allobaculum, Akkermansia, and Eubacterium_siraeum_group proliferation; increase the levels of major short-chain fatty acids (SCFAs), such as acetic acid, propionic acid, and butyric acid; and maintain the homeostasis of the intestinal flora. In conclusion, these results suggested that SA could reshape the structural composition of intestinal microbes, activate the PI3K/AKT/GLUT2 pathway, improve insulin resistance, and decrease blood glucose levels.

Heimao tea polysaccharides ameliorate obesity by enhancing gut microbiota-dependent adipocytes thermogenesis in mice fed with high fat diet

Heimao tea (HMT) is a kind of fermented dark tea that has various health benefits. However, the available information regarding the anti-obesity effect of HMT and its active ingredients is still limited. Herein, we extracted the polysaccharides from Heimao tea (HMTP) and evaluated the anti-obesity effect and the underlying mechanism of HMTP. 12-Week administration of HMTP ameliorated lipid accumulation in the adipose tissue and improved glucolipid metabolism in high-fat diet (HFD)-fed mice. HMTP also induced browning of inguinal white adipose tissue (iWAT) and enhanced the thermogenic activity of interscapular brown adipose tissue (iBAT) by upregulating the expression of a series of thermogenic genes, such as Ucp1, Prdm16, and Pgc1α. Interestingly, the anti-obesity effect of HMTP was closely associated with altered relative abundance of the gut microbes, especially Dubosiella and Romboutsia, with significant increases, in which the abundance of Dubosiella and Romboutsia was negatively correlated with the body weight (r = -0.567, p < 0.05; r = -0.407, p < 0.05) and positively correlated with the iBAT index (r = 0.520, p < 0.05; r = 0.315, p < 0.05). Our data suggest that the alteration of the gut microbiota may play a critical role in HMTP-induced iWAT browning and iBAT activation, and our findings may provide a promising way for preventing obesity.

Cedrol from ginger alleviates rheumatoid arthritis through dynamic regulation of intestinal microenvironment

The imbalance of intestinal flora would induce immune inflammation. Cedrol (CE), found from ginger by our group earlier, has been proven to play an excellent role in ameliorating rheumatoid arthritis (RA) via acting on JAK3, MAPK, and NF-κB. However, there have been no studies on CE ameliorating RA through the regulation of the micro-environment. In this study, the adjuvant arthritis model (AIA) is established to evaluate the weight, arthritis score, paw swelling, bone destruction, immune organ index, inflammatory cell infiltration, cartilage erosion, and metabolic enzymes of kidneys in AIA rats after CE intervention. The results indicated CE could alleviate paw swelling, reduce arthritis score, decrease the secretion of TNF-α, IL-6, and IL-1β in serum in a dose-dependent manner, and inhibit the immune organ index of the spleen while having no significant effect on metabolic enzymes of the kidney. In addition, pathological sections of ankle and knee joints suggested CE might significantly prevent inflammatory cell infiltration, synovial hyperplasia, and joint degeneration and protect articular cartilage. Then, for the first time, 16S rRNA gene was applied to analyze the regulatory effect of CE on intestinal flora. CE could effectively improve the uniformity, diversity, and richness of intestinal flora, reduce the number of pathogenic bacteria, and increase the proportion of beneficial bacteria, and it significantly inhibited the abundance of Prevotella in RA rats, which was 12.43 times smaller than that in methotrexate. The distribution and excretion of CE in vivo were detected by GC-MS. It was found that CE would massively accumulate in the gastrointestinal tract after oral administration, which is then mainly excreted through feces. Interestingly, the research suggested that CE, which plays a role in the dynamic regulation of the intestinal micro-environment, could be used as a potential component to prevent RA.

A Review of Development and Utilization for Edible Fungal Polysaccharides: Extraction, Chemical Characteristics, and Bioactivities

Edible fungi, commonly known as mushrooms, are precious medicinal and edible homologous gifts from nature to us. Because of their distinctive flavor and exceptional nutritional and medicinal value, they have been a frequent visitor to people’s dining tables and have become a hot star in the healthcare, pharmaceutical, and cosmetics industries. Edible fungal polysaccharides (EFPs) are an essential nutrient for edible fungi to exert bioactivity. They have attracted much attention because of their antioxidant, immunomodulatory, antitumor, hypoglycemic, and hypolipidemic bioactivities. As a result, EFPs have demonstrated outstanding potential over the past few decades in various disciplines, including molecular biology, immunology, biotechnology, and pharmaceutical chemistry. However, the complexity of EFPs and the significant impact of mushroom variety and extraction techniques on their bioactivities prevents a complete investigation of their biological features. Therefore, the authors of this paper thoroughly reviewed the comparison of different extraction methods of EFPs and their advantages and disadvantages. In addition, the molecular weight, monosaccharide composition, and glycosidic bond type and backbone structure of EFPs are described in detail. Moreover, the in vitro and in vivo bioactivities of EFPs extracted by different methods and their potential regulatory mechanisms are summarized. These provide a valuable reference for improving the extraction process of EFPs and their production and development in the pharmaceutical field.

Chitosan/Sodium Alginate/Velvet Antler Blood Peptides Hydrogel Promotes Diabetic Wound Healing via Regulating Angiogenesis, Inflammatory Response and Skin Flora

Background

Diabetic ulcer remains a clinical challenge due to impaired angiogenesis and persistent inflammation, requiring new alternative therapies to promote tissue regeneration.

Purpose

In this study, chitosan/sodium alginate/velvet antler blood peptides (CS/SA/VBPs) hydrogel (CAVBPH) was fabricated and used in the treatment of skin wounds in type 2 diabetes mellitus (T2D) for the first time.

Methods

VBPs were prepared by hydrolysis and ultrafiltration, and their sequences were identified using LC-MS/MS. The CAVBPH was further fabricated and characterized. A mouse model of T2D was induced by a high-sugar and high-fat diet (HSFD) and streptozotocin (STZ) injection. CAVBPH was applied topically to T2D wounds, and its effects on skin repair and potential biological mechanisms were analyzed by appearance observation, histopathological staining, bioinformatics analysis, Western blot, and 16S rRNA sequencing.

Results

VBPs had numerous short-chain active peptides, excellent antioxidant activity, and a low hemolysis rate. CAVBPH exhibited desirable biochemical properties and participated in the diabetic wound healing process by promoting cell proliferation (PCNA and α-SMA) and angiogenesis (capillaries and CD31) and alleviating inflammation (CD68). Mechanistically, the therapeutic effect of CAVBPH on chronic wounds might rely on activating the PI3K/AKT/mTOR/HIF-1α/VEGFA pathway and reversing the expression of inflammatory cytokines TNF-α and IL-1β. The results of 16S rRNA sequencing indicated that T2D significantly altered the diversity and structure of skin flora at the wound site. CAVBPH treatment elevated the relative abundance of beneficial microbes (e.g., Corynebacterium_1 and Lactobacillus) and reversed the structural imbalance of skin microbiota.

Conclusion

These results indicate that CAVBPH is a promising wound dressing, and its repair effect on diabetic wounds by regulating angiogenesis, inflammatory response, and skin flora may depend on the rich small peptides in VBPs.

Therapeutic potential of non-starch polysaccharides on type 2 diabetes: from hypoglycemic mechanism to clinical trials

Non-starch polysaccharides (NSPs) have been reported to exert therapeutic potential on managing type 2 diabetes mellitus (T2DM). Various mechanisms have been proposed; however, several studies have not considered the correlations between the anti-T2DM activity of NSPs and their molecular structure. Moreover, the current understanding of the role of NSPs in T2DM treatment is mainly based on in vitro and in vivo data, and more human clinical trials are required to verify the actual efficacy in treating T2DM. The related anti-T2DM mechanisms of NSPs, including regulating insulin action, promoting glucose metabolism and regulating postprandial blood glucose level, anti-inflammatory and regulating gut microbiota (GM), are reviewed. The structure-function relationships are summarized, and the relationships between NSPs structure and anti-T2DM activity from clinical trials are highlighted. The development of anti-T2DM medication or dietary supplements of NSPs could be promoted with an in-depth understanding of the multiple regulatory effects in the treatment/intervention of T2DM.

Fu Brick Tea Manages HFD/STZ-Induced Type 2 Diabetes by Regulating the Gut Microbiota and Activating the IRS1/PI3K/Akt Signaling Pathway

The antidiabetic effects of Fu brick tea aqueous extract (FTE) and its underlying molecular mechanism in type 2 diabetes mellitus (T2DM) mice were investigated. FTE treatment significantly relieved dyslipidemia, insulin resistance (IR), and hepatic oxidative stress caused by T2DM. FTE also ameliorated the T2DM-induced gut dysbiosis by decreasing the Firmicutes/Bacteroidota (F/B) ratio at the phylum level and promoting the proliferation of Bifidobacterium, Parabacteroides, and Roseburia at the genus level. Besides, FTE significantly improved colonic short-chain fatty acid levels of T2DM mice. Furthermore, the antidiabetic effects of FTE were proved to be mediated by the IRS1/PI3K/Akt and AMPK-mediated gluconeogenesis signaling pathways. Metabolomics analysis illustrated that FTE recovered the levels of 28 metabolites associated with T2DM to the levels of normal mice. Taken together, these findings suggest that FTE can alleviate T2DM by reshaping the gut microbiota, activating the IRS1/PI3K/Akt pathway, and regulating intestinal metabolites.

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.

Preparation, Physicochemical and Hypoglycemic Properties of Natural Selenium-Enriched Coarse Tea Glycoproteins

Various functional components in tea have been well developed, but less research has been explored on glycoproteins in tea. In this paper, three types of glycoprotein fractions, namely tea selenium-binding glycoprotein1-1 (TSBGP1-1), TSBGP2-1, and TSBGP3-1, respectively, were extracted and purified from selenium-enriched coarse green tea. Chemical analysis revealed that three fractions were glycoproteins, but their selenium content, molecular weight, and monosaccharide composition were significantly different. Fourier transforms infrared (FT-IR) analysis indicated that three fractions contained characteristic absorption peaks of glycoproteins but differed in secondary structural composition. Thermogravimetric (TG) analysis showed that the thermal stability of the three fractions was dramatically distinct. The in vitro hypoglycemic activity showed that TSBGPs significantly activated the insulin receptor substrate 2 (IRS2)/protein kinase B (Akt) pathway in LO2 cells, then enhanced glucose metabolism and inhibited gluconeogenesis, and finally ameliorated insulin resistance (IR) and glucose metabolism disorders. Furthermore, Pearson correlation analysis reveals that the hypoglycemic activity was significantly correlated with Se, protein, monosaccharide composition (especially glucose), molecular weight, and secondary structure. Our results show that Se-enriched tea glycoprotein is a desirable candidate for developing anti-diabetic food, and TSBGP-2 and TSBGP-3 had a better regulation effect. Our results can provide a research reference for the extraction, physicochemical property, and function of selenium-enriched plant glycoproteins.

Integration of intestinal microbiota and metabonomics to elucidate different alleviation impacts of non-saponification and saponification astaxanthin pre-treatment on paracetamol-induced oxidative stress in rats

Intestinal microbiota and metabonomics were integrated to investigate the efficiency of non-saponification or saponification astaxanthin (N-Asta or S-Asta) derived from Penaeus sinensis by-products on alleviating paracetamol (PCM)-induced oxidative stress. Pre-treatment with N-Asta or S-Asta for 14 days restored the cellular morphology of the intestine and increased glutathione (GSH) levels under PCM overdose in rats. However, S-Asta displayed higher adsorption than that of N-Asta. PCM overdose reduced the richness and diversity of intestinal microbiota in the model group. Comparably, N-Asta or S-Asta pre-treatment increased the Actinobacteria abundance. Increased phyla Bacteroidetes and Verrucomicrobia were only found in the S-Asta-pre-treated group. At the genus level, N-Asta pre-treatment increased Lactobacillus and Parasutterella abundance, whereas S-Asta pre-treatment elevated Bacteroidales_S24-7_group_norank and Ruminococcaceae_uncultured. Compared to the control and model groups, remarkable increases of fecal short-chain fatty acids were detected in both N-Asta and S-Asta pre-treatment groups, suggesting the contribution of N-Asta and S-Asta adsorption to SCFA-producing bacteria enrichment. Furthermore, the genera of Ruminococcaceae_uncultured, Ruminiclostridium_9, Ruminococcaceae_unclassified and Ruminococcus_1 showed high correlations with propionic acid, isobutyric acid, butyric acid, isovaleric acid and valeric acid increases in the S-Asta pre-treated group. Seventeen plasma biomarker metabolites in more than 10 metabolic pathways were responsible for the difference between the N-Asta and S-Asta pre-treated groups. Metabolites GSH, retinol, all-trans-Retinoic acid and taurine related to antioxidant activities were significantly accumulated in the S-Asta pre-treated group, while increasing taurocholic acid levels associated with the anti-inflammatory activity was found in the N-Asta-pre-treated group. Therefore, N-Asta and S-Asta could have potential applications in counterbalancing intestinal flora and metabolite disturbances by overdose chemical induction.