A natural anti-obesity reagent derived from sea buckthorn polysaccharides: Structure characterization and anti-obesity evaluation in vivo

Visual analysis of sea buckthorn fruit moisture content based on deep image processing technology

The effect of moisture content changes during drying processing on the appearance of sea buckthorn was studied. Using computer vision methods and various image processing methods to collect and analyze images during the drying process of sea buckthorn fruit. Sea buckthorn is dried in a drying oven at a temperature of 65 °C and Level 1 wind speed conditions. The images of the entire drying process of sea buckthorn fruit were collected at 30-min intervals. Deep mining and transformation of image information through various image processing methods. By calibrating and modeling the color components, real-time online detection of the moisture content of sea buckthorn fruit can be achieved. After modeling, this article attempted to use LSTM (Long Short Term Memory) to predict the appearance of sea buckthorn fruit with supercritical moisture content. Different agricultural products adapt to different color spaces, but after standard modeling with a certain amount of data, applying color components to detect moisture content is a very good method.

The carrier function and inhibition effect on benign prostatic hyperplasia of a glucan from Epimedium brevicornu Maxim

Epimedium, a traditional Chinese medicine commonly used as a dietary supplement, contains polysaccharides and flavonoids as its main bioactive ingredients. In this study, a neutral homogeneous polysaccharide (EPSN-1) was isolated from Epimedium brevicornu Maxim. EPSN-1 was identified as a glucan with a backbone of →4)-α-D-Glcp-(1→, branched units comprised α-D-Glcp-(1→6)-α-D-Glcp-(1→, β-D-Glcp-(1→6)-β-D-Glcp-(1→ and α-D-Glcp-(1→ connected to the C6 position of backbone. The conformation of EPSN-1 in aqueous solution indicated its potential to form nanoparticles. This paper aims to investigate the carrier and pharmacodynamic activity of EPSN-1. The findings demonstrated that, on the one hand, EPSN-1, as a functional ingredient, may load Icariin (ICA) through non-covalent interactions, improving its biopharmaceutical properties such as solubility and stability, thereby improving its intestinal absorption. Additionally, as an effective ingredient, EPSN-1 could help maintain the balance of the intestinal environment by increasing the abundance of Parabacteroides, Lachnospiraceae UGG-001, Anaeroplasma, and Eubacterium xylanophilum group, while decreasing the abundance of Allobaculum, Blautia, and Adlercreutzia. Overall, this dual action of EPSN-1 sheds light on the potential applications of natural polysaccharides, highlighting their dual role as carriers and contributors to biological activity.

Polysaccharides in fruits: Biological activities, structures, and structure-activity relationships and influencing factors-A review

Fruits are a rich source of polysaccharides, and an increasing number of studies have shown that polysaccharides from fruits have a wide range of biological functions. Here, we thoroughly review recent advances in the study of the bioactivities, structures, and structure-activity relationships of fruit polysaccharides, especially highlighting the structure-activity influencing factors such as extraction methods and chemical modifications. Different extraction methods cause differences in the primary structures of polysaccharides, which in turn lead to different polysaccharide biological activities. Differences in the degree of modification, molecular weight, substitution position, and chain conformation caused by chemical modification can all affect the biological activities of fruit polysaccharides. Furthermore, we summarize the applications of fruit polysaccharides in the fields of pharmacy and medicine, foods, cosmetics, and materials. The challenges and perspectives for fruit polysaccharide research are also discussed.

The "crosstalk" between gut microbiota, metabolites and genes in diet-induced hepatic steatosis mice intervened with Cordyceps guangdongensis polysaccharides

Cordyceps guangdongensis, a novel edible mushroom in China, has shown many positive health effects. In this study, we extracted the C. guangdongensis polysaccharides (CGP) from the fruiting bodies, and investigated the mechanism for CGP improved high-fat diet-induced (HFDI) metabolic diseases. We found that CGP notably reduced fat mass, improved blood lipid levels and hepatic damage, and restored the gut microbiota dysbiosis induced by high-fat diet (HFD). Metabolome analyses showed that CGP changed the composition of bile acids, and regulated HFDI metabolic disorder in hepatic tissue. Transcriptome comparison showed that the improvement of hepatic steatosis for CGP was mainly related to lipid and carbohydrate metabolism. Association analysis result revealed that Odoribacter, Bifidobacterium and Bi. pseudolongum were negatively correlated to fat and blood lipid indicators, and were significantly associated with genes and metabolites related to carbohydrate and lipid metabolism. Collectively, these results indicate that CGP may be a promising supplement for the treatment of obesity and related metabolic diseases.

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.

The regulatory effect of polysaccharides on the gut microbiota and their effect on human health: A review

Polysaccharides with low toxicity and high biological activities are a kind of biological macromolecule. Recently, growing studies have confirmed that polysaccharides could improve obesity, diabetes, tumors, inflammatory bowel disease, hyperlipidemia, diarrhea, and liver-related diseases by changing the intestinal micro-environment. Moreover, polysaccharides could promote human health by regulating gut microbiota, enhancing production of short-chain fatty acids (SCFAs), improving intestinal mucosal barrier, regulating lipid metabolism, and activating specific signaling pathways. Notably, the biological activities of polysaccharides are closely related to their molecular weight, monosaccharide composition, glycosidic bond types, and regulation of gut microbiota. The intestinal microbiota can secrete glycoside hydrolases, lyases, and esterases to break down polysaccharides chains and generate monosaccharides, thereby promoting their absorption and utilization. The degradation of polysaccharides can produce SCFAs, further regulating the proportion of gut microbiota and achieving the effect of preventing and treating various diseases. This review aims to summarize the latest studies: 1) effect of polysaccharides structures on intestinal flora; 2) regulatory effect of polysaccharides on gut microbiota; 3) effects of polysaccharides on gut microbe-mediated diseases; 4) regulation of gut microbiota on polysaccharides metabolism. The findings are expected to provide important information for the development of polysaccharides and the treatment of diseases.

Advance in Hippophae rhamnoides polysaccharides: Extraction, structural characteristics, pharmacological activity, structure-activity relationship and application

Hippophae rhamnoides (Sea buckthorn) is an excellent medicinal and edible plant owing to its high nutritional and health-promoting properties. As an important bioactive component, H. rhamnoides polysaccharides (HRPs) have aroused wide attention due to their various pharmacological activities, including hepatoprotective, immuno-modulatory, anti-inflammatory, anti-oxidant, anti-tumor, hypoglycemic, anti-obesity, and so on. Nevertheless, the development and utilization of HRP-derived functional food and medicines are constrained to a lack of comprehensive understanding of the structure-activity relationship, application, and safety of HRPs. This review systematically summarizes the advancements on the extraction, purification, structural characteristics, pharmacological activities and mechanisms of HRPs. The structure-activity relationship, safety evaluation, application, as well as the shortcomings of current research and promising prospects are also highlighted. This article aims to offer a comprehensive understanding of HRPs and lay a groundwork for future research and utilization of HRPs as multifunctional biomaterials and therapeutic agents.

Structural characterization of Astragalus polysaccharide-D1 and its improvement of low-dose metformin effect by enriching Staphylococcus lentus

To explore the adjuvant therapy drugs of low-dose metformin, one homogeneous polysaccharide named APS-D1 was purified from Astragalus membranaceus by DEAE-52 cellulose and Sephadex G-100 column chromatography. Its chemical structure was characterized by molecular weight distribution, monosaccharide composition, infrared spectrum, methylation analysis, and NMR. The results revealed that APS-D1 (7.36 kDa) consisted of glucose, galactose, and arabinose (97.51 %:1.56 %:0.93 %). It consisted of →4)-α-D-Glcp-(1→ residue backbone with →3)-β-D-Galp-(1→ residue and terminal-α/β-D-Glcp-(1→ side chains. APS-D1 could significantly improve inflammation (TNF-α, LPS, and IL-10) in vivo. Moreover, APS-D1 improved the curative effect of low-dose metformin without adverse events. APS-D1 combined with low-dose metformin regulated several gut bacteria, in which APS-D1 enriched Staphylococcus lentus to produce l-carnitine (one of 136 metabolites of S. lentus). S. lentus and l-carnitine could improve diabetes, and reduction of S. lentusl-carnitine production impaired diabetes improvement. The combination, S. lentus, and l-carnitine could promote fatty acid oxidation (CPT1) and inhibit gluconeogenesis (PCK and G6Pase). The results indicated that APS-D1 enhanced the curative effect of low-dose metformin to improve diabetes by enriching S. lentus, in which the effect of S. lentus was mediated by l-carnitine. Collectively, these findings support that low-dose metformin supplemented with APS-D1 may be a favorable therapeutic strategy for type 2 diabetes.

Medicinal and edible polysaccharides from ancient plants: extraction, isolation, purification, structure, biological activity and market trends of sea buckthorn polysaccharides

Sea buckthorn (Hippophae L.), a well-known medicinal and edible plant, is known as the "king of VC". Due to its excellent medicinal and nutritional value, it has been developed into a variety of functional products. Sea buckthorn polysaccharides (SPs), one of the important and representative active components, have attracted the attention of researchers in the fields of health food and medicine because of their potential beneficial effects on human health. Recently, SPs have shown various biological activities in in vitro and in vivo studies, such as anti-obesity, immunomodulatory, anti-tumor, antioxidant, anti-inflammatory, anti-fatigue, and hepatoprotective activities. This review provides a comprehensive and systematic summary of the extraction and purification methods, structural characterization, biological activity, and market trends of SPs to provide a theoretical basis for their therapeutic potential and sanitarian functions. A future scope is needed to further explore the medicinal and nutritional value of SPs and incorporate them in functional food products.

Extraction, purification, structural characterization and pharmacological activities of polysaccharides from sea buckthorn (Hippophae rhamnoides L.): A review

ETHNOPHARMACOLOGICAL RELEVANCE

Sea buckthorn (Hippophae rhamnoides L.) is an edible fruit with a long history in China as a medicinal plant. The fruits of H. rhamnoides are rich in a variety of nutrients and pharmacological active compounds. As one of the most important active ingredients in sea buckthorn, polysaccharides have attracted the attention of researchers due to their antioxidant, anti-fatigue, and liver protective qualities.

AIM OF THE REVIEW

This review summarizes recent studies on extraction, purification, structural characterization and pharmacological activities of polysaccharides from sea buckthorn. In addition, the relationship between the structure and the activities of sea buckthorn polysaccharides (SBPS) were discussed. This review would provide important research bases and up-to-date information for the future in-depth development and application of sea buckthorn polysaccharides in the field of pharmaceuticals and functional foods.

MATERIALS AND METHODS

By inputting the search term "Sea buckthorn polysaccharides", relevant research information was obtained from databases such as Web of Science, Google Scholar, PubMed, China Knowledge Network (CNKI), China Master Theses Full-text Database, and China Doctoral Dissertations Full-text Database.

RESULTS

The main extraction methods of SBPS include hot water extraction (HWE), ultrasonic assisted extraction (UAE), microwave-assisted extraction (MAE), flash extraction (FE), and ethanol extraction. More than 20 polysaccharides have been isolated from sea buckthorn fruits. The chemical structures of sea buckthorn polysaccharides obtained by different extraction, isolation, and purification methods are diverse. Polysaccharides from sea buckthorn display a variety of pharmacological properties, including antioxidant, anti-fatigue, liver protection, anti-obesity, regulation of intestinal flora, immunoregulation, anti-tumor, anti-inflammatory, and hypoglycemic activities.

CONCLUSIONS

Sea buckthorn has a long medicinal history and characteristics of an ethnic medicine and food. Polysaccharides are one of the main active components of sea buckthorn, and they have received increasing attention from researchers. Sea buckthorn polysaccharides have remarkable pharmacological activities, health benefits, and broad application prospects. In addition, further exploration of the chemical structure of SBPS, in-depth study of their pharmacological activities, identification of their material basis, characterization of disease resistance mechanisms, and potential health functions are still directions of future research. With the accumulation of research on the extraction and purification processes, chemical structure, pharmacological effects, molecular mechanisms, and structure-activity relationships, sea buckthorn polysaccharides derived from natural resources will ultimately make significant contributions to human health.

Structural elucidation of a highly branched α-D-glucan from Huangjiu and its hepatoprotective activity via gut microbiome regulation and intestinal barrier repairment

Polysaccharides in Huangjiu, a traditional fermented food, are expected to be potentially effective ingredients in protecting against alcoholic liver disease (ALD). Elucidating their precise structural and functional characteristics is essential for in-depth understanding of structure-activity relationships of hepatoprotective polysaccharides. Herein, a major polysaccharide component HJPS1-2 was purified from Huangjiu with an average molecular weight of 3.49 kDa. Structural analyses inferred that HJPS1-2 backbone was composed of (1 → 4)-linked α-D-Glcp and a single α(1 → 6)-D-Glcp-α(1 → 6)-D-Glcp branched unit for every three α(1 → 4)-D-Glcp. An ALD mouse model was further established to clarify the underlying effect of HJPS1-2 on ALD alleviation. Biochemical detection and histopathological assessment revealed that HJPS1-2 intervention remarkably improved ethanol-induced hepatic dysfunction and steatosis. HJPS1-2 treatment ameliorated gut microbiota dysbiosis of ALD mice in a dose-dependent manner, mainly manifested as restoration of microbial diversities, community structure and bacterial interaction patterns. Compared with ethanol group, the strikingly elevated intestinal short-chain fatty acids' levels and enhanced intestinal barrier function after HJPS1-2 intake might contribute to reduced serum and liver lipopolysaccharide levels and subsequently suppressed release of hepatic inflammatory cytokines, thus mitigating ALD. Collectively, this research supports the potential of food-derived polysaccharides to hinder the early formation and progression of ALD through maintaining intestinal homeostasis.

A Polysaccharide from Ficus carica L. Exerts Immunomodulatory Activity in Both In Vitro and In Vivo Experimental Models

Polysaccharides from Ficus carica L. (FCP) exert multiple biological activities. As a biological macromolecule, the available knowledge about the specific structures and mechanisms of the biological activity of purified 'Brunswick' fig polysaccharides is currently limited. In the present study, chemical purification and characteristics were identified via chemical and instrumental analysis, and then the impact of FCP on immunomodulation activity in vitro and in vivo was examined. Structural characteristics showed that the molecular weight of the FCP sample was determined to be 127.5 kDa; the primary monosaccharides present in the FCP sample were galacturonic acid (GalA), arabinose (Ara), galactose (Gal), rhamnose (Rha), glucose (Glc), and xylose (Xyl) at a ratio of 0.321:0.287:0.269:0.091:0.013:0.011. Based on the investigation of in vitro immunomodulatory activity, FCP was found to stimulate the production of NO, TNF-α, and IL-6, and increased the pinocytic activity of macrophages. Further analysis revealed that FCP activated macrophages by interacting with Toll-like receptor 4 (TLR4). Moreover, the in vivo test results indicate that FCP showed a significant increase in serum pro-inflammatory factors in immunosuppressed mice. Overall, this study suggests that FCP has the potential to be utilized as a novel immunomodulator in the pharmaceutical and functional food industries.

Microwave-assisted aqueous two-phase extraction of polysaccharides from Hippophae rhamnoide L.: Modeling, characterization and hypoglycemic activity

Natural polysaccharides are concerned for their high biological activity and low toxicity. Two kinds of polysaccharides were extracted from Hippophae rhamnoide L. by microwave-assisted aqueous two-phase system. Under the optimal conditions predicted by RSM model (K2HPO4/ethanol (18.93 %/28.29 %), liquid to material ratio 77 mL/g, power 625 W and temperature 61 °C), the yield of total polysaccharides reached 35.91 ± 0.76 %. Moreover, the polysaccharides extraction was well fitted to the Weibull model. After purification by Sepharose-6B, the polysaccharides from top phase (PHTP, purity of 81.44 ± 1.25 %) and bottom phase (PHBP, purity of 88.85 ± 1.40 %) were obtained. GC, FT-IR, methylation and NMR analyses confirmed the backbone of PHTP was composed of a repeated unit →4)-β-D-Glcp-(1 → 2)-α-L-Rhap-(1 → 4)-β-D-Galp-(1 → 4)-α-D-GalAp-(1 → 3)-α-L-Araf-(1 → 3)-α-D-Manp-(1→, while the repeated unit in PHBP was →3)-α-L-Araf-(1 → 2)-α-L-Rhap-(1 → 4)-β-D-Glcp-(1 → 3)-α-D-Manp-(1 → 4)-β-D-Galp-(1 → 4)-α-D-GalAp-(1→. Compared with PHTP (6.46 × 106 g/mol), PHBP with relatively low molecular weight (8.2 × 105 g/mol) exhibited the smaller particle size, better water-solubility, thermal and rheological property, stronger anti-glycosylation and α-amylase inhibitory effects. Moreover, PHTP and PHBP displayed a reversible inhibition on α-amylase in a competitive manner. This study provides a high-efficient and eco-friendly method for polysaccharides extraction, and lays a foundation for sea buckthorn polysaccharides as potential therapeutic agents in preventing and ameliorating diabetes.

Sea buckthorn, its bioactive constituents, and mechanism of action: potential application in female reproduction

Sea buckthorn (Hippophae rhamnoides L.) is a flowering shrub, and its berries have been utilized for decades as a raw ingredient in cuisines and herbal remedies. This evidence-based study focuses on its key bioactive constituents, and mechanism of protective effects with a focus on female reproductive processes. Parts of the plant contain phenols, carotenoids (lycopene, carotene, lutein, and zeaxanthin), flavonoids (isorhamnetin, quercetin, glycosides, and kaempferol), tocopherols, sterols, polyunsaturated fatty acids, minerals, vitamins, omega 3, 6, 9 and rare omega 7 fatty acids etc. Key polyphenolic flavonoids such as isorhamnetin and quercetin are believed to be mainly responsible behind its health benefits (against cardiovascular diseases, metabolic syndrome, obesity etc.) through properties including anti-cancer, antioxidant, and anti-inflammatory activities. These sea buckthorn constituents appear to mediate healthy ovarian cell proliferation, death, and hormone release, as well as decrease ovarian cancer possibly through apoptosis, and hormonal (estrogen) release. Thus, sea buckthorn and its bioactive ingredients may have potential in the management of gynecological problems such as uterine inflammation, endometriosis, and easing symptoms of vulvovaginal atrophy in postmenopausal women (by targeting inflammatory cytokines and vascular endothelial growth factor - VEGF). Apigenin, myricetin, and luteolin have also been recommended as prospective ovarian cancer preventative and adjuvant therapy options as they can inhibit ovarian cancerogenesis by triggering apoptosis and halting the cell cycle in ovarian tumors. Furthermore, its oil (containing carotenoid, sterol, and hypericin) has been speculated as an alternative to estrogen replacement therapy for postmenopausal women particularly to improve vaginal epithelial integrity. However, it is uncertain whether steroid hormone receptors, reactive oxygen species (ROS), and inflammatory regulators are actually behind sea buckhorn's actions. Sea buckthorn, and its compounds' health promoting potential warrants further validation not just in vitro and in animal research, but also in clinical trials to identify and/or standardize optimal methods of delivery of biologically active molecules.

Natural polysaccharides protect against diet-induced obesity by improving lipid metabolism and regulating the immune system

Unhealthy dietary patterns-induced obesity and obesity-related complications pose a great threat to human health all over the world. Accumulating evidence suggests that the pathophysiology of obesity and obesity-associated metabolic disorders is closely associated with dysregulation of lipid and energy metabolism, and metabolic inflammation. In this review, three potential anti-obesity mechanisms of natural polysaccharides are introduced. Firstly, natural polysaccharides protect against diet-induced obesity directly by improving lipid and cholesterol metabolism. Since the immunity also affects lipid and energy metabolism, natural polysaccharides improve lipid and energy metabolism by regulating host immunity. Moreover, diet-induced mitochondrial dysfunction, prolonged endoplasmic reticulum stress, defective autophagy and microbial dysbiosis can disrupt lipid and/or energy metabolism in a direct and/or inflammation-induced manner. Therefore, natural polysaccharides also improve lipid and energy metabolism and suppress inflammation by alleviating mitochondrial dysfunction and endoplasmic reticulum stress, promoting autophagy and regulating gut microbiota composition. Specifically, this review comprehensively summarizes underlying anti-obesity mechanisms of natural polysaccharides and provides a theoretical basis for the development of functional foods. For the first time, this review elucidates anti-obesity mechanisms of natural polysaccharides from the perspectives of their hypolipidemic, energy-regulating and immune-regulating mechanisms.

Digestion profile, antioxidant, and antidiabetic capacity of Morchella esculenta exopolysaccharide: in vitro, in vivo and microbiota analysis

BACKGROUND

Novel functional polysaccharides from fungi are important nutraceuticals. An exopolysaccharide, Morchella esculenta exopolysaccharide (MEP 2), was extracted and purified from the fermentation liquor of M. esculenta. The aim of this study was to investigate its digestion profile, antioxidant capacity, and effect on the microbiota composition in diabetic mice.

RESULTS

The study found that MEP 2 was stable during in vitro saliva digestion but was partially degraded during gastric digestion. The digest enzymes exerted a negligible effect on the chemical structure of MEP 2. Molecular weight and atomic force microscope (AFM) images suggest that both smaller chains and larger aggregations were produced. Scanning electron microscope (SEM) images reveal that the surface morphology was much altered after intestinal digestion. After digestion, the antioxidant ability increased as revealed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Both MEP 2 and its digested components showed strong α-amylase and moderate α-glucosidase inhibition activity, leading us to further investigate its ability to modulate the diabetic symptoms. The MEP 2 treatment ameliorated the inflammatory cell infiltration and increased the size of pancreas inlets. Serum concentration of HbA1c was significantly reduced. Blood glucose level during the oral glucose tolerance test (OGTT) was also slightly lower. The MEP 2 increased the diversity of the gut microbiota and modulated the abundance of several important bacteria including Alcaligenaceae, Caulobacteraceae, Prevotella, Brevundimonas, Demequina, and several Lachnospiraceae species.

CONCLUSION

It was found that MEP 2 was partially degraded during in vitro digestion. Its potential antidiabetic bioactivity may be associated with its α-amylase inhibition and gut microbiome modulation ability. © 2023 Society of Chemical Industry.

Current progress in the hypoglycemic mechanisms of natural polysaccharides

Unhealthy dietary pattern-induced type 2 diabetes mellitus poses a great threat to human health all over the world. Accumulating evidence has revealed that the pathophysiology of type 2 diabetes mellitus is closely associated with the dysregulation of glucose metabolism and energy metabolism, serious oxidative stress, prolonged endoplasmic reticulum stress, metabolic inflammation and intestinal microbial dysbiosis. Most important of all, insulin resistance and insulin deficiency are two key factors inducing type 2 diabetes mellitus. Nowadays, natural polysaccharides have gained increasing attention owing to their numerous health-promoting functions, such as hypoglycemic, energy-regulating, antioxidant, anti-inflammatory and prebiotic activities. Therefore, natural polysaccharides have been used to alleviate diet-induced type 2 diabetes mellitus. Specifically, this review comprehensively summarizes the underlying hypoglycemic mechanisms of natural polysaccharides and provides a theoretical basis for the development of functional foods. For the first time, this review elucidates hypoglycemic mechanisms of natural polysaccharides from the perspectives of their regulatory effects on glucose metabolism, insulin resistance and mitochondrial dysfunction.

Managing metabolic diseases: The roles and therapeutic prospects of herb-derived polysaccharides

Metabolic diseases have become a public health problem worldwide. Effective, novel and natural therapies are urgently needed to treat metabolic diseases. As natural bioactive compounds, polysaccharides have many physiological and medicinal properties. Recently, herb-derived polysaccharides have shown beneficial effects in the treatment of metabolic diseases, but the underlying mechanisms remain unclear. This review comprehensively summarizes the pharmacological progress and clinical evidence of herb-derived polysaccharides in the treatment of three metabolic diseases, namely type 2 diabetes mellitus, nonalcoholic fatty liver disease and obesity, and more importantly, discusses the molecular mechanism involved. Existing evidence has proved that herb-derived polysaccharides can maintain glucose homeostasis, promote insulin secretion, improve insulin resistance, reduce weight gain and hepatic steatosis, inhibit lipogenesis, alleviate oxidative stress and inflammation, and improve gut microbiota disorders in rodents with metabolic diseases. Notably, so far, human clinical trials of herb-derived polysaccharides for these three metabolic diseases remain rare. All in all, herb-derived polysaccharides may have good potential as drug candidates for the prevention and management of metabolic diseases. More high-quality clinical trials are needed to further validate its effectiveness and safety in human subjects.

Sea buckthorn polysaccharide ameliorates high-fat diet induced mice neuroinflammation and synaptic dysfunction via regulating gut dysbiosis

Currently, definitive treatment for neurodegenerative diseases without side effects has not been developed, therefore, exploring natural polysaccharides with neuroprotection to prevent the occurrences and progressions of cognitive dysfunctions has important significance. The purpose of this study was to investigate the effects of sea buckthorn polysaccharide (SBP) on high-fat diet (HFD) induced mice cognitive dysfunctions and attempted to explore its biological mechanisms. Behavior tests (Y-maze and Barnes maze) suggested that SBP effectively alleviated the HFD induced behavioral disorders, which was in accordance with the inhibition of neuroinflammation via suppressing the NF-κB pathway and amelioration of synaptic dysfunction via upregulating CREB/BDNF/TrkB pathway in mice brain. Furthermore, SBP alleviated the gut barrier impairment, inflammatory responses, and lipopolysaccharide invasion into blood circulation via regulating the gut microbiome structure, especially correcting the reduction of Ileibacterium and increase of Lactobacillus, Dubosiella, Olsenella, Helicobacter, and Ruminiclostridium_9 in HFD mice. Therefore, the reversal effects of SBP on gut dysbiosis might be the important reason for its positive effects on cognitive dysfunction induced by HFD in mice.

Phytochemistry, health benefits, and food applications of sea buckthorn (Hippophae rhamnoides L.): A comprehensive review

Sea buckthorn (Hippophae rhamnoides L.), an ancient miraculous plant, is of great interest because of its tenacity, richness in nutritional active substances, and biological activity. Sea buckthorn is a deciduous shrub or tree of the genus Hippophae in the family Elaeagnaceae. It is a pioneer tree species for soil improvement, wind and sand control, and soil and water conservation. Sea buckthorn contains many nutritional active components, such as vitamins, carotenoids, polyphenols, fatty acids, and phytosterols. Moreover, sea buckthorn has many health benefits, such as antioxidant, anticancer, anti-hyperlipidemic, anti-obesity, anti-inflammatory, antimicrobial, antiviral, dermatological, neuroprotective, and hepatoprotective activities. Sea buckthorn not only has great medicinal and therapeutic potential, but also is a promising economic plant. The potential of sea buckthorn in the human food industry has attracted the research interest of researchers and producers. The present review mainly summarizes the phytochemistry, nutrients, health benefits, and food applications of sea buckthorn. Overall, sea buckthorn is a dietary source of bioactive ingredients with the potential to be developed into functional foods or dietary supplements for the prevention and treatment of certain chronic diseases, which deserves further research.

Purification and Identification of Lipid-Lowering Protein from Barley Extract after Lactiplantibacillus plantarum dy-1 fermentation

Previous studies have found that the protein in barley extract fermented by Lactiplantibacillus plantarum dy-1 has the ability to inhibit lipid accumulation. However, the isolation, purification, and structural identification of the protein with lipid-lowering activity were still needed. In the present study, barley protein fermented by L. plantarum dy-1 with the optimal lipid-lowering ability was isolated and purified in three steps: using ammonium sulfate precipitation, anion-exchange chromatography, and size-exclusion chromatography. Combined with the model of HepG2 cells induced by oleic acid, the results showed that the pure protein LFBEP-C1 had the best lipid-lowering potential. Furthermore, our research found that LFBEP-C1 enriched the content of hydrophobic amino acids in LFBEP-C1. Ultraviolet spectroscopy analysis indicated that the glycosidic bond in LFBEP-C1 was an O-type glycosidic bond. The FTIR and circular dichroism spectra indicated that α-helix and random coil were the main secondary structures of LFBEP-C1. Mass spectrometry determined the theoretical molecular weight of LFBEP-C1 as 48 kDa, and its amino acid coverage was 63%. These findings suggest that the protein LFBEP-C1 with the best lipid-lowering activity was isolated and purified, and its structural characteristics were identified.

Fruits of Hippophaë rhamnoides in human leukocytes and Caco-2 cell monolayer models—A question about their preventive role in lipopolysaccharide leakage and cytokine secretion in endotoxemia

Preparations from Hippophaë rhamnoides L. (sea buckthorn) have been traditionally used in the treatment of skin and digestive disorders, such as gastritis, gastric and duodenal ulcers, uterine erosions, as well as oral, rectal, and vaginal mucositis, in particular in the Himalayan and Eurasian regions. An influence of an aqueous extract from the fruits of H. rhamnoides (HR) on leakage of lipopolysaccharide (LPS) from Escherichia coli through gut epithelium developed from the human colorectal adenocarcinoma (Caco-2) monolayer in vitro and glucose transporter 2 (GLUT2) translocation were the principal objectives of the study. Additionally, the effect of HR on the production of pro- and anti-inflammatory cytokines (interleukins: IL-8, IL-1β, IL-10, IL-6; tumor necrosis factor: TNF-α) by the Caco-2 cell line, human neutrophils (PMN), and peripheral blood mononuclear cells (PBMC) was evaluated. The concentration of LPS on the apical and basolateral sides of the Caco-2 monolayer was evaluated with a Limulus Amebocyte Lysate (LAL) assay. GLUT2 translocation was evaluated using an immunostaining assay, whereas secretion of cytokines by cell cultures was established with an enzyme-linked immunosorbent (ELISA) assay. HR (500 μg/ml) significantly inhibited LPS leakage through epithelial monolayer in vitro in comparison with non-treated control. The treatment of Caco-2 cells with HR (50–100 μg/ml) showed GLUT2 expression similar to the non-treated control. HR decreased the secretion of most pro-inflammatory cytokines in all tested models. HR might prevent low-grade chronic inflammation caused by metabolic endotoxemia through the prevention of the absorption of LPS and decrease of chemotactic factors released by immune and epithelial cells, which support its use in metabolic disorders in traditional medicine.

Structural Characteristics, Antioxidant, and Immunostimulatory Activities of an Acidic Polysaccharide from Raspberry Pulp

The extraction and characterization of new bioactive plant-derived polysaccharides with the potential for use as functional foods and medicine have attracted much attention. In the present study, A novel acidic polysaccharide (RPP-3a) with a weight-average molecular weight (Mw) of 88,997 Da was isolated from the raspberry pulp. RPP-3a was composed of rhamnose, arabinose, galactose, glucose, mannose, and galacturonic acid at a molar ratio of 13.1:28.6:16.8:1.4:6.2:33.9. Structural analysis suggested that the RPP-3a backbone was composed of repeating units of →4)-β-Galp-(1→3,4)-α-Rhap-(1→[4)-α-GalAp-(1→4)-α-GalAp-(1→]_n with branches at the C-4 position of rhamnose. The side chain of RPP-3a, containing two branch levels, was comprised of α-Araf-(1→, →5)-α-Araf-(1→, →3,5)-α-Araf-(1→, →3)-β-Galp-(1→, →3,6)-β-Galp-(1→, →4)-β-Glcp-(1→, and →2,6)-α-Manp-1→ residues. RPP-3a exhibited moderate reducing power and strong hydroxyl and superoxide anion radical scavenging abilities. RPP-3a significantly promoted the viability of RAW264.7 macrophages by increasing the production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) at both the expression and transcriptional levels. In summary, the immunostimulatory and antioxidant activities make RPP-3a a viable candidate as a health-beneficial functional dietary supplement.

Isolation, Structural Characterization and Macrophage Activation Activity of an Acidic Polysaccharide from Raspberry Pulp

The discovery of safe and effective plant polysaccharides with immunomodulatory effects has become a research hotspot. Raspberry is an essential commercial fruit and is widely distributed, cultivated, and consumed worldwide. In the present study, a homogeneous acidic polysaccharide (RPP-2a), with a weight-average molecular weight (Mw) of 55582 Da, was isolated from the pulp of raspberries through DEAE-Sepharose Fast Flow and Sephadex G-200 chromatography. RPP-2a consisted of rhamnose, arabinose, galactose, glucose, xylose, galacturonic acid and glucuronic acid, with a molar ratio of 15.4:9.6:7.6:3.2:9.1:54.3:0.8. The results of Fourier transform infrared spectroscopy (FT-IR), gas chromatography-mass spectrometer (GC-MS), 1D-, and 2D-nuclear magnetic resonance (NMR) analyses suggested that the backbone of RPP-2a was primarily composed of →2)-α-L-Rhap-(1→, →2,4)-α-L-Rhap-(1→, →4)-α-D-GalAp-(1→, and →3,4)-α-D-Glcp-(1→ sugar moieties, with side chains of α-L-Araf-(1→, α-L-Arap-(1→, and β-D-Galp-(1→3)-β-D-Galp-(1→ residues linked to the O-4 band of rhamnose and O-3 band of glucose residues. Furthermore, RPP-2a exhibited significant macrophage activation activity by increasing the production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and the expression of inducible nitric oxide synthase (iNOS) and cytokines at the transcriptional level in RAW264.7 cells. Overall, the results indicate that RPP-2a can be utilized as a potential natural immune-enhancing agent.