Structural characterization and immunomodulatory activity of novel polysaccharides from Citrus aurantium Linn. variant amara Engl

Size exclusion chromatography and asymmetrical flow field-flow fractionation for structural characterization of polysaccharides: A comparative review

Natural polysaccharides exhibit a wide range of biological activities, which are closely related to their structural characteristics, including their molecular weight distribution, size, monosaccharide composition, glycosidic bond types and spatial conformation, etc. Size exclusion chromatography (SEC) and asymmetrical flow field-flow fractionation (AF4), as two potent separation techniques, both harbor potential for continuous development and enhancement. This manuscript reviewed the fundamental principles and separation applications of SEC and AF4. The structural information and spatial conformation of polysaccharides can be obtained using SEC or AF4 coupled with multiple detectors. In addition, this manuscript elaborates in detail on the shear degradation of samples such as polysaccharides separated by SEC. In addition, the abnormal elution that occurs during the application of the two methods is also discussed. Both SEC and AF4 possess considerable potential for ongoing development and refinement, thereby offering increased possibilities and opportunities for polysaccharide separation and characterization.

Effect of Licorice polysaccharides before and after honey-processing on improving chronic fatigue syndrome and its mechanism

Honey-processed Licorice, a type of Glycyrrhizae Radix et Rhizome processed with honey, is renowned for its superior effectiveness in tonifying the spleen and invigorating Qi compared to the raw product. Our previous research showed that flavonoids and saponins in licorice changed after processing. Therefore, the purpose of this study was to investigate the changes of chemical composition and biological activity of polysaccharides after processing. The weight-average molecular weight (Mw) measured by HPGPC showed that the Mw distribution range of raw licorice polysaccharides (RLP) was 1.34 × 103-1.36 × 106 Da, and the Mw distribution range of honey-processed licorice polysaccharides (HPLP) was 1.15 × 103-1.17 × 106 Da, the Mw distribution range of the two were basically the same. The analysis of monosaccharide composition showed that the types of monosaccharide in RLP and HPLP were consistent, and the contents of mannose, rhamnose, glucuronic acid, galacturonic acid and glucose in HPLP were significantly higher than those in RLP. Furthermore, the impact of these polysaccharides on chronic fatigue syndrome (CFS) showed that the high-dose group of HPLP had significantly better improvement of IL-2, IFN-γ and IgA than RLP. Multi-omics analysis showed that both of them could affect the immune system by regulating immunoglobulin, B-cell signaling pathway and T cell phenotypic differentiation. Interestingly, the HPLP could affect the natural killer cells mediated cytotoxicity on this basis. The above results indicated the effects of honey processing on the chemical composition and biological activities of licorice polysaccharides and elucidated the underlying mechanism of the superior biological activities of HPLP over RLP.

Extraction, purification, chemical characterization, and in vitro hypoglycemic activity of polysaccharides derived from Rosa laevigata Michx

This study aimed to optimize the extraction process of polysaccharides from Rosa laevigata Michx. (RLMP) using an ultrasound-microwave-assisted method and investigate its in vitro hypoglycemic activity. Key factors affecting RLMP yield were identified using a Plackett-Burman design, followed by a Box-Behnken design and response-surface methodology, to determine the optimal extraction conditions. RLMP was purified using DEAE-52 cellulose, yielding two homogeneous fractions: RLMP-1 and RLMP-2. Monosaccharide composition was analyzed by gas chromatography, and structural characterization of RLMP, RLMP-1, and RLMP-2 was performed using FT-IR, SEM, and TEM. Methylation analysis and NMR were used to elucidate the sugar-chain structure of RLMP-1. In vitro hypoglycemic activity analysis showed that RLMP improved the glucose consumption and glycogen synthesis and enhanced the activities of pyruvate kinase and hexokinase in IR-HepG2 cells. Moreover, RLMP significantly increased the activities of antioxidant enzymes, such as CAT, SOD, and GSH-Px and decreased those of ROS and MDA. Western blotting analysis confirmed that RLMP enhances glucose and lipid metabolism and reduces oxidative stress by activating the PI3K/Akt/GLUT-4 signaling pathway, thereby exerting its hypoglycemic effect. These findings suggest that RLMP is a promising candidate for developing novel antioxidant agents or hypoglycemic drugs.

Antioxidant, Antimicrobial, and Anti-Inflammatory Effects of Liriodendron chinense Leaves

Liriodendron chinense has been widely utilized in traditional Chinese medicine to treat dispelling wind and dampness and used for alleviating cough and diminishing inflammation. However, the antioxidant, antimicrobial, and anti-inflammatory effects of L. chinense leaves and the key active constituents remained elusive. So, we conducted some experiments to support the application of L. chinense in traditional Chinese medicine by investigating the antioxidant, antibacterial, and anti-inflammatory abilities, and to identify the potential key constituents responsible for the activities. The ethanol extract of L. chinense leaves (LCLE) was isolated and extracted, and assays measuring ferric reducing antioxidant power, total reducing power, DPPH•, ABTS•+, and •OH were used to assess its in vitro antioxidant capacities. Antimicrobial activities of LCLE were investigated by minimal inhibitory levels, minimum antibacterial concentrations, disc diffusion test, and scanning electron microscope examination. Further, in vivo experiments including macro indicators examination, histopathological examination, and biochemical parameters measurement were conducted to investigate the effects of LCLE on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. LCLE was further isolated and purified through column chromatography, and LPS-induced RAW264.7 cells were constructed to assess the diminished inflammation potential of the identified chemical composites. ABTS•+ and •OH radicals were extensively neutralized by the LCLE treatment. LCLE administration also presented broad-spectrum antimicrobial properties, especially against Staphylococcus epidermidis by disrupting cell walls. LPS-induced ALI in mice was significantly ameliorated by LCLE intervention, as evidenced by the histological changes in the lung and liver tissues as well as the reductions of nitric oxide (NO), TNF-α, and IL-6 production. Furthermore, three novel compounds including fragransin B2, liriodendritol, and rhamnocitrin were isolated, purified, and identified from LCLE. These three compounds exhibited differential regulation on NO accumulation and IL-10, IL-1β, IL-6, TNF-α, COX-2, and iNOS mRNA expression in RAW264.7 cells induced by LPS. Fragransin B2 was more effective in inhibiting TNF-α mRNA expression, while rhamnocitrin was more powerful in inhibiting IL-6 mRNA expression. LCLE had significant antioxidant, antimicrobial, and anti-inflammatory effects. Fragransin B2, liriodendritol, and rhamnocitrin were probably key active constituents of LCLE, which might act synergistically to treat inflammatory-related disorders. This study provided a valuable view of the healing potential of L. chinense leaves in curing inflammatory diseases.

Sedative and hypnotic effects of Polygala tenuifolia willd. saponins on insomnia mice and their targets

ETHNOPHARMACOLOGICAL RELEVANCE

Polygala tenuifolia Willd. has been widely used in the treatment of cancer, forgetfulness, depression and other diseases.

AIM OF REVIEW

The purpose of this study was to investigate the sleep-enhancing effect and mechanism of P. tenuifolia saponins (PTS).

MATERIALS AND METHODS

The total saponin (YZ-I) and purified saponin (YZ-II) fractions were extracted and ICR mice model of insomnia was established by p-chlorophenylalanine (PCPA) induction to observe anxiety and depression behaviors. Effects of YZ-I and YZ-II on the levels of neurotransmitters, hormones, and inflammation cytokines were detected by ELISA, RT-qPCR and western blotting.

RESULTS

The results showed that YZ-I and YZ-II reduced the immobility time of mice and prolonged the sleep time of mice and significantly increased the concentrations of 5-HT, NE, PGD2, IL-1β and TNF-α. YZ-I and YZ-II regulated GABAARα2, GABAARα3, GAD65/67, 5-HT1A and 5-HT2A, while regulated the levels of inflammatory cytokines such as DPR, PGD2, iNOS and TNF-α to exert sedative and hypnotic effects.

CONCLUSION

PTS are mainly achieved sedative and hypnotic effects by altering serotonergic, GABAergic and immune systems, but the effects and mechanisms of action of YZ-I were different from YZ-II.

Effect of subcritical water temperature on the chain conformation and immune activity of ginger polysaccharides

In this study, the ginger polysaccharides extracted from hot water (HW-G) were modified with subcritical water (SW-G) to effectively regulate their immune activity, and the relationship between polysaccharide chain conformation and immune activity at different subcritical water temperatures was investigated. The results indicated that, compared with HW-G, the xylose and mannose were degraded at high temperatures. The molecular weight of ginger polysaccharide decreased from 1.083 × 106 g/mol to 3.113 × 105 g/mol after subcritical water modification (100-160 °C). The chain conformation transitioned from rigid rod chain to semi-rigid chain and eventually to random coil. The degree of relaxation of the polysaccharide chains showed a continuous increase trend. Additionally, ginger polysaccharide modified by subcritical water at 130 °C was found to promote the proliferation and phagocytosis of 264.7 cells more obviously and signally increase the secretion levels of NO, IL-6, TNF-α and IL-1β. When the subcritical water temperature exceeds 130 °C, the activity of ginger polysaccharide begins to decline rapidly. These findings demonstrate a close correlation between polysaccharide chain conformation and immunomodulatory activity, confirming the feasibility of the subcritical water temperature effect as a means of immune activity regulation, which opens up a new approach to obtaining highly active polysaccharides.

Chemical Composition and Biological Activities of the Essential Oil from Citrus reticulata Blanco Peels Collected from Agrowastes

Citrus fruits have a thick outer coat which is often discarded due to its low economic value and usually contributes to the waste. So this work focused on exploring the potential pharmacological properties of the discarded citrus peels. In the present study, we extracted the essential oil from peel wastes of Citrus reticulata Blanco (CREO) from the local market. The antioxidant, antibacterial, and anticancer properties of essential oil were evaluated. The CREO exhibited a strong antioxidant property with DPPH radical scavenging, ABTS radical scavenging, H2 O2 radical scavenging, Ferric reducing antioxidant power and for Lipid peroxidation inhibition respectively. Antibacterial properties of CREO was indicated against different pathogenic microbial strains like E. coli, P. aeruginosa, S. aureus, and S. enterica in terms of disc diffusion method and minimum inhibitory concentration (MIC). Further, anticancer properties studied on breast cancer cell lines MCF7 and MDA-MB-231 showed dose-dependent cytotoxicity with IC50 of 56.67±3.12 μg/mL and 76.44±2.53 μg/mL respectively. The GC-MS analysis of CREO revealed the presence of major compounds like S-limonene, α-pinene, α-myrcene, and cis-terpinene which might have played a significant role in strong antioxidant, antibacterial and anticancer properties. The study thus identified the potential health benefits of Citrus reticulata peel waste.

Chemical Composition and Antibacterial and Antiulcerative Colitis Activities of Essential Oil from Pruni Semen

This study was sought to investigate the chemical composition and antibacterial and antiulcerative colitis (UC) effects of essential oil from Pruni Semen (PSEO). A GC-MS assay showed that the major compounds in PSEO were products of amygdalin hydrolysis, which possessed great antibacterial and anti-inflammatory potential. In vitro antibacterial experiments demonstrated that PSEO treatment inhibited activity of four kinds of intestinal pathogens probably by disrupting the cell wall. Further in vivo studies showed that PSEO administration significantly improved physiological indexes, attenuated histopathological characteristics, and inhibited proinflammatory cytokine production in dextran sulfate sodium (DSS)-induced UC mice. Network pharmacology and molecular docking results predicted that PSEO might prevent UC via regulating the PI3K/AKT pathway. Western blotting and immunofluorescence assays were further conducted for verification, and the results evidenced that PSEO intervention significantly regulated the PI3K/AKT pathway and the expression of its downstream proteins in DSS-induced mice. PSEO might provide a new dietary strategy for UC treatment.

Phytoimmunomodulators: A review of natural modulators for complex immune system

In the past few decades, the medicinal properties of plants and their effects on the human immune system are being studied extensively. Plants are an incredible source of traditional medicines that help cure various diseases, including altered immune mechanisms and are economical and benign compared to allopathic medicines. Reported data in written documents such as Traditional Chinese medicine, Indian Ayurvedic medicine support the supplementation of botanicals for immune defense reactions in the body and can lead to safe and effective immunity responses. Additionally, some botanicals are well-identified as magical herbal remedies because they act upon the pathogen directly and help boost the immunity of the host. Chemical compounds, also known as phytochemicals, obtained from these botanicals looked promising due to their effects on the human immune system by modulating the lymphocytes which subsequently reduce the chances of getting infected. This paper summarises most documented phytochemicals and how they act on the immune system, their properties and possible mechanisms, screening conventions, formulation guidelines, comparison with synthetic immunity-enhancers, marketed immunity-boosting products, and immune-booster role in the ongoing ghastly corona virus wave. However, it focuses mainly on plant metabolites as immunomodulators. In addition, it also sheds light on the current advancements and future possibilities in this field. From this thorough study, it can be stated that the plant-based secondary metabolites contribute significantly to immunity building and could prove to be valuable medicaments for the design and development of novel immunomodulators even for a pandemic like COVID-19.

Hepatoprotective effects of peach gum polysaccharides against alcoholic liver injury: moderation of oxidative stress and promotion of lipid metabolism

Natural polysaccharides extracted from plants have received increasing attention due to their rich bioactivity. In our study, peach gum polysaccharides (PGPs) were extracted by water extraction-alcohol precipitation method. PGPs are typical pyranose polysaccharides with a mean molecular weight of 3.68 × 106 g/mol. The antioxidant activity and hepatoprotective capacity of PGPs were studied. In vitro, assays showed that PGPs scavenged DPPH, OH, and O2- in a dose-dependent manner. PGPs exhibited antioxidative properties against alcohol-induced HL7702 cells, as evidenced by the normalization of MDA, SOD, ROS, and GSH levels. To further elucidate the hepatoprotective mechanism of PGPs, we carried out in vivo experiments in male mice. PGPs exerted hepatoprotective effects in alcohol liver disease (ALD) mice by exerting antioxidant effects, decreasing the inflammatory response and modulating lipid metabolism. In addition, metabolomic analysis indicated that PGPs mainly regulate D-glutamine and D-glutamate metabolism, alanine, aspartate and glutamate metabolism, and arginine biosynthesis to promote hepatic metabolism and maintain body functions. Overall, this study revealed that the hepatoprotective mechanism of PGPs against ALD might be associated with the regulation of oxidative stress and lipid metabolism.

Structural characterization, anti-tumor and immunomodulatory activity of intracellular polysaccharide from Armillaria luteo-virens

Armillaria luteo-virens (A. luteo-virens) is a kind of edible fungus mainly exists in Qinghai-Tibet of China, but at present only very few studies focus on the bioactivities of its polysaccharides. This study aimed to purify and characterize the structure features of a novel intracellular polysaccharide (ALP-A) derived from A. luteo-virens and explore its potential anti-tumor and immunomodulatory activities. Through systematic separation and purification, we obtained a homogeneous ALP-A with an average molecular weight of 23693Da. Structural analysis indicated that ALP-A was mainly composed of glucose and mannose with a molar ratio of 6.02:1. The repeating unit of ALP-A was →4) -α-D-Glcp-(1→ backbone with α-Glcp-(1→ and α-Manp-(6→ side chains which branched at O-2 position. The anti-tumor assays in vivo suggested that ALP-A could effectively restrain S180 solid tumor growth, protect immune organs and promote the secretion of cytokines (IL2, IL6 and TNF-α) in serum. Besides, in vitro immunomodulatory assays indicated that ALP-A could improve proliferation, phagocytic capacity and raise the level of NO and cytokines in Raw264.7 cells. These results demonstrate that ALP-A which possess potential antitumor and immunomodulatory abilities can be developed as a new functional food.

Dietary Plant Polysaccharides for Cancer Prevention: Role of Immune Cells and Gut Microbiota, Challenges and Perspectives

Dietary plant polysaccharides, one of the main sources of natural polysaccharides, possess significant cancer prevention activity and potential development value in the food and medicine fields. The anti-tumor mechanisms of plant polysaccharides are mainly elaborated from three perspectives: enhancing immunoregulation, inhibiting tumor cell growth and inhibiting tumor cell invasion and metastasis. The immune system plays a key role in cancer progression, and immunomodulation is considered a significant pathway for cancer prevention or treatment. Although much progress has been made in revealing the relationship between the cancer prevention activity of polysaccharides and immunoregulation, huge challenges are still met in the research and development of polysaccharides. Results suggest that certain polysaccharide types and glycosidic linkage forms significantly affect the biological activity of polysaccharides in immunoregulation. At present, the in vitro anti-tumor effects and immunoregulation of dietary polysaccharides are widely reported in articles; however, the anti-tumor effects and in vivo immunoregulation of dietary polysaccharides are still deserving of further investigation. In this paper, aspects of the mechanisms behind dietary polysaccharides' cancer prevention activity achieved through immunoregulation, the role of immune cells in cancer progression, the role of the mediatory relationship between the gut microbiota and dietary polysaccharides in immunoregulation and cancer prevention are systematically summarized, with the aim of encouraging future research on the use of dietary polysaccharides for cancer prevention.

Structure characterization and biological activities evaluation of two hetero-polysaccharides from Lepista nuda: Cell antioxidant, anticancer and immune-modulatory activities

Polysaccharides LNP-1 and LNP-2 were extracted and purified from Lepista nuda, and their structural characteristics and biological activities were evaluated. The molecular weights of LNP-1 and LNP-2 were determined to be 16,263 Da and 17,730 Da, respectively. The monosaccharide composition analysis showed that LNP-1 and LNP-2 were composed of fucose, mannose, glucose, and galactose in a molar ratio of 1.00:2.42:1.09:4.04 and 1.00:2.39:1.61:4.23, respectively. The structure analysis revealed that these two polysaccharides were mainly composed of T-Fuc, T-Man, T-Glc, 1,6-Glc 1,6-Gal, and 1,2,6-Man, 1,2,6-Gal. Additionally, LNP-2 contained an additional 1,4-Glc glycosidic linkage in comparison to LNP-1. Both LNP-1 and LNP-2 exhibited anti-proliferation effects on A375 cells, but not on HepG2 cells. Furthermore, LNP-2 showed better cellular antioxidant activity (CAA) than LNP-1. RT-PCR results indicated that LNP-1 and LNP-2 could induce macrophages to secrete immune-modulatory factors NO, IL-6, and TNF-α by regulating their mRNA expression. Overall, this study provides a theoretical basis for the further development of the structure-function relationship of polysaccharides from L. nuda.

Structural characteristics and gel properties of pectin from citrus physiological premature fruit drop

This study is the first to extract and characterize pectin from citrus physiological premature fruit drop. The extraction yield of pectin reached 4.4 % by acid hydrolysis method. The degree of methoxy-esterification (DM) of citrus physiological premature fruit drop pectin (CPDP) was 15.27 %, indicating it was low-methoxylated pectin (LMP). The monosaccharide composition and molar mass test results showed CPDP was a highly branched macromolecular polysaccharide (β: 0.02, Mw: 2.006 × 10⁵ g/mol) with rich rhamnogalacturonan I domain (50.40 %) and long arabinose and galactose side chain (32.02 %). Based on the fact that CPDP is LMP, Ca²⁺ was used to induce CPDP to form gels. Textural and rheological tests showed that the gel strength and storage modulus of CPDP were higher than commercial citrus pectin (CP) used in this paper due to the lower DM and rich neutral sugar side chains of CPDP. Scanning electron microscope (SEM) results showed CPDP had stable gel network structure.

p-Synephrine ameliorates alloxan-induced diabetes mellitus through inhibiting oxidative stress and inflammation via suppressing the NF-kappa B and MAPK pathways

Oxidative stress and inflammation play important roles in the development of diabetes mellitus. p-Synephrine, the primary pharmacologically active protoalkaloid in Citrus species, has been popularly consumed as a dietary supplement for weight loss management. However, the effects of p-synephrine on diabetes mellitus and the action mechanisms have not been clearly elucidated. In this study, the in vitro antioxidant effects of p-synephrine were evaluated. The data showed that p-synephrine treatment exhibited significant scavenging effects against DPPH, ABTS and OH radicals and showed high reducing power. Diabetic mice were developed by alloxan injection, followed by p-synephrine administration to investigate its hypoglycemic effects in vivo. The results showed that p-synephrine intervention significantly prevented alloxan-induced alteration in body weight, organ indexes, serum uric acid content and serum creatinine content. Meanwhile, p-synephrine application significantly improved the lipid profiles, superoxide dismutase (SOD) and catalase (CAT) activities and glutathione (GSH) contents in the serum and kidneys of diabetic mice and reduced the malondialdehyde (MDA) content in the serum of diabetic mice. Further assays suggested that p-synephrine treatment improved alloxan-induced decreases of glucose tolerance and insulin sensitivity. Also, p-synephrine supplementation altered histopathological changes in the kidneys and interscapular brown adipose tissues in diabetic mice. In addition, p-synephrine administration inhibited renal inflammation through suppressing tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) gene expression levels, as well as CD45 expression levels. The anti-inflammatory effects were probably involved in the regulation of nuclear factor-κB (NF-κB) activation and mitogen-activated protein kinase (MAPK) phosphorylation. In conclusion, p-synephrine application significantly ameliorated alloxan-induced diabetes mellitus by inhibiting oxidative stress via suppressing the NF-κB and MAPK pathways.

Low Weight Polysaccharide of Hericium erinaceus Ameliorates Colitis via Inhibiting the NLRP3 Inflammasome Activation in Association with Gut Microbiota Modulation

Ulcerative colitis (UC), one of the typical inflammatory bowel diseases caused by dysregulated immunity, still requires novel therapeutic medicine with high efficacy and low toxicity. Hericium erinaceus has been widely used to treat different health problems especially gastrointestinal sickness in China for thousands of years. Here, we isolated, purified, and characterized a novel low weight polysaccharide (HEP10, Mw: 9.9 kDa) from the mycelia of H. erinaceus in submerged culture. We explored the therapeutic effect of HEP10 on UC and explored its underlying mechanisms. On one hand, HEP10 suppressed the production of TNF-α, IL-1β, IL-6, inducible iNOS, and COX-2 in LPS challenged murine macrophage RAW264.7 cells, as well as in colons from DSS-induced colitis mice. On the other hand, HEP10 treatment markedly suppressed the activation of NLRP3 inflammasome, NF-κB, AKT, and MAPK pathways. Moreover, HEP10 reversed DSS-induced alternation of the gut community composition and structure by significantly increasing Akkermansia muciniphila and also promoting functional shifts in gut microbiota. Structural equation modeling also highlighted that HEP10 can change widely through gut microbiota. In conclusion, HEP10 has a better prebiotic effect than the crude polysaccharides of H. erinaceus, which can be used as a novel dietary supplement and prebiotic to ameliorate colitis.

Effects of Sparassis latifolia neutral polysaccharide on immune activity via TLR4-mediated MyD88-dependent and independent signaling pathways in RAW264.7 macrophages

Background

Sparassis latifolia (S. latifolia) is a precious edible fungus with multiple biological activities. To date, no study has been investigated the underlying molecular mechanism of immunoregulation caused by the neutral polysaccharide of S. latifolia.

Materials and methods

To investigate immunomodulatory mechanism of S. latifolia neutral polysaccharide (SLNP), SLNP was obtained from S. latifolia and its structure, immune receptors and regulation mechanism were studied.

Results

S. latifolia neutral polysaccharide consisted of arabinose, galactose, glucose, xylose, and mannose with a molar ratio of 6:12:63:10:5. SLNP was a pyran polysaccharide with a relative molecular weight of 3.2 × 105 Da. SLNP promoted the proliferation of RAW264.7, which further induced the secretions of nitric oxide, TNF-α, IL-6, and IFN-β, and upregulated the immune receptor TLR4 expression. Moreover, SLNP increased remarkably the levels of TRAF6, IRF3, JNK, ERK, p38, and p38 mRNA and protein mediated by TLR4.

Conclusion

S. latifolia neutral polysaccharide regulated the immune function of RAW264.7 through MyD88-dependent and -independent signaling pathways mediated by TLR4 receptor, which suggests that SLNP is a new immunomodulator.

Physicochemical properties and immune-enhancing activity of graded polysaccharides from the peels of stem lettuce (Lactuca sativa) by cascade membrane technology

In this study, cascade membrane technology was applied to classify polysaccharides from the peels of stem lettuce (PPSLs), and three graded polysaccharides (PPSL100, PPSL10, and PPSL1) were obtained using ultrafiltration membranes of 100, 10, and 1 kDa in sequence. The physicochemical properties and immune-modulatory activity of three PPSLs fractions were analyzed and compared. Results showed that all three fractions have characteristic absorption peak of polysaccharides determined by FT-IR, and their monosaccharide composition only consisted of glucose determined by HPLC. PPSL10 had the highest contents of total sugar (88.09 ± 3.52%), uronic acid (2.55 ± 0.10%), and sulfate group (4.15 ± 0.20%). Besides, all three fractions exhibited immune-enhancing activities using RAW264.7 macrophages model, and PPSL10 was the best able to promote phagocytosis of neutral red and nitric oxide generation, which might relate to the high contents of above compositions and medium molecular weight (32 kDa). The findings indicated that PPSL10 could be developed as immune-modulator in the field of functional foods.

Role of polyphenols from Polygonum multiflorum Caulis in obesity-related disorders

ETHNOPHARMACOLOGICAL RELEVANCE

Polygoni Multiflori Caulis (PMC) has been widely consumed as folk medicine in China for anti-obesity, sleep-enhancing and many other pharmacological effects. However, the material basis and underlying mechanism of PMC on obesity-related disorders were still not clear.

AIM OF THE STUDY

To screen active constituents from PMC and explore their multitarget mechanisms in the treatment of obesity and its associated disorders.

MATERIALS AND METHODS

Several major constituents were extracted from PMC and LC-MS assay were used to identify the compounds. The lipase inhibitory activity and lipid accumulation in 3T3-L1 preadipocytes were determined. Furthermore, Caenorhabditis elegans (C. elegans) and high-fat diet (HFD)-induced mice were established to explore the potential pharmacological functions and related mechanisms using kits, RT-qPCR and biochemical analysis.

RESULTS

Regarding the lipase inhibitory activity, the inhibition rate of EA and n-Bu extracts at 4 mg/mL reached over 80%. Effects on 3T3-L1 preadipocytes proliferation and differentiation were also obvious, indicating that EA and n-Bu extracts might exert potential anti-obesity functions. LC-MS assay further showed that polyphenols including emodin and physcion comprised majority of EA and n-Bu extracts. EA and n-Bu extracts treatment could significantly modulate the antioxidant response and lipid accumulation in C. elegans, as evidenced by increased SOD and CAT contents, reduced MDA levels, higher TG contents and changes of related mRNA expression levels. In HFD-induced mice, the inhibition ratio of body weight as well as the histological and biochemical indexes of liver, plasma and epididymal adipose tissues were also reversed by EA and n-Bu extracts treatment. Moreover, EA and n-Bu extracts administration increased the microbial diversity, reshaped the microbiota structure and enhanced the relative abundance of Bifidobacterium.

CONCLUSIONS

This study demonstrated the multicomponent and multitarget characteristics of PMC in preventing obesity related disorders. The results provided novel insights for the development and utilization of PMC.

Optimization of the extract from flower of Citrus aurantium L. var. amara Engl. and its inhibition of lipid accumulation

Flower of Citrus aurantium L. var. amara Engl. (CAVA) has been confirmed to have promising anti-obesity effects. However, the regulation of alkaloid extracts from flower of CAVA (Al) on lipid metabolism remain unknown. In this study, Al was optimized by ultrasound-assisted extraction using response surface methodology. The optimal conditions were ultrasonic time 72 min, ethanol concentration 78% and liquid/solid ratio 30 ml/g with the maximum alkaloid yield 5.66%. LC-MS assay indicated that the alkaloid compounds were enriched in Al after optimization. Nine alkaloid compounds were identified in Al by LC-MS assay and stachydrine, caffeine and cathine appeared as the major alkaloid compounds. Bioactivity assay showed that Al treatment significantly increased superoxide dismutase (SOD) activity, and reduced malonaldehyde (MDA) and reactive oxygen species (ROS) levels. Al administration also reversed oleic acid-induced hepatic steatosis in Hep G2 cells by inhibiting the expression of lipogenesis-signaling genes including fatty acid synthase (FAS), peroxisome proliferator-activated receptor subtype γ (PPARγ), uncoupling protein 2 (UCP2), and retinol binding protein (RBP4). However, OA-induced reduction of lipolysis-related gene carnitine palmitoyl transferase 1A (CPT1A) in Hep G2 cells was not improved by Al supplementation. Moreover, the increased SOD activity and decreased MDA and ROS contents were also observed in Caenorhabditis elegans by Al addition. Al intervention exhibited the ability to inhibit lipid accumulation in C. elegans by suppressing expression of lipid metabolism-related genes. These results suggested that the alkaloid extracts from the flower of CAVA showed great potential to regulate lipid metabolism. PRACTICAL APPLICATIONS: The extraction of alkaloid extracts from the flower of CAVA was optimized with a maximum yield of 5.66%. The regulatory effects and mechanisms of Al on lipid metabolism of Hep G2 cells and Caenorhabditis elegans were also investigated. More clinical studies are required to evaluate the potential of using alkaloids from the flower of CAVA as therapeutic agents against lipid metabolic disorders.

A green and highly efficient method to deliver hydrophilic polyphenols of Salvia miltiorrhiza and Carthamus tinctorius for enhanced anti-atherosclerotic effect via metal-phenolic network

Salvia miltiorrhiza and Carthamus tinctorius are traditional Chinese medicines that have been widely used for the treatment of cardiovascular disease. Salvianic acid A (SAA), salvianic acid B (SAB), protocatechuic aldehyde (PCA) and hydroxysafflor yellow A (HSYA) are the major hydrophilic polyphenols of Salvia miltiorrhiza and Carthamus tinctorius, all of which have been documented as active compounds for the prevention and treatment of atherosclerosis (AS). However, high aqueous solubility, low permeability and poor stability properties of the four hydrophilic polyphenols might influence their bioavailability and thus hinder their clinical potential. In this work, we introduced a green and highly efficient method for the efficient delivery of the four hydrophilic components via metal-phenolic network. The four coordination polymers of SAA, SAB, PCA and HSYA were successfully fabricated, and confirmed by UV-vis, FTIR, XPS, ICP-MS and dynamic light scattering analysis. We found all of them displayed potent antioxidant activity, good biocompatibility and stability. Impressively, the four coordination polymers showed remarkably enhanced anti-atherosclerotic effect compared with free drugs. Collectively, metal-phenolic network-based coordination polymer might show great potential for safe and efficient delivery of the hydrophilic polyphenols of Salvia miltiorrhiza and Carthamus tinctorius for anti-atherosclerotic therapy.

Improvement effects of esculetin on the formation and development of atherosclerosis

Atherosclerosis is one of the potential causes of death in patients with cardiovascular disease. With the discovery of new anti atherosclerotic drugs becoming the pursuit of the pharmaceutical industry, natural products have attracted more and more attention because of their unique efficacy in the treatment of atherosclerosis. More and more studies have shown that esculetin, a coumarin mainly found in cortex fraxini, can improve atherosclerosis by participating in cellular antioxidant responses and reducing inflammation related pathogenesis. This paper summarizes the researches of esculetin on anti-atherosclerosis in the past two decades. Esculetin plays an anti atherosclerotic role through reducing blood triglyceride level, preventing the proliferation of vascular smooth muscle cells (VSMC) and the production of matrix metallopeptidase 9 (MMP-9), inhibiting the oxidation of low density lipoprotein (LDL) and the secretion of adhesion factors and chemokines, and increasing the outflow level of high density lipoprotein cholesterol (HDL-C). Esculetin is safe and reliable, easy to be absorbed by the body and can be synthesized in a variety of ways. Although there are still few clinical studies on anti-atherosclerosis, in vivo experiments have proved that esculetin has high bioavailability. From the current research, the anti-atherosclerotic effect of esculetin is positive and encouraging. However, much work remains to be done to clarify the molecular mechanism of esculetin in the treatment of atherosclerosis.

Isolation and Purification, Structural Characterization and Antioxidant Activities of a Novel Hetero-Polysaccharide from Steam Exploded Wheat Germ

A purified polysaccharide, designated as SE-WGPI, was isolated from wheat germ modified by steam explosion. The primary structure characteristics were determined by HPGPC, GC, periodate oxidation-Smith degradation, methylation analysis, FT-IR, NMR and Congo red test. The results showed that SE-WGPI was a homogeneous hetero-polysaccharide with the average molecular weight of 5.6 × 103 Da. The monosaccharide composition mainly consisted of glucose, arabinose and xylose with a molar ratio of 59.51: 20.71: 19.77. The main backbone of SE-WGPI consisted of →4,6)-α-D-Glcp(1→6)-α-D-Glcp(1→3)-β-D-Xylp(1→5)-α-L-Araf(1→ and the side chain was α-D-Glcp(1→ linked at the C4-position of →4,6)-α-D-Glcp(1→. SE-WGPI likely has a complex netted structure with triple helix conformation and good thermal stability. In addition, SE-WGPI had valid in vitro radical scavenging activities on DPPH and hydroxyl radicals. This study may provide structural information of SE-WGPI for its promising application in the fields of functional foods or medicines.

Structural characterization and anti-tumor activity in vitro of a water-soluble polysaccharide from dark brick tea

Recently, more and more attention has been paid to the structure and application of tea polysaccharides. Herein, a water-soluble homogeneous polysaccharide (DTP-1) from dark brick tea was purified, characterized, and investigated its anti-tumor activity in vitro. The DTP-1 with a molecular weight of 11,805 Da is mainly composed of glucose, galactose and arabinose. It has a backbone, which is composed of →4)-α-D-Glcp-(1→, →5)-α-L-Araf-(1→, →6)-β-D-Galp-(1→, →2)-α-L-Araf-(1→, →3)-β-D-Galp-(1→, with →4,6)-β-D-Galp-(1 → as branching point and →1)-β-D-Glcp as terminal. In addition, DTP-1 could significantly affect the viability of A549 and SMMC7721 cells with an inhibition rate of 31.71% and 33.38% (600 μg/mL, 24 h), respectively, by inducing apoptosis and inhibiting cell migration. Moreover, DTP-1 had no effect on corresponding normal cells. Therefore, DTP-1 showed great potential to become a functional food and an anti-tumor drug.

Chemical elucidation and rheological properties of a pectic polysaccharide extracted from Citrus medica L. fruit residues by gradient ethanol precipitation

Citron (Citrus. medica L.) fruits are commonly utilized in the production of essential oil, therefore, the fruits residues turn out to be industrial byproducts. In the present study, a crude polysaccharide was extracted from citron fruit residues by hot water extraction and precipitation of ethanol (95%), after deproteinization, a major polysaccharide component (CMLP-2) was obtained by gradient ethanol precipitation (20%-80%). The physicochemical properties of CMLP-2 such as surface morphology, functional groups, and thermostability were examined by FT-IR spectroscopy, SEM, and thermogravimetric analysis. Moreover, the chemical structure of CMLP-2 was elucidated that CMLP-2 is an acidic pectic polysaccharide consisting of arabinose (Ara), galacturonic acid (GalA), and rhamnose (Rha) in a molar ratio of 4:2:1 with a molecular weight of 202.18 kDa. CMLP-2 is a novel pectic polysaccharide rich in rhamnogalacturonan I (RG-I). Moreover, rheological tests revealed that CMLP-2 solution is pseudoplastic and temperature resistant. The result could be a good basis for the utilization of Citrus medica L. fruits residues as plant-derived food additive.

Ingredients with anti-inflammatory effect from medicine food homology plants

Inflammation occurs when the immune system responses to external harmful stimuli and infection. Chronic inflammation induces various diseases. A variety of foods are prescribed in the traditional medicines of many countries all over the world, which gave birth to the concept of medicine food homology. Over the past few decades, a number of secondary metabolites from medicine food homology plants have been demonstrated to have anti-inflammatory effects. In the present review, the effects and mechanisms of the medicine food homology plants-derived active components on relieving inflammation and inflammation-mediated diseases were summarized and discussed. The information provided in this review is valuable to future studies on anti-inflammatory ingredients derived from medicine food homology plants as drugs or food supplements.

Structure–immunomodulatory activity relationships of dietary polysaccharides

Polysaccharides are usually composed of more than ten monosaccharide units, which are connected by linear or branched glycosidic bonds. The immunomodulatory effect of natural polysaccharides is one of the most important bioactive function. In this review, molecular weight, monosaccharide (including galactose, mannose, rhamnogalacturonan-I arabinogalactan and uronic acid), functional groups (namely sulfate, selenium, and acetyl groups), types of glycoside bond connection (including β-1,3-D-glucosyl, α-1,4-D-glucosyl, β-1,4-D-glucosyl, α-1,6-D-glucosyl, β-1,4-D-mannosyl, and β-1,4-D-Xylopyranosyl), conformation and the branching degrees are systematically identified as their contribution to the immunostimulatory activity of polysaccharides. At present, studies on the structure-activity relationships of polysaccharides are limited due to their low purity and high heterogeneity. However, it is an important step in providing useful guidance for dietary supplements with polysaccharides. The chemical structures and the process of immune responses induced are necessary to be discussed. Polysaccharides may bind with the cell surface receptors to modulate immune responses. This review mainly discusses the structure-activity relationship of dietary polysaccharides.

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Structure - activity relationships of polysaccharides with immune-enhancing effect are proposed.

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Polysaccharides with the higher molecular weight are helpful to improve immunity.

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Higer galactose, mannose, rhamnogalacturonan-I, arabinogalacta,n and uronic acid contents have immunoregulation.

Anticancer Effects and Molecular Target of Theaflavins from Black Tea Fermentation in Vitro and in Vivo

Black tea is one of the most popular beverages in the world, and numerous epidemiological studies have shown that drinking black tea is good for health. As a natural tea pigment formed during the fermentation of black tea, the content of theaflavins accounts for only 2-6% of the dry weight of black tea, but they have a great impact on the color and taste of black tea soup. Recently, a large number of studies have shown that theaflavins have a significant anticancer effect. In this Perspective, we first state the physical and chemical properties, separation and purification methods, and biological formation pathways of theaflavins and analyze their safety and oral bioavailability and the structure-activity relationship of their antioxidant and anticancer activities; then, we describe in detail their anticancer effect in vitro and in vivo and highlight their various molecular targets involved in cancer inhibition. The anticancer molecular targets of theaflavins are mainly cell-cycle regulatory proteins, apoptosis-related proteins, cell-migration-related proteins, and growth transcription factors. Finally, the possibility of developing new health-care food based on theaflavins is discussed. This Perspective is expected to provide a theoretical basis for the anticancer application of theaflavins in the future.

Structural characterization and immunoregulatory activity of polysaccharides from Dendrobium officinale leaves

In this study, two kinds of polysaccharides from leaves of Dendrobium officinale, namely DLP-1 and DLP-2, were obtained by hot water extraction, ethanol sedimentation, and chromatographic separation using DEAE-52 cellulose and Sephadex G-100 columns. They were composed of different monosaccharides and the content of monosaccharides varied significantly while DLP-1 (M_w 1.38 × 10⁶  Da) was mainly composed of mannose (71.69%) and glucose (22.89%), and DLP-2 (M_w 1.93 × 10⁶  Da) was constituted by rhamnose (35.05%), arabinose (24.12%), and galactose (25.65%). A triple-helical conformation was exhibited by both of them. The scanning electron microscope image of DLP-1 showed an irregular and large lamellar shape, as well as a smooth surface and a porous interior, illustrating they had an amorphous structure. In contrast, DLP-2 revealed a rough, loose, and uneven surface consisting of large sponge-like particles. Nuclear magnetic resonance analysis showed that (1→4)-β-D-Manp, (1→4)-β-D-Glcp, and (1→4)-2-O-acetyl-β-D-Manp were the main linkage types of DLP-1, whereas DLP-2 was constituted by a large amount of (1→4)-β-D-Manp, (1→4)-β-D-Glcp, and other residues. Besides, DLP-1 and DLP-2 stimulated the proliferation and phagocytic capacities of RAW 264.7 cells and improved the production of nitric oxide, interleukin-6, TNF-α, and IL-1β. These results proved that both DLP-1 and DLP-2 possessed excellent immunoregulatory bioactivities and could be functional food or adjuvant drug. PRACTICAL APPLICATIONS: The leaf of Dendrobium officinale is a by-product with huge biomass. The lack of systematic research on its chemical composition and pharmacologic effect, leading to a great waste of resources. In order to maximize the value of D. officinale, this study aimed to investigate the structural characteristics and immunologic effects of two polysaccharide fractions (DLP-1 and DLP-2) from D. officinale leaves, showing that DLP-1 and DLP-2 in D. officinale leaves could be used as anti-inflammatory agents to avoid wasting.

Structural characteristics, anti-proliferative and immunomodulatory activities of a purified polysaccharide from Lactarius volemus Fr

Lactarius volemus Fr. is an edible mushroom widely consumed in China. Polysaccharide is an important nutritional component of L. volemus. This research aimed to isolate the polysaccharide from L. volemus and study its structure and bioactivities. A purified polysaccharide was identified and named as LVF-I whose primary structure was proposed considering the comprehensive results of monosaccharide composition, periodate oxidation-smith degradation, methylation analysis, FT-IR and 1D/2D NMR spectroscopy. Then the immunomodulation of LVF-I and its inhibition effect on H1299 and MCF-7 cells were investigated. Results showed that LVF-I (12,894 Da) contained fucose, mannose, glucose and galactose. It had a backbone consisting of →4)-α-D-Glcp-(1→, →6)-β-D-Manp-(1→, →6)-α-D-Galp-(1 → and →4)-β-D-Manp-(1→. And its side chains were branched at C2 of →4)-β-D-Manp-(1 → by →6)-α-D-Galp-(1→, α-D-Glcp-(1→, α-D-Galp-(1 → and α-L-Fucp-(1→. LVF-I (250-1000 μg/mL) could inhibit the proliferation of H1299 and MCF-7 cells, while enhance the proliferative response of splenocyte and the phagocytic ability of RAW264.7. Furthermore, LVF-I (250-1000 μg/mL) significantly induced the secretion of nitric oxide, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) by up-regulating their mRNA expression in macrophages. These results suggested that LVF-I had the potential to be developed as antitumor or immunomodulatory agents by inhibiting the proliferation of tumor cells and stimulating macrophages-mediated immune responses.

Targets and underlying mechanisms related to the sedative and hypnotic activities of saponins from Rhodiola rosea L. (crassulaceae)

Rhodiola rosea L. (Crassulaceae) are popularly used as a natural supplement for the treatment of insomnia and anxiety. Here, saponin extracts from R. rosea were investigated for their roles on relieving sleeplessness. The levels of neurotransmitters, hormones, and inflammation cytokines in plasma, and the expression of 5-hydroxytryptamine (5-HT), γ-aminobutyric acid (GABA), prostaglandin D2 (PGD2), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in the hypothalamus and hippocampus were detected using ELISA, RT-PCR, and western blotting. First, the butanol fraction extracted from R. rosea was collected as the total saponins (HJT-I), then a saponin-rich fraction (HJT-II) was obtained after the further purification of HJT-I. The saponin contents of HJT-I and HJT-II were 28.92% and 65.69%, respectively. Second, behavioral tests were performed and showed that both HJT-I and HJT-II could effectively reduce the duration of immobility in the tail suspension test, and shorten sleep latency and prolong the sleep duration time in the sodium barbital-induced sleeping test, with HJT-II better than HJT-I. Third, ELLISA results showed that the concentrations of GABA, 5-HT, norepinephrine (NA), PGD2, and IL-1β in plasma were significantly increased after HJT-I and HJT-II administration, while IL-6 was decreased. HJT-I and HJT-II also exhibited differential modulation of the receptors of 5-HT, GABA, PGD2, and IL-1β expression. In hypothalamus, HJT-II was more powerful than HJT-I in regulation of the GABA_ARα2, GABA_ARα3, and glutamic acid decarboxylase (GAD) 65/67 expression, as well as 5-HT_2A and IL-1β. As for DPR and PGD2, HJT-II was more effective in the hippocampus. The efficacy of HJT-I was better than HJT-II at stimulating GABA_ARα2, GAD 65/67, 5-HT_1A, and IL-1β expression in the hippocampus. In conclusion, the potential sedative and hypnotic effects of HJT-I and HJT-II may possibly be related to the serotonergic, GABA_Aergic, and immune systems, while the underlying mechanism of HJT-I and HJT-II differed from each other.

Flavonoids from Rosa davurica Pall. fruits prevent high-fat diet-induced obesity and liver injury via modulation of the gut microbiota in mice

Rosa davurica Pall. (RDP) fruits are popularly consumed as beverages and healthy food in China because of their various beneficial activities. In particular, flavonoids are one of the major active ingredients of RDP fruits with predominant pharmacological effects. However, the anti-obesity activities of flavonoids from RDP fruits and their regulation effect on the gut microbiota have not been determined. In the present study, the flavonoid-rich extracts (RDPF) were isolated from RDP fruits and their anti-obesity effects were investigated using a high-fat diet (HFD)-induced obese mouse model. The results showed that RDPF intervention significantly inhibited the body weight, liver weight, kidney weight and epididymal adipose tissue weight of HFD-fed mice without affecting the calorie intake. Plasma lipid levels were also significantly lowered by RDPF treatment. Histological examination showed that RDPF supplementation partially recovered HFD-induced hepatic steatosis in the liver. RDPF also prevented oxidative injury of the liver, as evidenced by the altered superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) levels. The expression levels of CCAAT/enhancer binding protein α (C/EBPα), sterol regulatory element binding protein-1C (SREBP-1C), fatty acid synthase (FAS), acyl-coenzyme A oxidase 1 (ACOX1), peroxisome proliferator-activated receptor (PPARα) and CAT mRNA in the livers of mice were also regulated by RDPF administration. 16S rRNA gene sequence data further indicated that RDPF addition increased the microbial diversity and reshaped the community composition. Intriguingly, RDPF intervention did not exhibit inhibitory tendency toward the ratio of Firmicutes to Bacteroidetes, but markedly decreased the relative abundance of Erysipelotrichaceae. This study provided novel insights into the application of RDPF in the food industry.

Inhibitory effect of chloroform extracts from Citrus aurantium L. var. amara Engl. on fat accumulation

BACKGROUND

Excess lipid accumulation can accelerate the development of various metabolic diseases. Blossoms of Citrus aurantium L. var. amara Engl. (CAVA) have been reported to possess inhibitory capacities on lipid deposition. However, the constituents responsible for the observed bioactivity and the underlying mechanisms are still not clearly understood.

PURPOSE

To screen constituents from blossoms of CAVA with inhibitory effects on lipid accumulation and to explore the action mechanism.

METHODS

The chloroform (CHL) extracts are prepared from blossoms of CAVA by fractional extraction and are characterized using LC-MS assay. 3T3-L1 preadipocytes are induced with differentiation medium (DMI) and treated with CHL extracts. High fat diet (HFD)-induced obese mice are further established and administrated with CHL extracts for 12 weeks. Hematoxylin and eosin (HE) staining, Oil Red O staining, ELISA, RT-qPCR, western blot and 16S rRNA gene sequence methods are employed.

RESULTS

14 compounds are identified in CHL extracts and trigonelline hydrochloride, nobiletin and 7-demethylsuberosin are most abundant. CHL extracts treatment significantly inhibit differentiation of 3T3-L1 cells by regulating expression of preadipocyte factor-1 (Pref-1), fatty acid synthase (FAS) and CCAAT/enhancer binding protein α (C/EBPα). CHL extracts intervention also significantly attenuate features of obesity and improved plasma biochemical profiles in HFD-fed mice. HFD-triggered hepatic steatosis and epididymal adipose tissues (EATs) hypertrophy are also reversed by CHL extracts administration through enhancing antioxidant responses and modulating lipogenesis and energy expenditure-related genes and proteins. 16S rRNA gene sequence data further show that CHL extracts enhance the diversity of gut microbiota. CHL extracts at lower concentrations reduce the ratio of Firmicutes to Bacteroidetes and the abundance of Erysipelotrichaceae. CHL extracts at higher doses markedly increase the abundance of Lachnospiraceae.

CONCLUSION

These findings suggest that CHL extracts probably suppress lipid accumulation through inhibiting differentiation of 3T3-L1 cells and attenuating metabolic syndromes in HFD-fed mice.

Study on extraction methods of polysaccharides from a processed product of Aconitum carmichaeli Debx

Traditional Chinese medicine PaoTianXiong (PTX) is a processed product of Aconitum carmichaeli Debx. with polysaccharide as the main ingredient. The properties of PTX polysaccharide (PTXP) may be affected by different extraction methods. To develop and utilize PTXP better, it is of great significance to study the extraction methods of PTXP. Thus, we extracted PTXPs with dilute alkaline water extraction, ultrasound-assisted extraction, cellulase-assisted extraction, and hot water extraction (HWE), respectively. The characterizations of PTXPs extracted by different methods were analyzed based on purity determination, infrared analysis, molecular weight and monosaccharide composition. And antioxidant experiments of PTXPs were conducted. The results showed that PTXPs extracted by the four extraction methods were all glucan. After purification, the PTXPs showed similar antioxidant activity in vitro. The molecular weight of polysaccharides extracted by the cellulase-assisted method was different from that extracted by the other three methods. Our results showed that not only the yield but also the effect of extraction methods on the properties of PTXP should be considered when selecting the best extraction method. Therefore, HWE was considered to be the best extraction method of PTXP. The yield and purity of purified PTXP were 24.5% and 97.1%, respectively. The optimized extraction conditions were: an extraction temperature of 90 °C, extraction time of 2.17 h, solid-liquid ratio of 1 : 29 (g mL-1), and number of extractions of 2.

Structural characterization of novel arabinoxylan and galactoarabinan from citron with potential antitumor and immunostimulatory activities

This study aimed to extract polysaccharides from citron and analyze their structures and potential bioactivities. Two novel polysaccharides CM-1 and CM-2 were purified from citron by DEAE-Sepharose Fast Flow and Sephadex G-100 column chromatography. Monosaccharide composition, linkage and NMR data were used to infer their sugar chains composition. The anti-breast cancer cells and immunoregulatory activities of CM-1 and CM-2 were investigated. Results indicated that CM-1 (Mw = 21,520 Da), composed of arabinose, xylose, mannose and glucose in a molar ratio of 10.78:11.53:1.00:1.70, was arabinoxylan (AX) with (1 → 4)-linked β-d-Xylp skeleton monosubstituted with α-l-Araf units at O-3 position. While CM-2 (Mw = 22,303 Da), composed of arabinose, mannose, glucose and galactose in a molar ratio of 25.46:1.45:1.00:6.57, was galactoarabinan (GA) with (1 → 5)-linked α-l-Araf backbone substituted by β-d-Galp units at O-2 and/or O-3 positions. Both polysaccharides exhibited potential inhibiting cancer and immunostimulatory activities in vitro, especially CM-1. These results provide a basis for further research on citron polysaccharides.

Structural characterization, anticancer, hypoglycemia and immune activities of polysaccharides from Russula virescens

Russula virescens is an edible wild mushroom that is widely distributed in south of China. This research aimed to analyze the structure characterization and evaluate the hypoglycemic, anticancer and immunological activities of two water soluble polysaccharides RVP-1 and RVP-2 from R. virescens. The results showed RVP-1 and RVP-2 were non-triple helix structured hetero-polysaccharides with different weight-average molecular weight 14,883 and 13,301 Da, respectively. Both RVP-1 and RVP-2 were composed of galactose, glucose, mannose and fructose, and the sugar residues were mainly linked by 1,6→, 1,2→, 1→ and 1,3,6→ glycosidic bonds. Moreover, the antidiabetic, anticancer and immune activities of RVP-1 and RVP-2 were explored in vitro methods. The two polysaccharides have potential for inhibiting α-glucosidase and α-amylase activities, suppressing HepG-2, A549 and MCF-7 cancer cells proliferation, and activating macrophage RAW 264.7 cells to secret immune cytokines for mediating cellular immune response. These findings provided a scientific basis for further utilization of polysaccharide from R. virescens.

A Skin Lipidomics Study Reveals the Therapeutic Effects of Tanshinones in a Rat Model of Acne

Tanshinone (TAN), a class of bioactive components in traditional Chinese medicinal plant Salvia miltiorrhiza, has antibacterial and anti-inflammatory effects, can enhance blood circulation, remove blood stasis, and promote wound healing. For these reasons it has been developed as a drug to treat acne. The purpose of this study was to evaluate the therapeutic effects of TAN in rats with oleic acid-induced acne and to explore its possible mechanisms of action through the identification of potential lipid biomarkers. In this study, a rat model of acne was established by applying 0.5 ml of 80% oleic acid to rats' back skin. The potential metabolites and targets involved in the anti-acne effects of TAN were predicted using lipidomics. The results indicate that TAN has therapeutic efficacy for acne, as supported by the results of the histological analyses and biochemical index assays for interleukin (IL)-8, IL-6, IL-β and tumor necrosis factor alpha. The orthogonal projection of latent structure discriminant analysis score was used to analyze the lipidomic profiles between control and acne rats. Ninety-six potential biomarkers were identified in the skin samples of the acne rats. These biomarkers were mainly related to glycerophospholipid and sphingolipid metabolism, and the regulation of their dysfunction is thought to be a possible therapeutic mechanism of action of TAN on acne.

Structural differences of polysaccharides from Astragalus before and after honey processing and their effects on colitis mice

Honey-processed Astragalus is a dosage form of Radix Astragali processed with honey, which exhibits better efficacy of tonifying Qi than the raw product. Polysaccharides are its main water-soluble active components. This work was designed to study the structural differences of homogeneous honey-processed Astragalus polysaccharides (HAPS3a) and Astragalus polysaccharides (APS3a) and their effects on colitis mice. The results showed that HAPS3a (Mw = 2463.5 kDa) and APS3a (Mw = 3373.2 kDa) differed in molecular weight, monosaccharide compositions, glycosidic bonds and degree of branching (DB). Notably, the molar ratios of galactose and galacturonic acid in HAPS3a were 22.66% and 33.24%, while those in APS3a were 11.87% and 49.55%, respectively. The uronic acid residues 1,4-β-GalpA and 1,6-α-GlcpA of the backbone in APS3a were converted into the corresponding neutral residues in HAPS3a after honey processing. The different DB of HAPS3a (15.35%) and APS3a (25.13%) suggested that the chain conformation became smoother. The anti-inflammatory effects on colitis mice revealed that HAPS3a exhibited better effects than APS3a by protecting intestinal mucosa, regulating the expression of cytokines and influencing microbiota diversity. Taken together, the differences in anti-inflammatory activity might be related to structural differences caused by honey processing. Our findings have laid a foundation for the processing mechanism of Astragalus.

The use of medicinal plants to prevent COVID-19 in Nepal

BACKGROUND

Medicinal plants are the fundamental unit of traditional medicine system in Nepal. Nepalese people are rich in traditional medicine especially in folk medicine (ethnomedicine), and this system is gaining much attention after 1995. The use of medicinal plants has increased during the COVID-19 pandemic as a private behavior (not under the control of government). A lot of misinterpretations of the use of medicinal plants to treat or prevent COVID-19 have been spreading throughout Nepal which need to be managed proactively. In this context, a research was needed to document medicinal plants used, their priority of use in society, their cultivation status, and the source of information people follow to use them. This study aimed to document the present status of medicinal plant use and make important suggestion to the concerned authorities.

METHODS

This study used a web-based survey to collect primary data related to medicinal plants used during COVID-19. A total of 774 respondents took part in the survey. The study calculated the relative frequencies of citation (RFC) for the recorded medicinal plants. The relationship between plants recorded and different covariates (age, gender education, occupation, living place, and treatment methods) was assessed using Kruskal-Wallis test and Wilcoxon test. The relationship between the information sources people follow and the respondent characteristics was assessed using chi-square test.

RESULTS

The study found that the use of medicinal plants has increased during COVID-19 and most of the respondents recommended medicinal plants to prevent COVID-19. This study recorded a total of 60 plants belonging to 36 families. The leaves of the plants were the most frequently used. The Zingiber officinale was the most cited species with the frequency of citation 0.398. Most of the people (45.61%) were getting medicinal plants from their home garden. The medicinal plants recorded were significantly associated with the education level, location of home, primary treatment mode, gender, and age class. The information source of plants was significantly associated with the education, gender, method of treatment, occupation, living with family, and location of home during the lockdown caused by COVID-19.

CONCLUSIONS

People were using more medicinal plants during COVID-19 claiming that they can prevent or cure COVID-19. This should be taken seriously by concerned authorities. The authorities should test the validity of these medicinal plants and control the flow of false information spread through research and awareness programs.

Prebiotic Potential and Anti-Inflammatory Activity of Soluble Polysaccharides Obtained from Soybean Residue

In the present study, we assessed the extraction of low molecular weight soluble polysaccharides (MESP) from soybean by-products using microwave-assisted enzymatic technology and proposed the chemical structure of MESP using Fourier transform-infrared spectroscopy, gas chromatography, and ¹H and ¹³C nuclear magnetic resonance spectrum analysis. The results suggested that MESP mainly comprised arabinose, rhamnose, and glucuronic acid with (1→4) glycosidic linkages in the backbone. Compared with inulin, MESP was found to selectively stimulate the growth of Lactobacillus probiotics. Moreover, the results of in vitro fermentation indicated that MESP significantly increased the concentrations of both acetate and butyrate (p < 0.05). MESP were treated on lipopolysaccharide (LPS)-stimulated RAW264.7 cells to determine the anti-inflammatory effect in vitro. It was observed that MESP inhibited nitric oxide, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 production. Furthermore, Western blotting results indicated that MESP significantly attenuated LPS-induced downregulation of phosphorylation levels of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) in macrophages. The underlying mechanism might involve inhibition of the expression of pro-inflammatory cytokines, presumably via JAK2/STAT3 pathway. Collectively, the results of our study paved way for the production of MESP, which may be potentially used as nutraceutical ingredients for prebiotics and anti-inflammatory agents, from soybean residue.

Potential roles of dietary flavonoids from Citrus aurantium L. var. amara Engl. in atherosclerosis development

Dietary consumption of flavonoids correlated positively with lower risk of cardiovascular disease. However, the precise roles of flavonoids from the blossoms of Citrus aurantium Linn variant amara Engl (CAVA) in atherosclerosis (AS) are still poorly understood. This study aimed to find novel flavonoid-type skeletons with protection against AS. Total flavonoids (CAVAF), homoeriodictyol (HE) and hesperetin-7-O-β-d-glucopyranoside (HG) were isolated from the blossoms of Citrus aurantium Linn variant amara Engl. by chromatography. Their suppressive effects on lipopolysaccharide (LPS)-induced inflammatory responses and ox-LDL-induced foam cell formation were systematically and comparatively investigated using macrophage RAW264.7 cells. HE was more powerful than HG in inhibiting LPS-induced production of nitric oxide (NO), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β) and gene expression in RAW264.7 cells. HE and HG showed different responses to extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinases (JNK), P38, P65, IκBα, IκKα/β phosphorylation, and nuclear factor-kappa B (NF-κB) nuclear translocation. HE and HG also differentially decreased oxidized low-density lipoprotein (ox-LDL)-induced foam cell formation by regulating peroxisome proliferator-activated receptor-gamma (PPARγ), phospholipid ATP-binding cassette transporter A1 (ABCA1), phospholipid ATP-binding cassette transporter G1 (ABCG1), scavenger receptor class B type I (SRB1), scavenger receptor class A type I (SRA1) and cluster of differentiation 36 (CD36) expression at gene and protein levels in RAW264.7 cells. HG showed weaker potential than HE in preventing AS development. Their chemical differences might partially explain the discrepancy in their bioactivity. In conclusion, HE and HG might be developed into novel therapeutic agents against inflammation and AS-associated diseases.

Characterization of the antioxidative polysaccharides from Ziziphus jujube cv. Goutouzao and its tumor-inhibitory effects on human colorectal carcinoma LoVo cells via immunocyte activation

Colorectal cancer, the most common malignancy in Asian and west world, is listed as the fourth lethal neoplastic disease with increasing incidence worldwide. Recently, Ziziphus jujube were reported with hepatoprotective, antihypertensive, and hypoglycemic functions. The polysaccharides from Ziziphus jujube was considered as the main component for these bioactivities. In this study, polysaccharides from Ziziphus jujube cv. Goutouzao (GZSP) was comprehensively investigated, and characterized as a heteropolysaccharide with antioxidant activity. Besides, it can stimulate the viability of immune cells RAW 264.7, which in turn inhibited the proliferation of colorectal carcinoma cells (LoVo) by inducing apoptosis, arresting cell cycle in G0/G1, and increasing intracellular ROS, as demonstrated by Flow Cytometric analyses. The results suggest that, different from chemotherapeutic modalities, GZSP can exert antitumor effects by activating immune reaction, providing more evidence for the development of GZSP-based functional foods and anticancer drugs serving as human colon cancer prevention. PRACTICAL APPLICATIONS: Natural products from medicinal and edible plant are great sources of phytochemicals beneficial to human health, such as tea polyphenols, carotenoids, and phytosterols, etc. In this study, GZSP, the polysaccharides from a well-received fruit, Ziziphus jujube cv. Goutouzao, has been comprehensively investigated. The results show that GZSP fights against free radicals commonly found in human circulation, a property that enables it to be used as an antioxidant food additive with jujube flavor. More importantly, GZSP impedes neoplastic progression by activating immune response, as evidenced by the inhibition of colorectal carcinoma (LoVo) cells. Comparing with chemotherapies usually imposing cytotoxicity on normal tissues, natural product GZSP is able to exert the antiproliferative effects on carcinoma cells with minimal side-effects. Therefore, GZSP-based functional foods and anticancer drugs with the purpose of preventing human colon cancer formation are promising to be developed.