Structural characterization, chain conformation and immunomodulatory activity of a heteropolysaccharide from Inonotus hispidus.

A new polysaccharide (IHP-1aa) was isolated from the fruiting body of Inonotus hispidus by hot water extraction, ethanol precipitation and column chromatography. The molecular weight of IHP-1aa was 26.9 kDa. Structural analysis showed that IHP-1aa consisted of glucose (Glc), galactose (Gal), fucose (Fuc), mannose (Man) and contained a certain amount of 3-O-methylgalactose (3-O-Me-Gal). The structure was mainly composed of →6)-α/ß-D-Glcp-(1→, →6)-α-D-Galp-(1→, →6)-(3-O-Me)-α-D-Galp-(1→, →6)-α-D-Manp-(1 â†’ and →2, 6)-α-D-Galp-(1 â†’ as the main chain. Branched at O-2 with single ß-L-Fucp-(1 â†’ 6)-α-D-Galp-(1 â†’ 6)-α-D-Glcp-(1 â†’ as major the side chain. The results of SEM, XRD and AFM combined with Congo red indicated that IHP-1aa may be amorphous granular chain conformation. In addition, IHP-1aa stimulated macrophage function and improved phagocytic ability of RAW264.7, as well as promoted the secretion of NO, TNF-α and IL-6. IHP-1aa, a 3-O-methylgalactose-containing heteropolysaccharide, was isolated for the first time from the I. hispidus, which may be used as a potential immunomodulator in functional foods.

The potential of dietary fiber in building immunity against gastrointestinal and respiratory disorders.

The numerous health benefits of dietary fibers (DFs) justify their inclusion in human diets and biomedical products. Given the short- and long-term human impacts of the COVID-19 virus on human health, the potential of DFs in building immunity against gastrointestinal and respiratory disorders is currently receiving high attention. This paper reviews the physicochemical properties of DFs, together with their immune functions and effects on the gastrointestinal tract and respiratory system mainly based on research in the last ten years. Possible modes of action of DFs in promoting health, especially building immunity, are explored. We seek to highlight the importance of understanding the exact physical and chemical characteristics and molecular behaviors of DFs in providing specific immune function. This review provides a perspective beyond the existing recognition of DFs' positive effects on human health, and offers a theoretical framework for the development of special DFs components and their application in functional foods and other therapeutic products against gastrointestinal and respiratory disorders. DFs enhance immunity from gastrointestinal and respiratory diseases to promote host health.

Rapid identification of α-glucosidase inhibitors from Poria using spectrum-effect, component knock-out, and molecular docking technique.

Instruction: Poria (Poria cocos) is known for its health-promoting effects and is consumed as a food due to its potential hypoglycemic activity. However, the composition of Poria is complex, and the bioactive compounds that inhibit α-glucosidase are not clear. Methods: In this study, the fingerprint of the Poria methanol extract characterized by high-performance liquid chromatography (HPLC) and the model of the corresponding spectrum-effect relationship for α-glucosidase was first established to screen the active compounds from Poria. Then, the predicted bioactive compounds were knocked out and identified using mass spectrometry. Finally, the potential binding sites and main bonds of each compound with α-glucosidase were studied using molecular docking. Results: The results have shown that at least 11 compounds from Poria could inhibit α-glucosidase effectively. Moreover, eight individual compounds, i.e., poricoic acid B (P8), dehydrotumulosic acid (P9), poricoic acid A (P10), polyporenic acid C (P12), 3- epidehydrotumulosic acid (P13), dehydropachymic acid (P14), 3-O-acetyl-16α-hydroxytrametenolic acid (P21), and pachymic acid (P22), were identified, and they exhibited effective inhibitory activity against α-glucosidase. Discussion: The possible inhibitory mechanism of them based on molecular docking showed that the binding sites are mainly found in the rings A, B, and C of these compounds, and C-3 C-16 and side chains of C-17, with the phenylalanine, arginine, tyrosine, histidine, and valine of α-glucosidase. The main interactions among them might be alkyl and hydrogen bonds, which theoretically verified the inhibitory activity of these compounds on α-glucosidase. The achievements of this study provided useful references for discovering bioactive compounds with hypoglycemic effects from Poria.

Inhibitory effect of quercetin-3-O-α-rhamnoside, p-coumaric acid, phloridzin and 4-O-ß-glucopyranosyl-cis-coumaric acid on rats liver microsomes cytochrome P450 enzyme activities.

P-coumaric acid, phloridzin, quercetin-3-O-α-rhamnoside and 4-O-ß-glucopyranosyl-cis-coumaric acid isolated in Malus micromalus Makino fruit were investigated the inhibitory activity of cytochrome CYP450 enzyme by the probe test method of rat liver microsomes in vitro, and determined the role in drug metabolism and/or toxicology. Enzymatic kinetics method was used to determine the inhibition type of these components and corresponding inhibition constants. The results demonstrated that all the 4 compounds had no significance to inhibit the activities of CYP2E1 and CYP2C11. P-coumaric acid, phloridzin and quercetin-3-O-α-rhamnoside had a weak inhibitory effect on CYP3A4, which belonged to the competitive inhibitory type with inhibitory constants of 10.56, 30.79 and 40.29 µmol L-1, respectively. 4-O-ß-glucopyranosyl-cis-coumaric acid had a moderate inhibitory effect on CYP3A4, which belonged to the anti-competitive inhibition type and the inhibition constant was 5.56 µmol L-1. The CYP1A2 could be weakly inhibited by p-coumaric acid in the competitive type, and the inhibition constant is 25.20 µmol L-1 4-O-ß-glucopyranosyl-cis-coumaric acid exhibited anti-competitive inhibition of CYP1A2 with an inhibition constant of 19.91 µmol L-1, and the inhibition effect was weak. The results will be useful to optimize the clinical dosage regimen and avoid drug-drug interactions when it is utilized comminating with other medicines in the clinic.

A glucomannogalactan from Pleurotus geesteranus: Structural characterization, chain conformation and immunological effect.

A water-soluble glucomannogalactan was isolated from P. geesteranus fruit bodies by hot water extraction and column chromatography method. The structure, chain conformation and immune effect of PGP-1c (20.9 kDa) were investigated comprehensively based on high purity and neutral sugar content (94.7 ± 0.5%). Confirmed by monosaccharide composition, methylation and NMR analysis, PGP-1c was composed of unsubstituted (1,6-α-Gal and 1,6-α-3-OMe-Gal) and monosubstituted (1,2,6-α-Gal and 1,2,6-α-3-OMe-Gal) galactose units in the backbone through α-(1 â†’ 6) glycosidic bonds and the possible branches that a long-branched chain composed of →3)-Glc-(1 â†’ Man and a few fucoses were connected at the O-2 of galactose with a branching degree of 48%. Through the conformational behavior of the molecular chain, it was observed that PGP-1c might have a long-branched or stacked macromolecular network caused by O-CH3 groups. Moreover, PGP-1c could promote the secretion of NO and cytokines significantly in a dose-dependent manner, which indicated a good immune-enhancing effect.

The Effect of Flammulina velutipes Polysaccharide on Immunization Analyzed by Intestinal Flora and Proteomics.

Proteomics and intestinal flora were used to determine the mechanism of immune modulatory effects of Flammulina velutipes polysaccharide on immunosuppressed mice. The results showed that compared with the model group, F. velutipes polysaccharide could increase thymus and spleen indices and improve thymus tissue structure in mice; IL-2 and IL-4 contents were significantly increased and IL-6 and TNF-α contents were significantly decreased; serum acid phosphatase (ACP), lactate dehydrogenase (LDH) and total antioxidant capacity (T-AOC) activities were increased (P < 0.05); in the liver, superoxide dismutase (SOD) and catalase (CAT) activities were increased (P < 0.001), while malondialdehyde (MDA) content was decreased (P < 0.001). Proteomics discovered that F. velutipes polysaccharides may exert immune modulatory effects by participating in signaling pathways such as immune diseases, transport and catabolism, phagosomes and influenza A, regulating the immune-related proteins Transferrin receptor protein 1 (TFRC) and Radical S-adenosyl methionine domain-containing protein 2 (RSAD2), etc. Gut microbial studies showed that F. velutipes polysaccharides could increase the abundance of intestinal flora and improve the flora structure. Compared to the model group, the content of short-chain fatty acids (SCFAs) and the relative abundance of SCFA-producers Bacteroides and Alloprevotella were increased in the F. velutipes polysaccharide administration group, while Lachnospiraceae_NK4A136_group and f_Lachnospiraceae_Unclassified decreased in relative abundance. Thus, F. velutipes polysaccharide may play an immunomodulatory role by regulating the intestinal environment and improving the balance of flora.

Nigella sativa: A Dietary Supplement as an Immune-Modulator on the Basis of Bioactive Components.

Nutrients can be considered as functional foods, which exert physiological benefits on immune system. The seeds of Nigella sativa, which have many active constituents, are mainly used for medicine, food spice, and nutritional supplements in Egypt. Much attention has been paid to N. sativa seeds for their anticancer, antibacterial, anti-inflammatory, and immune properties. However, their active constituents and mechanisms underlying functions from N. sativa seeds is unclear. Thus, the bioactive constituents with immune regulation in N. sativa seeds were systematically studied. A new compound (3-methoxythymol-6-O-ß-D-apiofuranosyl-(1→6)-ß-D-glucopyranoside 1) and 11 known compounds (2-12) were separated from the N. sativa seeds by chromatographic methods. Their structures were then elucidated by spectroscopic analysis of MS, UV, IR, 1H-, and 13C-NMR. Furthermore, immunomodulatory effects of those compounds in RAW 264.7 cells were evaluated by phagocytosis, nitric oxide (NO) and cytokine release, related mRNA transcription, and key proteins expression in vitro. Monosaccharide derivatives, Ethyl-α-D-furaarabinose (5), and Ethyl-ß-D-fructofuranoside (8) were shown to played bidirectional regulatory roles in immunity and anti-inflammation through the regulation of nuclear factor-κB (NF-κB) signaling pathways. The results showed the active compounds and mechanisms of immune regulation in N. sativa, thus indicating that N. sativa seeds could be used as dietary supplements in immunomodulation.

Activation of RAW264.7 cells by PCp-I, a polysaccharide from Psoralea corylifolia L, through NF-κB/MAPK signalling pathway.

PCp-I is a polysaccharide isolated and identified from the Psoralea corylifolia L. by our research group. In this study, the immunomodulatory effects of PCp-I on RAW264.7 cells was evaluated. PCp-I could enhance the level of NO along with up-regulation of iNOS mRNA in RAW264.7 cells. The PCp-I could significantly up-regulate the mRNA expression of TNF-α and IL-6 in RAW264.7 cells, and then the expression of TNF-α, IL-6, ROS and the phagocytic activity were increased. Additionally, PCp-I could significantly up-regulate the phosphorylation level of p65, p38, ERK and JNK proteins, which proved that PCp-I could activate the macrophages by MAPKs and NF-κB signalling pathway and the TLR4 may be one of the receptors of PCp-I regulate the RAW264.7 cells.

A rapid method and mechanism to identify the active compounds in Malus micromalus Makino fruit with spectrum-effect relationship, components knock-out and molecular docking technology.

Fingerprints of 20 batches of Malus micromalus Makino fruit were established by HPLC coupled with hierarchical cluster analysis (HCA) and principal component analysis (PCA) to estimate the common peaks on the basis of traditional similarity evaluation methods. Chromatographic peaks were identified as p-coumaric acid (P2), ferulic acid glycoside (P6), 4-O-ß-Glucopyranosyl-cis-coumaric acid (P8), phloretin-2'-xyloglucoside (P10), phloridzin (P11) and quercetin-3-O-α-rhamnoside (P12) by UPLC-MS/MS method. The results of tyrosinase kinetics experiments showed that: P2 and the concentration of P11 was greater than 0.50 mmol/L mainly had a competitive inhibitory effect on tyrosinase, and the concentration of phlorizin was less than at 0.25 mmol/L, it has a mixed inhibitory effect. P8 was mainly a non-competitive activation type in the concentration range, while P12 was a mixed activation type. The results of tyrosinase molecular docking showed that: P2, P8, P11, P12 was located in the active center of the hydrophobic pocket of the enzyme. They bound to tyrosinase residues by hydrogen bonds and interacted with many hydrophobic residues around them to maintain the structure of the complex. This research provides a rapid method to determine the active compounds in edible plants with the technology of spectrum-effect relationship, component knock-out and molecular docking.

Metabolites with Anti-Inflammatory Activity from the Mangrove Endophytic Fungus Diaporthe sp. QYM12.

One new diterpenoid, diaporpenoid A (1), two new sesquiterpenoids, diaporpenoids B-C (2,3) and three new α-pyrone derivatives, diaporpyrones A-C (4-6) were isolated from an MeOH extract obtained from cultures of the mangrove endophytic fungus Diaporthe sp. QYM12. Their structures were elucidated by extensive analysis of spectroscopic data. The absolute configurations were determined by electronic circular dichroism (ECD) calculations and a comparison of the specific rotation. Compound 1 had an unusual 5/10/5-fused tricyclic ring system. Compounds 1 and 4 showed potent anti-inflammatory activities by inhibiting the production of nitric oxide (NO) in lipopolysaccharide (LPS)-induced RAW264.7 cells with IC50 values of 21.5 and 12.5 µM, respectively.

Effects of edpetiline from Fritillaria on inflammation and oxidative stress induced by LPS stimulation in RAW264.7 macrophages.

The dry bulbs of Fritillaria cirrhosa species can help resolve phlegm, soothe cough, clear heat, and moisten the lung, and the main active components responsible for these effect are its alkaloids. However, it is unclear whether or how edpetiline in Fritillaria can inhibit the excessive inflammatory response and oxidative stress. In this research, we aimed to examine this aspect using lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages as an inflammatory model. The quantitative real-time polymerase chain reaction and western blot analysis results showed that edpetiline significantly inhibited the content and mRNA expression levels of proinflammatory cytokines (TNF-α and IL-6) in LPS-induced RAW264.7 cells, significantly increased the mRNA expression of IL-4 (anti-inflammatory cytokine), and markedly downregulated the inflammatory mediators inductible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA and protein expression levels. The oxidative stress induced by LPS was also inhibited by edpetiline, as the level of intracellular reactive oxygen species decreased notably. Edpetiline may exert anti-inflammatory and antioxidant effects through inhibiting the phosphorylation of IκB and the nuclear transcription of nuclear transcription factor-κB p65 and decreasing the phosphorylation of p38 and ERK in the mitogen-activated protein kinase signaling pathway, without activating the JNK/mitogen-activated protein kinase signaling pathway. These findings suggest that edpetiline may be a potential therapeutic agent for the prevention or treatment of inflammation- and oxidative stress-related pathophysiological processes and diseases.

Two Alkaloids From Delphinium brunonianum Royle, Their Anti-inflammatory and Anti-oxidative Stress Activity via NF-κB Signaling Pathway.

In this study, we isolated and identified four compounds in Delphinium brunonianum Royle, and they were Delbrunine (1), 4-O-α-D-Glucosyl benzoic acid (2), Kaempferol 3-O-ß-D-glucopyranoside 7-O-α-L-rhamnopyranoside (3) and Eldeline (4). Furthermore, the anti-inflammatory activity of these compounds was screened in RAW264.7 cells. The results showed that the anti-inflammatory activities of compounds 2 and 3 were weak, and 1, 4 had good anti-inflammatory activity. The macrophage inflammation model was established by lipopolysaccharide (LPS). Then, the anti-inflammatory activity was evaluated by ELISA kits, qRT-PCR experiment and western blot experiment. And the anti-oxidative stress activity was assessed by flow cytometry. The results showed that compounds 1, 4 could significantly inhibit the elevation of inflammatory factors nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and also had obvious inhibitory effects on the production of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2). In addition, compounds 1 and 4 could effectively inhibit the overexpression of reactive oxygen species (ROS) in RAW264.7 cells that activated by LPS. These results indicated that compounds 1 and 4 may exert anti-inflammatory and anti-oxidative stress effects through the NF-κB signaling pathway.

Anti-inflammatory and antioxidant effects of Chaetoglobosin Vb in LPS-induced RAW264.7 cells: Achieved via the MAPK and NF-κB signaling pathways.

There are few reports on the biological activities of chaetoglobosin Vb (Cha Vb) (a cytochalasin alkaloid). In this study, we investigated the molecular mechanisms underlying the anti-inflammatory and antioxidant effects of Cha Vb in the RAW264.7 cells stimulated lipopolysaccharide (LPS). LPS stimulation-induced oxidative stress (i.e. increase production of reactive oxygen species (ROS) and decreased expression of antioxidant superoxide dismutase (SOD)) was suppressed after a Cha Vb treatment. Cha Vb could significantly inhibit the upregulated expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene and protein induced by LPS whilst attenuating the production of pro-inflammatory cytokines TNF-α, IL-6 and IL-1ß. Such antioxidant and anti-inflammatory effects were achieved through the TLR4-mediated MyD88-dependent signaling pathways (via suppressing the phosphorylation of p38, ERK, JNK MAPK and translocation of the NF-κB p65 subunit into nucleus), and the TRIF-dependent signaling pathways (via reducing IFN-ß release without inhibiting interferon-regulated factor 3 (IRF3) and IRF7). At 25-100 µM (a concentration range with no cytotoxicity), Cha Vb dose-dependently influenced SOD enzyme activity and phosphorylation of p38, ERK1/2 and JNK, and at 100 µM, likely exerted the greatest inhibition towards LPS-induced oxidative stress and inflammatory response via the MAPK and NF-κB signaling pathway.

Natural Products: Review for Their Effects of Anti-HBV.

Hepatitis B is a global infectious disease, seriously endangering human health. Currently, there are mainly interferons and nucleoside analogues treatment of hepatitis B in the clinic, which have certain therapeutic effects on hepatitis B, but their side effects and drug resistance are increasingly prominent. Therefore, it is urgently needed to discover and develop new anti-HBV drugs, especially natural products, which have novel, high efficiency, and low toxicity anti-HBV compounds with novel antiviral mechanisms. In this manuscript, the natural products (polysaccharides and 165 compounds) with the activity of antihepatitis B virus are discussed according to their chemical classes, including 14 phenylpropanoids, 8 flavonoids,12 xanthones, 13 anthroquinones, 47 terpenoids, 6 alkaloids, 15 enediynes, 11 aromatics, 18 phenylalanine dipeptides compounds, and 13 others. In addition, the anti-HBV mechanism and targets of natural product were also discussed. The aim of this review is to report new discoveries about anti-HBV natural products and to provide reference for researchers.

Effect of Durio zibethinus rind polysaccharide on functional constipation and intestinal microbiota in rats.

The prevalence of constipation increases rapidly with the increased pressure of some people's life, which seriously affects the quality of life in related patients. In this study, the improvement of functional constipation by Durio zibethinus Murr rind polysaccharide (DZMP) and the effects of DZMP on intestinal microbiota were investigated in a constipation model of Sprague-Dawley (SD) rats established by loperamide hydrochloride. Results showed that DZMP at 200 mg/kg could significantly (P < 0.05) increase the intestinal transit rate, motilin, gastrin, substance P levels and concentration of short-chain fatty acids (SCFAs), reduce the somatostatin levels and improve the gastrointestinal peristalsis of rats. Sequencing showed that the Lachnospiraceae-NK4A136-group in the rats given 200 mg/kg DZMP (16.07%) was significantly higher than that of the model group (10.13%), while the Desulfovibrio was lower (2.99%) than that of the model group (4.19%). Principal co-ordinates analysis (PcoA) revealed a significant difference in intestinal microbiota composition between the model group and the high-dose DZMP group (200 mg/kg). The results demonstrated that DZMP has a regulatory effect of treating functional constipation and regulating intestinal flora in rats.

Recent Progress on Chemical Constituents and Pharmacological Effects of the Genus Nigella.

Seeds of the genus Nigella plants as folk medicine are often used to prevent and treat asthma, diarrhea, dyslipidemia, and other diseases around the world. Pharmacological researches showed that seed extract and seed oil have antibacterial, antioxidant, hypoglycemic, and hepatoprotective effects which attributed to their bioactive constituents such as alkaloids, saponins, flavones, and phenols. This paper has covered recent progresses on chemical and pharmacological researches on these plants, including their compounds and pharmacological effects. It was found that the chemical component researches were focused on the seed oil. Therefore, more attention should be paid to the profile of the whole constituents in the seeds.

Effects of Nigella sativa seed polysaccharides on type 2 diabetic mice and gut microbiota.

Effect of Nigella sativa seed polysaccharides (NSSP) on type 2 diabetic mice and its gut microbiota was investigated on the type 2 diabetic mice model feed by high-fat diet. Fasting blood glucose (FBG), biochemical parameters, expression levels of cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß), and phosphor-AKT (p-AKT) protein, membrane glucose transporter 4 (GLUT4) in skeletal muscles, as well as the change of gut microbiota profile in mice model were measured. Results showed that the high-dose NSSP could significantly lower the levels of FBG, glycosylated serum protein (GSP), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), malondialdehyde (MDA), TNF-α, IL-6 and IL-1ß, and significantly increased insulin (INS), high-density lipoprotein cholesterol (HDLC), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT) and the expression levels of p-AKT and GLUT4 in mice. Besides, the high-dose NSSP has significantly increased the abundance of f_Muribaculaceae_Unclassified and Bacteroides, which were significantly suppressed in the mice gut after the treatment of streptozotocin (STZ). These results indicated that NSSP could improve the abnormal state of diabetic mice by regulating the PI3K/AKT signaling pathway with simultaneous changes of the gut microbiota profile.

Effects of Polysaccharide from Malus halliana Koehne Flowers in Cyclophosphamide-Induced Immunosuppression and Oxidative Stress on Mice.

The immunomodulatory effects of Malus halliana flower polysaccharide (MHFP) were investigated in this paper. The model of immunosuppressive mice was established by cyclophosphamide, which was treated with different dosages of MHFP (600, 400, and 200 mg/kg·d-1). The results showed that MHFP significantly increased the index of the spleen and thymus and improved the atrophy of immune organs. MHFP enhanced the ability of carbon clearance and phagocytosis of mononuclear phagocytes in mice. Meanwhile, MHFP promoted the proliferation of splenic lymphocytes. MHFP could enhance the content of serum hemolysin and improve the decrease of hemolysin induced by cyclophosphamide. The contents of ACP and LDH in the serum and spleen were determined, indicating that MHFP could enhance the activity of macrophages. MHFP promoted the content of cytokines (IL-2, IL-6, TNF-α, and IFN-γ) and mRNA expression. At the same time, the pathological changes of the spleen tissue also showed that MHFP could improve the immunosuppression induced by cyclophosphamide. In addition, MHFP increased the content of SOD, T-AOC, and CAT in the serum and spleen tissue, decreased the level of MDA, and improved the oxidative stress caused by cyclophosphamide. In conclusion, MHFP could effectively improve the immunosuppression and oxidative stress induced by cyclophosphamide and enhance the immune capacity of mice.

Ionic Liquid-Based Ultrasonic-Assisted Extraction Coupled with HPLC and Artificial Neural Network Analysis for Ganoderma lucidum.

Ganoderma lucidum is widely used in traditional Chinese medicine (TCM). Ganoderic acid A and D are the main bioactive components with anticancer effects in G. lucidum. To obtain the maximum content of two compounds from G. lucidum, a novel extraction method, an ionic liquid-based ultrasonic-assisted method (ILUAE) was established. Ionic liquids (ILs) of different types and parameters, including the concentration of ILs, ultrasonic power, ultrasonic time, rotational speed, solid-liquid ratio, were optimized by the orthogonal experiment and variance analysis. Under these optimal conditions, the total extraction yield of the two compounds in G. lucidum was 3.31 mg/g, which is 36.21% higher than that of the traditional solvent extraction method. Subsequently, an artificial neural network (ANN) was developed to model the performance of the total extraction yield. The Levenberg-Marquardt back propagation algorithm with the sigmoid transfer function (logsig) at the hidden layer and a linear transfer function (purelin) at the output layer were used. Results showed that single hidden layer with 9 neurons presented the best values for the mean squared error (MSE) and the correlation coefficient (R), with respectively corresponding values of 0.09622 and 0.93332.