Effects of Lycium barbarum extract on production and immunomodulatory activity of the extracellular polysaccharopeptides from submerged fermentation culture of Coriolus versicolor

Structure-activity relationships of bioactive polysaccharides extracted from macroalgae towards biomedical application: A review

Macroalgae are valuable and structurally diverse sources of bioactive compounds among marine resources. The cell walls of macroalgae are rich in polysaccharides which exhibit a wide range of biological activities, such as anticoagulant, antioxidant, antiviral, anti-inflammatory, immunomodulatory, and antitumor activities. Macroalgae polysaccharides (MPs) have been recognized as one of the most promising candidates in the biomedical field. However, the structure-activity relationships of bioactive polysaccharides extracted from macroalgae are complex and influenced by various factors. A clear understanding of these relationships is indeed critical in developing effective biomedical applications with MPs. In line with these challenges and knowledge gaps, this paper summarized the structural characteristics of marine MPs from different sources and relevant functional and bioactive properties and particularly highlighted those essential effects of the structure-bioactivity relationships presented in biomedical applications. This review not only focused on elucidating a particular action mechanism of MPs, but also intended to identify a novel or potential application of these valued compounds in the biomedical field in terms of their structural characteristics. In the last, the challenges and prospects of MPs in structure-bioactivity elucidation were further discussed and predicted, where they were emphasized on exploring modern biotechnology approaches potentially applied to expand their promising biomedical applications.

Integrated Metabolome and Transcriptome during Fruit Development Reveal Metabolic Differences and Molecular Basis between Lycium barbarum and Lycium ruthenicum

Wolfberry (Lycium barbarum) is a traditional cash crop in China and is well-known worldwide for its outstanding nutritional and medicinal value. Lycium ruthenicum is a close relative of Lycium barbarum but differs significantly in size, color, flavor and nutritional composition. To date, the metabolic differences between the fruits of the two wolfberry varieties and the genetic basis behind them are unclear. Here, we compared metabolome and transcriptome data of two kinds of wolfberry fruits at five stages of development. Metabolome results show that amino acids, vitamins and flavonoids had the same accumulation pattern in various developmental stages of fruit but that Lycium ruthenicum accumulated more metabolites than Lycium barbarum during the same developmental stage, including L-glutamate, L-proline, L-serine, abscisic acid (ABA), sucrose, thiamine, naringenin and quercetin. Based on the metabolite and gene networks, many key genes that may be involved in the flavonoid synthesis pathway in wolfberry were identified, including PAL, C4H, 4CL, CHS, CHI, F3H, F3'H and FLS. The expression of these genes was significantly higher in Lycium ruthenicum than in Lycium barbarum, indicating that the difference in the expression of these genes was the main reason for the variation in flavonoid accumulation between Lycium barbarum and Lycium ruthenicum. Taken together, our results reveal the genetic basis of the difference in metabolomics between Lycium barbarum and Lycium ruthenicum and provide new insights into the flavonoid synthesis of wolfberry.

Lycium barbarum polysaccharide alleviates dextran sodium sulfate-induced inflammatory bowel disease by regulating M1/M2 macrophage polarization via the STAT1 and STAT6 pathways

Disruption of colonic homeostasis caused by aberrant M1/M2 macrophage polarization contributes to the development of inflammatory bowel disease (IBD). Lycium barbarum polysaccharide (LBP) is the primary active constituent of traditional Chinese herbal Lycium barbarum L., which has been widely demonstrated to have important functions in regulating immune activity and anti-inflammatory. Thus, LBP may protect against IBD. To test this hypothesis, the DSS-induced colitis model was established in mice, then the mice were treated with LBP. The results indicated that LBP attenuated the weight loss, colon shortening, disease activity index (DAI), and histopathological scores of colon tissues in colitis mice, suggesting that LBP could protect against IBD. Besides, LBP decreased the number of M1 macrophages and the protein level of Nitric oxide synthase 2(NOS2) as a marker of M1 macrophages and enhanced the number of M2 macrophages and the protein level of Arginase 1(Arg-1) as a marker of M2 macrophages in colon tissues from mice with colitis, suggesting that LBP may protect against IBD by regulating macrophage polarization. Next, the mechanistic studies in RAW264.7 cells showed that LBP inhibited M1-like phenotype by inhibiting the phosphorylation of STAT1, and promoted M2-like phenotype by promoting the phosphorylation of STAT6. Finally, immunofluorescence double-staining results of colon tissues showed that LBP regulated STAT1 and STAT6 pathways in vivo. The results in the study demonstrated that LBP could protect against IBD by regulating macrophage polarization through the STAT1 and STAT6 pathways.

The potential roles of natural plant polysaccharides in inflammatory bowel disease: A review

Inflammatory bowel disease (IBD) is a long-term chronic disease, about 20% of IBD patients deteriorate to colorectal cancer. Currently, there is no radical cure for IBD. Natural plant polysaccharides (NPP) have low toxic and side effects, which have immune and prebiotic activities and possesses positive effect on alleviating IBD. In this review, we will focus on the alleviating effect of NPP on IBD in vitro and in vivo from three aspects: regulating intestinal flora imbalance, repairing intestinal barrier injury and improving immunity. The relationship between the chemical structure of natural plant polysaccharides and the therapeutic effect of IBD are highlighted. Finally, the synergistic role of NPP as a carrier of drugs or active molecules to reduce side effects and enhance targeting function are discussed, especially pectic polysaccharides. Broadly, this review provides a valuable reference for NPP to be developed as functional food or health products to alleviate IBD.

Fermentation characteristics of novel Coriolus versicolor and Lentinus edodes kombucha beverages and immunomodulatory potential of their polysaccharide extracts

Medicinal mushrooms, Coriolus versicolor and Lentinus edodes are extremely attractive as nutraceuticals. Here we used fruiting bodies to prepare novel kombucha beverage. Microbiological, physicochemical and chemical properties were monitored for eleven days, while the immunological properties of kombucha polysaccharide extracts were determined in peripheral blood mononuclear cell (PBMC) cultures. FTIR analysis of polysaccharide extracts showed dominant presence of polysaccharides, in addition to phenols, lipids and proteins. C. versicolor kombucha extract displayed more complex polysaccharides, and a higher content of total polysaccharides, phenols and flavonoids compared to L. edodes kombucha extract. The extracts were not cytotoxic for PBMC in vitro up to 500 µg/ml, while immunomodulatory effects depended on their chemical compositions. The most prominent effect was on the reduction of Th2 cytokines and IL-10 in PBMC cultures. Based on these results, novel kombucha products could be recommended as functional beverages or nutraceuticals with potentially beneficial immunomodulatory effects in allergies.

Extraction, Structural Characterization, and Biological Functions of Lycium Barbarum Polysaccharides: A Review

Lycium barbarum polysaccharides (LBPs), as bioactive compounds extracted from L. barbarum L. fruit, have been widely explored for their potential health properties. The extraction and structural characterization methods of LBPs were reviewed to accurately understand the extraction method and structural and biological functions of LBPs. An overview of the biological functions of LBPs, such as antioxidant function, antitumor activity, neuroprotective effects, immune regulating function, and other functions, were summarized. This review provides an overview of LBPs and a theoretical basis for further studying and extending the applications of LBPs in the fields of medicine and food.

Chemical structure and biological properties of a polysaccharide isolated from Pleurotus sajor-caju

Herein, a polysaccharide obtained from Pleurotus sajor-caju was fractionated via anion-exchange column chromatography and purified using gel permeation column chromatography.

Comparative phenotype and microRNAome in developing anthers of wild-type and male-sterile Lycium barbarum L

Lycium barbarum L. (L. barbarum) is an economically important plant, as its fruit is highly marketable for its healthy nutrient content. In this study, we characterized the anther development of a major cultivar (Ningqi No. 1) and a male-sterile mutant (Ningqi No. 5) of L. barbarum. We initially investigated the phenotypes of Ningqi No. 1 and Ningqi No. 5 using microscopy and chemical staining, which showed that Ningqi No. 5 failed in the degradation of anther callose, leading to an absence of mature pollen grains and thus to male sterility. Then, to understand the dynamic profile of miRNA expression during the development of the anthers, we collected anther samples from both Ningqi No. 1 and Ningqi No. 5 throughout anther development, and we further identified 137 novel miRNAs from these anther samples by using next-generation deep sequencing technology. Of these 137 novel miRNAs, 96 miRNAs were conserved miRNAs classified into 65 miRNA families, including a few well-known miRNA families related to anther development, such as miR156, miR159 and miR172. In addition, the remaining 41 miRNAs were considered lineage-specific miRNAs, which had no orthologues in other species. The expression data showed that 45 of the 137 miRNAs were differentially expressed in the different samples, including 4 Ningqi No. 5-specific miRNAs and 15 stage-specific miRNAs. The expression patterns of six miRNAs and their predicted targets were verified by Q-PCR, and one of miRNAs and its target were chosen for transient co-expression in Nicotiana benthamiana leaves to verify the correlations between the miRNA and its predicted target. Overall, the identification of the miRNAs in the anther development of Ningqi No. 1 and Ningqi No. 5 provides a valuable resource for understanding the molecular mechanisms of male sterility in L. barbarum.

Potential activities and mechanisms of extracellular polysaccharopeptides from fermented Trametes versicolor on regulating glucose homeostasis in insulin-resistant HepG2 cells

Polysaccharides derived from mushrooms have potential to control blood sugar, reduce insulin resistance and prevent diabetic complications. The intracellular polysaccharopeptides of Trametes versicolor (TV) have been used as immunologic and oncologic adjuvants. The aim of this study was to investigate the potential activities and mechanisms of extracellular polysaccharopeptides (ePSP) obtained from TV strain LH-1 on regulating glucose homeostasis. Human hepatoma HepG2 cells incubated with normal glucose (5.5 mM, NG model), high glucose (33 mM, HG model), or high glucose (33 mM) plus high insulin (10⁻⁷ M, HGI model) concentrations were administered with TV LH-1 ePSP (50, 100, and 1000 μg/ml) for 24 hr. Glucose uptake of HepG2 cells, determined by flow cytometry, was significantly decreased in the HG and HGI models with insulin stimulation, suggesting insulin resistance of these cells; however, ePSP reversed this decrease in a dose-dependent manner (one-way ANOVA, p<0.05). In the HG and HGI models, ePSP significantly increased glycogen content, insulin receptor substrate-2 protein and phosphorylated AMP-activated protein kinase (AMPK), as determined by western blot analysis. In addition, ePSP significantly increased glucokinase in the NG and HG models, increased membrane glucose transporter-1 and decreased glycogen synthase kinase-3β in the HGI model, and increased glucose-6-phosphatase in the NG and HGI models (one-way ANOVA, p<0.05). In summary, TV LH-1 ePSP may elevate cellular glucose uptake to regulate glucose homeostasis via the activation of AMPK and glycogen synthesis in an insulin-independent manner. These results suggest that TV LH-1 ePSP may be a nutraceutical with anti-hyperglycemic activity.

Quorum sensing molecule-farnesol increased the production and biological activities of extracellular polysaccharide from Trametes versicolor

A novel strategy of exposing 2-day-old mycelia cultures to 0.8mM farnesol was developed to stimulate extracellular polysaccharide (EPS) production in Trametes versicolor submerged cultures. Farnesol, a quorum sensing molecule in fungi, could significantly increase EPS production by promoting polysaccharide biosynthesis and regulating mycelial morphology. EPS yield reached a maximum of 2.56g/L that was 2.7-fold greater than that of control cultures. Farnesol made T. versicolor develop into fluffy, loose and multi-hyphae morphology, which facilitated the excretion of intracellular polysaccharide into culture medium. Moreover, EPS from farnesol-induced cultures (EPS-F) with higher carbohydrate and uronic acid contents mainly contained high molecular weight polysaccharide (134kDa, 85%), and comprised glucose, mannose and galactose in a molar ratio of 34.2:2.1:1.0. These physicochemical properties led to stronger antioxidant and antitumor activities of EPS-F. This is the first report that farnesol can significantly improve the production of polysaccharide with higher biological activities. It provides a novel strategy to enhance the production and bioactivity of mushroom polysaccharide using microbial quorum sensing molecules.

Characterization of the binding of a glycosylated serine protease from Euphorbia cf. lactea latex to human fibrinogen

In this study, the binding of a glycosylated serine protease (EuP-82) with human fibrinogen was investigated by isothermal titration calorimetry (ITC). ITC analysis indicated that the binding of EuP-82 to fibrinogen in the conditions with or without the activator (Ca²⁺ ) was an exothermic reaction (dominant negative enthalpy), which tended to be driven by hydrogen bonding and van der Waals interactions. In contrast, the binding of fibrinogen-EuP-82 in the condition with the inhibitor (Zn²⁺ ) was an unfavorable endothermic reaction. EuP-82 could not inhibit the platelet activity in citrated whole blood via the ADP-receptor pathways (mainly, P2Y1 and P2Y12), but it could enhance the platelet aggregation. The ITC together with whole blood platelet aggregation suggested that EuP-82 provided multiple fibrinogen-binding sites that were not related to the arginine-glycine-aspartate (RGD) and the dodecapeptide sequences of fibrinogen. In addition, EuP-82 had neither thrombin-like activity nor anticoagulant activity. The SR-FTIR spectra revealed that EuP-82 was a glycoprotein. Deglycosylation of EuP-82 did not affect its proteolytic activity. Moreover, EuP-82 did not exhibit any toxicity to the living cells (NIH-3T3). This study supports that EuP-82 may be useful for wound-healing material through stabilizing the clot via the platelet induction for the first process.

LbCML38 and LbRH52, two reference genes derived from RNA-Seq data suitable for assessing gene expression in Lycium barbarum L

For quantitative real-time PCR (qRT-PCR) analysis, the key prerequisite that determines result accuracy is the selection of appropriate reference gene(s). Goji (Lycium barbarum L.) is a multi-branched shrub belonging to the Solanaceae family. To date, no systematic screening or evaluation of reference gene(s) in Goji has been performed. In this work, we identified 18 candidate reference genes from the transcriptomic sequencing data of 14 samples of Goji at different developmental stages and under drought stress condition. The expression stability of these candidate genes was rigorously analyzed using qRT-PCR and four different statistical algorithms: geNorm, BestKeeper, NormFinder and RefFinder. Two novel reference genes LbCML38 and LbRH52 showed the most stable expression, whereas the traditionally used reference genes such as LbGAPDH, LbHSP90 and LbTUB showed unstable expression in the tested samples. Expression of a target gene LbMYB1 was also tested and compared using optimal reference genes LbCML38 and LbRH52, mediocre reference gene LbActin7, and poor reference gene LbHSP90 as normalization standards, respectively. As expected, calculation of the target gene expression by normalization against LbCML38, LbActin7 or LbHSP90 showed significant differences. Our findings suggest that LbCML38 and LbRH52 can be used as reference genes for gene expression analysis in Goji.

Antitumor activities and immunomodulatory of rice bran polysaccharides and its sulfates in vitro

Polysaccharides purified from rice bran show antitumor activity against tumor cells, yet the mechanism of this action remains poorly understood. To address this issue, our study evaluated the effect of rice bran polysaccharides on mouse melanoma cell line B16, and Raw264.7 macrophages. Rice bran polysaccharides (RBP) failed to inhibit B16 cell growth in vitro. However, Raw264.7 macrophages treated by RBP enhancement of cytotoxic effects. The cytotoxicity was confirmed by the stimulation of nitric oxide (NO) production and tumor necrosis factor-α (TNF-α) secretion on Raw264.7 macrophages in a dose-dependent manner. RBP2, a fraction of RBP, notably enhanced the inhibition of B16 cells and boosted the immunepotentiation effect compared with RBP. To further enhance the inhibition of B16 cell growth, sulfated polysaccharides (SRBP) was derived using the chlorosulfonic acid-pyridine method. SRBP2 was found to suppress B16 cell growth, reduce B16 cell survival and stimulate NO and TNF-α production. However, SRBP2 displayed a cytotoxic effect on Raw264.7 macrophages. These results suggest that the antitumor activity of RBP and RBP2 is mediated mainly through the activation of macrophages. SRBP2 exerts its antitumor activity by inducing apoptosis in tumor cells and the secretion of NO and TNF-α.

Polysaccharides of Trametes versicolor Improve Bone Properties in Diabetic Rats

This study investigates the effects of Trametes versicolor (L.:Fr.) Pilát (TVP, also known as Yunzhi) on bone properties in diabetic rats. Forty-five male Wistar rats (8 weeks old) were fed either a chow diet (control) or a high-fat diet throughout the study period of 28 days. Animals in the high-fat-diet group were injected with nicotinamide and streptozotocin to induce diabetes mellitus (DM). The DM rats were divided into a group receiving distilled water (vehicle) and another group receiving TVP at 0.1 g/kg weight by gavage. Relative to the vehicle group, TVP gavage lowered postprandial blood sugar (225 ± 18 mg/dL for TVP vs 292 ± 15 mg/dL for vehicle, p < 0.001) on day 26. Compared to the vehicle group, TVP mitigated DM-induced bone deterioration as determined by increasing bone volume of proximal tibia (22.8 ± 1.4% for TVP vs 16.8 ± 1.3% for vehicle, p = 0.003), trabecular number (p = 0.011), and femoral bone strength (11% in maximal load, 22% in stiffness, 14% in modulus, p < 0.001), and by reducing loss of femoral cortical porosity by 25% (p < 0.001). Our study demonstrates the protective effect of TVP on bone properties was mediated through, in part, the improvement of hyperglycemic control in DM animals.

Finding of polysaccharide-peptide complexes in Cordyceps militaris and evaluation of its acetylcholinesterase inhibition activity

Acetylcholinesterase (AChE) inhibition enhances learning and cognitive ability for treatment of Alzheimer’s disease. Polysaccharide–peptide complexes were identified in Cordyceps militaris (CPSPs) and characterized for their AChE inhibitory properties. Three polymers (CPSP-F1, -F2, and -F3) were extracted and separated by ultrasound-assisted extraction and dieth-ylaminoethanol (DEAE)–Sepharose CL-6B column chromatography. Polysaccharide–peptide complexes were identified by DEAE–Sepharose CL-6B column chromatography and high-performance gel-filtration chromatography, Fourier transform infrared spectra, amino sugar composition analysis, and β-elimination reaction to identify polysaccharide–peptide bond categories. Separation of CPSP can increase AChE inhibitory activity from the crude poly-saccharide of C. militaris. CPSP-F1 and CPSP-F2 exhibited half maximal inhibitory concentrations of 32.2 ± 0.2 mg/mL and 5.3 ± 0.0 mg/mL. Thus, we identified polysaccharide–peptide complexes from C. militaris and suggest CPSP has great potential in AChE inhibition bioassay.

Analysis of flavonoids from leaves of cultivated Lycium barbarum L

Leaves of Lycium barbarum are widely used as medicine vegetables and functional tea in China. The main flavonoids present in the leaves were separated and identified by high performance liquid chromatography (HPLC), liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-(APCI) MS) and ultraviolet-visible spectra with shift additives. The predominant flavonoid was identified as rutin. Leaves are the rutin-rich parts (16.03-16.33 mg/g). In the wild and cultivated L. barbarum fruits, contents of rutin were determined very low (0.09-1.38 mg/g). The contents of total flavonoids (21.25 mg/g) of cultivated L. barbarum leaves were much higher than those in the wild L. barbarum leaves (17.86 mg/g), so cultivated barbarum leaves are a suitable source for medicine vegetables and functional tea.

Glycerogalactolipids from the fruit of Lycium barbarum

Four glycerogalactolipids (1-4), together with 11 other previously known homologues were isolated from the fruit of Lycium barbarum. Their structures were elucidated by chemical analyses including regio-selective enzymatic, alkaline and acidic hydrolyses and spectroscopic methods involving GCMS, HRESIMS and 1D and 2D NMR, respectively.