Structure elucidation, proliferation effect on macrophage and its mechanism of a new heteropolysaccharide from Lactarius deliciosus Gray

Developing and Characterization of a Biopolymeric Membrane Derived from Mature Banana Peel Biomass

Biopolymeric films derived from starch are gaining attention due to their potential applications, which are primarily attributed to their availability and biodegradability. Here, we report developing and characterizing a biopolymeric film utilizing banana peel waste (BM2). Analytical techniques were employed, including water absorption analysis, determination of soluble matter, UV-visible absorption spectrophotometry, tensile strength assessment, morphological examination using scanning electron microscopy (SEM), and thermal analysis through thermogravimetric analysis (TGA). The water absorption analysis revealed a noteworthy absorption percentage of 115.23% and 61.75% of soluble matter. The UV-visible absorption spectrophotometry results demonstrated a light absorbance degree ranging from 0.9 to 720 nm, particularly between 400 and 1000 nm. However, the mechanical strength tests indicated relatively low resistance at 0.8 MPa, attributed to the irregular surface observed in the film's morphology as evidenced by scanning electron microscopy (SEM). Thermal analysis conducted via TGA offered valuable insights into the degradation behavior of the film. The findings reveal a degradation temperature ranging from 160 to 300 °C, thereby elucidating the thermal stability of the film and its potential applications. While mechanical limitations were evident, the biopolymeric film derived from banana peel waste demonstrated noteworthy water absorption properties, presenting potential in specific applications, particularly those that do not necessitate elevated mechanical strength. Continued efforts in optimizing and refining the film's structure promise to bolster its mechanical properties, making it suitable for various applications.

Characterization and comparison of chemical compositions and biological activities of an edible mushroom (Lactarius volemus) of three different sizes

Characterization and comparison of the chemical compositions and biological activities of Lactarius volemus of three different sizes (large size, medium size, small size) were investigated in this work. By comparing three sizes of Lactarius volemus, the small-sized Lactarius volemus had the highest content of crude fiber, fat, crude protein, total sugar, reducing sugar, polyphenols, and total flavonoids, whereas medium-sized Lactarius volemus showed the highest content of ash and total amino acids. Meanwhile, the small-sized Lactarius volemus also exhibited the best 2,2-Diphenyl-1-picrylhy drazyl (DPPH) radical scavenging ability, α-amylase inhibitory activity, α-glucosidase inhibitory activity, and xanthine oxidase inhibitory activity. The small-sized Lactarius volemus had the highest chemical composition content and the best biological activities among the three different sizes. This work might provide basic data support for guiding the development of Lactarius volemus and also instruct consumers in selecting and purchasing high-quality Lactarius volemus.

Polysaccharide fractions extracted from Lactarius quieticolor mushroom exhibit immune stimulatory activities on macrophages

Several beneficial properties have already been observed for mushrooms extracts containing polysaccharides, one of the main components present in these fungi. In order to obtain these extracts and clarify their composition, different extraction and characterization methods can be applied, contributing to understanding its biological effects. In this research, we evaluated three different crude fractions obtained through cold water, hot water, and alkaline solution, from the mushroom Lactarius quieticolor. Each sample was totally characterized by NMR (1H, 13C, HSQC-DEPT, COSY), GC-MS (monosaccharide composition and methylation analysis) and HPSEC (homogeneity and relative Mw). The results showed a mixture of different polysaccharides, including D-galactans and D-glucans in each fraction. All the extracts presented immunostimulant activity in murine RAW 264.7 macrophages, stimulating NO secretion and inducing morphological alterations that were typical of activated cells. These effects were more intense for alkaline fraction (EA), which have higher amounts of mannose and 3,6-di-O-substituted-Glcp units. The results obtained show that crude fractions can potentially stimulate immune cells, which indicates that the consumption of this edible mushroom can bring great benefits to health, being considered an excellent food due to its good biological properties.

Structural characteristics and intestinal flora metabolism mediated immunoregulatory effects of Lactarius deliciosus polysaccharide

Lactarius deliciosus, a widely appreciated mushroom with delightful tastes and texture, has exhibited immunomodulatory activity in vitro, while the effects on intestinal flora metabolisms in vivo are ambiguous. In this study, a L. deliciosus polysaccharide (LDP) was extracted and purified, and the structural characteristics were evaluated, as well as the immunological enhancement on tumor-bearing mice through regulating intestinal flora metabolisms. Results showed that LDP was a heteropolysaccharide (average molecular weight of 1.44 × 107 Da) with a backbone of α-(1 → 6)-Manp and branches of α-(1 → 6)-Galp, α-(1 → 3)-Fucp, α-(1 → 6)-Glcp, α-(1 → 4)-Glcp. Animal experiments indicated that LDP could significantly protect immune organs of tumor-beraing mice and suppress solid tumors growth with inhibitory rate of 51.61 % (high-dose, 100 mg/kg), and improve the intestinal lactobacillus contents, promote adenine mediated zeatin biosynthesis, then competitively antagonize A2A receptor and enhance the activities of CD4+ T cells and CD8+ T cells, finally effectively facilitate the apoptosis and elimination of tumor cells. These results would provide powerful data supports for the further antitumor mechanisms development and practical applications of L. deliciosus polysaccharide in food and drug industries.

Structural characteristics, immune-activating mechanisms in vitro, and immunomodulatory effects in vivo of the exopolysaccharide EPS53 from Streptococcus thermophilus XJ53

Our previous investigations have successfully identified the repeating structural units of EPS53, an exopolysaccharide derived from Streptococcus thermophilus XJ53 fermented milk, and substantiated its potential immunomodulatory properties. The present study further elucidated the structural characteristics of EPS53 and investigated the underlying mechanisms governing its in vitro immunoreactivity as well as its in vivo immunoreactivity. The results obtained from multi-detector high performance gel filtration chromatography revealed that EPS53 adopted a rigid rod conformation in aqueous solution, with the weight-average molecular weight of 1464 kDa, the number-average molecular weight of 694 kDa, and the polydispersity index of 2.11. Congo red experiment confirmed the absence of a triple helix conformation. Scanning electron microscopy showed that EPS53 displayed a three-dimensional fibrous structure covered with flakes. The in vitro findings indicated that EPS53 enhanced phagocytosis ability, reactive oxygen species (ROS) production, and cytokine levels of macrophages via the TLR4-mediated NF-κB/MAPK signaling pathways as confirmed by immunofluorescence staining experiments, inhibition blocking experiments, and Western blot assay. Additionally, the in vivo experiments demonstrated that EPS53 significantly increased macrophage and neutrophil number while enhancing NO and ROS levels in zebrafish larvae; thus, providing further evidence for the immunomodulatory efficacy of EPS53.

Selected fungi of the genus Lactarius - screening of antioxidant capacity, antimicrobial activity, and genotoxicity

It is well-known that mushrooms of the genus Lactarius constitute a natural food resource providing health benefits as a nutritient. This genus contains 4 mushrooms identified as L. deliciosus, L. volemus, L. sanguifluus, L. semisanguifluus and L. piperatus which were collected in Serbia. The aim of this study aimed was to identify and characterize the content of phenolic compounds and examine the antioxidant potential of 5 wild edible mushrooms. L. sanguifluus contained the highest content of total phenol compounds (75.25 mg gallic acid equivalents (GAE) per g dry extract weight (GAE/g DE) and exhibited the greatest antioxidant activity through the ability to remove radicals as evidenced by ABTS assay (8.99 mg of trolox equivalents (TE) per g dry extract weight (mg TE/g DE); total reducing power (TRP) assay mg ascorbic acid equivalents per mg of dry extract weight (0.42 mg AAE/g DE) and CUPRAC (14.23 mg TE /g DE). L. deliciosus methanolic extract produced greatest scavenging of the DPPH radical (46%). The methanol mushroom extracts were screened for in vitro antimicrobial activity against a panel of pathogenic bacterial strains using the microdilution method. Of all the extracts tested, L. sanguifluus extract showed the best antibacterial properties. The cytokinesis block micronucleus assay results for the examined mushrooms demonstrated that extracts at a concentration of 3 μg/ml decreased the number of micronuclei (MN) in the range of 19-49% which is significant bearing in mind that radioprotectant amifostine reduced the frequency of MN by only 16.3%. Data thus demonstrate that the 5 wild edible mushrooms of genus Lactarius contain constituents that are beneficial not only as nutrients but also have the potential as antioxidants, antibacterial and antigenotoxic properties.

Structural characterization and protective effect on PC12 cells against H2O2-induced oxidative damage of a polysaccharide extracted from mycelia of Lactarius deliciosus Gray

The crude polysaccharide LDP was extracted from mycelia of Lactarius deliciosus Gray and then purified by DEAE-52 cellulose and Sephadex G-200 to obtain a novel polysaccharide named LDP-CP. LDP-CP was mainly composed of mannose, glucose and galactose with an average molecular weight of 2.33 × 10³ kDa. The structure of LDP-CP was determined by FT-IR, methylation and NMR analysis, and the results showed that the sugar linkage units of LDP-CP were composed of (1 → 3)-linked β-D-Manp, (1 → 2,4)-linked α-D-Manp, (1→)-linked α-D-Manp, (1 → 4)-linked β-D-Glcp, (1 → 2)-linked β-D-Manp, (1 → 4,6)-linked α-D-Manp, (1 → 4)-linked α-D-Galp, (1 → 2,3)-linked α-D-Glcp and (1→)-linked α-D-Glcf. The protective effects of LDP and LDP-CP on PC12 cells against H₂O₂-induced oxidative injury were exhibited by enhancing cell viability and morphological protection. The improvement to the level of LDH, SOD and GSH further indicated that LDP and LDP-CP had ability to alleviate H₂O₂-induced oxidative damage on PC12 cells. The polysaccharides in Lactarius deliciosus Gray mycelia exhibited the great advantages in the management of oxidative toxicity, which indicated that the polysaccharides can be further developed in application of natural functional food source.

Advances in Separation and Purification of Bioactive Polysaccharides through High-speed Counter-Current Chromatography

Polysaccharides, with an extensive distribution in natural products, represent a group of natural bioactive substances having widespread applications in health-care food products and as biomaterials. Devising an efficient system for the separation and purification of polysaccharides from natural sources, hence, is of utmost importance in the widespread applicability and feasibility of research for the development of polysaccharide-based products. High-speed counter-current chromatography (HSCCC) is a continuous liquid-liquid partitioning chromatography with the ability to support a high loading amount and crude material treatment. Due to its flexible two-phase solvent system, HSCCC has been successfully used in the separation of many natural products. Based on HSCCC unique advantages over general column chromatography and its enhanced superiority in this regard when coupled to aqueous two-phase system (ATPS), this review summarizes the separation and purification of various bioactive polysaccharides through HSCCC and its coupling to ATPS as an aid in future research in this direction.

Structure identification, antitumor activity and mechanisms of a novel polysaccharide from Ramaria flaccida (Fr.) Quél

It is an important aspect of current cancer research to search for effective and low-toxicity anticancer drugs and adjuvants. Polysaccharides, as immunomodulators, can improve the immune function of the body, kill tumor cells directly and prevent tumor development by increasing the resistance of the body to carcinogenic factors. The aim of the present study was to identify natural polysaccharide compounds with novel structure and antitumor activity via the separation and analysis of polysaccharide components from Ramaria flaccida (Fr.) Quél. (RF-1). In the present study, high-performance gel permeation chromatography, gas chromatography-mass spectrometry and nuclear magnetic resonance were used to identify the structure of polysaccharides from RF-1. Subsequently, the antitumor activity and mechanism of RF-1 were studied by establishing an in vivo S180 tumor model, and by using Illumina sequencing technology and enzyme-linked immunosorbent assay (ELISA). The present results revealed that the average molecular weight of RF-1 was 17,093 Da and that RF-1 was composed of the monosaccharides glucose and galactose, with a 2:1 ratio. The main chain of RF-1 consisted of (1→6, 2)-α-D-galactopyranose and (1→6, 4)- α-D-glucopyranose. One of the branched chains was linked to 4-O of the main glucose chain by (1→6)-α-D-glucopyranose and next linked by one (→4)-β-D-glucopyranose. The other two branched chains were both linked to 2-O of the main glucose chain by one (→4)-β-D-glucopyranose. In addition, RF-1 inhibited the growth of S180 tumors in vivo. When the concentration of RF-1 was 20 mg/kg, the inhibition rate of S180 tumors in mice was 48.4%. Compared with the blank control group, 1,971 differentially expressed genes were identified, of which 818 were upregulated and 1,153 were downregulated in the RF-1 group. A Gene Ontology enrichment analysis generated 47,091 assignments to biological processes, 5,250 assignments to cellular components, and 6,466 assignments to molecular functions. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the Wnt and MAPK signaling pathways were significantly enriched. The number of differentially annotated genes in these two pathways was 19 and 33, respectively. Additionally, ELISA results revealed that the protein levels of interleukin (IL)-1β, IL-6, vascular endothelial growth factor (VEGF) and VEGF receptor in the RF-1 group were significantly downregulated compared with the S180 blank control group (P<0.01).

Structural characterization and immune regulation of a novel polysaccharide from Maerkang Lactarius deliciosus Gray

The present study investigated the structural characterization and immune regulation of a novel polysaccharide from Maerkang Lactarius deliciosus Gray. Chemical methods, high performance gel permeation chromatography, fourier transform infrared spectroscopy, nuclear magnetic resonance spectrum and gas chromatography‑mass spectrometry were used to characterize the polysaccharide structure. The immunomodulatory abilities of the Maerkang L. deliciosus Gray polysaccharide (LDG‑M) were also investigated. LDG‑M was primarily composed of β‑D‑glucose and α‑D‑lyxose with the ratio of 2:1. The possible structure of LDG‑M had a backbone of 1,6‑linked‑β‑D‑glucose and 1,4,6‑linked‑β‑D‑glucose, with branches primarily composed of one (1→4)‑linked‑α‑D‑lyxose residue. The immunoregulatory activity results demonstrated that LDG‑M promoted the proliferation and phagocytosis of macrophages, and induced cytokine release. LDG‑M also promoted the proliferation of B cells by affecting the G0/G1, S and G2/M phases. The present study introduced LDG‑M as a valuable source with unique immunoregulatory properties.

Chemical Composition, Antioxidant and Antihyperglycemic Activities of the Wild Lactarius deliciosus from China

The wild mushroom Lactarius deliciosus from China was studied for the first time to obtain information about its chemical composition, antioxidant, and antihyperglycemic activities. Nutritional value, dietary fiber, fatty acids, metal elements, free sugars, free amino acids, organic acids, flavor 5′-nucleotides, and volatile aroma compounds were determined. Potential antioxidant and antihyperglycemic activities were also tested by investigating 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals scavenging activities, ferric ion reducing activity, as well as α-amylase and α-glucosidase inhibitory activities using ethanol and aqueous extracts. The results showed that L. deliciosus was a good wild mushroom with high protein, carbohydrate, and dietary fiber contents, while low in fat and calorie, extensive unsaturated fatty acids contents, with negligible health risks about harmful metal elements. Twenty kinds of free amino acids were detected with a total content 3389.45 mg per 100 g dw. Flavor 5′-nucleotides including 5′-CMP, 5′-UMP, 5′-IMP, and 5′-AMP were 929.85, 45.21, 311.75, and 14.49 mg per 100 g dw, respectively. Mannitol (7825.00 mg per 100 g dw) was the main free sugar, and quininic acid (729.84 mg per 100 g dw) was the main organic acid. Twenty-five kinds of volatile aroma compounds were identified, acids (84.23%) were the most abundant compounds based on content, while aldehydes (15 of 25) were the most abundant compounds based on variety. In addition, both ethanol and aqueous extracts from L. deliciosus exhibited excellent antioxidant activity. While in antihyperglycemic activity tests, only ethanol extracts showed inhibitory effects on α-amylase and α-glucosidase.

Structure elucidation and antitumor activity of a new polysaccharide from Maerkang Tricholoma matsutake

A new heteropolysaccharide was isolated from the fruiting bodies of Tricholoma matsutake which had a molecular weight of 12078 Da. The results of structural features analysis showed that T. matsutake polysaccharide, here named TMP-B, was mainly composed of α - D - glucose and α - D - galactose which ratios were 7:2 and had a backbone of 1, 4 - linked α - D - glucose which branches were mainly composed of two 6 - linked α - D - galactose residue, and the α - D - galactose was 1, 6 - linked. Antitumor activity results showed that heteropolysaccharide TMP-B could inhibit the growth of S180 tumor in vivo and promote the apoptosis of L929 cells in vitro. Immunoregulatory activity results showed that TMP-B could promote the proliferation of macrophages by affecting G0/G1 phase, S phases and G2/M phases and promote cytokines release and gene expression. The result of this study introduced Maerkang T. matsutake as a possible valuable source which helped to exhibit unique antitumor and immunoregulatory properties.

Cytoproliferative and Cytoprotective Effects of Striatisporolide A Isolated from Rhizomes of Athyrium multidentatum (Doell.) Ching on Human Umbilical Vein Endothelial Cells

OBJECTIVES

The aim of this study was to investigate the proliferative and protective effects of striatisporolide A (SA) obtained from the rhizomes of Athyrium multidentatum (Doell.) Ching on human umbilical vein endothelial cells (HUVECs).

METHODS

Cell viability was measured by the MTT method. Cell apoptosis was determined by flow cytometry. Intracellular ROS was measured by the 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe.

RESULTS

The viability rate in cells treated with 100 µM SA alone was increased to 128.72% ± 0.19% and showed a significant difference compared with the control group (p < 0.05). Meanwhile, SA augmented the cell viabilities in H₂O₂-treated HUVECs, and the cell viability was enhanced to 56.94% ± 0.13% (p < 0.01) when pre-incubated with 50 µM SA. The cell apoptosis rates were reduced to 2.17% ± 0.20% (p < 0.05) and 3.1% ± 0.34% (p < 0.01), respectively, after treatment with SA alone or SA/H₂O₂. SA inhibited the overproduction of reactive oxygen species (ROS) in HUVECs induced by H₂O₂ and the fluorescent intensity was abated to 9.47 ± 0.61 after pre-incubated with 100 μM SA.

CONCLUSIONS

The biological activities of SA were explored for the first time. Our results stated that SA exhibited significant cytoproliferative and minor cytoprotective effects on HUVECs. We presume that the mechanisms of the proliferation and protection actions of SA involve interference with the generation of ROS and the cell apoptosis. These findings provide a new perspective on the biological potential of butenolides.