Pleurotus nebrodensis polysaccharide induces apoptosis in human non-small cell lung cancer A549 cells

Polysaccharide-Based Stimulus-Responsive Nanomedicines for Combination Cancer Immunotherapy

Cancer immunotherapy is a promising antitumor approach, whereas nontherapeutic side effects, tumor microenvironment (TME) intricacy, and low tumor immunogenicity limit its therapeutic efficacy. In recent years, combination immunotherapy with other therapies has been proven to considerably increase antitumor efficacy. However, achieving codelivery of the drugs to the tumor site remains a major challenge. Stimulus-responsive nanodelivery systems show controlled drug delivery and precise drug release. Polysaccharides, a family of potential biomaterials, are widely used in the development of stimulus-responsive nanomedicines due to their unique physicochemical properties, biocompatibility, and modifiability. Here, the antitumor activity of polysaccharides and several combined immunotherapy strategies (e.g., immunotherapy combined with chemotherapy, photodynamic therapy, or photothermal therapy) are summarized. More importantly, the recent progress of polysaccharide-based stimulus-responsive nanomedicines for combination cancer immunotherapy is discussed, with the focus on construction of nanomedicine, targeted delivery, drug release, and enhanced antitumor effects. Finally, the limitations and application prospects of this new field are discussed.

Advances in the regulation of natural polysaccharides on human health: The role of apoptosis/autophagy pathway

Due to the multiple biological activities of polysaccharides, their great potential as "natural drugs" for many diseases has been the subject of continuous exploration in the field of food and nutrition. Apoptosis and autophagy play a key role in mammalian growth, development and maintenance of cellular homeostasis. Recent studies suggest that apoptosis/autophagy may be the key regulatory target for the beneficial effects of polysaccharides. However, the regulation of apoptosis and autophagy by polysaccharides is not consistent in different disease models. Therefore, this review outlined the relationship between apoptosis/autophagy and some common human diseases, then discussed the role of apoptosis/autophagy pathway in the regulation of human health by polysaccharides, Furthermore, the application of visualization, imaging and multi-omics techniques was proposed in the future trend. The present review may be beneficial to accelerate our understanding of the anti-disease mechanisms of polysaccharides, and promote the development and utilization of polysaccharides.

Promising anticancer activity of polysaccharides and other macromolecules derived from oyster mushroom (Pleurotus sp.): An updated review

Cancer dominates among many causes of mortality worldwide. Traditional chemotherapeutic agents are powerful anti-cancer agents employed for treatment of this deadly disease. However, they are always associated with toxic side effects and immunosuppression making person more vulnerable to tumor relapse and fatalities. A promising alternative could be identification, isolation and transfer of naturally occurring bioactive macromolecules to the tumorigenic population. Oyster mushroom, a major source of nutraceuticals, belonging to class basidiomycetes of kingdom Mycota is known to have immense therapeutic properties. It is a reservoir of macromolecules like β-glucan, α-glucan, resveratrol, concanavalin A, cibacron blue affinity protein, p-hydroxybenzoic acid, ergosterol, linoleic acid etc. that are responsible for mediating anti-tumor, immunomodulatory, antioxidant, and anti-diabetic roles. Various studies have shown that extracts derived from oyster mushroom is rich in polysaccharides like β-glucan and other macro molecules which have an anti-proliferative effect against cancer cell lines, without harming the normal cells. This review presents a brief highlight of the work covering the overall significance of oyster mushroom in different types of cancer treatment. It also explores the immunomodulatory effects of polysaccharides, proteoglycans and polypeptides derived from oyster mushroom that boosts the immune system to overcome the limitation of traditional cancer therapies.

A novel acid polysaccharide from Boletus edulis: extraction, characteristics and antitumor activities in vitro

A novel cold-water-soluble polysaccharide (BEP), with a molecular weight of 6.0 × 10⁶ Da, was isolated from Boletus edulis. BEP consists of galactose, glucose, xylose, mannose, glucuronic, and galacturonic acid in a ratio of 0.34:0.28:0.28:2.57:1.00:0.44. The IR results showed that BEP was an acid polysaccharide, containing α-type and β-type glucoside bonds. MTT assay showed BEP could inhibit cell proliferation significantly. Morphological observation demonstrated that BEP-treated MDA-MB-231 and Ca761 cells exhibited typical apoptotic morphological features. Flow cytometry analysis revealed that BEP caused mitochondrial membrane potential collapse. Annexin V-FITC/PI staining indicated that BEP induced apoptosis of MDA-MB-231 and Ca761 cells through cell block in S phase and G₀/G₁ phase, respectively. Western blot results showed that BEP could increase the Bax/Bcl-2 ratios, promote the release of cytochrome C, and activate the expression of caspase-3 and caspase-9 in MDA-MB-231 and Ca761 cells. In conclusion, our results demonstrated that BEP could inhibit the proliferation of breast cancer cells and induce apoptosis through mitochondrial pathways.

Polysaccharide from Pleurotus nebrodensis: Physicochemical, structural characterization and in vitro fermentation characteristics

A high Mw (5012 kDa) polysaccharide (PNPS) from the fruiting body of Pleurotus nebrodensis was isolated using water extraction followed by ethanol precipitation. The structural characteristics and in vitro fermentation behaviors of this polysaccharide was investigated. Chemical composition analysis showed the total sugar content of PNPS was up to 97.20 ± 1.80 wt%. Monosaccharide composition analysis showed PNPS contained mainly glucose (89.22 ± 5.70 mol%) while small percentage of mannose (5.60 ± 0.74 mol%) and galactose (5.18 ± 0.33 mol%) were also detected. According to the linkage pattern analysis (methylation analysis), PNPS comprised mainly 4-β-D-Glcp (58.90 mol%), while other residues including α-D-Glcp, 6-α-D-Galp, 3,6-α-D-Manp, 3-β-D-Glcp and 6-α-D-Glcp were detected with a comparable amount. Combined with results from 1D and 2D NMR spectrum, a proposed structure of PNPS was presented. In vitro fermentation of PNPS by gut microbiota showed total SCFA production of all treatment groups was higher than negative control group (NC) significantly (p < 0.05) after 48 h of fermentation. The formation of SCFAs was mainly acetic acid, followed by propionic acid and butyric acid, and the pH was decreased from 6.95 to 4.70. After 72 h, the total sugar content decreased from 5.813 ± 0.87 mg/L to 0.23 ± 0.065 mg/L, and the molecular weight of PNPS decreased.

Structural investigation and comparative cytotoxic activity of water-soluble polysaccharides from fruit bodies of the medicinal fungus quinine conk

The structures and cytotoxic activities of water-soluble polysaccharides were investigated to search for biologically active polysaccharides from the fruit bodies of quinine conks (Fomitopsis officinalis). The decoctions of this medical fungus are actively used in folk medicine in many countries and traditional Chinese medicine. From the fungal extract we prepared, only branched β-glucan had cytotoxic activity among all the water-soluble polysaccharides. This glucan is characterized by a regular structure. Its backbone is formed by 1,3-linked β-D-Glcp residues, of which every third residue is substituted at O-6 by a single β-D-Glcp residue. It has a triple helix conformation according to the data obtained from a colorimetric assay with Congo red dye and is characterized by a high-weight average molar mass (Mw > 800 kDa). β-Glucan possessed cytotoxic activity against HeLa cells (IC₅₀ = 318 ± 47 μg/mL) and induced the formation of apoptotic bodies around most cancer cells at a concentration of 200 μg/mL. It should be noted that extraction with boiling water, which is usually used to obtain extracts and decoctions, is unable to isolate active β-glucan. Active β-glucan can be obtained in an individual state by cold alkali extraction after dehydration of the fruit bodies and removal of the components extractable by boiling water.

Polysaccharides of mushroom Pleurotus spp.: New extraction techniques, biological activities and development of new technologies

The biodiversity of mushrooms Pleurotus spp. is impressive due to its complexity and diversity related to the composition of chemical structures such as polysaccharides, glycoproteins and secondary metabolites such as alkaloids, flavonoids and betalains. Recent studies of polysaccharides and their structural elucidation have helped to direct research and development of technologies related to pharmacological action, production of bioactive foods and application of new, more sophisticated extraction tools. The diversity of bioactivities related to these biopolymers, their mechanisms and routes of action are constant focus of researches. The elucidation of bioactivities has helped to formulate new vaccines and targeted drugs. In this context, in terms of polysaccharides and the diversity of mushrooms Pleurotus spp., this review seeks to revisit the genus, making an updated approach on the recent discoveries of polysaccharides, new extraction techniques and bioactivities, emphasising on their mechanisms and routes in order to update the reader on the recent technologies related to these polymers.

Chemical characterization, antioxidant properties and anticancer activity of exopolysaccharides from Floccularia luteovirens

Two polysaccharides, ALF1 and ALF2 were obtained from the fermentation liquid of Floccularia luteovirens. These fractions had good performance in scavenging radicals and ALF1 exhibited obvious antioxidant activities. Further, linkage analysis and NMR were used to characterize the structures of ALF1. Linkage and NMR data comprehensively showed that ALF1 mainly contained six kinds of linkage type units as →4)-β-D-Manp→, 1,3-α-Fucp→, α-L-Araf-C1→, →6)-β-D-Galp-C1→, →4)-α-D-GlcAp-(1→ and →3)-β-D-Glcp(1→. In addition, ALF1 had good bioactivities such as anticancer and antioxidant activities. ALF1 was proven to be able to inhibit tumor cells without affecting the normal cells. Besides, ALF1 improved the activities of SOD, GSH-Px and CAT, and decreased the production of MDA which result in protecting PC12 cells against H₂O₂-induced oxidative stress. ALF1 decreased ROS production, and stabilize mitochondrial membrane potential. The findings indicated that the fermentation liquid of Floccularia luteovirens could be used as a potential natural source of antioxidant.

Development of multi-layered gastric floating tablets based on konjac glucomannan: a modified calcium supplement with enhanced bioavailability

This study developed a gastric-floating delivery system of calcium based on konjac glucomannan (KGM).

Anti-hyperlipidemic and antioxidant effects of alkali-extractable mycelia polysaccharides by Pleurotus eryngii var. tuolensis

In this study, we noted that the Al-MPS from Pleurotus eryngii var. tuolensis provoked pharmacological effects on blood lipid profiles and oxidative stress. Animal studies demonstrated that Al-MPS showed potential effects on relieving hyperlipidemia and preventing oxidative stress, reflecting by decreasing the levels of serum enzyme activities (ALP, ALT and AST), restoring the activities of antioxidant enzymes (SOD, GSH-Px, CAT and T-AOC), down-regulating the MDA and LPO contents, as well as remitting the hepatic and cardiac tissues injury, respectively. The serum levels of TC, TG, LDL-C, VLDL-C, and HDL-C on mice treated with Al-MPS (500mg/kg bw) reached 2.48±0.08, 1.24±0.03, 0.84±0.02, 0.34±0.02, and 1.80±0.03mmol/L, which were lower/higher against the hyperlipidemia mice. The results clearly indicated that the Al-MPS could be used as a beneficial health food and potentially natural candidate medicine in preventing the high-fat emulsion-induced hyperlipidemia.

Anti-tumor effect of polysaccharide from Hirsutella sinensis on human non-small cell lung cancer and nude mice through intrinsic mitochondrial pathway

Our previous works had proved the structural properties of Hirsutella sinensis polysaccharide-III(HSP-III). Herein, its anti-tumor effect on lung cancer correlated with mitochondrial apoptosis pathway was investigated. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that HSP-III induces the apoptosis of H1299 cells; however the proliferation viability of normal lung epithelial cells is not affected. HSP-III treatment collapses the H1299 cell mitochondrial membrane potential, and western blot analysis of cytochrome C, Bax, caspase-3 and caspase-9 further indicates that apoptotic effects induced by HSP-III is through the mitochondrial pathway. Furthermore, we found the apoptotic effects of HSP-III are triggered by Reactive oxygen species (ROS) generation. Blue native Polyacrylamide Gel-Electrophoresis (PAGE) showed the expressions of mitochondrial respiratory chain complexes I-V were also decreased. Taken together, anti-tumor effect of HSP-III is through intrinsic mitochondrial apoptosis mechanism pathway and involving ROS increasing. Finally, in vivo nude mice experiment, HSP-III attenuated the growth of tumor compared with control. In contrast, N-acetyl-l-cysteine (NAC) could restore the cell apoptosis effects induced by HSP-III. These findings suggest that HSP-III induce apoptosis of H1299 cells and attenuated growth of nude mice tumor in vivo through the intrinsic mitochondrial pathway and stimulating ROS. HSP-III could be a composition for lung cancer treatment.

Grifola frondosa Glycoprotein GFG-3a Arrests S phase, Alters Proteome, and Induces Apoptosis in Human Gastric Cancer Cells

GFG-3a is a novel glycoprotein previously purified from the fermented mycelia of Grifola frondosa with novel sugar compositions and protein sequencing. The present study aims to investigate its effects on the cell cycle, differential proteins expression, and apoptosis of human gastric cancer SGC-7901 cells. Our findings revealed that GFG-3a induced the cell apoptosis and arrested cell cycle at S phase. GFG-3a treatment resulted in the differential expression of 21 proteins in SGC-7901 cells by upregulating 10 proteins including RBBP4 associated with cell cycle arrest and downregulating 11 proteins including RUVBL1, NPM, HSP90AB1, and GRP78 involved in apoptosis and stress response. qRT-PCR and Western blot analysis also suggested that GFG-3a could increase the expressions of Caspase-8/-3, p53, Bax, and Bad while decrease the expressions of Bcl2, Bcl-xl, PI3K, and Akt1. These results indicated that the stress response, p53-dependent mitochondrial-mediated, Caspase-8/-3-dependent, and PI3k/Akt pathways were involved in the GFG-3a-induced apoptosis process in SGC-7901 cells. These findings might provide a basis to prevent or treat human gastric cancer with GFG-3a and understand the tumor-inhibitory molecular mechanisms of mushroom glycoproteins.

Pleurotus nebrodensis polysaccharide(PN50G) evokes A549 cell apoptosis by the ROS/AMPK/PI3K/AKT/mTOR pathway to suppress tumor growth

Since the strong antineoplastic potential against A549 cells of Pleurotus nebrodensis polysaccharide (PN50G) in vitro has been proven previously, the definitive mechanism of PN50G-induced apoptosis in A549 cells in vivo was further investigated. All the results indicated that PN50G significantly suppressed tumor growth in A549 tumor-bearing mice. Tumor cells treated with PN50G were arrested in the G0/G1 phase, and marked changes in the expression of cell cycle-related proteins, including cyclin D1, cyclin A and cyclin B1, were observed. Moreover, western blotting analysis indicated that PN50G triggered the mitochondrial apoptotic pathway, for an increased Bax/Bcl-2 ratio, release of cytochrome c, cleavage of caspase-3 and PRPP in A549 tumor cells were observed. And the decrease in the expression of the translation related protein P70S6K was observed, because PN50G activated AMPK phosphorylation, but inhibited PI3K/AKT phosphorylation and suppressed the activation of the mammalian target of rapamycin (mTOR) induced by PN50G. In vivo imaging was performed on tumor-bearing mice, and the results indicated that PN50G significantly increased the intracellular levels of reactive oxygen species (ROS). Furthermore, it indicated that PN50G promoted the protein expression of Beclin 1 and LC-3 in a dose-dependent manner. All the results suggested that PN50G-mediated apoptosis and autophagy of A549 tumor cells in vivo mainly involved in the mitochondrial pathway and the AMPK/PI3K/mTOR pathway.

Safflower polysaccharide induces NSCLC cell apoptosis by inhibition of the Akt pathway

Lung cancer is the leading cause of cancer death in the world. Safflower polysaccharide (SPS) has been used for the improvement of immunomodulatory activities and treatment of cancers. However, studies on the effect of SPS on the progression of lung cancer have rarely been reported. To study the antitumor effect of SPS on human lung cancer and its potential mechanism, non-small cell lung cancer cell lines (NSCLC), A549 and YTMLC-90 were treated with SPS at various concentrations ranging from 0.04 to 2.56 mg/ml and BALB/c nude tumor-bearing mice were injected intraperitoneally with SPS at concentrations ranging from 15 to 135 mg/kg. Results showed that SPS suppressed the proliferation of A549 and YTMLC-90 cells and induced apoptosis by increasing mRNA levels of bax and caspase-3, and inhibited tumor growth in vivo. SPS induced cell cycle arrest in the G2/M phase by decreasing the expression of cdc25B and cyclin B1. Moreover, SPS decreased the expression of Akt, p-Akt and PI3K. In mice, SPS injection enhanced immunomodulatory activities by increasing levels of TNF-α and IL-6 in tumor-bearing mice. Our findings suggest that SPS suppresses tumor growth by enhancing immunomodulatory activities and blocking the PI3K/Akt pathway. This study provides new insight into the anticancer mechanism of SPS.