Induction of apoptosis in SGC-7901 cells by polysaccharide-peptide GFPS1b from the cultured mycelia of Grifola frondosa GF9801

Review on active components and mechanism of natural product polysaccharides against gastric carcinoma

One of the malignant tumors with a high occurrence rate worldwide is gastric carcinoma, which is an epithelial malignant tumor emerging from the stomach. Natural product polysaccharides are a kind of natural macromolecular polymers, which have the functions of regulating immunity, anti-oxidation, anti-fatigue, hypoglycemia, etc. Natural polysaccharides have remarkable effectiveness in preventing the onset, according to studies, and development of gastric cancer at both cellular and animal levels. This paper summarizes the inhibitory mechanisms and therapeutic significance of plant polysaccharides, fungi polysaccharides, and algal polysaccharides in natural product polysaccharides on the occurrence and development of gastric cancer in recent years, providing a theoretical basis for the research, development, and medicinal value of polysaccharides.

Grifola frondosa polysaccharides: A review on structure/activity, biosynthesis and engineering strategies

Polysaccharides are the main polymers in edible fungi Grifola frondosa, playing a crucial role in the physiology and representing the healthy benefits for humans. Recent efforts have well elucidated the fine structures and biological functions of G. frondosa polysaccharides. The recently-rapid developments and increasing availability in fungal genomes also accelerated the better understanding of key genes and pathways involved in biosynthesis of G. frondosa polysaccharides. Herein, we provide a brief overview of G. frondosa polysaccharides and their activities, and comprehensively outline the complex process, genes and proteins corresponding to G. frondosa polysaccharide biosynthesis. The regulation strategies including strain improvement, process optimization and genetic engineering were also summarized for maximum production of G. frondosa polysaccharides. Some remaining unanswered questions in describing the fine synthesis machinery were also pointed out to open up new avenues for answering the structure-activity relationship and improving polysaccharide biosynthesis in G. frondosa. The review hopefully presents a reasonable full picture of activities, biosynthesis, and production regulation of polysaccharide in G. frondosa.

Biopharmaceutical applications of microbial polysaccharides as materials: A review

Biological characteristics of natural polymers make microbial polysaccharides an excellent choice for biopharmaceuticals. Due to its easy purifying procedure and high production efficiency, it is capable of resolving the existing application issues associated with some plant and animal polysaccharides. Furthermore, microbial polysaccharides are recognized as prospective substitutes for these polysaccharides based on the search for eco-friendly chemicals. In this review, the microstructure and properties of microbial polysaccharides are utilized to highlight their characteristics and potential medical applications. From the standpoint of pathogenic processes, in-depth explanations are provided on the effects of microbial polysaccharides as active ingredients in the treatment of human diseases, anti-aging, and drug delivery. In addition, the scholarly developments and commercial applications of microbial polysaccharides as medical raw materials are also discussed. The conclusion is that understanding the use of microbial polysaccharides in biopharmaceuticals is essential for the future development of pharmacology and therapeutic medicine.

Phytochemicals and mitochondria: Therapeutic allies against gastric cancer

BACKGROUND

Mitochondria are the energy factories of cells with the ability to modulate the cell cycle, cellular differentiation, signal transduction, growth, and apoptosis. Existing drugs targeting mitochondria in cancer treatment have disadvantages of drug resistance and side effects. Phytochemicals, which are widely found in plants, are bioactive compounds that could facilitate the development of new drugs for gastric cancer. Studies have shown that some phytochemicals can suppress the development of gastric cancer.

METHODS

We searched for data from PubMed, China National Knowledge Infrastructure, Web of Science, and Embase databases from initial establishment to December 2021 to review the mechanism by which phytochemicals suppress gastric cancer cell growth by modulating mitochondrial function. Phytochemicals were classified and summarized by their mechanisms of action.

RESULTS

Phytochemicals can interfere with mitochondria through several mechanisms to reach the goal of promoting apoptosis in gastric cancer cells. Some phytochemicals, e.g., daidzein and tetrandrine promoted cytochrome c spillover into the cytoplasm by modulating the members of the B-cell lymphoma-2 protein family and induced apoptotic body activity by activating the caspase protein family. Phytochemicals (e.g., celastrol and shikonin) could promote the accumulation of reactive oxygen species and reduce the mitochondrial membrane potential. Several phytochemicals (e.g., berberine and oleanolic acid) activated mitochondrial apoptotic submission via the phosphatidylinositol-3-kinase/Akt signaling pathway, thereby triggering apoptosis in gastric cancer cells. Several well-known phytochemicals that target mitochondria, including berberine, ginsenoside, and baicalein, showed the advantages of multiple targets, high efficacy, and fewer side effects.

CONCLUSIONS

Phytochemicals could target the mitochondria in the treatment of gastric cancer, providing potential directions and evidence for clinical translation. Drug discovery focused on phytochemicals has great potential to break barriers in cancer treatment.

Microbial polysaccharides: An emerging family of natural biomaterials for cancer therapy and diagnostics

Microbial polysaccharides (MPs) offer immense diversity in structural and functional properties. They are extensively used in advance biomedical science owing to their superior biodegradability, hemocompatibility, and capability to imitate the natural extracellular matrix microenvironment. Ease in tailoring, inherent bio-activity, distinct mucoadhesiveness, ability to absorb hydrophobic drugs, and plentiful availability of MPs make them prolific green biomaterials to overcome the significant constraints of cancer chemotherapeutics. Many studies have demonstrated their application to obstruct tumor development and extend survival through immune activation, apoptosis induction, and cell cycle arrest by MPs. Synoptic investigations of MPs are compulsory to decode applied basics in recent inclinations towards cancer regimens. The current review focuses on the anticancer properties of commercially available and newly explored MPs, and outlines their direct and indirect mode of action. The review also highlights cutting-edge MPs-based drug delivery systems to augment the specificity and efficiency of available chemotherapeutics, as well as their emerging role in theranostics.

A cold-water polysaccharide-protein complex from Grifola frondosa exhibited antiproliferative activity via mitochondrial apoptotic and Fas/FasL pathways in HepG2 cells

Grifola frondosa (G. frondosa) is widely known for its anti-tumor potential, which has been demonstrated by numerous scientific researches. In this study, two water soluble polysaccharide-protein complexes were extracted from G. frondosa at 4 °C (GFG-4) and 100 °C (GFG-100) and purified. Compared with GFG-100, GFG-4 had a higher protein content and molecular weight. The main monosaccharides of GFG-4 and GFG-100 were rhamnose, glucose, and galactose, with an approximate ratio of 3.00: 1.00: 0.86 and 2.85: 1.00: 0.94, respectively. The Fourier transform infrared spectra indicated that the two polysaccharide-protein complexes displayed characteristic functional groups of polysaccharides and proteins, and mainly contain pyranose ring with α-glycosidic linkage. Atomic force microscope images showed that both GFG-4 and GFG-100 exhibited straight chains, and GFG-4 possessed a relatively abundant fraction of branched chains. Intriguingly, GFG-4 showed a stronger antiproliferative activity against HepG2 cells than GFG-100. The mechanisms were further investigated by quantitative real-time PCR and western blot, it found that GFG-4 inhibited the proliferation of HepG2 cells mainly through the intrinsic activation of mitochondrial pathway and the Fas/FasL-mediated Caspase-8/-3 pathway. Conclusively, G. frondosa cold-water extracted polysaccharide-protein complexes could be used as a functional food for preventing or treating hepatocellular carcinoma.

The β-1,3-glucan synthase gene GFGLS2 plays major roles in mycelial growth and polysaccharide synthesis in Grifola frondosa

β-1,3-Glucans are well-known biological and health-promoting compounds in edible fungi. Our previous results characterized a glucan synthase gene (GFGLS) of Grifola frondosa for the first time to understand its role in mycelial growth and glucan biosynthesis. In the present study, we identified and functionally reannotated another glucan synthase gene, GFGLS2, based on our previous results. GFGLS2 had a full sequence of 5944 bp including 11 introns and 12 exons and a coding information for 1713 amino acids of a lower molecular weight (195.2 kDa) protein with different conserved domain sites than GFGLS (5927 bp with also 11 introns and a coding information for 1781 aa). Three dual-promoter RNA-silencing vectors, pAN7-iGFGLS-dual, pAN7-iGFGLS2-dual, and pAN7-CiGFGLS-dual, were constructed to downregulate GFGLS, GFGLS2, and GFGLS/GFGLS2 expression by targeting their unique exon sequence or conserved functional sequences. Silencing GFGLS2 resulted in higher downregulation efficiency than silencing GFGLS. Cosilencing GFGLS and GFGLS2 had a synergistic downregulation effect, with slower mycelial growth and glucan production by G. frondosa. These findings indicated that GFGLS2 plays major roles in mycelial growth and polysaccharide synthesis and provides a reference to understand the biosynthesis pathway of mushroom polysaccharides. KEY POINTS: • The 5944-bp glucan synthase gene GFGLS2 of G. frondosa was cloned and reannotated • GFGLS2 showed identity and significant differences with the previously identified GFGLS • GFGLS2 played a major role in fermentation and glucan biosynthesis.

The preparation of a cold-water soluble polysaccharide from Grifola frondosa and its inhibitory effects on MKN-45 cells

In this study, a novel water soluble polysaccharide (named GFP-4) was extracted from Grifola frondosa at 4 ^oC, and its preliminary structure and inhibitory effects on human gastric carcinoma MKN-45 cells through the Fas/FasL death receptor apoptosis pathway were investigated. High-performance gel permeation chromatography (HPGPC), fourier-transform infrared spectroscopy (FT-IR), and ion chromatography (IC) results showed that GFP-4 was a 1.09 × 10⁶ Da neutral hetero polysaccharide with pyranose rings, and α- and β-type glycosidic linkages that contained galactose, glucose, and mannose at a molar ratio of 1.00:3.45:1.19. MTT results indicated that GFP-4 significantly inhibited the proliferation of MKN-45 cells in a concentration-dependent manner. The H&E staining and Hoechst 33342/PI double staining results showed that GFP-4-treated MKN-45 cells were subjected to underwent typical apoptotic morphologic changes such as nuclear pyknosis, chromatin condensation, and an increase of membrane permeability. Annexin V-FITC/PI double staining, cell cycle analysis, and western blot results revealed the GFP-4 induced MKN-45 cells apoptosis through the Fas/FasL-mediated death receptor pathway with cells arrested at the G0/G1 phase. These data indicate that GFP-4 is a promising candidate for treating gastric cancer and provide a theoretical basis for the future development and utilization of G. frondosa clinically.

In Vitro Anti-proliferative and Anti-invasive Effect of Polysaccharide-rich Extracts from Trametes Versicolor and Grifola Frondosa in Colon Cancer Cells

Colorectal cancer (CRC) is one of leading causes of mortality in western countries and novel treatment strategies are required. The medicinal application of mushrooms has been used in traditional medicine in many oriental countries. Polysaccharide-rich extracts obtained from certain medicinal mushroom species have shown antitumor effects in different experimental models. In the present study, we have developed polysaccharide-rich extracts from Trametes versicolor (TV) and Grifola frondosa (GF) fruit bodies. We aim to evaluate the anticancer effects of these polysaccharide-rich extracts in LoVo and HT-29 human colon cancer cells. The in vitro effects were determined by cytotoxicity assay, proliferation assay, wound healing assay and invasion assay. Moreover, the effect on anchorage independent-cell growth was also determined. Our results showed that TV and GF extracts did inhibit human colon cell proliferation and induce cytotoxicity. Furthermore, both fungal extracts significantly inhibited oncogenic potential, cell migration and invasion in colon cancer cells. In addition, extracts induce a more epithelial phenotype, observed by phase contrast images, together with an increase expression of the E-cadherin epithelial marker, detected by western-blotting analyses. Moreover, by using gelatin zymography assays, it was detected a decrease of MMP-2 enzyme activity, a crucial metalloproteinase important for the degradation of the extracellular matrix. Finally, the combination of the extracts with one the most clinical used agents for colorectal cancer, 5-fluorouracil, increases cell cytotoxicity. Taken together our results underscore a potential antitumor effect of polysaccharide-rich extracts obtained from TV and GF in human colon cancer cells lines. These finding may contribute to the reported health effects of fungal extracts.

Griflola frondosa (GF) produces significant antidepressant effects involving AMPA receptor activation in mice

CONTEXT

Griflola frondosa (Fr) S.F. Gray (Meripilaceae) (GF) is a medical mushroom, and its regulation of the immune system is of interest for the treatment of mood disorders. α-Amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors are the central mediator for the treatment of depression.

OBJECTIVE

This study examines the antidepressant effects of GF and the role of AMPA in these antidepressant effects.

MATERIALS AND METHODS

The CD-1 mice were fed with GF- or Pleurotus ostreatus [(Jacq.: Fr) Kumm (Pleurotaceae)] (PO)-containing food for 1 day or 5 days. The antidepressant effects was determined in the tail suspension test (TST), forced swim test (FST), and open field test (OFT). The involvement of AMPA receptors was determined by the application of the AMPA-specific blocker GYKI 52466.

RESULTS

Treatments with 20%, 33% or 50% of GF-containing food significantly decreased the immobility time (63.6, 56.9, and 52.0% in TST; and 50.8, 43.2, and 38.2% in FST) after 1 day and (62.3, 51.8, and 52.8% in TST; and 49.5, 45.1, and 40.3% in FST) after 5 days. GF-containing food did not cause hyperactive effects in the OFT. The antidepressant effects of the 33% of GF-containing food (down-to 51.3% in 1-day TST and 46.8% in 5-day FST) were significantly stronger than that of the 33% of PO-containing food (down-to 85.5% in 1-day TST and 82.0% in 5-day FST). AMPA-specific blocker GYKI 52466 was able to block the antidepressant effects of the GF-containing food.

CONCLUSION

GF demonstrated the potential as a safe medical food supplement for the patient with depression.

Grifola frondosa polysaccharides induce breast cancer cell apoptosis via the mitochondrial-dependent apoptotic pathway

Grifola frondosa, a type of food and medical fungus, has been shown to exhibit various pharmacological activities, including anticancer effects. As the most typical cancer diagnosed among female patients, breast cancer remains a huge concern threatening human health globally. In the present study, the anti-breast cancer effects of Grifola frondosa polysaccharides (GFPs) and the underlying mechanisms were investigated in MCF-7 and MDA-MB-231 cells, as well as in nude mice bearing MCF-7 tumor xenografts. GFPs exerted cytotoxic effects on the cells, as indicated by a decrease in cell viability, and an increase in the apoptototic rate, lactate dehydrogenase release and reactive oxygen species accumulation, inducing mitochondrial dysfunction. The increased expression of Bax, cleaved caspase-3 and caspase-8, and the reduced levels of B-cell lymphoma 2 (Bcl-2) and Bcl-extra large (Bcl-xL) were observed in the cells incubated with GFPs and in the tumor tissues of the mice treated with GFPs. Moreover, the GFPs significantly suppressed the phosphorylation of AKT/glycogen synthase kinase-3β and extracellular signal-regulated kinases in a time-dependent manner. Finally, the inhibition of MCF-7 tumor xenograft growth further confirmed the anti-breast cancer effects of GFPs. All these findings revealed that GFPs induced human breast cancer cell apoptosis via the mitochondrial-dependent apoptotic pathway, and provide experimental evidence to support the use of Grifola frondosa as a potential treatment for breast cancer.

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.

Synergistic Apoptotic Effect of D-Fraction From Grifola frondosa and Vitamin C on Hepatocellular Carcinoma SMMC-7721 Cells

The aim of this study was to investigate the anticancer effect of a combination of D-fraction polysaccharide from Grifola frondosa (DFP) and vitamin C (VC) on hepatocellular carcinoma in vitro. DFP is a bioactive extract from the maitake mushroom. Anticancer activity was demonstrated using various concentrations of DFP alone or in combination with VC against the human hepatocarcinoma SMMC-7721 cell line. To investigate the anticancer mechanism, studies designed to detect cell apoptosis were conducted. Results from the MTT assay indicated that a combination of DFP (0.2 mg/mL) and VC (0.3 mmol/L) led to a 70% reduction in cell viability. Flow cytometry results indicated that DFP/VC treatment induced apoptosis in approximately 65% SMMC-7721 cells. Cell cycle analysis identified cell cycle arrest at the G2/M phase following DFP/VC treatment for 48 hours. In addition, cellular morphological changes were observed using transmission electron microscopy. Western blot analysis revealed that the upregulation of BAX, downregulation of Bcl-2, activation of poly-(ADP-ribose)-polymerase (PARP), and the release of cytochrome c were observed in cells treated with the combination of DFP/VC, which showed that the mechanism of anticancer activity in the SMMC-7721 hepatocarcinoma cells involved induction of apoptosis.

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.

Composition of Lycium barbarum polysaccharides and their apoptosis-inducing effect on human hepatoma SMMC-7721 cells

Background

Lycium barbarum polysaccharide (LBP) is a natural functional component that has a variety of biological activities. The molecular structures and apoptosis-inducing activities on human hepatoma SMMC-7721 cells of two LBP fractions, LBP-d and LBP-e, were investigated.

Results

The results showed that LBP-d and LBP-e both consist of protein, uronic acid, and neutral sugars in different proportions. The structure of LBP was characterized by gas chromatography, periodate oxidation, and Smith degradation. LBP-d was composed of eight kinds of monosaccharides (fucose, ribose, rhamnose, arabinose, xylose, mannose, galactose, and glucose), while LBP-e was composed of six kinds of monosaccharides (fucose, rhamnose, arabinose, mannose, galactose, and glucose). LBP-d and LBP-e blocked SMMC-7721 cells at the G0/G1 and S phases with an inhibition ratio of 26.70 and 45.13%, respectively, and enhanced the concentration of Ca²⁺ in the cytoplasm of SMMC-7721.

Conclusion

The contents of protein, uronic acid, and galactose in LBP-e were much higher than those in LBP-d, which might responsible for their different bioactivities. The results showed that LBP can be provided as a potential chemotherapeutic agent drug to treat cancer.

Tissue invasion and metastasis: Molecular, biological and clinical perspectives

Cancer is a key health issue across the world, causing substantial patient morbidity and mortality. Patient prognosis is tightly linked with metastatic dissemination of the disease to distant sites, with metastatic diseases accounting for a vast percentage of cancer patient mortality. While advances in this area have been made, the process of cancer metastasis and the factors governing cancer spread and establishment at secondary locations is still poorly understood. The current article summarizes recent progress in this area of research, both in the understanding of the underlying biological processes and in the therapeutic strategies for the management of metastasis. This review lists the disruption of E-cadherin and tight junctions, key signaling pathways, including urokinase type plasminogen activator (uPA), phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene (PI3K/AKT), focal adhesion kinase (FAK), β-catenin/zinc finger E-box binding homeobox 1 (ZEB-1) and transforming growth factor beta (TGF-β), together with inactivation of activator protein-1 (AP-1) and suppression of matrix metalloproteinase-9 (MMP-9) activity as key targets and the use of phytochemicals, or natural products, such as those from Agaricus blazei, Albatrellus confluens, Cordyceps militaris, Ganoderma lucidum, Poria cocos and Silybum marianum, together with diet derived fatty acids gamma linolenic acid (GLA) and eicosapentanoic acid (EPA) and inhibitory compounds as useful approaches to target tissue invasion and metastasis as well as other hallmark areas of cancer. Together, these strategies could represent new, inexpensive, low toxicity strategies to aid in the management of cancer metastasis as well as having holistic effects against other cancer hallmarks.

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.

Induction of apoptosis in HepG2 cells by polysaccharide MEP-II from the fermentation broth of Morchella esculenta

A novel polysaccharide, MEP-II, isolated from the fermentation broth of Morchella esculenta inhibited the proliferation of human hepatoma cell line (HepG2) through an apoptotic pathway. After HepG2 cells were treated with 150-600 μg MEP-II/ml, typical apoptotic characteristics including externalization of phosphatidylserine residues on the cell surface, nuclear fragmentation, chromatin condensation and cytoplasm shrinkage were observed. Furthermore, reactive oxygen species (ROS) burst and the collapse of mitochondrial membrane potential (Δψm) also occurred in HepG2 cells after incubation of 150-600 μg MEP-II/ml. The antioxidant, 1 mM N-acetyl-L-cysteine inhibited MEP-II-induced apoptosis, suggesting that ROS are the key mediators for MEP-II-induced apoptosis. MEP-II is therefore a potential anti-tumor agent that induces apoptosis of HepG2 cells through ROS generation.

Bryonia dioica aqueous extract induces apoptosis through mitochondrial intrinsic pathway in BL41 Burkitt's lymphoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Bryonia dioica Jacq. is a climbing perennial herb with tuberous roots which is widely used in traditional medicine in Algeria for the treatment of cancers; it belongs to the genus Bryonia (Cucurbitaceae).

AIM OF THE STUDY

To investigate the cytotoxic and apoptogenic activities, the phytochemical composition and acute toxicity of the aqueous extract of Bryonia dioica roots growing in Algeria.

MATERIALS AND METHODS

Dried roots of Bryonia dioica were extracted with water (decoction). The cytotoxic effects of the aqueous extract in the Burkitt's lymphoma BL41 cell lines were evaluated by flow cytometry. Apoptosis induction was assessed by two corroborative assays; propidium iodide (PI) staining of cell DNA and flow cytometric light scatter analysis. The mitochondria membrane potential was investigated using a fluorescent dye DIOC6. The expression of caspases-3, -8, -9 and PARP was assessed by Western blot. The phytochemical screening of the roots of Bryonia dioica was performed using qualitative phytochemical standard procedures.

RESULTS

The Bryonia dioica aqueous extract induced cell death in a dose-dependent manner. The IC50 of Bryonia dioica aqueous extract was estimated to be approximately 15, 63μg/ml. This was accompanied by induction of apoptosis, activation of caspase-3 and -9, cleavage of PARP and loss of mitochondria membrane potential. Furthermore, the phytochemical screening of roots of Bryonia dioica showed the presence of various bioactive such as polyphenols, sterols and triterpenes, alkaloids, c-heterosides, carbohydrates and saponins.

CONCLUSION

The aqueous extract of Bryonia dioica induces apoptosis in the Burkitt's lymphoma BL41 cell lines via the mitochondrial pathway. The flavonoids, sterols and triterpens detected could be responsible for the cytotoxic and apoptogenic activities of the aqueous extract of Bryonia dioica. These findings suggest that Bryonia dioica could be considered as a promising source for developing novel therapeutics against Burkitt's lymphoma.

An exopolysaccharide from Trichoderma pseudokoningii and its apoptotic activity on human leukemia K562 cells

In this study, a novel exopolysaccharide (EPS) was isolated from the fermentation broth of Trichoderma pseudokoningii and its anticancer activities on human leukemia K562 cells were studied. EPS could significantly inhibited K562 cells proliferation in a time- and concentration-dependent manner. Meanwhile, characteristic of apoptosis, including apoptotic morphological features and the apoptosis rate were obtained. Sequentially, the dissipation of mitochondrial membrane potential, increase production of Reactive oxygen species (ROS), enhancement of the concentration of intracellular, up-regulation of Bax and p53 mRNA, down-regulation of Bcl-2 mRNA were also detected. The results indicate that the EPS could induce of K562 cells apoptosis, primarily in involved the mitochondrial pathways. The present studies suggest that EPS could be a new potential adjuvant chemotherapeutic and chemo preventive agent against human leukemia.

Recent developments in mushrooms as anti-cancer therapeutics: a review

From time immemorial, mushrooms have been valued by humankind as a culinary wonder and folk medicine in Oriental practice. The last decade has witnessed the overwhelming interest of western research fraternity in pharmaceutical potential of mushrooms. The chief medicinal uses of mushrooms discovered so far are as anti-oxidant, anti-diabetic, hypocholesterolemic, anti-tumor, anti-cancer, immunomodulatory, anti-allergic, nephroprotective, and anti-microbial agents. The mushrooms credited with success against cancer belong to the genus Phellinus, Pleurotus, Agaricus, Ganoderma, Clitocybe, Antrodia, Trametes, Cordyceps, Xerocomus, Calvatia, Schizophyllum, Flammulina, Suillus, Inonotus, Inocybe, Funlia, Lactarius, Albatrellus, Russula, and Fomes. The anti-cancer compounds play crucial role as reactive oxygen species inducer, mitotic kinase inhibitor, anti-mitotic, angiogenesis inhibitor, topoisomerase inhibitor, leading to apoptosis, and eventually checking cancer proliferation. The present review updates the recent findings on the pharmacologically active compounds, their anti-tumor potential, and underlying mechanism of biological action in order to raise awareness for further investigations to develop cancer therapeutics from mushrooms. The mounting evidences from various research groups across the globe, regarding anti-tumor application of mushroom extracts unarguably make it a fast-track research area worth mass attention.

Enhancement of in vitro and in vivo anticancer activities of polysaccharide peptide from Grifola frondosa by chemical modifications

CONTEXT

Grifola frondosa (Polyporaceae), maitake, is a widely consumed edible mushroom in some Asian countries. The fruit bodies and mycelia of maitake have shown different bioactive compounds with anticancer and other therapeutic properties.

OBJECTIVE

This study evaluated three chemically modified maitake polysaccharide-peptides' (MPSP) adjuvant effect (in vivo) and anticancer activity (in vitro growth inhibitory effect) compared with crude MPSP from G. frondosa.

MATERIALS AND METHODS

We investigated the possibility of enhancing the adjuvant effect and anticancer effect of crude MPSP by using simple chemical modification methods to convert crude MPSP to phosphorylated, acetylated or esterified MPSPs. The adjuvant effect and growth inhibitory effect were evaluated by C6 cell inoculated rat model with cyclophosphamide (CPA) treatment and in vitro cell viability assay, respectively.

RESULTS

All four tested MPSPs showed significant adjuvant effect to CPA treatment on rats inoculated with C6 cancer cells. In addition, an obvious growth inhibitory effect was observed in C6 cancer cells but not in normal brain cells treated with various forms of MPSPs. Only phosphorylation could significantly (p < 0.05) improve the adjuvant effect (in vivo) and growth inhibitory effect. A same rank order (phosphorylated MPSP > esterified MPSP ≥ acetylated MPSP ≥ crude MPSP) of efficacy was observed in both the in vivo and in vitro assays.

DISCUSSION AND CONCLUSION

This study showed chemical phosphorylation could markedly enhance both adjuvant effects and growth inhibitory effects. This study demonstrated the feasibility of enhancing the efficacy of MPSP by using a simple chemical modification method, and this provides a foundation for future study in this area.

Antiproliferation of melanoma cells by polysaccharide isolated from Zizyphus jujuba

OBJECTIVE

Zizyphus jujuba, a traditional Chinese herb rich in functional components such as polysaccharide, has been widely consumed in Asian countries. The objective of this study was to determine the antiproliferation effect of melanoma cells as affected by deproteinized polysaccharide (DPP) isolated from Z. jujuba.

METHODS

Deproteinized polysaccharide was obtained through boiling water extraction, ethanol precipitation, deproteinization, and dialysis, and the molecular weight of DPP was determined by high-performance gel-filtration chromatography. Melanoma cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the cell cycle was analyzed by flow cytometry, the formation of apoptotic bodies was observed under a fluorescence microscope at 450 nm, and caspase-3 and caspase-9 were measured by an assay kit.

RESULTS

Deproteinized polysaccharide was composed of two fractions with average molecular weights of 143 108 and 67 633 Da. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test showed that the antiproliferation effect of DPP on melanoma cells followed a dose- and time-dependent course. The 50% inhibitory concentration of DPP in inhibiting melanoma cell growth was 3.99 ± 0.10 mg/mL after 24-h treatment but decreased significantly to 3.36 ± 0.14 mg/mL after 48 h. The cell cycle assay revealed melanoma cells to be arrested in G2/M phase. Moreover, with DPP treatment, the apoptotic bodies were generated, accompanied by an increase in caspase-3 and caspase-9 activity.

CONCLUSIONS

This outcome suggested that DPP may be used as a potential anti-skin cancer agent for further in vivo and clinical trial experiments.

Changes of constituents and activity to apoptosis and cell cycle during fermentation of tea

Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher in the fermented black tea and pu-erh tea, while the polyphenol level was higher in the unfermented green tea. Hence, a treatment of tea aqueous extract and the components, which are emerging as promising anticancer agents, were pursued to determine whether this treatment could lead to enhance apoptosis and cell cycle arrest. In the human gastric cancer cell line SGC-7901, the cell viability and flow cytometry analysis for apoptotic cells indicated effects in a dose-dependent inhibition manner for the three tea treatment groups. The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism. Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins. CCC-HEL-1 normal cells were not sensitive to tea extract. These findings suggest that the fermentation process causes changes of the compounds which might be involved in the changes of cell proliferation inhibition, apoptosis induction and cell cycle arrest.

Purification and characterization of inulin fructotransferase (DFA III-forming) from Arthrobacter aurescens SK 8.001

The soil bacterium Arthrobacter aurescens SK 8.001 produces inulin fructotransferase (IFTase), and liquid chromatography-mass spectrometry (LC-MS) and carbon-13 nuclear magnetic resonance (13C NMR) analysis demonstrated that the main product of the enzyme was difructose anhydride III (DFA III). The IFTase was purified by ethanol precipitation, DEAE Sepharose Fast Flow, and Superdex 200 10/300 GL gel chromatography. Its molecular mass was estimated to be 40 kDa by SDS-PAGE and 35 kDa by gel filtration. The enzyme showed maximum activity at pH 5.5 and 60-70 °C, and retained 86.5% of its initial activity after incubation at 60 °C for 4 h. Chemical modification results suggested that a tryptophan residue is essential to enzyme activity. The N-terminal amino acid sequence was determined as AEGAKASPLNSPNVYDVT. The kinetic values, Km and Vmax, were estimated to be 0.52 mM and 0.3 μmol/ml min. Nystose was observed to be the smallest substrate for the produced IFTase. This IFTase provides a promising way to utilize inulin for the production of DFA III.

Fractionation, partial characterization and bioactivity of water-soluble polysaccharides and polysaccharide-protein complexes from Pleurotus geesteranus

Fractionation and purification of mushroom polysaccharides is a critical process for mushroom clinical application. After a hot-water treatment, the crude Pleurotus geesteranus (PG) was further fractionated into four fractions (PG-1, -2, -3, -4) using gradient precipitation with water and ammonia sulphate. By controlling the initial polymer concentration and ratio of solvents, this process produced PG fractions with high chemical uniformity and narrow Mw distribution without free proteins. Structurally, PG-1 and PG-2 are pure homopolysaccharide mainly composed of glucose; and PG-3 and PG-4 are heteropolysaccharide-protein complexes. PG-2, a high M(w) fraction mainly composed of glucose presented significant cytotoxicity at the concentration of 200 and 100 μg/ml to human breast cancer cells. Here, we report a new mushroom polysaccharides extraction and fractionation method, with which we produced four fractions of PG with PG-2 appearing effective anti-tumour activity.

Characterization and anti-tumor activities of sulfated polysaccharide SRBPS2a obtained from defatted rice bran

A novel chemically sulfated polysaccharide SRBPS2a with potent anti-tumor activity was derived from defatted rice bran by chlorosulfonic acid-pyridine (CSA-Pyr) method. The average molecular weight of SRBPS2a was 3.5 x 10(5) Da and the degree of sulfation (DS) was 1.29. The Fourier-transform infrared spectra (FT-IR) and 13C NMR spectroscopy analysis revealed that SRBPS2a was mainly consist of beta-(1-->3)-D-galactopyranosyl residues, the sulfate substitution site was on C-2 and C-4 while the side chains were cut off during the sulfated reaction. Furthermore, SRBPS2a exhibited evident growth inhibition on mouse mammary tumor EMT-6 cells both in vitro and in vivo.

[The fungus maitake (Grifola frondosa) and its therapeutic potential]

Grifola frondosa (Dicks.) Gray is a polyporaceous fungus and, due to its medical properties, has been used in Eastern cultures for thousands of years. A review of previously published literature on this fungus, its ethnomycological, nutritional, pharmacological and medical aspects were investigated.

Study on the structure-activity relationships of phoxalone and induction of apoptosis in H446 tumor cells

A novel macrolide with dioxa and double ring pentadecanone, named as phoxalone, isolated from the culture broth of a myxobacterium Sorangium cellulosum WXNXJ-C, was well investigated. The chemical structure of Phoxalone was elucidated by spectroscopic analysis including UV, IR, (1)H NMR, MALDI-TOF-MS, and LC/MS spectra. The results of cytotoxic bioactivities on human non-small lung cancer H446, in vitro, showed that not only did phoxalone express higher antitumor bioactivity than many antitumor drugs, but it also displayed less cytotoxicity to normal human liver L02 cell lines (IC(50), 286 microg mL(-1)). Further cytotoxic bioactivity study indicated that phoxalone could induce H446 cell line apoptosis in vitro. More investigation results of flow-cytometric analysis suggested that phoxalone arrested the mitosis of H446 cell line at G2/M phase. Hence, phoxalone and its derivatives or analogs would reveal huge research value and fascinating foreground.