The Pharmacological Rationales and Molecular Mechanisms of Ganoderma lucidum Polysaccharides for the Therapeutic Applications of Multiple Diseases

As a versatile Chinese herb, Ganoderma lucidum (Leyss. ex Fr.) Karst (G. lucidum) has been applied to treat multiple diseases in clinics and improve the quality of life of patients. Among all of its extracts, the main bioactive components are G. lucidum polysaccharides (GLPs), which possess many therapeutic effects, such as antitumor, immunoregulatory, anti-oxidant, antidiabetic, antibacterial, and antifungal effects and neuroprotection activities. This review briefly summarized the recent studies of the pharmacological rationales of GLPs and their underlying molecular signaling transmission mechanisms in treating diseases. Until now, the clear mechanisms of GLPs for treating diseases have not been reported. In this review, we used the keywords of "Ganoderma lucidum polysaccharides" and "tumor" to search in PubMed (years of 1992-2020), then screened and obtained 160 targets of antitumor activities in the literatures. The network pharmacology and mechanism framework were employed in this study as powerful approaches to systematically analyze the complicated potential antitumor mechanisms and targets of GLPs in cancer. We then found that there are 69 targets and 21 network pathways in "Pathways in cancer". Besides, we summarized the effects of GLPs and the models and methods used in the research of GLPs. In conclusion, GLPs have been studied extensively, but more in-depth research is still needed to determine the exact mechanisms and pathways. Therefore, this review might provide new insights into the vital targets and pathways for researchers to study the pharmacological mechanisms of GLPs for the treatment of diseases.

Antitumor effects of different Ganoderma lucidum spore powder in cell- and zebrafish-based bioassays

OBJECTIVE

Ganoderma lucidum spore (GLS) is gaining recognition as a medicinal part of G. lucidum and has been reported to possess various pharmacological properties, such as antitumor activity. In this work, wall-broken GLS powder (BGLSP) and wall-removed GLS powder (RGLSP), two kinds of GLS powder with different manufacturing techniques, were compared in terms of contents of active constituents and in vivo and in vitro antitumor effects.

METHODS

The ultraviolet and visible spectrophotometry method was used to determine the contents of polysaccharides and total triterpenoids in BGLSP and RGLSP. Seventeen individual triterpenoids were further quantified using ultra-high-performance liquid chromatography and quantitative analysis of multi-components by single marker. The antitumor effects of BGLSP and RGLSP were evaluated using in vitro cell viability assay against human gastric carcinoma SGC-7901, lung carcinoma A549 and lymphoma Ramos and further validated by in vivo zebrafish xenograft models with transplanted SGC-7901, A549 and Ramos.

RESULTS

The results showed that the contents of polysaccharides, total triterpenoids and individual triterpenoids of RGLSP were significantly higher than those of BGLSP. Although both BGLSP and RGLSP inhibited the three tumor cell lines in vitro in a dose-dependent manner, the inhibitory effects of RGLSP were much better than those of BGLSP. In the in vivo zebrafish assay, RGLSP exhibited more potent inhibitory activities against tumors transplanted into the zebrafish compared with BGLSP, and the inhibition rates of RGLSP reached approximately 78%, 31% and 83% on SGC-7901, A549 and Ramos, respectively.

CONCLUSION

The results indicated that the antitumor effects of GLS were positively correlated with the contents of the polysaccharides and triterpenoids and demonstrated that the wall-removing manufacturing technique could significantly improve the levels of active constituents, and thereby enhance the antitumor activity.

Polysaccharide from Ganoderma lucidum ameliorates cognitive impairment by regulating the inflammation of the brain-liver axis in rats

Ganoderma lucidum (G. lucidum) polysaccharide-1 (GLP-1) is one of the polysaccharides isolated from the fruiting bodies of G. lucidum. Inflammation in the brain-liver axis plays a vital role in the progress of cognitive impairment. In this study, the beneficial effect of GLP-1 on d-galactose (d-gal) rats was carried out by regulating the inflammation of the brain-liver axis. A Morris water maze test was used to assess the cognitive ability of d-gal rats. ELISA and/or western blot analysis were used to detect the blood ammonia and inflammatory cytokines levels in the brain-liver axis. Metabolomic analysis was used to evaluate the changes of small molecule metabolomics between the brain and liver. As a result, GLP-1 could obviously ameliorate the cognitive impairment of d-gal rats. The mechanism was related to the decreasing levels of TNF-α, IL-6, phospho-p38MAPK, phospho-p53, and phospho-JNK1 + JNK2 + JNK3, the increasing levels of IL-10 and TGF-β1, and the regulation of the metabolic disorders of the brain-liver axis. Our study suggests that G. lucidum could be exploited as an effective food or health care product to prevent and delay cognitive impairment and improve the quality of life.

Ganoderma spore lipid protects mouse bone marrow mesenchymal stem cells and hematopoiesis from the cytotoxicity of the chemotherapeutic agent

Cancer chemotherapeutic agents are frequently toxic to bone marrow and impair bone marrow functions. It is unclear whether ganoderma spore lipid (GSL) can protect bone marrow cells from the cytotoxicity of chemotherapy. To investigate the protective effects of GSL on bone marrow mesenchymal stem cells (MSCs) and hematopoiesis, we examined the effects of GSL on MSCs in vitro and hematopoiesis in vivo after treatment with the chemotherapeutic agent cyclophosphamide. MSCs and peripheral blood cells were isolated and counted from the bone marrow of normal mice were pre-treated with GSL before CTX treatment or co-treated with GSL and CTX, followed by examining the changes in phenotype, morphology, proliferation, apoptosis, and differentiation potentials. The results showed that GSL could reduce the CTX-induced changes in the phenotype of MSCs and maintain the elongated fibroblast-like morphology. MTT and annexin V/propidium iodide (PI) analyses found that GSL pre-treatment and co-treatment increased the proliferation and decreased the apoptosis in CTX-treated MSCs. Furthermore, GSL improved the osteogenic and adipogenic differentiation potentials of CTX-treated MSCs. In vivo, GSL treatment increased the number of peripheral blood cells including white blood cells (WBC) and platelets (PLT) in the CTX-treated mice and enhanced the in vitro formation of hematopoietic lineage colonies (erythrocyte colony forming unit, CFU-E; erythroid burst-forming units, BFU-E; and granulocyte macrophage colony-forming units, CFU-GM) from bone marrow cells in these mice. These findings suggest GSL could protect MSCs and hematopoiesis from the cytotoxicity of CTX and might become an effective adjuvant to attenuate side effects of chemotherapy during cancer treatment.

Cellular and Molecular Mechanism of Ganoderma (Lingzhi) Against Tumor

The anticancer potential of Ganoderma (Lingzhi) and its extracts has been widely demonstrated, including antiproliferative and apoptosis inductive, antimetastatic, antiangiogenic, and multidrug resistance reversional activities, involving a variety of cellular and molecular mechanisms besides antitumor immunology. Intrinsic- and extrinsic-initiated apoptotic pathway in association with cell cycle arresting, telomerase inhibiting, autophagy, and oxidative stress is involved in the antiproliferative and apoptosis inductive activities of Ganoderma and its extracts. The inhibition of tumor cell adhesion, invasion, and migration by Ganoderma and its extracts involves molecular mechanisms such as AP-1, NF-κB, MMP, cadherin, β-integrin, c-Met, FAK, EMT, and so on. Targeting the major pro-angiogenic stimulus, VEGF, and its receptor contributes to the inhibition of tumor angiogenesis by Ganoderma and its extracts. Inhibition against the ATP-dependent transmembrane drug transporter such as P-glycoprotein (P-gp) on the surface of resistant tumor cells to prevent reduction of the intracellular accumulation of anticancer drugs by pumping out the drugs plays an important role in the activities of Ganoderma and its extracts to reverse tumor cell multidrug resistance.

Structure and bioactivities of a polysaccharide isolated from Ganoderma lucidum in submerged fermentation

In this study, a Ganoderma lucidum polysaccharide GLP-1-1 was isolated from a culture broth with Mw of 22014 Da. Monosaccharide contained glucose, mannose, and galactose with mole percentages of 92.33%, 7.55%, and 0.22%, respectively. Moreover, FTIR and methylation analysis were conducted to characterize the structural properties of GLP-1-1. The results of antioxidant activity analysis showed that GLP-1-1 had a great DPPH and ABTS radical scavenging activity. Meanwhile, GLP-1-1 also exhibited anti-tumor activity to A431 and MDA-MB-231 cells, and inhibitory rates were dose-dependent. During culturing with GLP-1-1, the G1/G0 cell percentage of A431 cells was increased from 48.64% to 84.52%, and the G1/G0 cell percentage of MDA-MB-231 cells was increased from 57.14% to 73.48%. Therefore, the anti-tumor activity of GLP-1-1 may be caused by inducing the G1/G0 arrest of tumor cells.

Restoration of the tumor-suppressor function to mutant p53 by Ganoderma lucidum polysaccharides in colorectal cancer cells

Ganoderma lucidum polysaccharides (GLPs), isolated from spores, mycelia and fruiting bodies of Ganoderma lucidum, have been suggested to possess anticancer activities in a large number of basic studies. A recent survey revealed that GLP-induced inhibition of cancer cell growth was dependent on the existence of functional p53. However, the actual role of p53-mediated tumor-suppressing pathways in facilitating the anticancer effect of GLPs is still unclear. In the present study, we investigated the interaction between GLPs and mutant p53 that exists in more than half of the known types of cancers. Our results showed that GLPs reactivated mutant p53 in colorectal cancer HT29 (p53R273H) and SW480 (p53R273H&P309S) cells while applied alone or together with 5-fluorouracil (5-FU). This reactivation further induced cell growth inhibition and apoptosis. In addition, western blot assay and in vitro cell-free apoptosis assay suggested that the activation of mutant p53 was effective in both a transcriptional-dependent and -independent pathway. Altogether, our data demonstrated for the first time that GLPs show prominent anticancer activities by reactivating several types of mutant p53. Therefore, targeting mutant p53 by GLPs alongside other chemotherapeutics may be considered as a novel treatment strategy for cancer.