Immunomodulatory Activity and Its Mechanisms of Two Polysaccharides from Poria cocos

Polyporaceae is an important fungal family that has been a source of natural products with a range of pharmaceutical activities in China. In our previous study, two polysaccharides, PCWPW and PCWPS, with significant antioxidant and antidepressant activity were obtained from Poria cocos. In this study, we evaluated their potential molecular mechanisms in the immunomodulation of macrophages. PCWPW and PCWPS were characterized by GC-MS analysis to contain 1,3-linked Glcp. ELISA assays results demonstrated that the secretion of TNF-α was significantly enhanced by PCWPW/PCWPS. RNA-seq data demonstrated that PCWPS treatment modulated the expression of immune-related genes in macrophages, which was further confirmed by RT-qPCR assays. The activation of TNF-α secretion was found to be mannose receptor (MR) dependent and suppressed by MR inhibitor pretreatment. Moreover, the amount of TNF-α cytokine secretion in PCWPW/PCWPS-induced RAW264.7 cells was decreased when pretreated with NF-κB or MAPK signaling pathway inhibitors. Collectively, our results suggested that PCWPW and PCWPS possessed immunomodulatory activity that regulates TNF-α expression through the NF-κB/MAPK signaling pathway by binding to mannose receptors. Therefore, PCWPW and PCWPS isolated from Poria cocos have potential as drug candidates for immune-related disease treatment.

[Effect and mechanism of Poria cocos polysaccharides on myocardial cell apoptosis in rats with myocardial ischemia-reperfusion injury by regulating Rho-ROCK signaling pathway]

This study aimed to investigate the effect and underlying mechanism of Poria cocos polysaccharides(PCP) on myocardial cell apoptosis in the rat model of myocardial ischemia-reperfusion injury(MI/RI). Male SPF-grade SD rats were randomly divided into a sham group(saline), a model group(saline), low-and high-dose PCP groups(100 and 200 mg·kg~(-1)), and a fasudil group(10 mg·kg~(-1)), with 16 rats in each group. Except for the sham group, the other four groups underwent left anterior descending coronary artery ligation for 30 min followed by reperfusion for 2 h to establish the MI/RI model. The myocardial infarct area was assessed by TTC staining. Histological changes were observed through HE staining. Myocardial cell apoptosis was evaluated using TUNEL staining. Serum lactate dehydrogenase(LDH), creatine kinase MB(CK-MB), interleukin-1β(IL-1β) and IL-18 levels, myocardial superoxide dismutase(SOD) activity and malondialdehyde(MDA) levels were detected by ELISA. Protein expression of B-cell lymphoma 2(Bcl-2), Bcl-2 associated X protein(Bax), cleaved caspase-3, Ras homolog gene A(RhoA), myosin phosphatase target subunit 1(MYPT-1), phosphorylated MYPT-1(p-MYPT-1), and Rho-associated coiled-coil forming kinase 1(ROCK 1) were measured by Western blot. Pathological staining of myocardial tissue revealed that in the model group, there was focal necrosis of myocardial tissue, myocardial cell swelling, unclear boundaries, and neutrophil infiltration. These pathological changes were alleviated in the low-and high-dose PCP groups and the fasudil group. Compared with the model group, the low-and high-dose PCP groups and the fasudil group showed significantly reduced myocardial infarct area and myocardial cell apoptosis rate. Compared with the sham group, the model group exhibited elevated serum LDH, CK-MB, IL-1β and IL-18 levels, increased MDA levels, relative protein expression of Bax, cleaved caspase-3, RhoA, ROCK1 and p-MYPT-1, and decreased myocardial SOD levels and Bcl-2 protein expression. Compared with the model group, the PCP groups and the fasudil group showed lowered serum LDH, CK-MB, IL-1β and IL-18 levels, decreased MDA levels, relative protein expression of Bax, cleaved caspase-3, RhoA, ROCK1 and p-MYPT-1, and increased myocardial SOD levels and Bcl-2 protein expression. PCP exhibited a certain preventive effect on myocardial tissue pathological damage and myocardial cell apoptosis in MI/RI rats, possibly related to the inhibition of the Rho-ROCK signaling pathway activation, thereby reducing oxidative stress and inflammatory responses.

Four polysaccharides isolated from Poria cocos mycelium and fermentation broth supernatant possess different activities on regulating immune response

Four polysaccharide fractions were isolated and purified from the culture supernatant and mycelium of Poria cocos, and differences in their immunomodulatory activity were investigated. The average molecular weights of EPS-0M, EPS-0.1M, IPS-0M, and IPS-0.1M were 1.77 × 10³, 2.01 × 10³, 0.03 × 10³ and 4.97 × 10³ kDa, respectively. They all mainly consisted of 5 monosaccharides, including glucose, mannose, galactose, fucose and rhamnose, but with different molar ratios. At a dose of 50 μg/mL, EPS-0M, EPS-0.1M, and IPS-0.1M significantly increased the production of nitric oxide (NO), as well as the mRNA and protein levels of pro-inflammatory factors including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in RAW264.7 cells, suggesting that they enhanced macrophage-mediated innate immunity. Moreover, based on the in vitro inflammation model of lipopolysaccharide (LPS)-stimulated RAW264.7 cells, EPS-0M, EPS-0.1M and IPS-0M but not IPS-0.1M could inhibit the LPS-induced excessive inflammatory response, including NO, IL-6, TNF-α, IL-1β production and gene transcription. Interestingly, IPS-0M showed a relatively poor immunostimulatory effect, but had the strongest inhibitory effect against the LPS-induced RAW264.7 inflammatory response. Furthermore, our results indicate that the nuclear factor-kappa B (NF-κB) pathway is associated with the immunomodulatory effects of the polysaccharide samples on RAW264.7 cells. This study can provide a reference for the more targeted application of different polysaccharide components from Poria cocos for human health.

Poria cocos polysaccharide-functionalized graphene oxide nanosheet induces efficient cancer immunotherapy in mice

Introduction: Tumor vaccines that induce robust humoral and cellular immune responses have attracted tremendous interest for cancer immunotherapy. Despite the tremendous potential of tumor vaccines as an effective approach for cancer treatment and prevention, a major challenge in achieving sustained antitumor immunity is inefficient antigen delivery to secondary lymphoid organs, even with adjuvant aid. Methods: Herein, we present antigen/adjuvant integrated nanocomplexes termed nsGO/PCP/OVA by employing graphene oxide nanosheet (nsGO) as antigen nanocarriers loaded with model antigen ovalbumin (OVA) and adjuvant, Poria cocos polysaccharides (PCP). We evaluated the efficacy of nsGO/PCP/OVA in activating antigen-specific humoral as well as cellular immune responses and consequent tumor prevention and rejection in vivo. Results: The optimally formed nsGO/PCP/OVA was approximately 120-150 nm in diameter with a uniform size distribution. Nanoparticles can be effectively engulfed by dendritic cells (DCs) through receptor-mediated endocytosis, induced the maturation of DCs and improved the delivery efficiency both in vitro and in vivo. The nsGO/PCP/OVA nanoparticles also induced a significant enhancement of OVA antigen-specific Th1 and Th2 immune responses in vivo. In addition, vaccination with nsGO/PCP/OVA not only significantly suppressed tumor growth in prophylactic treatments, but also achieved a therapeutic effect in inhibiting the growth of already-established tumors. Conclusion: Therefore, this potent nanovaccine platform with nanocarrier nsGO and PCP as adjuvants provides a promising strategy for boosting anti-tumor immunity for cancer immunotherapy.

Poria cocos polysaccharides rescue pyroptosis-driven gut vascular barrier disruption in order to alleviates non-alcoholic steatohepatitis

ETHNOPHARMACOLOGICAL RELEVANCE

Poria cocos polysaccharides (PCP) are abundant in Poria cocos (Schw.) Wolf (Poria). This is a common traditional Chinese medicine used to treat gastrointestinal and liver diseases. Poria cocos dispel dampness and enhance gastrointestinal functions, strongly affecting the treatment of non-alcoholic fatty liver disease. Still, the mechanism is not yet clear.

AIM OF THE STUDY

The latest research found that protecting the integrity of the intestinal barrier can slow down the progression of non-alcoholic fatty liver disease (NAFLD). Hence, our research ought to explore the protective mechanism of PCP on the intestinal barrier under a high-fat diet and to clarify the relationship between intestinal barrier damage and steatohepatitis.

MATERIALS AND METHODS

H&E staining was done to evaluate pathological damage, whereas Nile red and oil red O staining was conducted to evaluate hepatic fat infiltration. Immunofluorescence staining and immunohistochemical staining were used to detect protein expression and locations. Bone marrow-derived macrophages were isolated for in vitro experiments. ONOO- and ROS fluorescent probes and MDA, SOD, and GSH kits assessed the levels of nitrogen and oxidative stress. LPS levels were detected with a Limulus Amebocyte Lysate assay. The Western blot analysis and reverse transcription-quantitative PCR detected the expression of related proteins and genes. The Elisa kit detected the level of the inflammatory factors in the cell supernatant. For the vivo NAFLD experiments, in briefly, mice were randomly chosen to receive either a High-fat diet or control diet for 12 weeks. Drug treatments started after 4 weeks of feeding. Zebrafish larvae were raised separately in fish water or 7 mM thioacetamide as the control or model group for approximately 72 h. In the therapy groups, different concentrations of PCP were added to the culture environment at the same time.

RESULTS

In zebrafish, we determined the safe concentration of PCP and found that PCP could effectively reduce the pathological damage in the liver and intestines induced by the NAFLD model. In mice, PCP could slow down weight gain, hyperlipidemia, and liver steatosis caused by a high-fat diet. More importantly, PCP could reduce the destruction of the gut-vascular barrier and the translocation of endotoxins caused by a high-fat diet. Further, we found that PCP could inhibit intestinal pyroptosis by regulating PARP-1. Pyroptosis inhibitors, such as MCC950, could effectively protect the intestinal and liver damage induced by a high-fat diet. We also found that pyroptosis mainly occurred in intestinal macrophages. PCP could effectively improve the survival rate of bone marrow-derived macrophages in a high-fat environment and inhibit pyroptosis.

CONCLUSIONS

These results indicated that PCP inhibited the pyroptosis of small intestinal macrophages to protect the intestinal barrier integrity under a high-fat diet. This resulted in decreased endotoxin translocation and progression of steatohepatitis.

Poria cocos polysaccharides exert prebiotic function to attenuate the adverse effects and improve the therapeutic outcome of 5-FU in ApcMin/+ mice

BACKGROUND

As a first-line chemotherapeutic agent, 5-fluorouracil (5-FU) exhibits many side effects, weakening its efficacy in cancer treatment. In this study, we hypothesize that Poria cocos polysaccharides (PCP), a traditional Chinese herbal medicine with various bioactivities and prebiotic effects, might improve the therapeutic effect of 5-FU by restoring the homeostasis of the gut microenvironment and the commensal gut microflora.

METHODS

Apc^Min/+ mice were employed to evaluate the anti-cancer effect of 5-FU in conjunction with PCP treatment. Body weight and food consumption were monitored weekly. Polyp count was used to assess the anti-cancer effect of PCP and 5-FU. Expressions of mucosal cytokines and gut epithelial junction molecules were measured using qRT-PCR. 16S rRNA gene sequencing of fecal DNAs was used to evaluate the compositional changes of gut microbiota (GM). Transplantation of Lactobacillus johnsonii and Bifidobacterium animalis were performed to verify the prebiotic effects of PCP in improving the efficacy of 5-FU.

RESULTS

The results showed that PCP treatment alleviated the weight loss caused by 5-FU treatment and reduced the polyp burden in Apc^Min/+ mice. Additionally, PCP treatment eased the cytotoxic effects of 5-FU by reducing the expressions of pro-inflammatory cytokines, increasing the anti-inflammatory cytokines; and significantly improving the gut barriers by enhancing the tight junction proteins and associated adhesion molecules. Furthermore, 16S rRNA gene sequencing data showed that PCP alone or with 5-FU could stimulate the growth of probiotic bacteria (Bacteroides acidifaciens, Bacteroides intestinihominis, Butyricicoccus pullicaecorum, and the genera Lactobacillus, Bifidobacterium, Eubacterium). At the same time, it inhibited the growth of potential pathogens (e.g., Alistipes finegoldii, Alistipes massiliensis, Alistipes putredinis., Citrobacter spp., Desulfovibrio spp., and Desulfovibrio desulfuricans). Moreover, the results showed that transplantation of L.johnsonii and B.animalis effectively reduced the polyp burden in Apc^Min/+ mice being treated with 5-FU.

CONCLUSION

Our study showed that PCP could effectively improve the anti-cancer effect of 5-FU by attenuating its side effects, modulating intestinal inflammation, improving the gut epithelial barrier, and modulating the gut microbiota of Apc^Min/+ mice.

The improvement of nonalcoholic steatohepatitis by Poria cocos polysaccharides associated with gut microbiota and NF-κB/CCL3/CCR1 axis

BACKGROUND

Nonalcoholic steatohepatitis (NASH) has been linked to inflammation induced by intestinal microbiota. Poria cocos polysaccharides (PCP) possesses anti-inflammation and immunomodulation functions; however, its preventive effects against NASH and potential mechanisms need to be explored.

METHODS

The composition of PCP was determined using ion chromatography. C57BL/6 mice were administered the methionine and choline deficient (MCD) diet for 4 weeks to establish the NASH model or methionine-choline-sufficient (MCS) diet to serve as the control. Mice were assigned to the MCS group, MCD group, low-dose PCP (LP) group, and high-dose PCP (HP) group, and were administered the corresponding medications via gavage. Serum biochemical index analysis and liver histopathology examination were performed to verify the successful establishment of NASH model and to evaluate the efficacy of PCP. The composition of intestinal bacteria was profiled through 16S rRNA gene sequencing. Hepatic RNA sequencing (RNA-Seq) was performed to explore the potential mechanisms, which were further confirmed using qPCR, western blot, and immunohistochemistry.

RESULTS

PCP consists of glucose, galactose, mannose, D-glucosamine hydrochloride, xylose, arabinose, and fucose. PCP could significantly alleviate symptoms of NASH, including histological liver damage, impaired hepatic function, and increased oxidative stress. Meanwhile, HP could reshape the composition of intestinal bacteria by significantly increasing the relative abundance of Faecalibaculum and decreasing the level of endotoxin load derived from gut bacteria. PCP could also downregulate the expression of pathways associated with immunity and inflammation, including the chemokine signaling pathway, Toll-like receptor signaling pathway, and NF-kappa B signaling pathway. The expression levels of CCL3 and CCR1 (involved in the chemokine signaling pathway), Tlr4, Cd11b, and NF-κb (involved in the NF-kappa B signaling pathway), and Tnf-α (involved in the TNF signaling pathway) were significantly reduced in the HP group compared to the MCD group.

CONCLUSIONS

PCP could prevent the development of NASH, which may be associated with the modulation of intestinal microbiota and the downregulation of the NF-κB/CCL3/CCR1 axis.

[Extracts of Poria cocos polysaccharides improves alcoholic liver disease in mice via CYP2E1 and NF-κB inflammatory pathways]

The present study investigated the effect of extract of Poria cocos polysaccharides(PCP) on cytochrome P450 2 E1(CYP2 E1) and nuclear factor κB(NF-κB) inflammatory signaling pathways in alcoholic liver disease(ALD) mice and explored its protective effect and mechanism. Sixty male C57 BL/6 N mice of SPF grade were randomly divided into a control group, a model group, a positive drug group(bifendate, 200 mg·kg~(-1)), and high-(200 mg·kg~(-1)) and low-dose(50 mg·kg~(-1)) PCP groups. Gao-binge mo-del was induced and the mice in each group were treated correspondingly. Liver morphological and pathological changes were observed and organ index was calculated. Serum levels of alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were detected. Malondialdehyde(MDA) and superoxide dismutase(SOD) in liver tissues were detected by assay kits. The levels of interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) were detected by ELISA. The activation of macrophages was observed by immunofluorescence staining and protein expression of CYP2 E1, Toll-like receptor 4(TLR4), NF-κB p65, and phosphorylated NF-κB p65(p-NF-κB p65) were analyzed by Western blot. The ALD model was properly induced. Compared with the model group, the PCP groups significantly improved the pathological injury of liver tissues. Immunofluorescence staining revealed that compared with the model group, the groups with drug intervention showed decreased macrophages in liver tissues. Additionally, the PCP groups showed reduced ALT, AST, MDA, IL-6, and TNF-α(P<0.05), and potentiated activity of SOD(P<0.01). PCP extract has the protective effect against alcoholic liver injury in mice, and the underlying mechanism may be related to the regulation of the expression of CYP2 E1 and inhibition of TLR4/NF-κB inflammatory signaling pathway to reduce oxidative stress and inflammatory injury, thereby inhibiting the development of ALD.

Multiple-fingerprint analysis of Poria cocos polysaccharide by HPLC combined with chemometrics methods

In this study, the multiple fingerprints, which were integrated with HPGFC-ELSD (high performance gel filtration chromatography - evaporative light scattering detector) fingerprint, PMP-HPLC-DAD (1-phenyl-3-methyl-5-pyrazolone-high performance liquid chromatography - diode array detector) fingerprint of complete acid hydrolysates and HILIC-HPLC-ELSD (hydrophilic interaction - high performance liquid chromatography - evaporative light scattering detector) fingerprint of enzyme hydrolysates, were established to evaluate the quality of polysaccharides from Poria cocos (PCPs). The similarity evaluation showed that 16 batches of PCPs from different origins had high similarity in structural characteristics based on the multiple fingerprints. The chromatographic data of multiple fingerprints of PCPs were fused, processed and analyzed by chemometric methods including HCA (hierarchical cluster analysis), PCA (principal component analysis) and PLS-DA (partial least squares discriminant analysis). The 16 batches of PCPs were divided into 3 categories in PCA, indicating a certain relationship between the structural characteristics and the origins. PLS-DA analysis indicated that Man, Glc, Gal, Fuc, the components with m/z of 2.22 × 10⁴∼1.53 × 10⁴ Da and 3.46 × 10³∼2.69 × 10³ Da, oligosaccharides with DPs of 6 and 7, respectively, could be regarded as potential chemical markers for the classification of PCPs from different origins. According to the multiple fingerprints and chemometric analysis, the two commercial samples were proved to be adulterants.

[Research progress on chemical structures and pharmacological activities of Poria cocos polysaccharide and its derivatives]

Poria cocos is a both medicinal and edible Chinese herb variety, with the effects of diuretic, spleen-enhancing and tranquilizing. P. cocos polysaccharide(PCP) is one of the most important active substances of P. cocos. Pharmacological research shows that PCP has a variety of pharmacological activities such as regulating immunity, anti-inflammatory, anti-oxidation, antitumor, and liver protection, with a huge development and utilization value. By consulting the relevant literature, we systematically summarized the chemical structures and the research progress on pharmacological activities of PCP and its derivatives in recent years to explore the chemical compositions and activities of PCP thoroughly. In addition, the current problems were discussed in this article to provide reference for further exploration of the structure-activity relationship of PCP and its further development and utilization.

Antihepatotoxic benefits of Poria cocos polysaccharides on acetaminophen-lesioned livers in vivo and in vitro

In our previous study, preliminary data indicates that Poria cocos polysaccharides (PCP) shows beneficial hepatoprotection against acetaminophen (APAP)-induced liver injury in mice. However, biological molecular mechanism warrants to be further discussed. In current study, a number of biochemical tests and immunoassays were subjected to respective PCP-dosed mice in vivo and liver cells in vitro. As a result, PCP-treated mice showed reduced contents of inflammatory cytokines (tumor necrosis factor [TNF]-β and TNFsR-I), enzymological molecules (alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase [LDL]), and heat shock protein 90 (Hsp90) after APAP exposure. Additionally, immunostaining assays exhibited that lowered-positive cells of cleaved-caspase-3, cleaved-poly ADP ribose polymerase, and Hsp90-labeled cells in PCP-treated livers were observed, and increased cluster of differentiation 29 (CD29), CD73-positive cells in the spleen were detected. Further, PCP-treated mouse liver cells resulted in increased cell growth, reduced LDL level. Increased proliferating cell nuclear antigen (PCNA), P38 mitogen-activated protein kinase (MAPK)-labeled cells and decreased Hsp90-positive cells in APAP-exposed liver cells were observed dose-dependently after PCP cotreatments. Collectively, our present experimental findings elucidate that PCP beneficially play hepatoprotective effects against APAP-lesioned liver cells in vivo and in vitro, potentially through the molecular mechanisms of suppressing cell death, reducing hepatocellular inflammatory stress and Hsp90 bioactivity.