Anti-tumor activity of exopolysaccharide from Rhizopus nigricans Ehrenb on S180 tumor-bearing mice

Bacillus amyloliquefaciens TL promotes gut health of broilers by the contribution of bacterial extracellular polysaccharides through its anti-inflammatory potential

The focal point of probiotic efficacy and a crucial factor influencing poultry cultivation lies in the level of intestinal inflammation. In conventional farming processes, the reduction of intestinal inflammation generally proves advantageous for poultry growth. This study investigated the impact of Bacillus amyloliquefaciens TL (B.A.-TL) on inflammatory factor expression at both tissue and cellular levels, alongside an exploration of main active secondary metabolites. The results demonstrated that broiler feeding with a basal diet containing 4 × 109 CFU/kg B.A.-TL markedly enhanced chicken growth performance, concomitant with a significant decrease in the expression of genes encoding inflammatory cytokines (e.g., CCL4, CCR5, XCL1, IL-1β, IL-6, IL-8, LITAF, and LYZ) in jejunum and ileum tissues. The extracellular polysaccharides of B.A.-TL (EPS-TL) exhibited notable suppression of elevated inflammatory cytokine expression induced by Escherichia coli O55 lipopolysaccharides (LPS) in chicken macrophage-like cells (HD11) and primary chicken embryonic small intestinal epithelial cells (PCIECs). Moreover, EPS-TL demonstrated inhibitory effect on NF-κB signaling pathway activation. These findings suggested that the metabolic product of B.A.-TL (i.e., EPS-TL) could partly mitigate the enhanced expression of inflammatory factors induced by LPS stimulation, indicating its potential as a key component contributing to the anti-inflammatory effects of B.A.-TL.

Extracellular Polysaccharide from Rhizopus nigricans Inhibits Hepatocellular Carcinoma via miR-494-3p/TRIM36 Axis and Cyclin E Ubiquitination

BACKGROUND AND AIMS

This study was designed to uncover the mechanism for extracellular polysaccharide (EPS1-1)-mediated effects on hepatocellular carcinoma (HCC) development.

METHODS

HCC cells were treated with EPS1-1, miR-494-3p mimic, sh-TRIM36, and pcDNA3.1-TRIM36. The levels of miR-494-3p and TRIM36 were measured in normal hepatocytes, THLE-2, and HepG2 and HuH7HCC cell lines, along with the protein expression of cyclin D/E and p21. The proliferation, cell cycle, and apoptosis of HCC cells were assayed. The interactions between miR-494-3p and TRIM36, and between TRIM36 and cyclin E were assessed. Finally, the expression and localization of TRIM36 and cyclin E were monitored, and tumor apoptosis was detected, in tumor xenograft model.

RESULTS

EPS1-1 suppressed HCC cell proliferation and cyclin D/E expression and promoted apoptosis and p21 expression. miR-494-3p was upregulated and TRIM36 was downregulated in HCC cells. Transfection with miR-494-3p mimic or sh-TRIM36 facilitated HCC cell proliferation and the expression of cyclin D/E protein but they inhibited apoptosis and p21 expression in the presence of EPS1-1. Overexpression of TRIM36 further consolidated EPS1-1-mediated inhibition of HCC proliferation, cyclin D/E, and the promotion of apoptosis and p21 expression. Those effects were reversed by miR-494-3p overexpression. TRIM36 was a target gene of miR-494-3p, and TRIM36 induced cyclin E ubiquitination. EPS1-1 suppressed cyclin E expression, promoted TRIM36 expression and tumor apoptosis, all of which were abrogated by increasing the expression of miR-494-3p in vivo.

CONCLUSIONS

EPS1-1 protected against HCC by limiting its proliferation and survival through the miR-494-3p/TRIM36 axis and by inducing cyclin E ubiquitination.

The Regulation of Micro-Organisms' Extra-Cellular Polysaccharides on Immunity: A Meta-Analysis

Extra-cellular polysaccharides (EPSs) have excellent immunomodulatory functions. In order to further promote their application, we studied the ability of extra-cellular polysaccharides from different sources to regulate immunity. We studied the association of extra-cellular polysaccharides with immune factors (Interleukin (IL-2, IL-4, IL-10), Interferon γ (IFN-γ), tumor necrosis factor-α (TNF-α), Immunoglobulin A (IgA), and Immunoglobulin G (IgG)) and different concentrations of EPSs and interfering media on experimental results by using a forest plot under fixed-effect or random-effects models. Through Google, PubMed, Embase, ScienceDirect, and Medline, from 2000 to 2021, 12 articles were included. We found that exopolysaccharides (from bacteria or fungi) could significantly increase the immune index of spleen and thymus, spleen index (SMD: 2.11, ‘95%CI: [1.15, 3.08]’; p < 0.01), and thymus index (SMD: 1.62, ‘95%CI: [0.93, 2.32]’; p = 0.01 < 0.05). In addition, exopolysaccharides had a significant effect on TNF-α (SMD: 0.94, ‘95%CI: [0.29, 1.59]’; p = 0.01 < 0.05). For IL-4 (SMD: 0.49, ‘95%CI: [0.01, 0.98]’; p = 0.046 < 0.05), extra-cellular polysaccharides had a statistically significant effect on immunity. Although the data of other immune factors were not ideal, the comprehensive analysis showed that exopolysaccharides also had an effect on the release of these five immune factors. In the sub-group analysis, different concentrations of EPSs affected the results of experiments on the spleen and thymus, and the CY intervention had a relatively significant effect on immune regulation. Taken together, our study highlighted that EPSs have a significant impact on immune regulation.

Antitumor and immunoregulatory activities of a novel polysaccharide from Astragalus membranaceus on S180 tumor-bearing mice

The Astragalus membranaceus polysaccharide (APS4) with direct cytotoxicity on various cancer cells has been prepared in our previous study, while the underlying therapeutic role of APS4 on solid tumors in vivo hasn't been investigated yet. Therefore, in this paper, the lymphocytes-mediated antitumor and immunoregulatory activities of APS4 were researched by establishing S180 tumor-bearing mice model. Flow cytometry analysis revealed that APS4 could effectively regulate the percentages of CD3⁺, CD4⁺, CD8⁺ T cells and CD19⁺ B cells in thymus, peripheral blood and spleen of S180 tumor-bearing mice, dose-dependently. H&E staining and cell cycle determination of solid tumors manifested that APS4 treatment could significantly inhibit the growth of solid tumors by inducing cells apoptosis. Furthermore, two-dimensional electrophoresis and western blot analysis further demonstrated that APS4 could activate antitumor-related immune cells and promote anaerobic metabolism of tumor microenvironment, thereby causing the apoptosis of S180 tumor cells. These data implicated that APS4 could be used as a potential dietary supplement for immune enhancement.

Effects of Rhizopus Nigricans Exopolysaccharide on Proliferation, Apoptosis, and Migration of Breast Cancer MCF-7 Cells and Akt Signaling Pathway

Objective. To study the effect of Rhizopus nigricans exopolysaccharide EPS1-1 on the proliferation, apoptosis, and migration of breast cancer MCF-7 cells. Methods. Human breast cancer MCF-7 cells were cultured in vitro and treated with different concentrations of EPS1-1. The effect of EPS1-1 on cell proliferation was tested by the CCK-8 experiment, and the effect of EPS1-1 on cell apoptosis was determined by flow cytometry. And the scratch test was used to detect the impact of EPS1-1 on cell migration. Western blot then was used to measure the expression changes of related proteins in the Akt signaling pathway. Results. Compared with the control group, treatment with EPS1-1 significantly reduced the proliferation, migration, and invasion ability of MCF-7 cells and promoted the apoptosis of MCF-7 cells in a dose-dependent manner. In terms of the underlying mechanism, EPS1-1 can significantly inhibit the phosphorylation of Akt at threonine 308 and serine 473 and cause the expression changes of downstream proliferation-related genes CCND1 and p21, apoptosis-related genes Bcl-2 and Bax, and migration-related genes Vimentin and E-cadherin in terms of their protein levels. Conclusion. EPS1-1 can inhibit the proliferation, migration, and invasion of breast cancer MCF-7 cells and promote the apoptosis of MCF-7 cells by inhibiting the activation of the Akt signaling pathway. Therefore, EPS1-1 can be used as a potential new drug or adjuvant drug for the treatment of breast cancer.

Exopolysaccharides isolated from Rhizopus nigricans induced colon cancer cell apoptosis in vitro and in vivo via activating the AMPK pathway

Colorectal cancer (CRC) is a leading cause of cancer-related human deaths. The exopolysaccharide (EPS1-1), isolated from Rhizopus nigricans, has been described as exhibiting anti-tumor and pro-apoptotic activity against CRC, although the underlying mechanism is poorly understood. Herein, we investigate how EPS1-1 induces apoptosis of CRC cells in vitro and in vivo. Our results show that, in vitro, EPS1-1 suppressed cell growth and facilitated apoptosis in a dose- and time-dependent manner by activating the AMP-activated protein kinase (AMPK) pathway in mouse colon cancer CT26 cells. However, treatment with small interfering RNAs (siRNAs) targeting AMPKα or with compound C, an AMPK inhibitor, interfered with the pro-apoptosis effects of EPS1-1. We also show that EPS1-1 initiated the release of reactive oxygen species (ROS) and liver kinase B1 (LKB1), both of which are necessary signals for AMPK activation. Furthermore, EPS1-1-mediated apoptosis is regulated by inactivation of mammalian target of rapamycin complex 1 (mTORC1) and activation of the jun-NH₂ kinase (JNK)-p53 signaling axis dependent on AMPK activation. In vivo, azoxymethane/dextran sulfate sodium (AOM/DSS)-treated CRC mice, when administered EPS1-1, exhibited activation of the AMPK pathway, inhibition of mTORC1, and accumulation of p53 in tumor tissues. Collectively, these findings suggest that EPS1-1-induced apoptosis relies on the activation of the AMPK pathway. The present study provides evidence suggesting that EPS1-1 may be an effective target for development of novel CRC therapeutic agents.

Structure and Anti-Tumor Activities of Exopolysaccharides from Alternaria mali Roberts

In this study, an extracellular polysaccharide from Alternaria mali Roberts (AMEP) was extracted, and its structure was characterized, in addition to its antitumor activity in vitro. Neutral polysaccharide AMEP-1 and anionic polysaccharide AMEP-2 were isolated from AMEP, and their monosaccharide compositions consisted of mannose (Man), glucose (Glc), and galactose (Gal) but at different ratios. The linking mode of both AMEP-1 and AMEP-2 is Manp-(1→4) and Glcp-(1→6), and the branched chains are connected to the main chain through O-6. AMEP-2 inhibited the proliferation of BGC-823 cells in a time- and concentration-dependent manner. AMEP-2 also induced the apoptosis of BGC-823 cells, and showed anti-tumor effects by inducing cell cycle arrest in the S phase, reactive oxygen species production, and mitochondrial membrane potential reduction in BGC-823 cells. Therefore, AMEP-2 shows potential for further development as a novel anti-tumor agent.

The inhibitory effect of polysaccharide from Rhizopus nigricans on colitis-associated colorectal cancer

An extracellular polysaccharide (EPS1-1) of Rhizopus nigricans was found to enhance immunity and reduce colon cancer cell proliferation. Here, the effect of EPS1-1 on a mouse model of colitis-associated cancer (CAC) induced by azoxymethane (AOM)/dextran sodium sulfate (DSS) was investigated. Pathological symptoms, including weight loss, piloerection, hematochezia and insensitivity caused by AOM/DSS, were relieved by EPS1-1. Anatomical results showed a 100% tumor incidence, a series of neoplasms, disordered cell structure and hyperplastic glands in the model group, while the abnormal behaviors were relieved and the tumors decreased in the EPS1-1 group. Compared with the model group, the EPS1-1 group showed decreased oncogenic protein (COX-2, β-catenin, CyclinD1 and C-Myc) expression. TUNEL staining showed that EPS1-1 increased the apoptosis of colon cancer cells in mice. Furthermore, the expression of proliferative proteins (Ki-67 and PCNA) and an antiapoptotic gene transcript (Bcl-2) were significantly down regulated by EPS1-1, while apoptotic gene transcripts (p53 and Bax) were enhanced. In addition, EPS1-1 notably decreased the number of cells positive for CD68, F4/80 and NF-κB and reduced the concentrations of inflammatory factors (TNF-α and IL-6) in serum compared with those in the model group. Taken together, these results suggest that EPS1-1 may be a therapeutic option for the prevention and treatment of CAC.

Antitumor and Immunoregulatory Activities of Seleno-β-Lactoglobulin on S180 Tumor-Bearing Mice

Degeneration of immune organs like thymus and spleen has been discovered in tumor-bearing mice; which increases the difficulties on oncotherapy. More effective drugs which target the protection of immune organs are expected to be researched. In this study; we aim to analyze the antitumor and immunoregulatory activities of seleno-β-lactoglobulin (Se-β-lg) on S180 tumor-bearing mice. Results indicated that Se-β-lg exhibited a remarkable inhibitory effect on S180 solid tumors with the inhibition rate of 48.38%; and protected the thymuses and spleens of S180-bearing mice. In addition, Se-β-lg could also balance the proportions of CD4⁺ and CD8⁺ T cells in spleens; thymuses and peripheral bloods; and improve Levels of IL-2; IFN-γ; TNF-α in mice serums. β-lg showed weaker bioactivities while SeO₂ showed stronger toxicity on mice. Therefore our results demonstrated that Se-β-lg possessed stronger antitumor and immunoregulatory activities with lower side effects and had the potential to be a novel immunopotentiator and antitumor agent.

Litopenaeus vannamei hemocyanin exhibits antitumor activity in S180 mouse model in vivo

Hemocyanin is a multifunctional glycoprotein, which also plays multiple roles in immune defense. While it has been demonstrated that hemocyanin from some mollusks can induce potent immune response and is therefore undergoing clinical trials to be used in anti-tumor immunotherapy, little is currently known about how hemocyanin from arthropods affect tumors. In this study we investigated the anti-tumor activity of hemocyanin from Litopenaeus vannamei on Sarcoma-180 (S180) tumor-bearing mice model. Eight days treatment with 4mg/kg bodyweight of hemocyanin significantly inhibited the growth of S180 up to 49% as compared to untreated. Similarly, histopathology analysis showed a significant decrease in tumor cell number and density in the tissues of treated mice. Moreover, there was a significant increase in immune organs index, lymphocyte proliferation, NK cell cytotoxic activity and serum TNF-α level, suggesting that hemocyanin could improve the immunity of the S180 tumor-bearing mice. Additionally, there was a significant increase in superoxide dismutase (SOD) activity and a decrease in the level of malondialdehyde (MDA) in serum and liver, which further suggest that hemocyanin improved the anti-oxidant ability of the S180 tumor-bearing mice. Collectively, our data demonstrated that L. vannamei hemocyanin had a significant antitumor activity in mice.

Protective mechanisms of purified polyphenols from pinecones of Pinus koraiensis on spleen tissues in tumor-bearing S180 mice in vivo

The present study was designed to evaluate the protective effects of the purified polyphenols from pinecones ofPinus koraiensis(PPP-40) on spleen tissues of S180 micein vivo.

Synergistic antitumor efficacy of antibacterial helvolic acid from Cordyceps taii and cyclophosphamide in a tumor mouse model

The antibacterial agent helvolic acid, which was isolated from the active antitumor fraction of Cordyceps taii, showed potent cytotoxicity against different human cancer cells. In the present study, the in vivo antitumor effect of helvolic acid was investigated in murine sarcoma S180 tumor-bearing mice. Doses of 10 and 20 mg/kg/day helvolic acid did not exert significant antitumor activity. Interestingly, co-administration of 10 mg/kg/day helvolic acid and 20 mg/kg/day cyclophosphamide (CTX) - a well-known chemotherapy drug - showed promising antitumor activity with a growth inhibitory rate of 70.90%, which was much higher than that of CTX alone (19.5%). Furthermore, the combination markedly prolonged the survival of tumor-bearing mice. In addition, helvolic acid enhanced the immune organ index. The protein expression levels of β-catenin, cyclin D1, and proliferating cell nuclear antigen were significantly suppressed in mice treated with 20 mg/kg/day helvolic acid and in those receiving combination therapy. Taken together, these results indicated that helvolic acid in combination with CTX showed potent in vivo synergistic antitumor efficacy, and its mechanism of action may involve the Wnt/ β-catenin signaling pathway.