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Macrophages, an important component of inflammatory microenvironment and tumor microenvironment, are closely related to tumor development and progression. Our previous studies showed that apple polysaccharide (AP) could prevent from colitis associated colorectal carcinogenesis. Herein, we further our study to observe the effect of AP on the polarization of macrophages in Raw 264.7 cells and a colitis associated colorectal cancer mouse model, and to investigate the possible mechanisms. Forty male ICR mice were administered with azoxymethane (AOM) and dextran sodium sulfate (DSS). Twenty mice were given no further treatment as model mice, the rest twenty were fed basal diet mixed with 5% of AP. Raw 264.7 cells were treated with 0.5 mg/mL AP. AP could protect ICR mice against AOM/DSS-induced carcinogenesis, keep the colon of AOM/DSS-treated mice in a moderative inflammatory state, and shift macrophage polarization toward M1 phenotype. In vitro study showed that AP could upregulate TLR-4 signaling mildly and trigger M1 macrophage transition. Moreover, AP-induced transition of macrophage phenotype was suppressed by a TLR-4 antagonist, TAK-242. These data may provide a novel molecular basis for understanding how apples act to prevent colorectal cancer (CRC) and indicate that AP has a potential to prevent and treat CRC., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: Obesity, substantially increasing the risk of diseases such as metabolic diseases, becomes a major health challenge. In this study, we, therefore, investigated the effect of modified apple polysaccharide (MAP) on obesity., Methods: Twelve male C57BL/6J mice were given a 45% high-fat diet (HFD) for 12 weeks to replicate an obesity model and six mice were given normal diet as control. Then, 1 g/kg MAP was administrated to six mice by gavage for 15 days. Illumina Miseq PE300 sequencing platform was used to analyze the microbial diversity of fecal samples. Flow cytometry was employed to investigate the effects of MAP on immune cells in adipose tissue. Bacterial culture and qPCR were used to assess the effects of MAP on the growth of whole fecal bacteria and representative microbiota in vitro., Results: MAP could alleviate HFD-induced obesity and decrease body weight of mice effectively. The results of α diversity showed that Shannon index in HFD group was significantly lower than that in control group; Shannon index in MAP group was higher than that in HFD group. The results of β diversity showed that the microbiota of MAP group was more similar to that of control group. HFD increased the number of T cells and macrophages in adipocytes; while MAP decreased the number of T cells and macrophages. MAP could promote the growth of fecal bacteria, and demonstrated a facilitated effect on the proliferation of Bacteroidetes, Bacteroides, Lactobacillus, and an inhibitory effect on Fusobacterium., Conclusions: MAP could reduce HFD-induced obesity of mice effectively. The possible mechanisms are that MAP restored HFD-induced intestinal microbiota disorder, downregulated the number of T cells and macrophages in adipose tissue.

It is widely accepted that regulating microbiome could improve human health. We previously observed apple polysaccharide (AP) reversed high-fat-induced microbial dysbiosis, but the mechanism remains to be elucidated. In this study, the function of AP in vitro was evaluated in Bifidobacterium longum (B. longum) and Lactobacillus rhamnosus (L. rhamnosus). The effects of AP on the composition of fecal bacteria of normal SD rats were investigated by qPCR, TA cloning and 16S sequencing. 0.125-2% AP showed no significant effect on the growth of B. longum and L. rhamnosus. DNA concentration of fecal bacteria cultured with 1% AP was significantly higher than that of control group. qPCR revealed that the number of Bifidobacterium and Lactobacillus in fecal flora incubated by 1% AP was significantly higher than that of control group. Three strains of escherichia coli (E. coli) in fecal bacteria were screened out and analyzed. AP can be utilized by one E. coli and the metabolic products of AP could enhance the proliferation of B. longum. These data suggest that AP could promote the growth of B. longum indirectly, and provide another basis to understand the health care function of apple., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The present study tried to assess the effects of modified apple polysaccharide (MAP) on colitis associated carcinogenesis and the expression of Mucin 1(MUC1). One hundred and twenty 5-week-old male ICR mice were used. The control mice were just administrated with saline, and the rest mice were injected intraperitoneally with 1, 2-dimethyl-hydrazine (DMH) and dextran sodium sulfate (DSS). In the 7th week, the mice in MAP-treated groups were bred with the basal diets mixed with different doses of MAP (w/w: 1.25%, 2.5% and 5%) for 13 weeks. The pathological findings demonstrated that: in the 20th week, adenocarcinoma and/or adenoma occurred in the colons of all the mice in model group. MAP treatment decreased the incidence of colorectal cancer significantly. In the early phase of inflammation, MUC1 expression in colonic mucosa had no significant changes. However, when the inflammation developed and tumor formed, MUC1 expression increased remarkably (P < 0.01). And the MAP treatment (especially at the dose of 5%) reduced MUC1 expression significantly. These data suggested that MAP could prevent against colitis associated colorectal cancer in ICR mice effectively, and MUC1 may be a potential therapeutic target in colorectal cancer prevention and treatment., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Treatment of colorectal cancer (CRC) remains a clinical challenge, since current therapies are associated with obvious side effects and high expenses. These limitations highlight an urgent need for developing novel and safe treatment strategies. It is suggested that combinatorial strategies could be more effective and much safer than monotherapy in cancer treatment. In our previous study, an apple oligogalactan (AOG) has been found to show beneficial effect on treating CRC. This study tried to investigate whether AOG could enhance the growth inhibitory effect of 5-FU in human CRC cells (HT-29 and SW-620), a mouse model of colitis associated colorectal cancer and a murine model of xenograft tumor. The IC 50 values of 5-FU were 26.70±0.21μM in HT-29 cells and 26.71±2.06μM in SW-620 cells. Pretreatment with 0.05 or 0.1mM AOG down-regulated IC 50 values of 5-FU to 22.44±1.01 or 18.67±1.16μM in HT-29 and 21.21±1.49 or 17.99±1.42μM in SW-620 cells. AOG enhanced 5-FU-induced cell apoptosis and S phase arrest. The combination not only protected ICR mice against intestinal toxicities and carcinogenesis induced by 1,2-dimethylhydrazine and dextran sodium sulfate, but also decreased the xenograft tumor size, triggered apoptosis and inhibited proliferation of tumor cells in nude mice. The mechanisms of AOG on enhancing the growth inhibitory effect of 5-FU may be through the influence of TLR-4/NF-κB pathway. Taken together, the combinatorial therapy using AOG and 5-FU is a promising strategy for the treatment of colorectal cancer., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The saying "An apple a day keeps the doctor away" has been known for over 150 years, and numerous studies have shown that apple consumption is closely associated with reduced risks of chronic diseases. It has been well accepted that dysbiosis is the reflection of various chronic diseases. Therefore, this study investigates the effects of apple polysaccharides (AP) on gut dysbiosis. High-fat diet (HFD) fed rats were treated for 14 weeks with AP. The microbiota composition, microbiota-generated short chain fatty acids (SCFAs), gut permeability and chronic inflammation were analyzed. AP treatment showed higher abundance of Bacteroidetes and Lactobacillus while lower Firmicutes and Fusobacteium. AP significantly increased total SCFAs level that contributed by acetic acid and isobutyric acid. Moreover, AP dramatically alleviated dysbiosis-associated gut permeability and chronic inflammation with decreased plasma LBP, up-regulation of Occludin, down-regulation of tumor necrosis factor a (TNF-a), monocyte chemotactic protein 1 (MCP-1), chemokine ligand 1 (CXCL-1) and interleukin 1 beta (IL-1β). The potential mechanism is due to the fact that AP reduces gut permeability, which involves the induction of autophagy in goblet cells. Therefore, AP exerts health benefits through inhibiting gut dysbiosis and chronic inflammation and modulating gut permeability in HFD-induced dysbiosis rats., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Multiple studies have indicated that selective cyclooxygenase-2 (COX-2) inhibitors possess clinically chemopreventive and preclinically anticancer activities. Their long-term use, however, may be limited by the cardiovascular toxicity. This study tried to investigate whether an apple oligogalactan (AOG) could enhance the growth inhibitory effect of celecoxib on colorectal cancer. Caco-2 and HT-29 cell lines were exposed to different concentrations of AOG (0-1 g/L), celecoxib (0-25 μmol/L), and their combination. COX-2 levels were assessed by reverse transcription PCR and Western blot. COX-2 activity was evaluated by measuring prostaglandin E2 concentration. A colitis-associated colorectal cancer (CACC) mouse model was used to determine the effect of the combination in vivo. AOG (0.1-0.5 g/L) could potentiate the inhibitory effect of physiologic doses of celecoxib (5 μmol/L) on cell growth and decrease COX-2 expressions both at RNA and protein levels. In vivo, the combination (2.5% AOG plus 0.04% celecoxib, w/w) prevented against CACC in mice effectively. Our data indicate that AOG could potentiate the growth inhibitory effect of celecoxib on colorectal cancer both in vitro and in vivo through influencing the expression and function of COX-2 and phosphorylation of MAPKs, which suggests a new possible combinatorial strategy in colorectal cancer therapy.

Colorectal cancer (CRC) is one of the most common cancers and a leading cause of cancer-related mortality in developed countries. Many ingredients of apples have been proven to have anti-inflammatory and anti-carcinogenic characteristics, and show benefits for CRC prevention. The aim of this study, therefore, was to evaluate inhibitory effect of an apple oligogalactan (AOG) on pro-inflammatory endotoxin lipopolysaccharide (LPS)-activated human colon carcinoma cells HT-29 and SW-620 and investigate the possible mechanisms. The two cell lines were pretreated with AOG (0.1-1 g/L) for 30 min and then treated with 10 μg/mL LPS. Real time PCR, Western blot, electrophoretic mobility shift assay (EMSA), and ELISA were used to detect the expression and activity of cyclooxygenase-2 (COX-2), NF-κB and MAPKs pathways. AOG significantly inhibited the expression and activity of COX-2 in LPS-activated human colon carcinoma cells HT-29 and SW-620. The mechanisms of AOG-suppressed COX-2 expression may be through inhibiting the phosphorylation of MAPKs and the activation of NF-κB and AP-1. These data may provide another molecular basis for understanding how apples act to prevent CRC and indicate that AOG may be useful for treatment of colitis and prevention of carcinogenesis., (Copyright © 2013 Elsevier B.V. All rights reserved.)

It is reported that apple polysaccharide can prevent colon cancer growth and impede colon cancer progression. Apple oligosaccharide was prepared by the combination of alkaline hydrolysis and enzymolysis of apple polysaccharides, and purified by anion column chromatography. The aim of this study is to explore the effect of apple oligosaccharide on the cellular viability of human colon carcinoma cells (HT29 cells) and its mechanism. The results showed that apple oligosaccharide decreased the cellular viability of HT29 cells in dose-dependent manner. Meanwhile it enhanced the expression of Bax; and decreased the levels of Bcl-2 and Bcl-xl. Apple oligosaccharide induced cell cycle arrest in S phase, which correlated with the decreased expression of Cdk 2 and cyclin B1. These results indicated that apple oligosaccharide attenuated HT29 cell viability by inducing cell apoptosis and cell cycle arrest. Apple oligosaccharide is a potential chemoprevention agent or anti-tumor agent and is worthy of further study., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Certain components of apples have been shown to prevent cancer growth and impede cancer progression. We hypothesized that extracted apple polysaccharides (APs) might, therefore, have anticancer effects, through a mechanism involving the induction of apoptosis in cancer cells, partly via the NF-κB pathway. Two human colorectal cancer (CRC) cell lines, HT-29 and SW620, were exposed to different concentrations of APs (0.01, 0.1 or 1 mg/ml). Cell apoptosis was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay by flow cytometry and incorporation of 5'-bromodeoxyuridine (BrdU) into DNA to identify the proliferating cell fraction, using fluorescence microscopy in vitro. The protein levels of NF-κB/p65, I-κBα, pI-κBα, Bax, Bcl-xl and Bcl-2 were evaluated by western blotting. The target sites of APs on CRC cells were assessed by flow cytometry. At concentrations of 0.1 and 1 mg/ml, APs showed apoptosis-inducing effects, increased expressions of Bax, nuclear p65 and cytoplasmic pI-κBα, and decreased expressions of Bcl-2, Bcl-xl and cytoplasmic I-κBα. APs induced apoptosis by slightly activating the NF-κB pathway; the AP target site could be the Toll-like receptor 4 on the cell membrane. These results demonstrate the potential of APs as agents for clinical prevention and treatment of CRC.

Dietary components play an important role in cancer prevention. Many ingredients from apples have been proven to have antitumor potency. We thus made low molecular weight apple polysaccharides (LMWAP) and evaluated the effects of it on colorectal cancer (CRC). The effects of LMWAP on human colon carcinoma cells (HT-29) were evaluated using a microarray. Then, cell-cycle distribution was measured by flow cytometric analysis. A colitis-associated colorectal cancer mouse model was used to assess the effect of LMWAP on in vivo CRC prevention. Treatment of HT-29 cells with LMWAP resulted in 333 genes expression over cutoff values (≥2-fold). Further analysis demonstrated that pathways of cell cycle were mainly influenced. At the concentrations from 0.001 to 0.1 mg/mL, LMWAP induced a G(0)/G(1) phase block in HT-29 cells in a dose-dependent way. In vivo studies revealed that administration of LMWAP could protect ICR mice against CRC effectively. The results of Western blot suggested LMWAP induced cell-cycle arrest in a p53 independent manner. These data indicate that LMWAP could inhibit the development of CRC through affecting cell cycle, and it has potential for clinical prevention for colon cancer.

Background: Colorectal cancer (CRC) is one of the most common and preventable cancers. Regular consumption of apples is conducive to reduction in CRC risk., Aim of the Study: To evaluate effects of modified apple polysaccharide (MAP) on tumorigenesis in a mouse model of colitis-associated colon cancer., Methods: One hundred male ICR mice were administered with 1, 2-dimethyl-hydrazine (DMH) and dextran sodium sulfate (DSS). Forty mice were given no further treatment, the rest were fed basal diet blended with three different doses of MAP; 2.5, 5, and 10% (20 mice in each group)., Results: MAP significantly protected ICR mice against DMH/DSS-induced tumorigenesis. The incidence of tumor development was 90% (18/20) in the mice treated with DMH/DSS, but that was reduced to 25% (5/20), 15% (3/20), and 5% (1/20), respectively, in the mice treated with basal diets plus 2.5, 5, and 10% of MAP. Study of apoptosis of colonic epithelial cells revealed that MAP moderately increased apoptosis, suggesting that the anti-tumor potency of MAP was probably attributed to its ability to induce apoptosis. Western blot analysis demonstrated that carbohydrate-binding protein galectin-3 changed in both the nucleus and the cytoplasm during the process from colitis to colon cancer in the model. And MAP could inhibit the binding of galectin-3 to its ligand: this is, at least in part, the possible mechanism of MAP by enhancing apoptosis and preventing tumorigenesis., Conclusions: These data suggest that MAP has a potential role in clinical prevention and treatment for colon cancer.

Multiple studies have pointed out that dietary components could inhibit cancer progression and metastasis, and it has been proven that many ingredients of apple have benefits for cancer prevention. We, therefore, extracted modified apple polysaccharides (MAP) from apple and hypothesized that MAP have a cancer-preventive effect as do other ingredients of apple. Three human colorectal cancer cell lines: SW-1116, HT-29, and Caco-2 were exposed to different concentrations of MAP (0% to 0.1%). Inhibition of cell proliferation was measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. DNA fragmentation was visualized by agarose-gel electrophoresis. The amount of apoptotic cells was assessed by flow cytometry, and protein level of caspase 3, 8, 9, Bax, and Bcl-2 was evaluated by Western blot. At the concentrations of 0.01% to 0.1%, MAP showed growth-inhibiting and apoptosis-inducing effects on cancer cells. It increased the expression of caspase 3, 8, 9, and Bax, while decreased of Bcl-2, which denoted that MAP may induce apoptosis through both the mitochondrial-mediated and death receptor-mediated apoptotic ways. These data indicate that MAP has the potential for clinical prevention and treatment for colon cancer.