Expression and Purification of Recombinant Bowman-Birk Trypsin Inhibitor from Foxtail Millet Bran and Its Anticolorectal Cancer Effect In Vitro and In Vivo.

Trypsin inhibitors derived from plants have various pharmacological activities and promising clinical applications. In our previous study, a Bowman-Birk-type major trypsin inhibitor from foxtail millet bran (FMB-BBTI) was extracted with antiatherosclerotic activity. Currently, we found that FMB-BBTI possesses a prominent anticolorectal cancer (anti-CRC) activity. Further, a recombinant FMB-BBTI (rFMB-BBTI) was successfully expressed in a soluble manner in host strain Escherichia coli. BL21 (DE3) was induced by isopropyl-ß-d-thiogalactoside (0.1 mM) at 37 °C for 3.5 h by the pET28a vector system. Fortunately, a purity greater than 93% of rFMB-BBTI with anti-CRC activity was purified by nickel-nitrilotriacetic acid affinity chromatography. Subsequently, we found that rFMB-BBTI displays a strikingly anti-CRC effect, characterized by the inhibition of cell proliferation and clone formation ability, cell cycle arrest at the G2/M phase, and induction of cell apoptosis. It is interesting that the rFMB-BBTI treatment had no obvious effect on normal colorectal cells in the same concentration range. Importantly, the anti-CRC activity of rFMB-BBTI was further confirmed in the xenografted nude mice model. Taken together, our study highlights the anti-CRC activity of rFMB-BBTI in vitro and in vivo, uncovering the clinical potential of rFMB-BBTI as a targeted agent for CRC in the future.

The interaction between apigenin and PKM2 restrains progression of colorectal cancer.

Apigenin, a flavonoid that widely existed in vegetables and fruits, possesses anticarcinogenic, low toxicity, and no mutagenic properties, suggesting that apigenin is a potential therapeutic agent for tumors. However, the underlying anti-cancer molecular target of apigenin is still unclear. Therefore, to reveal the direct target and amino acid site of apigenin against colorectal cancer is the focus of this study. In the present study, the results proved that the anti-CRC activity of apigenin was positively correlated with pyruvate kinase M2 (PKM2) expression, characterized by the inhibition of cell proliferation and increase of apoptotic effects induced by apigenin in LS-174T cells of knock down PKM2. Next, pull-down and MALDI-TOF/TOF analysis determined that apigenin might interact directly with PKM2 in HCT-8 cells. Further, the study confirmed that lysine residue 433 (K433) was a key amino acid site for PKM2 binding to apigenin. Apigenin restricted the glycolysis of LS-174T and HCT-8 cells by targeting the K433 site of PKM2, thereby playing an anti-CRC role in vivo and in vitro. Meanwhile, apigenin markedly attenuated tumor growth without any adverse effects. Taken together, these findings reveal that apigenin is worthy of consideration as a promising PKM2 inhibitor for the prevention of CRC.

Identification of a Novel Strain Lactobacillus Reuteri and Anti-Obesity Effect through Metabolite Indole-3-Carboxaldehyde in Diet-Induced Obese Mice.

The potentially beneficial effects of probiotics in the treatment of obesity have been generally demonstrated. In the present study, a new strain of Lactobacillus reuteri SY523 (L. reuteri SY523) with an anti-obesity effect was isolated from the fecal microbiota of diet-induced obese mice. Untargeted metabolomics analysis of mice serum showed that the significantly differential metabolite indole-3-carboxaldehyde (3-IAId) was markedly elevated in the L. reuteri SY523-treated group, and interestingly, the abundance of 3-IAId was significantly negatively associated with obesity-related indicators. As expected, in the HepG2 cell induced by free fatty acids, the potential activity of 3-IAId in restraining lipid deposition was verified. Further, we found that 3-IAId was involved in the anti-obesity effect of L. reuteri SY523 mainly via regulating the cGMP/cAMP signaling pathway. The highlight of this study lies in clarifying the pivotal role of metabolite 3-IAId in the anti-obesity effect induced by L. reuteri SY523, which is conducive to the development of probiotics for anti-obesity agents.

Coprococcus eutactus, a Potent Probiotic, Alleviates Colitis via Acetate-Mediated IgA Response and Microbiota Restoration.

Inflammatory bowel disease (IBD) is a complex disease characterized by relapsing episodes of inflammation of the colonic mucosa. Research into IBD suggests that this disease condition is caused by alterations in resident mucosal bacterial populations. Our previous study showed that Coprococcus was significantly elevated during the improvement of IBD. Human metagenome database GMrepo also indicates Coprococcus, in particular, Coprococcus eutactus (C. eutactus), which was negatively associated with IBD. The current study implied the alleviated effects and mechanisms of C. eutactus on dextran sodium sulfate-induced experimental colitis mice. Gavage with C. eutactus-ameliorated acute colitis, as evidenced, relieved weight loss, decreased concentrations of proinflammatory cytokines TNF-α, IL-1ß, and IL-6, and increased anti-inflammatory factors, IL-4, IL-5, and IL-10. In addition, C. eutactus enhanced the maturation of goblet cells and the expressions of mucins and restored the expressions of tight junction proteins such as claudin-1, occludin, and ZO-1. As a short-chain fatty acid-producing bacterium, C. eutactus mainly generates acetic acid. Interestingly, not only high levels of secretory immunoglobulin A (SIgA) but also increased IgA-producing plasma cells were observed in colitis mice during the administration of C. eutactus. Importantly, our data demonstrated that colonic SIgA is specifically coated on pathogens of Enterobacteriaceae. Owing to the selective binding effect of SIgA on microorganisms, the microbial diversity in the intestinal lumen and mucosa of C. eutactus-treated colitis mice was significantly restored, and the microbiota structure was remodeled. These findings provide substantial insight that C. eutactus as a promising probiotic can ameliorate colitis. In conclusion, our findings may deliver a novel approach to the prevention and biotherapy of IBD.

Millet shell polyphenols ameliorate atherosclerosis development by suppressing foam cell formation.

Polyphenols are bioactive compounds that occur naturally in plants, and they are widely used for disease prevention and health maintenance. In present study, the effects of millet shell polyphenols (MSPs) in thwarting atherosclerosis were explored. The results found that MSPs effectively inhibited the ability of macrophages to phagocytose lipids, and reduced the secretion of inflammatory factors IL-1ß and TNF-α by obstructing the expression of STAT3 and NF-κB in macrophages. Eventually, MSPs hindered the formation of macrophage-derived foam cells. On the other hand, MSPs promoted the transformation of HASMCs from synthesis to contraction by regulating the gene expression levels of smooth muscle myosin heavy chain (SMMHC), desmin (DES), smoothelin (SMTN) and elastin (ELN). Lipid phagocytosis inhibited along with this process, thereby reducing the formation of smooth muscle cell-derived foam cells. In addition, experiments in ApoE-/- mice also showed that MSPs increased high-density lipoprotein cholesterol (HDL-C). Collectively, MSPs play a role in preventing atherosclerosis by impeding foam cell production. This study offers an integrative strategy for thwarting plaque formation in the early stages of atherosclerosis in cardiovascular disease.

Millet Bran Protein Hydrolysate Displays the Anti-non-alcoholic Fatty Liver Disease Effect via Activating Peroxisome Proliferator-Activated Receptor γ to Restrain Fatty Acid Uptake.

Non-alcoholic fatty liver disease (NAFLD) is a serious health problem worldwide. Impeding fatty acid uptake may be an attractive therapeutic strategy for NAFLD. In the current study, we found that millet bran protein hydrolysate (MBPH) prepared by in vitro gastrointestinal bionic digestion exhibits the potential of anti-NAFLD in vitro and in vivo, characterized by the alleviation of hepatic steatosis and the reduction of lipid accumulation. Further, MBPH significantly decreased the expression levels of fatty acid uptake related genes (FABP1, FABP2, FABP4, CD36, and CPT-1α) of liver tissue in a NAFLD mice model through activating peroxisome proliferator-activated receptor γ (PPARγ) and efficiently restrained the fatty acid uptake of liver tissue, thus exerting anti-NAFLD activity. As expected, the anti-NAFLD effect induced by MBPH, characterized by the alleviation of hepatic vacuolar degeneration, hepatic steatosis, and fibrosis, was effectively abrogated with PPARγ inhibitor (GW9662) treatment. These results indicate that the retardant of fatty acid uptake induced by PPARγ activation may be the critical factor for the anti-NAFLD effect of MBPH. Collectively, MBPH has the potential as a next-generation dietary supplementation for the prevention and treatment of NAFLD.

Polyphenols from foxtail millet bran ameliorate DSS-induced colitis by remodeling gut microbiome.

Introduction: Polyphenols from plants possess the anti-inflammatory and gut microbiota modulated properties. Foxtail millet (Setaria italica L., FM) has potential medical and nutritional functions because of rich phenolic and other phytochemical components. Methods: Here, the study explored the effects of bound polyphenol of inner shell (BPIS) from FM bran on dextran sodium sulfate (DSS)-induced experimental colitis mice. Results: Results showed that BPIS administration effectively relieved the weight loss, decreased disease active index (DAI) scores, restrained the secretion of pro-inflammatory cytokines TNF-α, IL-6 and IL-1ß, increased anti-inflammatory cytokines IL-10, IL-4, IL-5. BPIS prevented gut barrier damage by enhancing tight junction proteins Claudin1, ZO-1 and Occludin, increasing the number of goblet cells and facilitating the gene expressions of mucin family. In addition, BPIS restored the gut microbiota composition and increased the relative abundance of commensal bacteria such as Lachnospiraceae and Rikenellaceae and restrained the growth of S24-7 and Staphylococcaceae. Concentrations of short-chain-fatty acids (SCFAs) generated by gut microbiota were elevated in BPIS treated colitis mice. Conclusion: These data suggest that BPIS effectively ameliorates DSS-induced colitis by preventing intestinal barrier damage and promoting gut microbiota community.

Peroxidase from foxtail millet bran exerts anti-colorectal cancer activity via targeting cell-surface GRP78 to inactivate STAT3 pathway.

Molecular targeted therapy has become an emerging promising strategy in cancer treatment, and screening the agents targeting at cancer cell specific targets is very desirable for cancer treatment. Our previous study firstly found that a secretory peroxidase of class III derived from foxtail millet bran (FMBP) exhibited excellent targeting anti-colorectal cancer (CRC) activity in vivo and in vitro, whereas its underlying target remains unclear. The highlight of present study focuses on the finding that cell surface glucose-regulated protein 78 (csGRP78) abnormally located on CRC is positively correlated with the anti-CRC effects of FMBP, indicating it serves as a potential target of FMBP against CRC. Further, we demonstrated that the combination of FMBP with the nucleotide binding domain (NBD) of csGRP78 interfered with the downstream activation of signal transducer and activator of transcription 3 (STAT3) in CRC cells, thus promoting the intracellular accumulation of reactive oxygen species (ROS) and cell grown inhibition. These phenomena were further confirmed in nude mice tumor model. Collectively, our study highlights csGRP78 acts as an underlying target of FMBP against CRC, uncovering the clinical potential of FMBP as a targeted agent for CRC in the future.

Bowman-Birk Major Type Trypsin Inhibitor Derived from Foxtail Millet Bran Attenuate Atherosclerosis via Remodeling Gut Microbiota in ApoE-/- Mice.

Foxtail millet proteins and their hydrolysates have the potential to prevent atherosclerosis (AS). In our present study, a novel Bowman-Birk type major trypsin inhibitor from foxtail millet bran (FMB-BBTI) with an anti-AS effect was obtained by in vitro gastrointestinal bionic digestion. Further, the anti-AS activity of FMB-BBTI was verified by the classic apoE-/- mice model, characterized by the decreases of the inflammatory cytokines (TNF-α and IL-1ß) and atherosclerotic plaque. Importantly, FMB-BBTI remodeled the structure of gut microbiota in apoE-/- mice, including the increase of Firmicutes at the phylum level, and the abundance alteration of five genera at the genus level, especially significant enrichment of Lactobacillus. Collectively, FMB-BBTI markedly restrains the AS progress, suggesting that the remodeling of gut microbiota induced by FMB-BBTI may be the critical factor for its anti-AS activity. This study indicates that FMB-BBTI may serve as a vital functional component contributing to the anti-AS potential of foxtail millet bran.

Millet shell polyphenols prevent atherosclerosis by protecting the gut barrier and remodeling the gut microbiota in ApoE-/- mice.

Atherosclerosis, the major cause of cardiovascular disease, is a chronic inflammatory disease. The anti-inflammatory effect of certain polyphenols has been recognized. Active polyphenols were extracted from millet shells (MSPs), and their main components including 3-hydroxybenzylhydrazine, luteolin-3',7-diglucoside, N-acetyltyramine, p-coumaric acid, vanillin, sinapic acid, ferulic acid and isophorone exhibited the anti-atherosclerotic potential in vitro. To explore the anti-atherosclerotic activity of MSPs in vivo, a classic atherosclerosis model was constructed in ApoE-/- mice fed with a high-fat diet. The results showed that MSPs effectively inhibited the development of atherosclerotic plaques in the aorta and reduced the levels of lipopolysaccharide (LPS) and inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß). A further study found that the expression of tight junction proteins (occludin, zona occludens-1 and claudin1) was obviously up-regulated in the MSPs-treated group at the mRNA and protein levels. Interestingly, MSPs significantly changed the structure of gut microbiota in ApoE-/- mice with a high-fat diet, which is characterized by the enriched Oscillospira and Ruminococcus, and the abridged Allobaculum at the genus level. Collectively, these results suggest that MSPs regulate the integrity of the gut barrier and the structure of the gut microbiota, ultimately inhibiting the development of atherosclerotic plaques. This study provides new insights into the potential cardiovascular protective effects induced by millet shell polyphenols.

Inhibitory effect of bound polyphenol from foxtail millet bran on miR-149 methylation increases the chemosensitivity of human colorectal cancer HCT-8/Fu cells.

Nature polyphenols widely present in plants and foods are promising candidates in cancer chemotherapy. Emerging evidence has shown that plant polyphenols regulate the expression of miRNAs to exert the anti-Multidrug resistance (MDR) activity, which partly attributes to their regulation on miRNAs methylation. Our previous study found that bound polyphenol from foxtail millet bran (BPIS) had potential as an anti-MDR agent for colorectal cancer (CRC), but its mechanism remains unclear. The present findings demonstrated that BPIS upregulated the expression of miR-149 by reducing the methylation of its CpG islands, which subsequently induced the cell cycle arrest in G2/M phase, resulting in enhancing the chemo-sensitivity of HCT-8/Fu cells. Mechanically, BPIS and its active components (FA and p-CA) reduced miR-149 methylation by inhibiting the expression levels of DNA methyltransferases, promoting a remarkable increase of miR-149 expression. Further, the increased miR-149 induced cell cycle arrest in G2/M phase by inhibiting the expression of Akt, Cyclin B1 and CDK1, thus increasing the chemosensitivity of HCT-8/Fu cells. Additionally, a strong inducer of DNA de-methylation (5-aza-dc) treatment markedly increased the chemosensitivity of CRC through elevating miR-149 expression, which indicates the hypermethylation of miR-149 may be the key cause of drug resistance in CRC. The study indicates that the enhanced chemosensitivity of BPIS on CRC is mainly attributed to the increase of miR-149 expression induced by methylation inhibition.

Polyphenol from millet bran increases the sensitivity of colorectal cancer cells to oxaliplatin by blocking the ganglioside GM3 catabolism.

Colorectal cancer (CRC) is an aggressive malignancy with very limited therapeutic approaches. Drug resistance develops as a frequent characteristic in many patients with CRC, which leads to a decrease in the therapeutic efficacy of anticancer agents. Our previous evidences showed that bound polyphenol from millet bran (BPIS) possesses the potential of inhibiting cancer cell proliferation, and its main anticancer components are ferulic acid (FA) and p-coumaric acid (p-CA). In the present study, we found that BPIS significantly increases the sensitivity of human drug-resistant CRC cell line to oxaliplatin (OXA), a commonly used chemotherapy drug against CRC. Mechanistically, we indicated that BPIS significantly impairs the expression of a gene encoding multidrug resistance protein 1 (MDR1), a well-known permeability glycoprotein (P-gp), by preventing ganglioside GM3 catabolism. Neuraminidase 3 (NEU3) is a key enzyme catalyzing the conversion of ganglioside GM3 to ceramide trihexosides (Gb3), whose expression is increased in drug-resistant HCT-116/L cells. BPIS treatment increased GM3 level, but reduced Gb3 and P-gp levels by inhibiting NEU3 expression, which subsequently boosted the chemotherapy sensitivity of drug-resistant HCT-116/L cells to OXA. These findings reveal that BPIS increases the chemo-sensitivity by remodeling NEU3-mediated ganglioside GM3 catabolism, and it may be applied as a novel drug for facilitating the effectiveness of chemotherapeutic agents in CRC.

Inhibitory Effects of Peroxidase from Foxtail Millet Bran on Colitis-Associated Colorectal Carcinogenesis by the Blockage of Glycerophospholipid Metabolism.

Abnormal glycerophospholipid (GPL) metabolism represented by phosphatidylcholine (PC) and phosphatidylethanolamine (PE) has been as a universal metabolic hallmark of cancer, which is involved in tumor progression. Our previous finding showed that peroxidase from foxtail millet bran (FMBP) exhibited significant anticolorectal cancer (CRC) activity in vitro and in nude mice. Presently, the potential of FMBP in clinical application was further evaluated by an azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colitis-associated carcinogenesis (CAC) mice model, revealed the pivotal role of GPL metabolism in anti-CRC effects of FMBP. Excitedly, FMBP significantly reduced the number and volume of CAC polyps of mice and effectively improved physiological indexes of CAC mice. Meanwhile, the elevated expressions of CRC early markers (cyclooxygenase 2, tumor-proliferating nuclear antigen Ki-67, and EGF module-containing mucin-like receptor 1) in CAC mice were efficiently prevented by FMBP treatment. Metabolomics analysis showed that the elevated abundances of PC and PE involved in GPL metabolism in CAC mice were markedly decreased in FMBP-treated groups, which was also verified in human CRC cells. Further, FMBP reduced the expression levels of PE and PC key metabolic enzymes, resulting in the blockage of GPL metabolism and insufficient adenosine triphosphate to maintain CRC growth. Collectively, FMBP has the potential as a preventive and therapeutic candidate for CRC through the blockage of GPL metabolism.

Fruiting body polysaccharides of Hericium erinaceus induce apoptosis in human colorectal cancer cells via ROS generation mediating caspase-9-dependent signaling pathways.

The fruiting bodies of Hericium erinaceus (Bull.) Pers. are commonly used in China in the treatment of digestive system diseases. In this work, the polysaccharides from the fruiting bodies of Hericium erinaceus (HEFPs) were extracted, and their effects on human colorectal cancer cells (HCT-116 and DLD1) were investigated in vitro. Our results showed that HEFPs were mainly composed of arabinose, galactose, glucose, and mannose at a molar ratio of 8.99 : 11.15 : 1.2 : 1.97. They significantly inhibited the growth of these cells by inducing apoptosis by the modulation of Bax and Bcl-2 expression, which in turn induced the loss of mitochondrial membrane potential, leading to the activation of cleaved-caspase-9 and cleaved-caspase-3. These results suggested that HEFPs induced apoptosis via the caspase-9-depedent intrinsic mitochondrial pathway. Furthermore, HEFPs increased the level of reactive oxygen species (ROS) in HCT-116 and DLD1 cells. The addition of the antioxidant N-acetyl-l-cysteine reduced the ability of HEFPs to trigger the intrinsic mitochondrial pathway, indicating the role of ROS generation in the upstream pathway of HEFP-induced apoptosis. Therefore, the results described in this study could be of interest for further studies in finding functional foods or alternative therapeutic agents against colorectal cancer.

Inhibitory Effects of Bound Polyphenol from Foxtail Millet Bran on Colitis-Associated Carcinogenesis by the Restoration of Gut Microbiota in a Mice Model.

Colorectal cancer (CRC) is a common malignant tumor occurring in the colon. It has been known that the gut microbiota is a complex ecosystem and plays an important role in the pathogenesis of colorectal cancer. Our previous study showed that bound polyphenol of the inner shell (BPIS) from foxtail millet bran exhibited significant antitumor activities in cancer cells and nude mice models. In the present study, the anticancer potential of BPIS is evaluated in the azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced mouse CRC model. Results showed that BPIS could decrease the number and volume of tumors and protect the epithelial architecture from damage. Certain biomarkers associated with CRC formation, such as COX-2, EMR1, PCNA, and caspase-3, were strongly changed by BPIS. Moreover, by 16S rRNA gene sequence analysis, it was found that BPIS could remodel the overall structure of the gut microbiota from tumor-bearing mice toward that of the normal counterparts, including two phyla and eight genera, together with regulations on several genes that are responsible for 17 signaling pathways.

Cloning, expression of the truncation of recombinant peroxidase derived from millet bran and its reversal effects on 5-Fu resistance in colorectal cancer.

A novel peroxidase (FMBP) was extracted and purified from foxtail millet bran in our previous study and it possessed excellent anti-colon cancer activity both in vitro and in vivo. However, the active fragment of FMBP responsible for the anti-colon cancer effects remains unclear. In present, three different truncated sequences of FMBP were designed and cloned into a plasmid vector (pMal-s). Three recombinant segments were successfully expressed in host strain Escherichia coli DH5α induced by IPTG (0.3 mM) at 37 °C for 4 h, respectively named MBP-FMBP-1, MBP-FMBP-2 and MBP-FMBP-3. MTT assay showed that only MBP-FMBP-2 possessed significant anti-colon cancer activity, and its anti-colon cancer activity was equivalent to FMBP. Further, the results showed that MBP-FMBP-2 significantly reversed the 5-Fu resistance in human colorectal cancer HCT-8/Fu cell through inhibiting cell proliferation, promoting cell apoptosis and increasing the intracellular accumulation of 5-Fu. RT-PCR and western blot assays showed that MBP-FMBP-2 also decreased the expression levels of multi-drug resistance protein 1 (MRP1), P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP). These results indicate that MBP-FMBP-2 is the effective segment of FMBP which exhibits anti-colon cancer activity and has potential as an outstanding chemotherapeutic agent against colon cancer.

Reversal Effects of Bound Polyphenol from Foxtail Millet Bran on Multidrug Resistance in Human HCT-8/Fu Colorectal Cancer Cell.

Foxtail millet is the second-most widely planted species of millet and the most important cereal food in China. Our previous study showed that bound polyphenol of inner shell (BPIS) from foxtail millet bran displayed effective antitumor activities in vitro and in vivo. The present research further implied that BPIS has the ability to reverse the multidrug resistance of colorectal cancer in human HCT-8/Fu cells, the IC50 values of 5-fluorouracil (5-Fu), oxaliplatin (L-OHP), and vincristine (VCR) were decreased form 6593 ± 53.8, 799 ± 48.9, and 247 ± 10.3 µM to 5350 ± 22.3 (3261 ± 56.9), 416 ± 16.6 (252 ± 15.6), and 144 ± 8.30 (83.8 ± 5.60) µM when HCT-8/Fu cells were pretreated with 0.5 (1.0) mg/mL BPIS for 12 h. The 12 phenolic acid compounds of BPIS were identified by ultraperformance liquid chromatography-triple-time of flight/mass spectrometry (UPLC-Triple-TOF/MS) method. Especially, the fraction of molecular weight (MW) < 200 of BPIS reversed the multidrug resistance in HCT-8/Fu cells, and ferulic acid and p-coumaric acid were the main active components, the IC50 values were 1.23 ± 0.195 and 2.68 ± 0.163 mg/mL, respectively. The present data implied that BPIS significantly enhanced the sensitivity of chemotherapeutic drugs through inhibiting cell proliferation, promoting cell apoptosis, and increasing the accumulation of rhodamine-123 (Rh-123) in HCT-8/Fu cells. Real-time polymerase chain reaction (RT-PCR) and Western blot data indicated that BPIS also decreased the expression levels of multidrug resistance protein 1 (MRP1), P-glycoprotein (P-gp), and breast cancer resistance protein (BCRP). Collectively, these results show that BPIS has potential ability to be used as a new drug-resistance reversal agent in colorectal cancer.

Anti-inflammatory effects of millet bran derived-bound polyphenols in LPS-induced HT-29 cell via ROS/miR-149/Akt/NF-κB signaling pathway.

The pro-inflammatory and anti-inflammatory maladjustment has been acknowledged as one of the chief causations of inflammatory diseases and even cancers. Previous studies showed that plant-derived polyphenolic compounds were the most potent anti-oxidant and anti-inflammatory agents among all natural compounds. The present study indicates that bound polyphenols of inner shell (BPIS) from foxtail millet bran can display anti-inflammatory effects in LPS-induced HT-29 cells and in nude mice. Mechanistically, BPIS restrained the level of various pro-inflammatory cytokines (IL-1ß, IL-6, IL-8), and enhanced the expression level of anti-inflammatory cytokine (IL-10) by blocking the nuclear factor-kappaB (NF-κB)-p65 nuclear translocation. Further, we found the elevated miR-149 expression by BPIS-induced ROS accumulation, directly targeted the Akt expression to block NF-κB nuclear translocation. Taken together, these novel findings provide new insights into the development of BPIS as an anti-inflammatory agent via the signaling cascade of ROS/miR-149/Akt/NF-κB axis.

Apigenin Restrains Colon Cancer Cell Proliferation via Targeted Blocking of Pyruvate Kinase M2-Dependent Glycolysis.

Apigenin (AP), as an anticancer agent, has been widely explored. However, the molecular targets of apigenin on tumor metabolism are unclear. Herein, we found that AP could block cellular glycolysis through restraining the tumor-specific pyruvate kinase M2 (PKM2) activity and expression and further significantly induce anti-colon cancer effects. The IC50 values of AP against HCT116, HT29, and DLD1 cells were 27.9 ± 2.45, 48.2 ± 3.01 and 89.5 ± 4.89 µM, respectively. Fluorescence spectra and solid-phase AP extraction assays proved that AP could directly bind to PKM2 and markedly inhibit PKM2 activity in vitro and in HCT116 cells. Interestingly, in the presence of d-fructose-1,6-diphosphate (FBP), the inhibitory effect of AP on PKM2 was not reversed, which suggests that AP is a new allosteric inhibitor of PKM2. RT-PCR and Western blot assays showed that AP could ensure a low PKM2/PKM1 ratio in HCT116 cells via blocking the ß-catenin/c-Myc/PTBP1 signal pathway. Hence, PKM2 represents a novel potential target of AP against colon cancer.

Targeted anti-colon cancer activities of a millet bran-derived peroxidase were mediated by elevated ROS generation.

Foxtail millet (Setaria italica) is the sixth most important cereal in the world. In particular, the millet-derived active components play important roles in disease prevention. In this study, we found that a peroxidase from foxtail millet bran, named FMBP, displayed profound inhibitory effects on the growth of human colon cancer cells, but not on that of the normal colon epithelial cells. Mechanistic investigations suggested that the selective anti-cancer effects of FMBP were mainly achieved by inducing more accumulation of reactive oxygen species (ROS) in colon cancer cells than normal cells. The preferential ROS accumulation in cancer cells by FMBP appears to be partially attributed to the down-regulation of NF-E2-related factor 2 (Nrf2) expression, and the reduction of catalase activities and glutathione contents. The increased ROS accumulation is speculated to block the STAT3 signaling pathway, which results in the anti-proliferative effects on colon cancer cells. Therefore, these results suggest that the millet bran-derived peroxidase has a therapeutic potential in the management of colon cancer.