Japanese bog orchid (Eupatorium japonicum) extract suppresses expression of inducible nitric oxide synthase and cyclooxygenase-2 induced by toll-like receptor agonists

Toll-like receptors (TLR) play an important role in the recognition of many pathogen-associated molecular patterns and the induction of innate immunity. Dysregulated activation of TLR signaling pathways is associated with certain inflammatory diseases. Japanese bog orchid (Eupatorium japonicum), which belongs to a family of Asteraceae plants, is consumed as a tea. The present study investigated the effect of the ethanol extracts of flowers of Japanese bog orchid (EJE) on nuclear factor (NF)-κB activation and expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) by TLR agonists in murine macrophages. EJE suppressed NF-κB activation and iNOS and COX-2 expression induced by lipopolysaccharide (TLR4 agonist), polyriboinosinic polyribocytidylic acid (TLR3), and macrophage-activating 2 kDa lipopeptide (TLR2 and TLR6). These results suggest that EJE can regulate TLR signaling pathways and indicated its potential as a potent anti-inflammatory drug.     

Lycopene inhibits growth of human colon cancer cells via suppression of the Akt signaling pathway

The aberrant regulation of the phosphoinositide 3-kinase/Akt survival signaling pathway in cancer has prompted significant interest in suppression of this pathway to treat cancer. Previous studies identified an important role for phosphoinositide 3-kinase/Akt in colon cancer progression. Lycopene, a major component in tomato, exhibited potential anti-carcinogenic activity. Consumption of tomato has been associated with reduced risk of several types of human cancer. However, the inhibitory mechanisms of lycopene on the proliferation of human colon cancer have not been studied well yet. Thus we investigated the inhibitory effects of lycopene on the Akt signaling pathway in human colon cancer HT-29 cells. Lycopene inhibited cell proliferation in human colon cancer HT-29 cells with a IC(50) value of 10 microM. Lycopene treatment suppressed Akt activation and non-phosphorylated beta-catenin protein level in human colon cancer cells. Immunocytochemical results indicated that lycopene increased the phosphorylated form of beta-catenin proteins. These effects were also associated with reduced promoter activity and protein expression of cyclin D1. Furthermore, lycopene significantly increased nuclear cyclin-dependent kinase inhibitor p27(kip)abundance and inhibited phosphorylation of the retinoblastoma tumor suppressor protein in human colon cancer cells. In conclusion, lycopene inhibited cell proliferation of human colon cancer cells via suppression of the Akt signaling pathway and downstream targeted molecules.     

Acetate regulates milk fat synthesis through the mammalian target of rapamycin/eukaryotic initiation factor 4E signaling pathway in bovine mammary epithelial cells

Acetate is a short-chain fatty acid (SFA) that is the major substrate for de novo fatty acid synthesis. The mammalian target of rapamycin/eukaryotic initiation factor 4E (mTOR/eIF4E) signaling pathway is involved in fat synthesis. However, the effect and mechanism of acetate on fatty acid synthesis by the mTOR/eIF4E signaling pathway is unclear in bovine mammary epithelial cells (BMECs). The objectives of this study were to investigate the effect of acetate on cell viability, triacylglycerol (TG), and mRNA expression of the genes related to lipid synthesis. The mechanism of acetate regulation milk fat synthesis through the mTOR/eIF4E signaling pathway was assessed by blocking the mTOR signaling pathway and silencing eIF4E in BMECs. Third-passage BMECs were allocated to 6 treatments including 0, 4, 6, 8, 10, and 12 mM acetate to evaluate the effect of acetate on lipid synthesis; the optimum concentration in the first study was selected for the subsequent study. Subsequently, cells were randomly allocated to 4 treatments, 1 control group and 3 treated groups, consisting of acetate (6 mM), rapamycin (100 nM), and acetate + rapamycin to test the role of mTOR signaling pathway response to acetate in milk lipid synthesis. Finally, eIF4E was silenced by small interfering RNA (siRNA) to detect the role of eIF4E in milk lipid synthesis. Treatments included control, eIF4E siRNA, acetate (6 mM), and acetate+ eIF4E siRNA. Results showed that acetate increased TG accumulation and the relative expression of fatty acid synthase (FASN), acetyl-coenzyme A carboxylase α (ACACA), fatty acid-binding protein 3 (FABP3), sterol regulatory element binding protein 1 (SREBP1), peroxisome proliferator-activated receptor gamma (PPARG), mTOR, eIF4E, P70 ribosomal protein S6 kinase-1 (S6K1), and 4E-binding protein-1 (4EBP1) in a dose-dependent manner. Rapamycin effectively inhibited the positive effect of acetate on the relative expression of mTOR, eIF4E, S6K1, 4EBP1, FASN, ACACA, FABP3, stearoyl-CoA desaturase (SCD1), SREBP1, and PPARG. The upregulation of acetate on the relative expressions of FASN, ACACA, SCD1, and SREBP1 was suppressed when eIF4E was knocked down. It suggested that acetate regulated milk fat synthesis through mTOR/eIF4E signaling pathway in BMECs.     

Reduced signaling through the hedgehog pathway in the uterine stroma causes deferred implantation and embryonic loss

The role of the hedgehog (HH) signaling pathway in implantation was studied in mice in which the HH signal transducer, smoothened (SMO), was conditionally deleted in the stromal compartment of the uterus, using CRE recombinase expressed through the Amhr2(cre) allele. In Amhr2(cre/+)Smo(null/flox)-mutant mice, Smo mRNA in uterine stroma was reduced 49% compared to that in Amhr2(+/+)Smo(null/flox) control mice, while levels in the luminal epithelium were not different. Litter size was reduced 60% in mutants compared with controls, but ovulation rate and the number of implantation sites on day 7 of pregnancy did not differ. The number of corpora lutea was equivalent to the number of implantation sites, indicating that most ovulations resulted in implanted embryos. However, on days 13 to 15, the rate of embryo resorption was elevated in mutants. In control mice, on day 5, implantation sites were present and blastocysts were well-attached. In contrast, blastocysts were readily flushed from uteri of mutant mice on day 5 and implantation sites were rare. On days 5.5 and 6, implantation sites were present in mutant mice, and by day 6 embryos could not be flushed from the uterus. The weight of implantation sites on day 7 was decreased by 42% in mutant mice, consistent with delayed development. Signaling through SMO in the endometrial stroma is required for optimal timing of implantation, and deferred implantation leads to defective embryo development and subsequent pregnancy loss.     

Nutrient availability and lactogenic hormones regulate mammary protein synthesis through the mammalian target of rapamycin signaling pathway

The nutritional and endocrine factors affecting protein translation in the bovine mammary gland, and the molecular mechanisms mediating their effects, are not well understood. The objective of this study was to assess the role of the mammalian target of rapamycin (mTOR) signaling pathway in the regulation of mammary protein synthesis by nutrients and hormones. Mammary epithelial acini isolated from lactating dairy cows were treated in medium containing, alone or in combination, a mixture of AA or glucose and acetate (GA) as energy substrates, or a combination of the lactogenic hormones hydrocortisone, insulin, and prolactin (HIP). Changes in the rate of mammary protein synthesis and the phosphorylation state of components of the mTOR signaling pathway were measured. Mammary protein synthesis was 50% higher with increased availability of AA in medium. The presence of GA or treatment of mammary acini with HIP alone did not affect mammary protein synthesis. The stimulation of mammary protein synthesis by AA was enhanced by HIP treatment, but not by the presence of GA in medium. Treatment of mammary acini with HIP induced the phosphorylation of protein kinase B. This effect was augmented in the presence of either AA or GA in medium. The stimulation of mammary protein synthesis by AA and its enhancement by HIP were associated with increased phosphorylation of the mTOR substrates, p70 ribosomal protein S6 kinase-1, and eukaryotic initiation factor 4E (eIF4E)-binding protein-1 (4E-BP1), and dissociation of 4E-BP1 from eIF4E. The results suggest that nutrients and hormones may modulate mammary protein synthesis through the mTOR signaling pathway.     

Protective and alleviative effects from 4 cysteine-containing compounds on ethanol-induced acute liver injury through suppression of oxidation and inflammation

ABSTRACT:  In vivo protective and alleviative effects of s-allyl cysteine (SAC), s-ethyl cysteine (SEC), s-methyl cysteine (SMC), and s-propyl cysteine (SPC) against alcohol-induced hepatotoxicity in Balb/cA mice were studied. In the preventive study, SAC, SEC, SMC, or SPC, each agent at 1 g/L, was added into the drinking water for 3 wk, and the mice were then treated with ethanol to induce acute liver injury. In the alleviative study, mice were first treated by ethanol followed by the 4 agent treatments for 3 wk. The preintake of these agents significantly attenuated subsequent alcohol-induced lipid oxidation, glutathione (GSH) depletion, and activity reduction of catalase and glutathione peroxidase ( P < 0.05); also attenuated were the alcohol-induced elevation of c-reactive protein (CRP), interleukin-6 (IL-6), IL-10 and tumor necrosis factor (TNF)-alpha ( P < 0.05). The preintake of these agents also significantly retarded alcohol-induced cytochrome P450 2E1 (CYP2E1) activity increase ( P < 0.05). In the alleviative study, posttreatments from the 4 agents restored liver GSH content ( P < 0.05); however, only SEC and SPC posttreatments significantly reduced lipid oxidation and alleviated the alcohol-induced elevation of CRP, IL-6, IL-10, and TNF-alpha ( P < 0.05). SEC and SPC posttreatments also significantly diminished alcohol induced CYP2E1 activity ( P < 0.05). These results support that SEC and SPC could provide both preventive and alleviative effects against alcohol-induced hepatotoxicity through suppression of oxidation and inflammation.     

Curcumin induced G2/M cycle arrest in SK-N-SH neuroblastoma cells through the ROS-mediated p53 signaling pathway

Neuroblastoma (NB) is a solid tumor in the nervous system and has a high mortality rate in children. Curcumin has well-characterized anticancer properties, while there is no effective method in clinical treatment. MTT assays revealed that curcumin dramatically inhibited the proliferation of SK-N-SH cells. Compared with the control group, curcumin markedly restrained the migration of SK-N-SH cells. Curcumin induced SK-N-SH cell apoptosis by G2/M cycle arrest and activated caspase-3 activity. Furthermore, curcumin promoted the overproduction of intracellular ROS and apoptosis induced by activating p53 and Bcl-2 signal pathways. This finding demonstrated the application of curcumin is an effective strategy for the therapeutics of NB     

Antimetastatic activity of polyphenol-rich extract of Ecklonia cava through the inhibition of the Akt pathway in A549 human lung cancer cells

An ethyl acetate extract (ECE) of a brown alga, Ecklonia cava, was examined for its anti-metastatic effect, using A549 human lung carcinoma cells. ECE treatment significantly suppressed the migration and invasion of A549 cells in a concentration-dependent manner. It also strongly down-regulated the matrix metalloproteinase (MMP)-2 activity of the cancer cells by gelatin zymography assay. For elucidating its mechanism of action in cancer cell metastasis, ECE was further investigated for various cell signalling pathways, including JNK, ERK, p38, and Akt. In this, ECE showed an anti-metastatic effect in a concentration- and time-dependent manner by the mechanism of suppression of Akt and p38, but not JNK and ERK. These results, for the first time, suggest that ECE (a polyphenol-enriched, highly anti-oxidative fraction of brown alga, E. cava) may have therapeutic potential in metastatic lung cancer, based on its strong inhibitory effects on the migration and invasiveness of A549 human lung adenocarcinoma cells.     

Wheat sprouts (Triticum aestivum Linn.) cultured by a smart farm system ameliorate NAFLD through the AMPK-mediated SREBP signaling pathway

Wheat is cultivated worldwide and is the most widely distributed food crop. Wheat is a staple crop in many countries. However, the effects of various cultivation methods on the efficacy of wheat sprouts have not been determined. This study investigated wheat sprouts obtained using a standardized smart farm system (WS-S) to improve the effects of non-alcoholic fatty liver disease (NAFLD) and molecular mechanism. Wheat sprouts significantly attenuated the accumulation of lipid droplets in FFA-induced HepG2 cells through AMPK pathway activity. In vivo experiments showed that WS-S significantly lowered body weight gain and decreased adipose tissue, lipid, aspartate transaminase, and alanine aminotransferase levels in HFD/F-treated mice. Furthermore, WS-S stimulated the phosphorylation of ACC and peroxisome proliferator-activated receptor alpha via the AMPK pathway and inhibited SREBP-1/FAS signaling to inhibit de novo adipogenesis and increase fatty acid oxidation. These results suggest that WS-S ameliorates NAFLD by regulating fatty acid metabolism via the AMPK pathway.

     

Combination of mineral trioxide aggregate and propolis promotes odontoblastic differentiation of human dental pulp stem cells through ERK signaling pathway

Food Science and Biotechnology - The aim of this study is to investigate combined effects of mineral trioxide aggregate (MTA) and propolis on odontoblastic differentiation of human dental pulp stem...     

Cruciferous vegetable phytochemical sulforaphane affects phase II enzyme expression and activity in rat cardiomyocytes through modulation of Akt signaling pathway

The isothiocyanate sulforaphane (SF), abundant in Cruciferous vegetables, is known to induce antioxidant/detoxification enzymes in many cancer cell lines, but studies focused on its cytoprotective action in nontransformed cells are just at the beginning. Since we previously demonstrated that SF elicits cardioprotection through an indirect antioxidative mechanism, the aim of this study was to analyze the signaling pathways through which SF exerts its protective effects. Using cultured rat cardiomyocytes, we investigated the ability of SF to activate Akt/protein kinase B (PKB) and extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling pathways, which are implicated in cardiac cell survival, and to increase the phosphorylation of Nuclear factor E2-related factor 2 (Nrf2) and its binding to the antioxidant response element. By means of specific inhibitors, we demonstrated that the Phosphatidylinositol 3-kinase (PI3K)/Akt pathway represents a mechanism through which SF influences both expression and activity of glutathione reductase, glutathione-S-transferase, thioredoxin reductase, and NAD(P)H:quinone oxidoreductase-1, analyzed by western immunoblotting and spectrophotometric assay, respectively, and modulates Nrf2 binding and phosphorylation resulting in a cytoprotective action against oxidative damage. Results of this study confirm the importance of phase II enzymes modulation as cytoprotective mechanism and support the nutritional assumption of Cruciferous vegetables as source of nutraceutical cardioprotective agents.     

A combination of lactic acid bacteria regulates Escherichia coli infection and inflammation of the bovine endometrium

Uterine function in cattle is compromised by bacterial contamination and inflammation after calving. The objective of this study was to select a combination of lactic acid bacteria (LAB) to decrease endometrium inflammation and Escherichia coli infection. Primary endometrial epithelial cells were cultured in vitro to select the most favorable LAB combination modulating basal tissue inflammation and E. coli infection. Supernatants were obtained to determine expression of pro-inflammatory cytokines, and E. coli infection was evaluated after harvesting the tissue and plate counting. The selected LAB combination was tested in uterus explants to assess its capacity to modulate basal and acute inflammation (associated with E. coli infection). The combination of Lactobacillus rhamnosus, Pediococcus acidilactici, and Lactobacillus reuteri at a ratio of 25:25:2, respectively, reduced E. coli infection in vitro with (89.77%) or without basal tissue inflammation (95.10%) compared with single LAB strains. Lactic acid bacteria treatment reduced CXCL8 and IL1B expression 4.7- and 2.2-fold, respectively, under acute inflammation. Ex vivo, the tested LAB combination reduced acute inflammation under E. coli infection, decreasing IL-8, IL-1β, and IL-6 up to 2.2-, 2.5-, and 2.2-fold, respectively. In the total inflammation model, the LAB combination decreased IL-8 1.6-fold and IL-6 1.2-fold. Ultrastructural evaluation of the tissue suggested no direct interaction between the LAB and E. coli, although pathological effects of E. coli in endometrial cells were greatly diminished or even reversed by the LAB combination. This study shows the promising potential of LAB probiotics for therapeutic use against endometrial inflammation and infection.     

The use of dermal fibroblasts as a predictive tool of the toll-like receptor 4 response pathway and its development in Holstein heifers

The innate immune system comprises the host's first line of defense against invading pathogens, and variation in the magnitude of this response between animals has been shown to affect susceptibility to mastitis. The toll-like receptor (TLR) family of proteins initiates the response to invading bacteria, specifically with TLR4 recognizing lipopolysaccharide (LPS) of gram-negative microbes. The underlying genetic variation in the TLR4 pathway leading to differential response is not well understood; therefore, the objective of this work was to determine the efficacy in which the response to LPS by dermal fibroblasts could be used to predict the actual systemic response of that animal to an intravenous endotoxin challenge. To accomplish this, dermal fibroblasts were isolated from 15 Holstein heifers at 5, 11, and 16 mo of age and exposed to either LPS or IL-1β; then, the production of IL-8 in medium was quantified by ELISA. Animals were ranked based upon the magnitude of the fibroblast IL-8 response, and 8 heifers were selected [4 low responders (LR) and 4 high responders (HR)] for challenge with an intravenous bolus dose (0.5 μg/kg of body weight) of LPS. Overall, between-animal variation in fibroblast IL-8 production following LPS or IL-1β was high, indicating appreciable differences in the TLR4 pathway of the animals. Ranking of the fibroblast responses was consistent across the 3 sampling times for each animal; however, the absolute response increased, and the age at which the fibroblasts were obtained was consistent with the potential for age-related changes in cell function to affect immune function processes. Following systemic LPS challenge, HR heifers had higher plasma concentrations of tumor necrosis factor-α and IL-8 than LR heifers. However, LR heifers had a stronger febrile response than HR heifers. The use of dermal fibroblasts under laboratory conditions appears to represent a practical model for predicting the innate immune response in vivo and could act as an important tool in mapping genetic differences of the TLR4 pathway.     

Diet‐induced obesity regulates the galanin‐mediated signaling cascade in the adipose tissue of mice

Galanin is a neuropeptide that regulates the food intake, neurogenesis, memory, and gut secretion. This study was conducted to evaluate the high‐fat diet (HFD)‐induced regulation of the galanin receptors (GalRs) and the associated signaling molecules in the adipose tissues of mice. Twenty C57BL/6J mice were given either an HFD or a normal diet for 12 wk. The results of the semiquantitative RT‐PCR analyses indicated that the HFD upregulated the expression of GalR1, GalR2, GalR3, resistance to audiogenic seizures, peroxisome proliferator‐activated receptorγ2, adipocyte protein 2, and protein kinase Cδ and downregulated the expression of peroxisome proliferative activated receptor γ coactivator 1α and uncoupling protein 1 in the adipose tissues. The immunoblot results showed that the protein levels of peroxisome proliferator‐activated receptorγ2 and adipocyte protein 2, and the phosphorylation of c‐Raf and extracellular signal‐regulated kinase 1/2 were increased, while the phosphorylation of cyclic adenosine monophosphate‐responsive element‐binding protein, which regulates peroxisome proliferative activated receptor γ coactivator 1α and uncoupling protein 1, was decreased in the epididymal adipose tissues of the HFD‐fed mice. These results suggest the possible association of the galanin‐mediated signaling pathways in the manifestation of the HFD‐induced activation of adipogenesis along with the suppression of thermogenesis in the adipose tissues of mice.