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Lactobacilli have been widely used as probiotics because of their benefits for intestinal health and physiological functions. Among a variety of Lactobacillus genera, Limosilactobacillus reuteri has been studied for its ability to exert anti-inflammatory functions and its role in controlling metabolic disorders, as well as the production of the antimicrobial compound reuterin. However, the effects and mechanisms of L. reuteri on enhancing immune responses in the immunosuppressed states have been relatively understudied. In this study, we isolated an immunomodulatory strain, namely, L. reuteri KBL346 (KBL346), from a fecal sample of a 3-month-old infant in Korea. We evaluated the immunostimulatory activity and hematopoietic function of KBL346 in macrophages and cyclophosphamide (CPA)-induced immunosuppressed mice. KBL346 increased the phagocytic activity against Candida albicans MYA-4788 in macrophages, and as biomarkers for this, increased secretions of nitric oxide (NO) and prostaglandin E2 (PGE2) were confirmed. Also, the secretions of innate cytokines (TNF-α, IL-1β, and IL-6) were increased. In CPA-induced immunosuppressed mice, KBL346 at a dosage of 1010 CFU/kg protected against spleen injury and suppressed levels of immune-associated parameters, including NK cell activity, T and B lymphocyte proliferation, CD4+ and CD8+ T cell abundance, cytokines, and immunoglobulins in vivo. The effects were comparable or superior to those in the Korean red ginseng positive control group. Furthermore, the safety assessment of KBL346 as a probiotic was conducted by evaluating its antibiotic resistance, hemolytic activity, cytotoxicity, and metabolic characteristics. This study demonstrated the efficacy and safety of KBL346, which could potentially be used as a supplement to enhance the immune system. [ABSTRACT FROM AUTHOR]

Loss of immunity is an important cause in the pathology of infectious disease. This study investigates the effect of Litsea japonica fruit extract (LJFE) as a potential functional food on immunity and hematopoietic function in immunosuppressed BALB/c mice. Immunity-stimulating activity was observed in mice supplemented with LJFE at low (25 mg/kg), medium (50 mg/kg), and high (100 mg/kg) dosage for seven days after administration of cyclophosphamide. LJFE treatment significantly improved spleen injury score (p < 0.001) and body weight (p < 0.02) by approximately two-fold with a high dosage of LJFE (100 mg/kg). Spleen-derived lymphocyte analysis demonstrated that the numbers of clusters of differentiation (CD)4+ and CD8+ T-cells were notably increased by approximately two-fold (p < 0.001) with a high dosage of LJFE (100 mg/kg). In mouse splenocytes differentiated into T- and B-lymphocytes, LJFE significantly induced proliferation up to approximately 90% of control for T- (p < 0.001) and B-lymphocytes (p < 0.01) with a high dosage of LJFE (100 mg/kg). Furthermore, LJFE significantly recovered the numbers of white blood cells, red blood cells, and platelets. Enzyme-linked immunosorbent assay revealed that serum levels of immune-related cytokines, such as tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-2, and interferon (IFN)-γ, were notably Increased. In addition, serum levels of immunoglobulin (Ig) A, IgM, and IgG were restored by LJFE treatment. This study provides a reference to use L. japonica as a functional food ingredient to improve immunity and hematological function in humans. [ABSTRACT FROM AUTHOR]

Numerous studies have linked particulate matter2.5 (PM2.5) to ocular surface diseases, but few studies have been conducted on the biological effect of PM2.5 on the cornea. The objective of this study was to evaluate the harmful effect of PM2.5 on primary rat corneal epithelial cells (RCECs) in vitro and identify the toxic mechanism involved. Primary cultured RCECs were characterized by pan-cytokeratin (CK) staining. In PM2.5-exposed RCECs, cell viability, microarray gene expression, inflammatory cytokine levels, mitochondrial damage, DNA double-strand break, and signalling pathway were investigated. Exposure to PM2.5 induced cytotoxicity and morphological changes in RCECs. In addition, PM2.5 markedly up-regulated pro-inflammatory mediators but down-regulated the wound healing-related transforming growth factor-β. Furthermore, PM2.5 promoted mitochondrial reactive oxygen species (ROS) production and mediated cellular damage to mitochondria and DNA, whereas these cellular alterations induced by PM2.5 were markedly suppressed by a potential ROS scavenger. Noteworthy, removal of ROS selectively down-regulated the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and the activation of the nuclear factor-κB (NF-κB) p65 in PM2.5-stimulated cells. Additionally, SB203580, a p38 MAPK inhibitor, markedly suppressed these PM2.5-mediated cellular dysfunctions. Taken together, our findings show that PM2.5 can promote the ROS/p38 MAPK/NF-κB signalling pathway and lead to mitochondrial damage and DNA double-strand break, which is ultimately caused inflammation and cytotoxicity in RCECs. These findings indicate that the ROS/p38 MAPK/NF-κB signalling pathway is one mechanism involved in PM2.5-induced ocular surface disorders. [ABSTRACT FROM AUTHOR]

Retinal pigment epithelial (RPE) cells occupy the outer layer of the retina and perform various biological functions. Oxidative damage to RPE cells is a major risk factor for retinal degeneration that ultimately leads to vision loss. In this study, we investigated the role of spermidine in a hydrogen peroxide (H2O2)-induced oxidative stress model using human RPE cells. Our findings showed that 300 μM H2O2 increased cytotoxicity, apoptosis, and cell cycle arrest in the G2/M phase, whereas these effects were markedly suppressed by 10 μM spermidine. Furthermore, spermidine significantly reduced H2O2-induced mitochondrial dysfunction including mitochondrial membrane potential and mitochondrial activity. Although spermidine displays antioxidant properties, the generation of intracellular reactive oxygen species (ROS) upon H2O2 insult was not regulated by spermidine. Spermidine did suppress the increase in cytosolic Ca2+ levels resulting from endoplasmic reticulum stress in H2O2-stimulated human RPE cells. Treatment with a cytosolic Ca2+ chelator markedly reversed H2O2-induced cellular dysfunction. Overall, spermidine protected against H2O2-induced cellular damage by blocking the increase of intracellular Ca2+ independently of ROS. These results suggest that spermidine protects RPE cells from oxidative stress, which could be a useful treatment for retinal diseases. [ABSTRACT FROM AUTHOR]

Isorhamnetin is an O-methylated flavonol that is predominantly found in the fruits and leaves of various plants, which have been used for traditional herbal remedies. Although several previous studies have reported that this flavonol has diverse health-promoting effects, evidence is still lacking for the underlying molecular mechanism of its anti-cancer efficacy. In this study, we examined the anti-proliferative effect of isorhamnetin on human bladder cancer cells and found that isorhamnetin triggered the gap 2/ mitosis (G2/M) phase cell arrest and apoptosis. Our data showed that isorhamnetin decreased the expression of Wee1 and cyclin B1, but increased the expression of cyclin-dependent kinase (Cdk) inhibitor p21WAF1/CIP1, and increased p21 was bound to Cdk1. In addition, isorhamnetin-induced apoptosis was associated with the increased expression of the Fas/Fas ligand, reduced ratio of B-cell lymphoma 2 (Bcl-2)/Bcl-2 associated X protein (Bax) expression, cytosolic release of cytochrome c, and activation of caspases. Moreover, isorhamnetin inactivated the adenosine 5′-monophosphate-activated protein kinase (AMPK) signaling pathway by diminishing the adenosine triphosphate (ATP) production due to impaired mitochondrial function. Furthermore, isorhamnetin stimulated production of intracellular reactive oxygen species (ROS); however, the interruption of ROS generation using a ROS scavenger led to an escape from isorhamnetin-mediated G2/M arrest and apoptosis. Collectively, this is the first report to show that isorhamnetin inhibited the proliferation of human bladder cancer cells by ROS-dependent arrest of the cell cycle at the G2/M phase and induction of apoptosis. Therefore, our results provide an important basis for the interpretation of the anti-cancer mechanism of isorhamnetin in bladder cancer cells and support the rationale for the need to evaluate more precise molecular mechanisms and in vivo anti-cancer properties. [ABSTRACT FROM AUTHOR]

We examined the anti-cancer effect of genistein, a soy-derived isoflavone, in human bladder transitional cell carcinoma T24 cells. According to our data, genistein induced G2/M phase arrest of the cell cycle and apoptosis. Genistein down-regulated the levels of cyclin A and cyclin B1, but up-regulated the levels of p21WAF1/CIP1, cyclin-dependent kinase (Cdk) inhibitor, that was complexed with Cdc2 and Cdk2. Furthermore, genistein induced the activation of caspases (caspase-3, -8 and -9), and cleavage of poly (ADP-ribose) polymerase cleavage. However, genistein-induced apoptosis was significantly inhibited by a pan-caspase inhibitor, indicating that the induction of apoptosis by genestein was caspase-dependent. In addition, genistein increased the cytosolic release of cytochrome c by increasing the Bax/Bcl-2 ratio and destroying mitochondria integrity. Moreover, genistein inactivated the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway, while LY294002, a PI3K/Akt inhibitor, increased the apoptosis-inducing effect of genistein. Genistein further increased the accumulation of reactive oxygen species (ROS), which was significantly suppressed by N-acetyl cysteine (NAC), a ROS scavenger, and in particular, NAC prevented genistein-mediated inactivation of PI3K/Akt signaling, G2/M arrest and apoptosis. Therefore, the present results indicated that genistein promoted apoptosis induction in human bladder cancer T24 cells, which was associated with G2/M phase cell cycle arrest via regulation of ROS-dependent PI3K/Akt signaling pathway. [ABSTRACT FROM AUTHOR]

Sea tangle (Laminaria japonica Aresch), a brown alga, has been used for many years as a functional food ingredient in the Asia-Pacific region. In the present study, we investigated the effects of fermented sea tangle extract (FST) on receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-stimulated osteoclast differentiation, using RAW 264.7 mouse macrophage cells. FST was found to inhibit the RANKL-stimulated activation of tartrate-resistance acid phosphatase (TRAP) and F-actin ring structure formation. FST also down-regulated the expression of osteoclast marker genes like TRAP, matrix metalloproteinase-9, cathepsin K and osteoclast-associated receptor by blocking RANKL-induced activation of NF-κB and expression of nuclear factor of activated T cells c1 (NFATc1), a master transcription factor. In addition, FST significantly abolished RANKL-induced generation of reactive oxygen species (ROS) by activation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and its transcriptional targets. Hence, it seems likely that FST may have anti-osteoclastogenic potential as a result of its ability to inactivate the NF-κB-mediated NFATc1 signaling pathway and by reducing ROS production through activation of the Nrf2 pathway. Although further studies are needed to inquire its efficacy in vivo, FST appears to have potential use as an adjunctive or as a prophylactic treatment for osteoclastic bone disease. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) are components of the innate immune system and form the first defense against pathogens for various organisms. In the present study, we assessed whether CSP32, a novel AMP oligomer of bacitracin isolated from a strain of Bacillus spp ., regulates the polarization of murine macrophage-like RAW 264.7 cells. CSP32 stimulated phagocytosis while inducing the appearance of the typical M1 polarized macrophage phenotype; these M1 macrophages play a role in host defense against pathogens. Furthermore, our results showed that CSP32 enhanced the expression and production of pro-inflammatory mediators, such as cytokines and chemokines. In addition, the CSP32-stimulated inflammatory mediators were induced mainly by the mitogen-activated protein kinase/nuclear factor kappa B (MAPK/NF-κB) signaling pathway during M1 macrophage polarization. In particular, CSP32 markedly increased the numbers of Ca 2+ -positive macrophages while upregulating phospholipase C and activating protein kinase Cε. Furthermore, the inhibition of intracellular Ca 2+ by BAPTA-AM, a Ca 2+ chelator, significantly suppressed the CSP32-mediated phagocytosis, inflammatory mediator production, and NF-κB activation. In conclusion, our data suggested that CSP32-stimulated M1 macrophage polarization is dependent on the calcium signaling pathway and may result in enhanced immune capacities., Competing Interests: The authors declare no conflict of interest.