p-Coumaroyl Anthocyanin Mixture Isolated from Tuber Epidermis of Solanum tuberosum Attenuates Reactive Oxygen Species and Pro-inflammatory Mediators by Suppressing NF-κB and STAT1/3 Signaling in LPS-Induced RAW264.7 Macrophages.

Previously, we first reported the identification of four p-coumaroyl anthocyanins (petanin, peonanin, malvanin, and pelanin) from the tuber epidermis of colored potato (Solanum tuberosum L. cv JAYOUNG). In this study, we investigated the anti-oxidative and anti-inflammatory effects of a mixture of peonanin, malvanin, and pelanin (10 : 3 : 3; CAJY). CAJY displayed considerable radical scavenging capacity of 1, 1-diphenyl-2-picryl-hydrazyl (DPPH), increased mRNA levels of the catalytic and modulatory subunit of glutamate cysteine ligase, and subsequent cellular glutathione content. These increases preceded the inhibition of lipopolysaccharide (LPS)-induced intracellular reactive oxygen species (ROS) production. CAJY inhibited inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a concentration-dependent manner at the protein, mRNA, and promoter activity levels. These inhibitions caused attendant decreases in the production of prostaglandin E2 (PGE2). CAJY suppressed the production and mRNA expression of tumor necrosis factor (TNF)-α and interleukin (IL)-6. Molecular data revealed that CAJY inhibited the transcriptional activity and translocation of nuclear factor κB (NF-κB) and phosphorylation of signal transducer and activator of transcription 1 (STAT1) and STAT3. Taken together, these results suggest that the anthocyanin mixture exerts anti-inflammatory effects in macrophages, at least in part by reducing ROS production and inactivating NF-κB and STAT 1/3.

Moutan Cortex Protects Hepatocytes against Oxidative Injury through AMP-Activated Protein Kinase Pathway.

Moutan Cortex, the root bark of Paeonia suffruticosa ANDREWS in Ranunculaceae, has widely demonstrated analgesic, anti-spasmodic, and anti-inflammatory effects in various cancer and immune cell lines. Oxidative stress is associated with development of several diseases, including liver disease. We prepared the water extract of Moutan Cortex (MCE) to investigate the cytoprotective activities and its mechanism. MCE protected hepatocytes from arachidonic acid (AA)+iron induced oxidative stress, as indicated by reactive oxygen species (ROS) production and cell viability analysis. MCE also suppressed mitochondrial dysfunction in AA+iron-treated human hepatocyte-derived hepatocellular carcinoma cell line, HepG2 cells. In addition, MCE treatment induces AMP-activated protein kinase (AMPK) and liver kinase B1 phosphorylation, which play a role in inhibition of oxidative stress induced cell death. Moreover, one of the MCE compounds, chlorogenic acid, exerted protective effects against oxidative stress and apoptosis. Taken together, MCE protected hepatocytes against AA+iron-induced oxidative stress through AMPK activation, and may be a candidate for the treatment of liver disease.

Lactobacillus sakei K040706 evokes immunostimulatory effects on macrophages through TLR 2-mediated activation.

Lactobacillus sakei K040706 is the most populous lactic acid bacteria (LAB) in over ripened Doenjang, a traditional Korean fermented soybean paste. In this study, we investigated the immunostimulating effects of L. sakei K040706 (K040706) in macrophages and in cyclophosphamide-induced immunosuppressed mice. Upon exposure to K040706, significant increases in phagocytic activity and in the productions of nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were observed in rIFN-γ-primed RAW 264.7 macrophages. K040706 also increased the expressions of inducible nitric oxide synthase (iNOS) at the protein and promoter binding levels, and the expressions of iNOS, TNF-α, and IL-6, at the mRNA level. In addition, K040706 significantly increased the transcriptional activities and DNA binding of nuclear factor-κB (NF-κB), which was accompanied by parallel enhancement of the nuclear translocation of p65 via the phosphorylations inhibitory kappa B-α (IκB-α) and IκB-kinase (IKK). On the other hand, pretreatment with NF-κB inhibitors reduced K040706-induced NO production in IFN-γ-primed RAW 264.7 macrophages. Furthermore, K040706 induced-NO production was completely abolished by anti-Toll-like receptor 2 (TLR2) antibody. In our cyclophosphamide-induced immunosuppressed mouse model, administration of K040706 restored thymus and spleen indices. Taken together, our findings suggest that K040706 improves immune function by regulating immunological parameters, such as, the productions of NO, TNF-α, and IL-6 via NF-κB activation, and by activating TLR2 in rIFN-γ-primed macrophages. In parallel, K040706 restored immunological parameters in cyclophosphamide-induced immunosuppressed mice and may warrant further evaluations as potential immunomodulatory agent.

Immunostimulatory polysaccharide isolated from the leaves of Diospyros kaki Thumb modulate macrophage via TLR2.

The objective of this study was to investigate the immunostimulatory effects of a polysaccharide fraction from the leaves of Diospyros kaki Thumb (PLE0) and the molecular mechanism responsible for its action in RAW 264.7 macrophages as well as in vivo effects on cyclophosphamide-induced immunosuppression in mice. PLE0 concentration-dependently activated the expressions of inducible nitric oxide synthase (iNOS) at the protein and mRNA levels and its promoter activity, and that these activations caused attendant increases the nitric oxide (NO) production. In addition, PLE0 increased the mRNA expressions of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6. Molecular data revealed that PLE0 increased the transcriptional activity and nuclear translocation of nuclear factor-κB (NF-κB) by inducing the degradation of inhibitory κBα (IκBα) and the phosphorylation of inhibitory κB kinase (IKK). Moreover, anti-toll-like receptor 2 (TLR2) antibody and myeloid differentiation primary response gene 88 (MyD88)-specific siRNA significantly reduce PLE0-induced NO production in RAW 264.7 macrophages. Pretreatment with PLE0 recovered cyclophosphamide-induced reductions in thymus and spleen indices as well as neutrophil counts. Taken together, our data suggest that PLE0 up-regulates the expressions of iNOS, TNF-α, IL-1ß, and IL-6 genes by activating TLR2-mediated NF-κB activations, and that these actions are responsible for its immunostimulatory effects.

α-Chaconine isolated from a Solanum tuberosum L. cv Jayoung suppresses lipopolysaccharide-induced pro-inflammatory mediators via AP-1 inactivation in RAW 264.7 macrophages and protects mice from endotoxin shock.

In this study, we investigated the molecular mechanisms underlying the anti-inflammatory effects of α-chaconine in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages and in LPS-induced septic mice. α-Chaconine inhibited the expressions of cyclooxygenase-2 (COX-2), interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α (TNF-α) at the transcriptional level, and attenuated the transcriptional activity of activator protein-1 (AP-1) by reducing the translocation and phosphorylation of c-Jun. α-Chaconine also suppressed the phosphorylation of TGF-ß-activated kinase-1 (TAK1), which lies upstream of mitogen-activated protein kinase kinase 7 (MKK7)/Jun N-terminal kinase (JNK) signaling. JNK knockdown using siRNA prevented the α-chaconine-mediated inhibition of pro-inflammatory mediators. In a sepsis model, pretreatment with α-chaconine reduced the LPS-induced lethality and the mRNA and production levels of pro-inflammatory mediators by inhibiting c-Jun activation. These results suggest that the anti-inflammatory effects of α-chaconine are associated with the suppression of AP-1, and support its possible therapeutic role for the treatment of sepsis.

Reduced food intake is the major contributor to the protective effect of rimonabant on islet in established obesity-associated type 2 diabetes.

PURPOSE: Although the presence of cannabinoid type 1 (CB1) receptor in islets has been reported, the major contributor to the protective effect of rimonabant on islet morphology is unknown. We determined whether the protective effect of rimonabant on pancreatic islet morphology is valid in established diabetes and also whether any effect was independent of decreased food intake. MATERIALS AND METHODS: After diabetes was confirmed, Otsuka Long-Evans Tokushima Fatty rats, aged 32 weeks, were treated with rimonabant (30 mg/kg/d, rimonabant group) for 6 weeks. Metabolic profiles and islet morphology of rats treated with rimonabant were compared with those of controls without treatment (control group), a pair-fed control group, and rats treated with rosiglitazone (4 mg/kg/d, rosiglitazone group). RESULTS: Compared to the control group, rats treated with rimonabant exhibited reduced glycated albumin levels (p<0.001), islet fibrosis (p<0.01), and improved glucose tolerance (p< 0.05), with no differences from the pair-fed control group. The retroperitoneal adipose tissue mass was lower in the rimonabant group than those of the pair-fed control and rosiglitazone groups (p<0.05). Rimonabant, pair-fed control, and rosiglitazone groups showed decreased insulin resistance and increased adiponectin, with no differences between the rimonabant and pair-fed control groups. CONCLUSION: Rimonabant had a protective effect on islet morphology in vivo even in established diabetes. However, the protective effect was also reproduced by pair-feeding. Thus, the results of this study did not support the significance of islet CB1 receptors in islet protection with rimonabant in established obesity-associated type 2 diabetes.