Broussonetia papyrifera Root Bark Extract Exhibits Anti-inflammatory Effects on Adipose Tissue and Improves Insulin Sensitivity Potentially Via AMPK Activation

The chronic low-grade inflammation in adipose tissue plays a causal role in obesity-induced insulin resistance and its associated pathophysiological consequences. In this study, we investigated the effects of extracts of Broussonetia papyrifera root bark (PRE) and its bioactive components on inflammation and insulin sensitivity. PRE inhibited TNF-alpha-induced NF-kappa B transcriptional activity in the NF-kappa B luciferase assay and pro-inflammatory genes' expression by blocking phosphorylation of I kappa B and NF-kappa B in 3T3-L1 adipocytes, which were mediated by activating AMPK. Ten-week-high fat diet (HFD)-fed C57BL6 male mice treated with PRE had improved glucose intolerance and decreased inflammation in adipose tissue, as indicated by reductions in NF-kappa B phosphorylation and pro-inflammatory genes' expression. Furthermore, PRE activated AMP-activated protein kinase (AMPK) and reduced lipogenic genes' expression in both adipose tissue and liver. Finally, we identified broussoflavonol B (BF) and kazinol J (KJ) as bioactive constituents to suppress pro-inflammatory responses via activating AMPK in 3T3-L1 adipocytes. Taken together, these results indicate the therapeutic potential of PRE, especially BF or KJ, in metabolic diseases such as obesity and type 2 diabetes

Verminoside from Pseudolysimachion rotundum var. subintegrum sensitizes cisplatin-resistant cancer cells and suppresses metastatic growth of human breast cancer

Breast cancer is one of the most common cancers in women and is associated with a high mortality rate. The majority of deaths resulting from breast cancer are attributable to metastatic growth; in addition, chemoresistance is a major concern in the treatment of patients with breast cancer. However, limited drugs are available for the treatment of metastatic breast cancer. In this study, the chemoadjuvant effects of a methanolic extract from the leaves of Pseudolysimachion rotundum var. subintegrum (NC13) and an active component isolated from the plant, verminoside (Vms), were evaluated. Furthermore, their potent anti-metastatic activities were validated in vitro and in vivo in animal models. The anti-metastatic and chemosensitizing activities of NC13 and Vms on cisplatin treatment were found to be partly mediated by suppression of the epithelial-mesenchymal transition of cancer cells. Collectively, our results implied that NC13 and its bioactive component Vms could be developed as effective chemoadjuvants in combination with conventional therapeutics

Regulation of TM4SF5-mediated tumorigenesis through induction of cell detachment and death by tiarellic acid

mRNA for four-transmembrane L6 family member 5 (TM4SF5), a homolog of tumor antigen L6, was previously shown to be highly expressed in diverse tumors. We recently found that human hepatocarcinoma tissues also overexpressed TM4SF5 protein, in comparison to normal liver tissues.We also found that tiarellic acid (TA) caused cell detachment-related apoptosis in cells expressing endogenous or stably-overexpressing TM4SF5. When cells expressing TM4SF5 were treated with TA, we observed reduced phosphorylation of focal adhesion kinase, paxillin, and p130Cas, but not c-Src. TA treatment also caused focal adhesion loss and reduced cell adhesion, and increased the numbers of floating cells and apoptotic cells. These effects were blocked by overexpression of focal adhesion molecules, suggesting that treatment with TA mediates anoikis of TM4SF5-expressing cells. However, TM4SF5-null cells were not affected by TA, indicating that these effects occur specifically in TM4SF5-positive cells. TA administration reduced tumor formation in nude mice injected with TM4SF5-expressing cells, presumably through increased apoptosis in TM4SF5-positive tumors. These observations indicate that TM4SF5-positive tumorigenesis can be inhibited by TA via induction of cell detachment-related apoptosis, and suggest that TA may be developed as a putative therapeutic reagent against TM4SF5-positive tumorigenesis

Zanthoxylum ailanthoides

Zanthoxylum ailanthoides (ZA) has been used as folk medicines in East Asian and recently reported to have several bioactivity; however, the studies of ZA on the regulation of triacylglycerol (TG) biosynthesis have not been elucidated yet. In this study, we examined whether the methanol extract of ZA (ZA-M) could reduce oleic acid- (OA-) induced intracellular lipid accumulation and confirmed its mode of action in HepG2 cells. ZA-M was shown to promote the phosphorylation of AMPK and its upstream LKB1, followed by reduction of lipogenic gene expressions. As a result, treatment of ZA-M blocked de novo TG biosynthesis and subsequently mitigated intracellular neutral lipid accumulation in HepG2 cells. ZA-M also inhibited OA-induced production of reactive oxygen species (ROS) and TNF-α, suggesting that ZA-M possess the anti-inflammatory feature in fatty acid over accumulated condition. Taken together, these results suggest that ZA-M attenuates OA-induced lipid accumulation and inflammation through the activation of LKB1/AMPK signaling pathway in HepG2 cells

Fargesin Inhibits EGF-Induced Cell Transformation and Colon Cancer Cell Growth by Suppression of CDK2/Cyclin E Signaling Pathway

Although the lignan compound fargesin is a major ingredient in Shin-Yi, the roles of fargesin in carcinogenesis and cancer cell growth have not been elucidated. In this study, we observed that fargesin inhibited cell proliferation and transformation by suppression of epidermal growth factor (EGF)-stimulated G1/S-phase cell cycle transition in premalignant JB6 Cl41 and HaCaT cells. Unexpectedly, we found that signaling pathway analyses showed different regulation patterns in which fargesin inhibited phosphatidylinositol 3-kinase/AKT signaling without an alteration of or increase in mitogen activated protein kinase (MAPK) in JB6 Cl41 and HaCaT cells, while both signaling pathways were abrogated by fargesin treatment in colon cancer cells. We further found that fargesin-induced colony growth inhibition of colon cancer cells was mediated by suppression of the cyclin dependent kinase 2 (CDK2)/cyclin E signaling axis by upregulation of p21WAF1/Cip1, resulting in G1-phase cell cycle accumulation in a dose-dependent manner. Simultaneously, the suppression of CDK2/cyclin E and induction of p21WAF1/Cip1 were correlated with Rb phosphorylation and c-Myc suppression. Taken together, we conclude that fargesin-mediated c-Myc suppression inhibits EGF-induced cell transformation and colon cancer cell colony growth by the suppression of retinoblastoma (Rb)-E2F and CDK/cyclin signaling pathways, which are mainly regulated by MAPK and PKB signaling pathways

Theophylline Attenuates BLM-Induced Pulmonary Fibrosis by Inhibiting Th17 Differentiation

Idiopathic pulmonary fibrosis (IPF) is a chronic and refractory interstitial lung disease. Although there are two approved drugs for IPF, they were not able to completely cure the disease. Therefore, the development of new drugs is required for the effective treatment of IPF. In this study, we investigated the effect of theophylline, which has long been used for the treatment of asthma, on pulmonary fibrosis. The administration of theophylline attenuated the fibrotic changes of lung tissues and improved mechanical pulmonary functions in bleomycin (BLM)-induced pulmonary fibrosis. Theophylline treatment suppressed IL-17 production through inhibiting cytokines controlling Th17 differentiation; TGF-β, IL-6, IL-1β, and IL-23. The inhibition of IL-6 and IL-1β by theophylline is mediated by suppressing BLM-induced ROS production and NF-κB activation in epithelial cells. We further demonstrated that theophylline inhibited TGF-β-induced epithelial-to-mesenchymal transition in epithelial cells through suppressing the phosphorylation of Smad2/3 and AKT. The inhibitory effects of theophylline on the phosphorylation of Smad2/3 and AKT were recapitulated in BLM-treated lung tissues. Taken together, these results demonstrated that theophylline prevents pulmonary fibrosis by inhibiting Th17 differentiation and TGF-β signaling

Constituents of Cryptotaenia japonica Inhibit Melanogenesis via CREB- and MAPK-Associated Signaling Pathways in Murine B16 Melanoma Cells

Melanin plays an important role in protecting the skin against ultraviolet light and is responsible for skin color. However, overproduction of melanin is related to several skin disorders, such as age spots, freckles, café au lait spots, Becker’s nevus and other hyperpigmentation syndromes. The aim of this study was to identify the effects of kaempferol-7-O-β-d-glucuronide (K7G) and tilianin, isolated from Cryptotaenia japonica, on melanogenesis and their mechanisms of action in murine B16 melanoma cells. The α-melanocyte-stimulating hormone (α-MSH)-induced melanin production was significantly inhibited by K7G and tilianin in a dose-dependent manner. The effects of these compounds on the signaling pathway of melanogenesis were examined. K7G and tilianin downregulated the expression of microphthalmia-associated transcription factor (MITF) and melanocyte-specific enzymes, i.e., tyrosinase and TRP1. These compounds also inhibited the phosphorylation of cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB) in a dose-dependent manner. In addition, these compounds increased the phosphorylation of extracellular signal-regulated kinase (ERK) but decreased the phosphorylation of c-Jun N-terminal kinase (JNK) in B16 cells. Based on the above results, the anti-melanogenic effects of these compounds are caused by suppression of the MAPK signaling pathway through the down-regulation of α-MSH-induced CREB accumulation. This finding suggests that K7G and tilianin may be good candidates for further research to develop therapeutic agents for hyperpigmentation diseases

Brazilein Suppresses Inflammation through Inactivation of IRAK4-NF-κB Pathway in LPS-Induced Raw264.7 Macrophage Cells

The medicinal herbal plant has been commonly used for prevention and intervention of disease and health promotions worldwide. Brazilein is a bioactive compound extracted from Caesalpinia sappan Linn. Several studies have showed that brazilein exhibited the immune suppressive effect and anti-oxidative function. However, the molecular targets of brazilein for inflammation prevention have remained elusive. Here, we investigated the mechanism underlying the inhibitory effect of brazilein on LPS-induced inflammatory response in Raw264.7 macrophage cells. We demonstrated that brazilein decreased the expression of IRAK4 protein led to the suppression of MAPK signaling and IKKβ, and subsequent inactivation of NF-κB and COX2 thus promoting the expression of the downstream target pro-inflammatory cytokines such as IL-1β, MCP-1, MIP-2, and IL-6 in LPS-induced Raw264.7 macrophage cells. Moreover, we observed that brazilein reduced the production of nitrite compared to the control in LPS-induced Raw264.7. Thus, we suggest that brazilein might be a useful bioactive compound for the prevention of IRAK-NF-κB pathway associated chronic diseases

Genkwadaphnin Induces IFN-γ via PKD1/NF-κB/STAT1 Dependent Pathway in NK-92 Cells

<div><p>The flower buds of <i>Daphne genkwa</i> Sieb. et Zucc. have been used as a traditional Chinese medicine although their functional mechanisms have not been discovered yet. We have studied the potential effects of the plant extracts on natural killer (NK) cell activation, and isolated an active fraction. Genkwadaphnin (GD-1) displayed a potent efficacy to induce IFN-γ transcription in NK cells with concentration- and time-dependent manners. GD-1 treatment triggered the phosphorylation of PKD1, a member of PKC family, MEK and ERK, resulting in IKK activation to induce IκB degradation, and the nuclear localization of p65, an NF-κB subunit, which regulates IFN-γ transcription. GD-1 effect on IFN-γ production was blocked by the addition of Rottlerin, a PKC inhibitor, CID 755673, a PKD inhibitor, or Bay11-7082, an IKKα inhibitor. The nuclear localization of p65 was also inhibited by the kinase inhibitors. Secreted IFN-γ activates STAT1 phosphorylation as autocrine-loops to sustain its secretion. GD-1 induced the phosphorylation of STAT1 probably through the increase of IFN-γ. STAT1 inhibitor also abrogated the sustained IFN-γ secretion. These results suggest that GD-1 is involved in the activation of PKD1 and/or ERK pathway, which activate NK-κB triggering IFN-γ production. As positive feedback loops, secreted IFN-γ activates STAT1 and elongates its production in NK-92 cells.</p></div