Apigenin-7-glycoside (AP7Glu) with multiple biological activities is a flavonoid that is currently prescribed to treat inflammatory diseases such as upper respiratory infections. Recently, several studies have shown that its anti-inflammatory activities have been strongly linked to the inhibition of secretion of pro-inflammatory proteins, such as inducible nitric oxide synthase (iNOs) and cyclooxygenase-2 (COX-2) induced through phosphorylation nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPK) pathways. Additionally, inflammation, which can decrease the activities of antioxidative enzymes (AOEs) is also observed in these studies. At the same time, flavonoids are reported to promote the activities of heme oxygenase-1 (HO-1) decreased by LPS. The purpose of this study was to assess these theories in a series of experiments on the suppressive effects of AP7Glu based on LPS-induced nitric oxide production in RAW264.7 macrophages in vitro and acute lung injury in mice in vivo. After six hours of lipopolysaccharide (LPS) stimulation, pulmonary pathological, myeloperoxidase (MPO) activity, total polymorphonuclear leukocytes (PMN) cells, cytokines in bronchoalveolar lavage fluid (BALF) and AOEs, are all affected and changed. Meanwhile, our data revealed that AP7Glu not only did significantly inhibit the LPS-enhanced inflammatory activity in lung, but also exhibited anti-inflammatory effect through the MAPK and inhibitor NF-κB (IκB) pathways.

Molecular networks are the basis of biological processes. Such networks can be decomposed into smaller modules, also known as network motifs. These motifs show interesting dynamical behaviors, in which co-operativity effects between the motif components play a critical role in human diseases. We have developed a motif-searching algorithm, which is able to identify common motif types from the cancer networks and signal transduction networks (STNs). Some of the network motifs are interconnected which can be merged together and form more complex structures, the so-called coupled motif structures (CMS). These structures exhibit mixed dynamical behavior, which may lead biological organisms to perform specific functions.

Imperatorin (IMP) could downregulate several inflammatory transcription factor signaling pathways. Some studies have pointed out that IMP could interfere with toll-like receptor 4 (TLR4) signaling. This study evaluates how IMP interferes with the TLR4 co-receptors signaling through the protein-ligand docking model, Western blotting, immunofluorescence (IF), and atomic force microscopy (AFM) assays in lipopolysaccharide (LPS) stimulated macrophage-like RAW264.7 cells in vitro. The results of the protein-ligand docking demonstrate that IMP interferes with LPS binding to the LPS-binding protein (LBP), the cluster of differentiation 14 (CD14), and the toll-like receptor 4/myeloid differentiation factor 2 (TLR4/MD-2) co-receptors in LPS-stimulated RAW264.7 cells. Compared with TLR4 antagonist CLI-095 or dexamethasone, IMP could suppress the protein expressions of LBP, CD14, and TLR4/MD-2 in LPS-stimulated cells. Furthermore, the three-dimensional (3D) image assay of the AFM showed IMP could prevent the LPS-induced morphological change in RAW264.7 cells. Additionally, IMP could activate the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, and it increased the antioxidative protein expression of heme oxygenase-1 (HO-1), superoxidase dismutase (SOD), and catalase (CAT). Our results are the first to reveal that the anti-inflammatory effect of IMP interferes with LPS binding to TLR4 co-receptor signaling and activates the antioxidative Nrf2 signaling pathway.

Obesity-associated hyperglycemia underlies insulin resistance, glucose intolerance, and related metabolic disorders including type 2 diabetes, renal damage, and nonalcoholic fatty liver disease. Turmeric root is commonly used in Asia, and curcumin, one of its pharmacological components, can play a role in preventing and treating certain chronic physiological disorders. Accordingly, this study examined how high-fat diet (HFD)-induced hyperglycemia and hyperlipidemia are reduced by curcumin through changes in fatty liver scores, chromium distribution, and renal injury in mice. Relative to the control group, also fed an HFD, the curcumin group weighed less and had smaller adipocytes; it also had lower daily food efficiency, blood urea nitrogen and creatinine levels, serum alanine aminotransferase and aspartate aminotransferase levels, serum and hepatic triglyceride levels, and hepatic lipid regulation marker expression. The curcumin-treated obese group exhibited significantly lower fasting blood glucose, was less glucose intolerant, had higher Akt phosphorylation and glucose transporter 4 (GLUT4) expression, and had greater serum insulin levels. Moreover, the group showed renal damage with lower TNF-α expression along with more numerous renal antioxidative enzymes that included superoxide dismutase, glutathione peroxidase, and catalase. The liver histology of the curcumin-treated obese mice showed superior lipid infiltration and fewer FASN and PNPLA3 proteins in comparison with the control mice. Curcumin contributed to creating a positive chromium balance by decreasing the amount of chromium lost through urine, leading to the chromium mobilization needed to mitigate hyperglycemia. Thus, the results suggest that curcumin prevents HFD-induced glucose intolerance, kidney injury, and nonalcoholic fatty liver disease.

Chronic inflammation induces autoimmune disorders and chronic diseases. Several natural products activate nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, attenuating inflammatory responses. Ergosta-7,9(11),22-trien-3β-ol (EK100) isolated from Cordyceps militaris showed anti-inflammatory and antioxidative activity, but those mechanisms are still unclear. This study is the first to investigate EK100 on antioxidant Nrf2 relative genes expression in LPS-stimulated macrophage-like cell lines. The results showed that EK100 reduced IL-6 (interleukin-6) and tumor necrosis factor-α production. EK100 also attenuated a mitogen-activated protein kinase/activator protein-1 (MAPK/AP-1) pathway and interleukin-6/Janus kinase/signal transducer and activator of transcription (IL-6/JAK/STAT) pathway in LPS-stimulated cells. Toll-like receptor 4 (TLR4) inhibitor CLI-095 and MAPK inhibitors can synergize the anti-inflammatory response of EK100 in LPS-stimulated cells. Moreover, EK100 activated Nrf2/HO-1 (heme oxygenase-1) signaling in LPS-stimulated murine macrophage-like RAW 264.7 cells, murine microglial BV2 cells, and human monocytic leukemia THP-1 cells. However, Nrf2 small interfering RNA (Nrf2 siRNA) reversed EK100-induced antioxidative proteins expressions. In conclusion, EK100 showed anti-inflammatory responses via activating the antioxidative Nrf2/HO-1 signaling and inhibiting TLR4 related MAPK/AP-1 induced IL-6/JAK/STAT pathways in the LPS-stimulated cells in vitro. The results suggest EK100 acts as a novel antioxidant with multiple therapeutic targets that can potentially be developed to treat chronic inflammation-related diseases.