Wen-Chung Huang

Evaluation of the anti-inflammatory effects of phloretin and phlorizin in lipopolysaccharide-stimulated mouse macrophages.

Many reports suggest that phloretin and phlorizin have antioxidant properties and can inhibit glucose transportation, the anti-inflammatory effects and mechanism of phloretin and phlorizin remain unclear. This study aims to evaluate the anti-inflammatory effects of phloretin and phlorizin in LPS-stimulated murine RAW264.7 macrophages. RAW264.7 cells were pretreated with various concentrations of phloretin or phlorizin (3-100 μM) and cell inflammatory responses were induced with LPS. Pretreated with 10 μM phloretin significantly inhibited the levels of NO, PGE(2), IL-6, TNF-α, iNOS and COX-2. Furthermore, it was demonstrated that phloretin suppressed the nuclear translocation of NF-κB subunit p65 proteins, and decreased phosphorylation in MAPK pathways. Surprisingly, phlorizin did not suppress the inflammatory response in LPS-stimulated RAW264.7 cells. These results suggest that phloretin has an anti-inflammatory effect that reduces levels of proinflammatory cytokines and mediators in RAW264.7 cells.

Phloretin and phlorizin promote lipolysis and inhibit inflammation in mouse 3T3‐L1 cells and in macrophage‐adipocyte co‐cultures

SCOPE Previous studies found that phloretin (PT) and phlorizin (PZ) could inhibit glucose transport, with PT being a better inhibitor of lipid peroxidation. This study aimed to evaluate the antiobesity effects of PT and PZ in 3T3-L1 cells and if they can modulate the relationship between adipocytes and macrophages. METHODS AND RESULTS Differentiated 3T3-L1 cells were treated with PT or PZ. Subsequently, transcription factors of adipogenesis and lipolysis proteins were measured. In addition, RAW 264.7 macrophages treated with PT or PZ were cultured in differentiated media from 3T3-L1 cells to analyze inflammatory mediators and signaling pathways. PT significantly enhanced glycerol release and inhibited the adipogenesis-related transcription factors. PT also promoted phosphorylation of AMP-activated protein kinase and increased activity of adipose triglyceride lipase and hormone-sensitive lipase. PT suppressed the nuclear transcription factor kappa-B and mitogen-activated protein kinase pathways when RAW 264.7 cells were cultured in differentiated media from 3T3-L1 cells. PZ improved lipolysis and inhibited the macrophage inflammatory response less effectively than PT. CONCLUSION This study suggests that PT is more effective than PZ at increasing lipolysis in adipocytes. In addition, PT also suppresses inflammatory response in macrophage that is stimulated by differentiated media from 3T3-L1 cells.

Long-term oral administration of Gynostemma pentaphyllum extract attenuates airway inflammation and Th2 cell activities in ovalbumin-sensitized mice.

Our previous report demonstrated that the oral administration of short-term high dose Gynostemma pentaphyllum extract (5 g/kg per day for 7days) decreased allergic reactions in ovalbumin (OVA)-sensitized mice. The aim of this study was to determine whether long-term oral administration of G. pentaphyllum attenuated airway inflammation in OVA-sensitized mice. Mice were sensitized and challenged with normal saline or OVA. OVA-sensitized mice were fed with 1.75 g/kg (low dose, GPL) or 5 g/kg (high dose, GPH) G. pentaphyllum extract, five days a week for 4 weeks. The airway hyperresponsiveness (AHR) and eosinophilia in bronchoalveolar lavage fluid (BALF) were examined. The cytokine levels or antibodies in BALF, serum and spleen cell culture supernatants were also determined. Both high and low dose extracts reduced AHR, serum OVA-IgE, and Th2-associated cytokine levels in spleen cell supernatants and BALF in OVA-sensitized mice. These results show that long-term orally administered G. pentaphyllum extract reduced allergic reactions in OVA-sensitized mice.

Matrine attenuates allergic airway inflammation and eosinophil infiltration by suppressing eotaxin and Th2 cytokine production in asthmatic mice

ETHNOPHARMACOLOGICAL RELEVANCE Matrine has been isolated from Sophora flavescens, and found to show anti-inflammatory effects in macrophages and anti-cachectic effects in hepatomas. The present study investigated whether matrine suppressed eosinophil infiltration and airway hyperresponsiveness (AHR) in mice, and decreased the inflammatory response of tracheal epithelial cells. MATERIALS AND METHODS BALB/c mice were sensitized and challenged with ovalbumin to induce allergic asthma in mice. These asthmatic mice were given various doses of matrine by intraperitoneal injection. Additionally, activated human tracheal epithelial cells (BEAS-2B cells) were treated with matrine, and evaluated for levels of proinflammatory cytokines and chemokines. RESULTS We found that matrine significantly decreased AHR, and suppressed goblet cell hyperplasia, eosinophil infiltration, and inflammatory response in the lung tissue of asthmatic mice. Matrine also reduced the levels of Th2 cytokines and chemokines in bronchoalveolar lavage fluid, and suppressed OVA-IgE production in serum. Furthermore, matrine treatment of activated BEAS-2B cells decreased production of proinflammatory cytokines and eotaxins, as well as suppressed ICAM-1 expression and thus adhesion of eosinophils to inflammatory BEAS-2B cells in vitro. CONCLUSIONS Our findings suggest that matrine can improve allergic asthma in mice, and therefore has potential therapeutic potential in humans.

Casticin inhibits COX-2 and iNOS expression via suppression of NF-κB and MAPK signaling in lipopolysaccharide-stimulated mouse macrophages

ETHNOPHARMACOLOGICAL RELEVANCE The fruits of Vitex rotundifolia L. are widely used to treat inflammation of the airway in Traditional Chinese medicine. Previous studies found that casticin, isolated from Vitex rotundifolia, could induce apoptosis of tumor cells. In this study, we evaluated the anti-inflammatory effects of casticin and its underlying molecular mechanism in lipopolysaccharide (LPS)-stimulated macrophages. MATERIALS AND METHODS RAW264.7 cells were pretreated with various concentrations of casticin (0.3-10μM), and then treated with LPS to induce inflammation. We assayed the levels of proinflammatory cytokines and prostaglandin E2 (PGE2) using ELISA, and examined the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and heme oxygenase (HO)-1 by Western blot. We also investigated the anti-inflammatory molecular mechanism by analyzing inflammatory-associated signaling pathways, including the nuclear transcription factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. RESULTS We found casticin inhibited the levels of nitric oxide and PGE2, and decreased the production of proinflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor α (TNF-α). In addition, iNOS and COX-2 expression levels were suppressed and casticin increased HO-1 and Nrf2 production in a concentration-dependent manner. Furthermore, casticin significantly inhibited NF-κB subunit p65 proteins in the nucleus and decreased Akt and MAPK activation. CONCLUSION These results suggest that the anti-inflammatory effect of casticin is due to inhibition of proinflammatory cytokines and mediators by blocking the NF-κB, Akt, and MAPK signaling pathways.

Oral lovastatin attenuates airway inflammation and mucus secretion in ovalbumin-induced murine model of asthma.

Purpose Lovastatin is an effective inhibitor of cholesterol synthesis. A previous study demonstrated that lovastatin can also suppress airway hyperresponsiveness (AHR) in murine model of asthma. We aimed to investigate the effect of lovastatin on mucus secretion and inflammation-associated gene expression in the lungs of murine model of asthma. Methods Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) by intraperitoneal injection, and orally administered lovastatin from days 14 to 27 post-injection. Gene expression in lung tissues was analyzed using real-time polymerase chain reaction. AHR and goblet cell hyperplasia were also examined. BEAS-2B human bronchial epithelial cells were used to evaluate the effect of lovastatin on the expression of cell adhesion molecules, chemokines, and proinflammatory cytokines in vitro. Results We showed that lovastatin inhibits the expression of Th2-associated genes, including eotaxins and adhesion molecules, in the lungs of murine model of asthma. Mucin 5AC expression, eosinophil infiltration and goblet cell hyperplasia were significantly decreased in the lung tissue of murine model of asthma treated with lovastatin. Furthermore, lovastatin inhibited AHR and expression of Th2-associated cytokines in bronchoalveolar lavage fluid. However, a high dose (40 mg/kg) of lovastatin was required to decrease specific IgE to OVA levels in serum, and suppress the expression of Th2-associated cytokines in splenocytes. Activated BEAS-2B cells treated with lovastatin exhibited reduced IL-6, eotaxins (CCL11 and CCL24), and intercellular adhesion molecule-1 protein expression. Consistent with this, lovastatin also suppressed the ability of HL-60 cells to adhere to inflammatory BEAS-2B cells. Conclusions These data suggest that lovastatin suppresses mucus secretion and airway inflammation by inhibiting the production of eotaxins and Th2 cytokines in murine model of asthma.

Matrine Attenuates COX-2 and ICAM-1 Expressions in Human Lung Epithelial Cells and Prevents Acute Lung Injury in LPS-Induced Mice

Matrine is isolated from Sophora flavescens and shows anti-inflammatory effects in macrophages. Here we evaluated matrines suppressive effects on cyclooxygenase 2 (COX-2) and intercellular adhesion molecule-1 (ICAM-1) expressions in lipopolysaccharide- (LPS-) stimulated human lung epithelial A549 cells. Additionally, BALB/c mice were given various matrine doses by intraperitoneal injection, and then lung injury was induced via intratracheal instillation of LPS. In LPS-stimulated A549 cells, matrine inhibited the productions of interleukin-8 (IL-8), monocyte chemotactic protein-1, and IL-6 and decreased COX-2 expression. Matrine treatment also decreased ICAM-1 protein expression and suppressed the adhesion of neutrophil-like cells to inflammatory A549 cells. In vitro results demonstrated that matrine significantly inhibited mitogen-activated protein kinase phosphorylation and decreased nuclear transcription factor kappa-B subunit p65 protein translocation into the nucleus. In vivo data indicated that matrine significantly inhibited neutrophil infiltration and suppressed productions of tumor necrosis factor-α and IL-6 in mouse bronchoalveolar lavage fluid and serum. Analysis of lung tissue showed that matrine decreased the gene expression of proinflammatory cytokines, chemokines, COX-2, and ICAM-1. Our findings suggest that matrine improved lung injury in mice and decreased the inflammatory response in human lung epithelial cells.

Partially purified extract and viscolin from Viscum coloratum attenuate airway inflammation and eosinophil infiltration in ovalbumin-sensitized mice.

AIM OF THE STUDY Viscum coloratum Nakai is used in traditional Chinese medicine to treat various diseases, including hemorrhage, hypertension, and inflammatory diseases. A previous study demonstrated a partially purified extract (PPE-SVC) and viscolin from Viscum coloratum Nakai inhibited phosphodiesterase activity. In this study, we evaluated the anti-asthmatic effects of PPE-SVC and viscolin, from Viscum coloratum Nakai, in OVA-sensitized mice. MATERIALS AND METHODS Female BALB/c mice were sensitized and challenged with ovalbumin (OVA). The mice were randomized into groups and treated with PPE-SVC, viscolin, or rolipram by intraperitoneal injection on 1h before each inhalation of OVA and airway hyperresponsiveness (AHR). RESULTS PPE-SVC and viscolin suppressed AHR and reduced eosinophil infiltration of the lungs in OVA-sensitized mice. Moreover, PPE-SVC and viscolin inhibited chemokines, including CCL11 and CCL24, and Th2-associated cytokines in bronchoalveolar lavage fluid. However, PPE-SVC and viscolin could not decrease IL-4, IL-5, and IL-13 levels in cultures of OVA-activated spleen cells. CONCLUSION PPE-SVC and viscolin attenuate airway inflammation and eosinophil infiltration in OVA-sensitized mice.

Sesamol suppresses the inflammatory response by inhibiting NF-κB/MAPK activation and upregulating AMP kinase signaling in RAW 264.7 macrophages

Objectives and designSesamol is a lignan isolated from sesame seed oil. In recent years, it was found that sesamol could decrease lung inflammation and lipopolysaccharide (LPS)-induced lung injury in rats. In this study, we investigated whether sesamol exhibited anti-inflammatory activity in LPS-stimulated macrophages.Materials and methodsRAW 264.7 cells were treated with sesamol, then treated with LPS to induce inflammation. The levels of proinflammatory cytokines were analyzed with ELISA. The gene and protein expression of cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS), and nuclear factor erythroid-2-related factor 2 (Nrf2) were evaluated with real-time PCR and Western blots, respectively. We also examined inflammatory signaling pathways, including nuclear transcription factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways.ResultsSesamol inhibited production of nitric oxide, prostaglandin E2 (PGE2), and proinflammatory cytokines. Sesamol markedly suppressed mRNA and protein expression of iNOS and COX-2. Sesamol enhanced the protective antioxidant pathway represented by Nrf2 and HO-1. Moreover, sesamol suppressed NF-κB transport into the nucleus and decreased MAPK activation, but it promoted adenosine monophosphate-activated protein kinase (AMPK) activation.ConclusionsThese data suggested that sesamol ameliorated inflammatory and oxidative damage by upregulating AMPK activation and Nrf2 signaling and blocking the NF-κB and MAPK signaling pathways.

Ginkgolide C Suppresses Adipogenesis in 3T3-L1 Adipocytes via the AMPK Signaling Pathway

Ginkgolide C, isolated from Ginkgo biloba leaves, is a flavone reported to have multiple biological functions, from decreased platelet aggregation to ameliorating Alzheimer disease. The study aim was to evaluate the antiadipogenic effect of ginkgolide C in 3T3-L1 adipocytes. Ginkgolide C was used to treat differentiated 3T3-L1 cells. Cell supernatant was collected to assay glycerol release, and cells were lysed to measure protein and gene expression related to adipogenesis and lipolysis by western blot and real-time PCR, respectively. Ginkgolide C significantly suppressed lipid accumulation in differentiated adipocytes. It also decreased adipogenesis-related transcription factor expression, including peroxisome proliferator-activated receptor and CCAAT/enhancer-binding protein. Furthermore, ginkgolide C enhanced adipose triglyceride lipase and hormone-sensitive lipase production for lipolysis and increased phosphorylation of AMP-activated protein kinase (AMPK), resulting in decreased activity of acetyl-CoA carboxylase for fatty acid synthesis. In coculture with an AMPK inhibitor (compound C), ginkgolide C also improved activation of sirtuin 1 and phosphorylation of AMPK in differentiated 3T3-L1 cells. The results suggest that ginkgolide C is an effective flavone for increasing lipolysis and inhibiting adipogenesis in adipocytes through the activated AMPK pathway.