Do-Wan Shim

Anti-inflammatory and anti-allergic effects of Agrimonia pilosa Ledeb extract on murine cell lines and OVA-induced airway inflammation

ETHNOPHARMACOLOGICAL EVIDENCE Agrimonia pilosa Ledeb (Rosaceae, AP) has long been used as a traditional medicine in Korea and other Asian countries to treat various diseases. AIM OF THE STUDY In the present study, the anti-inflammatory and anti-allergic effects of AP extract in in vitro cell lines and in vivo mouse model of inflammation and the molecular mechanisms involved were reported. MATERIALS AND METHODS Using Raw 264.7 murine macrophages the effects of methanol extract of AP in lipopolysaccharide (LPS)-induced production of inflammatory mediators were measured. Further IgE-DNP-induced interleukin (IL)-4 production and degranulation in RBL-2H3 rat basophilic cell lines was also estimated. To investigate the anti-asthmatic effect of AP in vivo, airway inflammation in ovalbumin (OVA)-induced mouse model was used. RESULTS AP attenuated the production of inflammatory mediators such as NO, PGE(2) and pro-inflammatory cytokines in LPS-induced Raw 264.7 cells. Further, AP inhibited IL-4 production and degranulation in IgE-DNP-induced RBL-2H3 cells. Furthermore, AP attenuated the infiltration of immune cells into lung, cytokines production in broncho-alveolar lavage fluid (BALF) and airway-hyperresponsiveness (AHR) on OVA-induced mouse model of inflammation. CONCLUSION Our results showed that AP attenuated the activation of macrophages, basophils, and inhibited the OVA-induced airway inflammation. The molecular mechanisms leading to APs potent anti-inflammatory and anti-allergic effects might be through regulation of TRIF-dependent and Syk-PLCγ/AKT signaling pathways, suggesting that AP may provide a valuable therapeutic strategy in treating various inflammatory diseases including asthma.

Anti-Inflammatory Effect of Emodin via Attenuation of NLRP3 Inflammasome Activation

Emodin, an active constituent of oriental herbs, is widely used to treat allergy, inflammation, and other symptoms. This study provides the scientific basis for the anti-inflammasome effects of emodin on both in vitro and in vivo experimental models. Bone marrow-derived macrophages were used to study the effects of emodin on inflammasome activation by using inflammasome inducers such as ATP, nigericin, and silica crystals. The lipopolysaccharide (LPS)-induced endotoxin shock model was employed to study the effect of emodin on in vivo efficacy. Emodin treatment attenuated interleukin (IL)-1β secretion via the inhibition of NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation induced by ATP, nigericin, and silica crystals. Further, emodin ameliorated the severity of NLRP3 inflammasome-mediated symptoms in LPS-induced endotoxin mouse models. This study is the first to reveal mechanism-based evidence, especially with respect to regulation of inflammasome activation, substantiating traditional claims of emodin in the treatment of inflammation-related disorders.

Carpesium macrocephalum attenuates lipopolysaccharide-induced inflammation in macrophages by regulating the NF-κB/IκB-α, Akt, and STAT signaling pathways.

Carpesium macrocephalum (CM) Fr. et Sav. (Compositae) has been used in Chinese folk medicine as an analgesic, hemostatic, antipyretic, and to suppress inflammatory conditions. In the present study we aimed to provide scientific evidence for the anti-inflammatory properties of CM extract and evaluate the intrinsic mechanisms involved in both in vitro and in vivo experimental models. In in vitro findings, CM significantly inhibited the LPS-stimulated release of proinflammatory mediators such as nitric oxide, tumor necrosis factor-alpha, prostaglandin E2, and interleukin-6 in RAW264.7 macrophages in a concentration-dependent fashion. The attenuation of inflammatory responses in LPS-activated RAW264.7 cells by CM was closely associated with the suppression of nuclear factor-kappa B (NF-κB) phosphorylation, IκB-α degradation, and phosphorylation of Akt. CM treatment also attenuated the phosphorylation of STAT through TRIF dependent pathways in LPS-activated RAW264.7 cells. In vivo studies revealed that CM extract concentration dependently suppressed the acetic acid-induced vascular permeability in mice. Considering the data obtained regulation of multiple signaling mechanisms involving TRIF and Akt/NF-κB pathways might be responsible for the potent anti-inflammatory action of CM, substantiating its traditional use in inflammatory diseases.

Streptochlorin suppresses allergic dermatitis and mast cell activation via regulation of Lyn/Fyn and Syk signaling pathways in cellular and mouse models.

Allergic diseases are chronic inflammatory conditions with specific immune and inflammatory mechanisms. Scientific interest in understanding the mechanisms and discovering novel agents for the prevention and treatment of allergic disease is increasing. Streptochlorin, a small compound derived from marine actinomycete possesses anti-angiogenic and anti-tumor activities. However, the anti-allergic effects and underlying mechanisms remain to be elucidated. In the present study, we investigated the effect of streptochlorin on allergic responses in vitro and in vivo. Streptochlorin inhibited degranulation and production of tumor necrosis factor-α and IL-4 by antigen-stimulated mast cells. Streptochlorin also inhibited the phosphorylation of Akt and the mitogen-activated protein kinases (MAPKs), including p38, ERK, and JNK. Further, streptochlorin reduced the phosphorylation of Syk in RBL-2H3 cells and inhibited the activity of Lyn and Fyn. Furthermore, administration of streptochlorin suppressed the allergic reactions in both passive cutaneous anaphylaxis reaction and 2, 4-dinitrofluorobenzene (DNFB)-induced allergic dermatitis in mice model. Considering the data obtained, we report for the first time that streptochlorin possess anti-allergic properties. The underlying mechanism of streptochlorin in exhibiting potent anti-allergic activity might be through the inhibition of the Lyn/Fyn and Syk signaling pathways.

Lysimachia clethroides Duby extract attenuates inflammatory response in Raw 264.7 macrophages stimulated with lipopolysaccharide and in acute lung injury mouse model

ETHNOPHARMACOLOGICAL RELEVANCE Lysimachia clethroides Duby (LC) is a traditional medicinal herb used to treat edema, hepatitis and inflammatory diseases in China and other Asian countries. In this study, the anti-inflammatory effects of LC extract and the mechanisms underlying were explored in both in vitro cell lines and acute lung injury (ALI) animal model of inflammation in vivo. MATERIALS AND METHODS Lipopolysaccharide (LPS)-stimulated Raw 264.7 murine macrophages were used to study the regulatory effects of LC extract on inflammatory mediators such as nitric oxide (NO) and proinflammatory cytokine expression. Western blotting or ELISA techniques were employed to estimate protein levels. RT-PCR was used for analyzing the interferon (IFN)-β production. LPS-induced ALI mouse model in vivo was employed to study the effect of LC extract. Further high-performance liquid chromatography (HPLC) fingerprinting technique was used to evaluate the active constituents present in LC extract, compared with reference standards. RESULTS Pre-treatment with LC extract inhibited the LPS-stimulated NO release, interleukin (IL)-1β and IL-6 production in Raw 264.7 cells dose dependently. LC extract inhibited the LPS-stimulated IRF3 and STAT1 phosphorylation. Further, in vivo experiments revealed that LC extract suppressed the infiltration of immune cells into the lung and proinflammatory cytokine production in broncho-alveolar lavage fluid (BALF) in the LPS-induced ALI mouse model. CONCLUSIONS Our results indicate that LC extract attenuates LPS-stimulated inflammatory responses in macrophages via regulating the key inflammatory mechanisms, providing a scientific support for its traditional use in treating various inflammatory diseases.

Anti-inflammatory effect of Impatiens textori Miq. extract via inhibition of NLRP3 inflammasome activation in in vitro and in vivo experimental models

ETHNOPHARMACOLOGICAL RELEVANCE Impatiens textori Miq. (I. textori, Balsaminaceae) is a traditional medicinal herb used for centuries to treat several inflammatory related skin infections and allergic disorders in Asian countries. AIM OF THE STUDY In this study, we elucidated the effects of whole plant extracts of I. textori on inflammasome activation using in vitro and in vivo models. MATERIALS AND METHODS LPS-stimulated murine bone marrow macrophages were used to study the regulatory effect of I. textori extract (IT) on inflammasome activation. ATP, nigericin and MSU were used as danger-associated molecules to activate the NLRP3 inflammasome. An LPS-induced acute lung injury (ALI) mouse model was used to study the in vivo effect of IT on inflammasome activation. RESULTS IT treated at 25, 50, and 100μg/mL concentrations suppressed interleukin-1β secretion through the attenuation of NLRP3 inflammasome activation (p<0.001 at 100μg/mL) leading to the decreased amount of ASC oligomerization and caspase-1 maturation. For the in vivo model, IT inhibited the NLRP3 expression and cell recruitment at the lung tissue in the ALI mouse model. CONCLUSION IT exhibited potent anti-inflammatory effects via the attenuation of NLRP3 inflammasome activation supporting the traditional claims and may provide a valuable therapeutic strategy in treating various inflammation-related disorders.

Emodin attenuates A23187-induced mast cell degranulation and tumor necrosis factor-α secretion through protein kinase C and IκB kinase 2 signaling.

Mast cells are known to play a pivotal role in allergic diseases. Cross-linking of the high-affinity IgE receptor (FcεRI) is known to be one of the major causes that lead to degranulation and allergic inflammation. An increase in intracellular calcium (Ca(2+)) concentration also triggers degranulation, bypassing receptor activation. Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is known to exhibit a variety of pharmacological activities including anti-allergic effects. However, the detailed molecular mechanisms involved in exhibiting anti-allergic effects by emodin were remained to be clarified. In the present investigation we report the regulatory function of emodin on the allergic signal mediators through Ca(2+) ionophore activation in mast cells. Emodin significantly inhibited A23187-induced tumor necrosis factor-α production and degranulation through the attenuation of protein kinase C, IκB kinase 2, and soluble N-ethylmaleimide-sensitive fusion factor attachment protein receptor complex formation, bypassing FcεRI activation. Data from our study indicated that emodin acts by regulating multiple signaling pathways in inhibiting the allergic reactions in mast cells.

Anti-Inflammatory Action of an Antimicrobial Model Peptide That Suppresses the TRIF-Dependent Signaling Pathway via Inhibition of Toll-Like Receptor 4 Endocytosis in Lipopolysaccharide-Stimulated Macrophages

Antimicrobial peptides (AMPs), also called host defense peptides, particularly those with amphipathic helical structures, are emerging as target molecules for therapeutic development due to their immunomodulatory properties. Although the antimicrobial activity of AMPs is known to be exerted primarily by permeation of the bacterial membrane, the mechanism underlying its anti-inflammatory activity remains to be elucidated. We report potent anti-inflammatory activity of WALK11.3, an antimicrobial model peptide with an amphipathic helical conformation, in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. This peptide inhibited the expression of inflammatory mediators, including nitric oxide, COX-2, IL-1β, IL-6, INF-β, and TNF-α. Although WALK11.3 did not exert a major effect on all downstream signaling in the MyD88-dependent pathway, toll-like receptor 4 (TLR4)- mediated pro-inflammatory signals were markedly attenuated in the TRIF-dependent pathway due to inhibition of the phosphorylation of STAT1 by attenuation of IRF3 phosphorylation. WALK11.3 specifically inhibited the endocytosis of TLR4, which is essential for triggering TRIF-mediated signaling in macrophage cells. Hence, we suggest that specific interference with TLR4 endocytosis could be one of the major modes of the anti-inflammatory action of AMPs. Our designed WALK11 peptides, which possess both antimicrobial and anti-inflammatory activities, may be promising molecules for the development of therapies for infectious inflammation.

Juniperus rigida Sieb. extract inhibits inflammatory responses via attenuation of TRIF-dependent signaling and inflammasome activation

ETHNOPHARMACOLOGICAL RELEVANCE Juniperus rigida Sieb. (J. rigida) is used for medicinal purposes in Asian countries to treat inflammation-related disorders, such as neuralgia, dropsy, and gout. AIM OF THE STUDY The anti-inflammatory effects of J. rigida extract (JR) and its underlying mechanisms were explored both in in vitro cell lines and in vivo metabolic disease models. MATERIAL AND METHODS Lipopolysaccharide (LPS)-stimulated RAW264.7 murine macrophages were used to study the changes in inflammatory responses in vitro. Bone marrow-derived macrophages (BMDMs) were used to study the regulatory effect of JR on inflammasome activation. The murine model for monosodium urate (MSU)-induced peritonitis and high-fat diet (HFD)-induced type 2 diabetes were employed to study the effect of JR on in vivo efficacy. RESULTS JR suppressed the MSU-induced in vivo inflammatory response by attenuation of proinflammatory cytokines, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α). In the in vitro study, JR suppressed IL-1β secretion via regulation of apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization, leading to the inhibition of inflammasome activation. JR also inhibited the LPS-stimulated release of proinflammatory mediators, such as nitric oxide (NO), TNF-α, and IL-6 in RAW264.7 cells. The inhibitory effects of JR were mediated through the regulation of the TRIF-dependent signaling pathway from JAK1/STAT1 phosphorylation. Furthermore, JR showed inhibitory effects on HFD-induced type 2 diabetes in a mouse model through the regulation of blood glucose and serum IL-1β. CONCLUSIONS Our results indicate that JR attenuates both LPS-stimulated and danger-signal-induced inflammatory responses in macrophages via regulation of the key inflammatory mechanisms, providing scientific support for its traditional use in the treatment of various inflammation-related metabolic disorders.

Protective effects of Cinnamomum cassia (Lamaceae) against gout and septic responses via attenuation of inflammasome activation in experimental models

ETHNOPHARMACOLOGICAL RELEVANCE Cinnamomum cassia (C. cassia, Lauraceae family), commonly used for treating dyspepsia, gastritis, blood circulation, and inflammatory diseases is considered as one of the 50 fundamental herbs in traditional Chinese medicine. AIM OF THE STUDY The anti-inflammatory action of an ethanol extract of C. cassia (CA), and its underlying mechanisms were explored in both in vitro cellular and in vivo murine models. MATERIALS AND METHODS Bone marrow-derived macrophages (BMDMs) were used to study the regulatory effect of CA on inflammasome activation. A lipopolysaccharide (LPS)-induced sepsis mouse model and a monosodium urate (MSU)-induced gout model were employed to study the effect of CA on in vivo efficacy. RESULTS CA improved the survival rate in the LPS-induced septic shock mouse model and inhibited inflammasome activation including NLRP3, NLRC4, and AIM2, leading to suppression of interleukin-1β secretion. Further, ASC oligomerization and its speck formation in cytosol were attenuated by CA treatment. Furthermore, CA improved both survival rate of LPS-induced septic shock and gout murine model. CONCLUSIONS CA treatment significantly attenuated danger signals-induced inflammatory responses via regulation of inflammasome activation, substantiating the traditional claims of its use in the treatment of inflammation-related disorders.