Anti-arthritic and anti-inflammatory effects of (-)-Epicatechin-3-O-ß-d-allopyranoside, a constituent of Davallia formosana.

BACKGROUND: (-)-Epicatechin-3-O-ß-d-allopyranoside (ECAP) is isolated from the popular Chinese herbal medicine Davallia formosana, which has been used to treat bone diseases including bone fracture, arthritis, and osteoporosis. PURPOSE: To investigate the antiarthritic and the anti-inflammatory effect of ECAP on a mouse model of collagen-induced arthritis (CIA) and in vitro. METHODS: Male DBA/1 J mice were immunized by administering an intradermal injection of 100 µg of type II collagen in Freund's complete adjuvant. The control groups (vehicle) and ECAP were administered orally at doses of 1 ml/kg (H2O), 50 and 100 mg/ml/kg once a day from Day 22 to Day 42 after primary immunization. Paw swelling, arthritis severity score, and histological changes were examined. Enzyme-linked immunosorbent assay was used to measure the levels of cytokines, including tumor necrosis factor alpha (TNF-α), interleukin (IL)-10, IL-17, IL-4, and interferon-γ (IFN-γ), in splenocytes. Furthermore, the anti-inflammatory activities of ECAP were investigated in vitro by measuring nitric oxide (NO) levels in lipopolysaccharide (LPS)-activated RAW264.7 macrophages. RESULTS: In the CIA model, the oral administration of ECAP ameliorated paw edema and reduced the arthritis severity score and disease incidence. Histopathological examination demonstrated that ECAP treatment effectively protected the bone and cartilage of knee joints from erosion, lesion formation, and deformation compared with the vehicle treatment. ECAP also reduced IL-1ß and MMP-9 expression in inflamed joints. Compared with the vehicle-treated mice with CIA, the reduced severity of the disease in ECAP-treated mice was associated with decreased levels of TNF-α and IL-17 and increased levels of IL-10 and IL-4 in the supernatants of splenocyte cultures. Flow cytometry analysis demonstrated that ECAP increased the population of CD4+CD25+ regulatory T cells, thereby inhibiting the B cell population. Anticollagen IgG1 and IgG2a levels decreased in the serum of ECAP-treated mice. ECAP suppressed LPS-induced NO production in RAW264.7 macrophages. CONCLUSION: The administration of ECAP effectively suppressed inflammation and inflammatory pain and adjuvant-induced arthritis, indicating its therapeutic potential in the treatment of rheumatoid arthritis.

(-)-Epicatechin 3-O-ß-D-allopyranoside prevent ovariectomy-induced bone loss in mice by suppressing RANKL-induced NF-κB and NFATc-1 signaling pathways.

BACKGROUND: Davallia formosana Hayata is a herb that has been used in Chinese medicine to treat bone diseases, including arthritis, bone fractures and osteoporosis. The rhizome of D. formosana H. has been found to be rich in (-)-Epicatechin 3-O-ß-D-allopyranoside (ECAP), which is considered to be the active component of the plant in terms of its antiosteoporotic effect. This study investigated the molecular mechanism of the antiosteoporotic property of ECAP isolated from the roots of D. formosana H. using both in vitro and in vivo models. METHODS: We studied the effects of ECAP on the signaling pathways of the receptor activator of nuclear factor-κB ligand (RANKL)-stimulated osteoclastogenesis and ovariectomy-induced osteoporosis. In the in vitro study, the inhibitory action of ECAP on RANKL-induced osteoclastogenesis and the expression of osteoclast-related marker genes were investigated, and in the in vivo study, the effects of ECAP on bone were evaluated using ovariectomized (OVX) mice orally-administered ECAP for 4 weeks. RESULTS: We demonstrated that ECAP dose-dependently inhibited RANKL- and nuclear factor of activated T-cells, and cytoplasmic 1 (NFATc-1)-induced osteoclastogenesis by RAW 264.7 cells, and reduced the extent of bone resorption. Furthermore, µCT images and TRAP staining showed that oral administration of ECAP to OVX mice prevented bone loss. ECAP administration also exerted recovery effects on serum C-terminal telopeptide of type I collagen and osteocalcin levels in OVX mice. In addition, we also found that MMP-9 expression was decreased in vivo and in vitro. CONCLUSIONS: Overall, our findings suggested that ECAP suppresses RANKL-induced osteoclastogenesis through NF-κB and NFATc-1 signaling pathways, and has the potential for use in osteoporosis treatment.

Kinsenoside inhibits the inflammatory mediator release in a type-II collagen induced arthritis mouse model by regulating the T cells responses.

BACKGROUND: Anoectochilus formosanus has been used as a Chinese folk medicine and is known as the "King of medicine" in Chinese society due to its versatile pharmacological effects such as anti-hypertension, anti-diabetes, anti-heart disease, anti-lung and liver diseases, anti-nephritis and anti-Rheumatoid arthritis. Kinsenoside is an essential and active compound of A. formosanus (Orchidaceae). However, the anti-arthritic activity of kinsenoside has still not been demonstrated. In the present study, we confirmed that the kinsenoside treatment rheumatoid arthritis induced by collagen-induced arthritis in mice. METHODS: Male DBA/1 J mice were immunized by intradermal injection of 100 µg of type II collagen in CFA. Kinsenoside was administered orally at a dose of 100 and 300 mg/kg once a day after 2nd booster injection. Paw swelling, arthritic score and histological change were measured. ELISA was used to measure cytokines including tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), interleukin-17 (IL-17) and interferon-γ (IFN-γ) in the splenocyte according to the manufacturer's instructions. RESULTS: Compared with model group, kinsenoside significantly inhibited paw edema and decreased the arthritis score and disease incidence. Histopathological examination demonstrated that kinsenoside effectively protected bone and cartilage of knee joint from erosion, lesion and deformation versus those from the CIA group. Kinsenoside also decreased IL-1ß, TNF-α, and MMP-9 expression, and increased the expression of IL-10 in inflamed joints. The administration of kinsenoside significantly suppressed levels of TNF-α, IFN-γ, and IL-17, but increased concentrations of IL-10 in the supernatants of each of the splenocytes in CIA mice compared with that in the H2O-treated mice with CIA. Using flow cytometric analysis, we demonstrated that kinsenoside increases the population of CD4(+)CD25(+) regulatory T cells, thereby inhibiting the Th1 cell and B cell populations. Anticollagen IgG1 and IgG2a levels decreased in the serum of kinsenoside-treated mice. CONCLUSIONS: These results suggest that the administration of kinsenoside effectively suppressed inflammatory mediators' production and bone erosion in mice with collagen-induced arthritis showing the potential as an anti-arthritis agent.

Development of a microfluidic-based optical sensing device for label-free detection of circulating tumor cells (CTCs) through their lactic acid metabolism.

This study reports a microfluidic-based optical sensing device for label-free detection of circulating tumor cells (CTCs), a rare cell species in blood circulation. Based on the metabolic features of cancer cells, live CTCs can be quantified indirectly through their lactic acid production. Compared with the conventional schemes for CTC detection, this label-free approach could prevent the biological bias due to the heterogeneity of the surface antigens on cancer cells. In this study, a microfluidic device was proposed to generate uniform water-in-oil cell-encapsulating micro-droplets, followed by the fluorescence-based optical detection of lactic acid produced within the micro-droplets. To test its feasibility to quantify cancer cells, experiments were carried out. Results showed that the detection signals were proportional to the number of cancer cells within the micro-droplets, whereas such signals were insensitive to the existence and number of leukocytes within. To further demonstrate its feasibility for cancer cell detection, the cancer cells with known cell number in a cell suspension was detected based on the method. Results revealed that there was no significant difference between the detected number and the real number of cancer cells. As a whole, the proposed method opens up a new route to detect live CTCs in a label-free manner.

Delivery of human EV71 receptors by adeno-associated virus increases EV71 infection-induced local inflammation in adult mice.

Enterovirus71 (EV71) is now recognized as an emerging neurotropic virus in Asia and one major causative agent of hand-foot-mouth diseases (HFMD). However potential animal models for vaccine development are limited to young mice. In this study, we used an adeno-associated virus (AAV) vector to introduce the human EV71 receptors P-selectin glycoprotein ligand-1 (hPSGL1) or a scavenger receptor class-B member-2 (hSCARB2) into adult ICR mice to change their susceptibility to EV71 infection. Mice were administered AAV-hSCARB2 or AAV-hPSGL1 through intravenous and oral routes. After three weeks, expression of human SCARB2 and PSGL1 was detected in various organs. After infection with EV71, we found that the EV71 viral load in AAV-hSCARB2- or AAV-hPSGL1-transduced mice was higher than that of the control mice in both the brain and intestines. The presence of EV71 viral particles in tissues was confirmed using immunohistochemistry analysis. Moreover, inflammatory cytokines were induced in the brain and intestines of AAV-hSCARB2- or AAV-hPSGL1-transduced mice after EV71 infection but not in wild-type mice. However, neurological disease was not observed in these animals. Taken together, we successfully infected adult mice with live EV71 and induced local inflammation using an AAV delivery system.

Toll-like receptor 9-mediated protection of enterovirus 71 infection in mice is due to the release of danger-associated molecular patterns.

Enterovirus 71 (EV71), a positive-stranded RNA virus, is the major cause of hand, foot, and mouth disease (HFMD) with severe neurological symptoms. Antiviral type I interferon (alpha/beta interferon [IFN-α/ß]) responses initiated from innate receptor signaling are inhibited by EV71-encoded proteases. It is less well understood whether EV71-induced apoptosis provides a signal to activate type I interferon responses as a host defensive mechanism. In this report, we found that EV71 alone cannot activate Toll-like receptor 9 (TLR9) signaling, but supernatant from EV71-infected cells is capable of activating TLR9. We hypothesized that TLR9-activating signaling from plasmacytoid dendritic cells (pDCs) may contribute to host defense mechanisms. To test our hypothesis, Flt3 ligand-cultured DCs (Flt3L-DCs) from both wild-type (WT) and TLR9 knockout (TLR9KO) mice were infected with EV71. More viral particles were produced in TLR9KO mice than by WT mice. In contrast, alpha interferon (IFN-α), monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor-alpha (TNF-α), IFN-γ, interleukin 6 (IL-6), and IL-10 levels were increased in Flt3L-DCs from WT mice infected with EV71 compared with TLR9KO mice. Seven-day-old TLR9KO mice infected with a non-mouse-adapted EV71 strain developed neurological lesion-related symptoms, including hind-limb paralysis, slowness, ataxia, and lethargy, but WT mice did not present with these symptoms. Lung, brain, small intestine, forelimb, and hind-limb tissues collected from TLR9KO mice exhibited significantly higher viral loads than equivalent tissues collected from WT mice. Histopathologic damage was observed in brain, small intestine, forelimb, and hind-limb tissues collected from TLR9KO mice infected with EV71. Our findings demonstrate that TLR9 is an important host defense molecule during EV71 infection. Importance: The host innate immune system is equipped with pattern recognition receptors (PRRs), which are useful for defending the host against invading pathogens. During enterovirus 71 (EV71) infection, the innate immune system is activated by pathogen-associated molecular patterns (PAMPs), which include viral RNA or DNA, and these PAMPs are recognized by PRRs. Toll-like receptor 3 (TLR3) and TLR7/8 recognize viral nucleic acids, and TLR9 senses unmethylated CpG DNA or pathogen-derived DNA. These PRRs stimulate the production of type I interferons (IFNs) to counteract viral infection, and they are the major source of antiviral alpha interferon (IFN-α) production in pDCs, which can produce 200- to 1,000-fold more IFN-α than any other immune cell type. In addition to PAMPs, danger-associated molecular patterns (DAMPs) are known to be potent activators of innate immune signaling, including TLR9. We found that EV71 induces cellular apoptosis, resulting in tissue damage; the endogenous DNA from dead cells may activate the innate immune system through TLR9. Therefore, our study provides new insights into EV71-induced apoptosis, which stimulates TLR9 in EV71-associated infections.

Kinsenoside, a high yielding constituent from Anoectochilus formosanus, inhibits carbon tetrachloride induced Kupffer cells mediated liver damage.

AIM: In the present study, we have evaluated the hepatoprotective ability of kinsenoside, a major component of Anoectochilus formosanus, in vitro and in vivo. MATERIALS AND METHODS: The inhibitory action of kinsenoside on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells and Kupffer cells were investigated. Mice hepatic injury was produced by CCl(4) twice a week for 3 weeks. Mice in the three CCl(4) group were treated daily with water and kinsenoside throughout the experimental period. RESULTS: In LPS-stimulated macrophage RAW 264.7 cells and Kupffer cells, kinsenoside inhibited nitric oxide (NO) production and also blocked LPS-induced inducible NO synthase expression. Furthermore, kinsenoside inhibited the NF-κB activation induced by LPS, and this is associated with the abrogation of IκBα degradation, with subsequent decreases in nuclear p65 and p50 protein levels. Moreover, the phosphorylations of p38, ERK and JNK in LPS-stimulated RAW 264.7 cells were suppressed by kinsenoside. In the in vivo study, kinsenoside significantly protected the liver from injury, by reducing the activities of plasma aminotransferase, and by improving the histological architecture of the liver. kinsenoside inhibited Kupffer cell activation by reducing the CD 14 mRNA and protein expressions. CONCLUSION: These results indicate that kinsenoside alleviates CCl(4)-induced liver injury, and this protection is probably due to the suppression of Kupffer cell activation.

Kinsenoside isolated from Anoectochilus formosanus suppresses LPS-stimulated inflammatory reactions in macrophages and endotoxin shock in mice.

In the present study, we reported that kinsenoside, a major component of Anoectochilus formosanus, inhibited inflammatory reactions in mouse peritoneal lavage macrophages and protects mice from endotoxin shock. In LPS-stimulated mouse peritoneal lavage macrophages, kinsenoside inhibited the inflammatory mediators, such as nitric oxide, TNF-[alpha], IL-1[beta], monocyte chemoattractant protein 1, and macrophage migration inhibitory factor production. Furthermore, kinsenoside decreased the formation of a nuclear factor [kappa]B-DNA complex and nuclear p65 and p50 protein levels. Kinsenoside inhibited nuclear factor [kappa]B translocation through both I[kappa]B[alpha]-dependent and -independent pathway. In contrast, it stimulated anti-inflammatory cytokine IL-10 generation and enhanced the mRNA expression of IL-10 and suppressor of cytokine signaling 3 in the same cells induced by LPS. In an animal model, both pretreatment and posttreatment of kinsenoside increased the survival rate of ICR mice challenged by LPS (80 mg/kg, i.p.). Pretreatment with kinsenoside decreased serum levels of TNF-[alpha], IL-1[beta], IL-10, monocyte chemoattractant protein 1, and migration inhibitory factor at 1 h after sublethal dose of LPS (40 mg/kg, i.p.) in mice. In contrast, kinsenoside enhanced serum IL-10 level at 24 h after LPS injection in mice. In conclusion, kinsenoside inhibited the production of inflammatory mediators and enhanced anti-inflammatory cytokine generation. Therefore, kinsenoside can alleviate acute inflammatory hazards.