Dihydroartemisinin suppresses ovalbumin-induced airway inflammation in a mouse allergic asthma model

Abstract

Asthma is a complex disease characterized by reversible airway obstruction, airway hyper-responsiveness (AHR) and chronic inflammation of the airways. Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua, has been shown to possess antimalarial and antitumor activities, but whether it can be used in asthma treatment has not been investigated. In this study, we attempted to determine whether DHA regulates inflammatory mediators in the ovalbumin (OVA)-induced mouse asthma model. BALB/c mice were sensitized and challenged by OVA to induce chronic airway inflammation. The intragastrical administration of DHA at 30?mg/kg significantly decreased the number of infiltrating inflammatory cells, T-helper type 2 (Th2) cytokines, OVA-specific immunoglobulin E (IgE) and AHR. Treatment with DHA also attenuated OVA-induced mRNA expression of Muc5ac and chitinase 3-like protein 4 (Ym2) in lung tissues. In addition, lung histopathological studies revealed that DHA inhibited inflammatory cell infiltration and mucus hypersecretion. Then signal transduction studies showed that DHA significantly inhibited extracellular signal-regulated protein kinase (ERK), p38 mitogen-activated protein kinase phosphorylation. DHA also inhibited nuclear factor-κB (NF-κB) activation via the inhibition of phosphorylation of IκBα. These findings provide new insight into the immunopharmacological role of DHA in terms of its effects in a mouse model of asthma.     

Epigallocatechin gallate stimulates the neuroreactive salivary secretomotor system in autoimmune sialadenitis of MRL-Faslpr mice via activation of cAMP-dependent protein kinase A and inactivation of nuclear factor κB

Abstract

The water channel aquaporin 5 (AQP5) plays a crucial role in regulating salivary flow rates. Xerostomia is often observed in patients with Sjögren's syndrome, and this is attributed to reduced AQP5 expression in the salivary glands. Recently, anti-type 3 muscarinic cholinergic receptors (M₃R) autoantibodies and nuclear factor κB (NF-κB) have been found to be negative regulators of AQP5 expression in the salivary gland. Anti-M₃R autoantibodies desensitize M₃R to salivary secretagogues in Sjögren's syndrome, while activated NF-κB translocates to nuclei and binds to the AQP5 gene promoter, resulting in the suppression of AQP5 expression. We previously documented that epigallocatechin gallate (EGCG), which is a robust antioxidant contained in green tea, ameliorates oxidative stress-induced tissue damage to the salivary glands of MRL/MpJ-lpr/lpr (MRL-Fas^lpr) mice, which are widely used as a model of Sjögren's syndrome. Reactive oxygen species (ROS) can activate NF-κB and inactivate protein kinase A (PKA), which is a key driver of AQP5 expression. In this study, we examined the effects of administering EGCG to MRL-Fas^lpr mice with autoimmune sialadenitis on the levels of AQP5, activated NF-κB p65 subunit, activated PKA, activated c-Jun N-terminal kinase (JNK) (an activator of NF-κB), inhibitor κB (IκB) and histone deacetylase 1 (HDAC1) (an inhibitor of NF-κB). In EGCG-treated mice, intense aster-like immunostaining for AQP5 was observed on the apical plasma membranes (APMs) of submandibular gland acinar cells. Likewise, PKA, IκB and HDAC1 were highly expressed in salivary gland tissues, whereas the expression of JNK and NF-κB p65 was negligible. Rank correlation and partial correlation analyses revealed that treatment with EGCG upregulated AQP5 expression on the APM of acinar cells through activation of PKA and inactivation of NF-κB, while IκB and HDAC1 played a pivotal role in the induction of AQP5 expression by PKA. Our study indicates that EGCG may have therapeutic potential for Sjögren's syndrome patients.     

The regulatory mechanism of β-eudesmol is through the suppression of caspase-1 activation in mast cell–mediated inflammatory response

β-Eudesmol is sesquiterpenoid alcohol which contains the rhizome of Atractylodes lancea. Although it has multiple pharmacological effects, the anti-inflammatory effect of β-eudesmol and its molecular mechanisms are poorly elucidated. In this study, we investigated the regulatory mechanism of β-eudesmol on mast cell–mediated inflammatory response. The results indicated that β-eudesmol inhibited the production and expression of interleukin (IL)-6 on phorbol 12-myristate 13-acetate and calcium ionophore A23187-stimulated human mast cell (HMC). In activated HMC-1 cells, β-eudesmol suppressed activation of p38 mitogen-activated protein kinase (MAPKs) and nuclear factor-κB. In addition, β-eudesmol suppressed the activation of caspase-1 and expression of receptor-interacting protein-2. These results provide new insights into the pharmacological actions of β-eudesmol as a potential molecule for use in therapy in mast cell–mediated inflammatory diseases.     

Anti-inflammatory and antioxidant effects of coumarins isolated from Foeniculum vulgare in lipopolysaccharide-stimulated macrophages and 12-O-tetradecanoylphorbol-13-acetate-stimulated mice

Abstract

Context: Foeniculum vulgare (F. vulgare) is traditionally used to treat inflammatory diseases. Recently, anti-inflammatory and antioxidant activities of methanol extract of the fruits of F. vulgare were reported. To identify biologically active compounds responsible for the anti-inflammatory activity, we isolated four coumarins, scopoletin, 8-methoxypsoralen, bergapten and imperatorin from the fruits of F. vulgare.

Objective: This study assessed the anti-inflammatory and antioxidant effects of coumarins isolated from F. vulgare in lipopolysaccharide (LPS)-stimulated macrophages and 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated mice.

Materials and methods: RAW 264.7 cells were treated with the coumarins (30?µM) and then stimulated with LPS (100 ng/ml). Ears of ICR mice were treated with TPA (1?µg/ear) once a day. Ten microliters each of the four coumarins (200?μg/ml) were topically applied to the ears for 3 days. Antioxidant activities were examined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid (ABTS) scavenging assays.

Results: All the tested coumarins showed excellent antioxidant activities in DPPH and ABTS radical scavenging assays. Among the coumarins, imperatorin had the greatest anti-inflammatory activities as measured by inhibition of the pro-inflammatory cytokines production including interleukin (IL)-6 and tumor necrosis factor (TNF)-α in LPS-stimulated RAW 264.7 cells through blockade of the IκB kinase (IKK)/inhibitor of kappa B (IκB)/nuclear factor-κB (NF-κB) pathway. In vivo experiments showed that imperatorin reduced TPA-induced ear thickness/weight, cutaneous cytokines expression and improved histopathological features.

Conclusion: Although four coumarins isolated from the fruits of F. vulgare provide effective anti-inflammatory and antioxidant activities, imperatorin is most potent.     

Tubeimoside-1 inhibits the proliferation and activation of mouse T lymphocytes through signal transduction pathways

Abstract

Tubeimoside-1 (TBMS1) is one of the important components in Bolbostemma paniculatum (Maxim.) Franque. In the study, its immunosuppressive effects on murine T lymphocyte responses were evaluated in vitro and in vivo. The data showed that TBMS1 inhibited ConA-induced T lymphocyte proliferation, decreased the ratio of CD4⁺/CD8⁺, suppressed IL-2, IFN-γ, IL-4 and IL-6 production and mRNA expression, down-regulate activation of NF-κB, NFAT2 and AP-1 signal transduction pathways in vitro. In addition, administration of TBMS1 significantly inhibited T cell-mediated DTH response in vivo. These findings indicated that TBMS1 inhibits the proliferation and activation of T lymphocytes in mice.     

Molecular Basis of the Anti-Inflammatory Property Exhibited by Cyclo-Pentano Phenanthrenol Isolated from Lippia nodiflora

The objective of this study was to assess the anti-inflammatory potential of the active molecule isolated from Lippia nodiflora and to understand its molecular dynamics in Vitro inflammation models. Human Peripheral Blood Mononuclear Cells were used as models to study mitogen induced lymphocyte proliferation, cytokine mRNA expression (TNF-α, IL-1β and IL-6) and intracellular protein levels of pro-inflammatory mediators (MAPK and NF-κB). The NO release levels, on treatment with the extract and molecule, were correlated with the underlying iNOS mRNA expression in the murine macrophage cell line RAW 264.7. RT-PCR for COX-2, MMP2 and MMP9 were also performed in the cell line. The rat basophilic leukemia cell line RBL-2H3 was used as an in Vitro model for PLA2 activity. Then, 20 μg/ml of Lippia nodiflora crude methanol extract and 10 μg/ml of the purified CPP were used for subsequent studies based on the IC50 values obtained in the proliferation assay. Results demonstrate that the isolated Cyclo-pentano phenanthrenol inhibits TNF-α, IL-1β and IL-6 expression, NO release via iNOS suppression, prostaglandin biosynthesis via PLA2 and COX-2 inhibition and the activation of intracellular targets, MAPK and NF-κB. We conclude, cyclo-pentano phenanthrenol exerts its anti-inflammatory effect via inhibition of MAPK phosphorylation and NF-κB translocation.     

Rebamipide potentially mitigates methotrexate-induced nephrotoxicity via inhibition of oxidative stress and inflammation: A molecular and histochemical study

Methotrexate (MTX) is a widely used chemotherapeutic agent; nevertheless, the nephrotoxicity associated with its use has limited its clinical use. Rebamipide (REB) is a gastro-protective agent with diverse promising biological activities. Here, we investigated the renoprotective effects of REB against MTX-induced nephrotoxicity in rats. Male Wistar rats were allocated into four groups: the normal control group, the REB group (100 mg kg⁻¹ day⁻¹, PO, for 12 days), the MTX group (which received a single injection of 20 mg/kg, ip), and the REB + MTX group (which received 100 mg kg⁻¹ day⁻¹ REB for 7 days before and 5 days after being injected with 20 mg/kg MTX). Interestingly, MTX triggered kidney injury, characterized by renal dysfunction along with histopathological alterations. Moreover, increased reactive oxygen species level and inflammatory response were detected in the kidney of MTX-treated rats. However, REB prevented MTX-induced oxidative kidney injury and boosted an antioxidant balance. Mechanistically, REB markedly activated the NRF-2 protein and upregulated the expression of both SIRT-1 and FOXO-3 genes. Additionally, REB administration strongly inhibited the inflammatory response by downregulating both NF-κB-p65 and TLR-4. Finally, the coadministration of REB and MTX activated the mTOR/PI3K/AKT signaling pathway. Simultaneously, REB treatment attenuated the reduction in glomerular size, the widening of the capsular spaces, and the tubular cell damage due to MTX administration. Taken together, these results indicate the potential of REB as adjuvant therapy to prevent nephrotoxicity in patients receiving MTX treatment.     

RETRACTED: Resibufogenin suppresses growth and metastasis through inducing caspase-1-dependent pyroptosis via ROS-mediated NF-κB suppression in non-small cell lung cancer

The purpose of this study is to explore the antitumor properties of resibufogenin (RB) in non-small cell lung cancer (NSCLC) and elucidate its underlying mechanism. A549 and H520 cells were treated with various concentrations of RB with or without NLRP3 inhibitor (MCC950), caspase-1 inhibitor (VX765), or N-acetyl-l -cysteine (an ROS scavenger). Cell counting kit-8 and colony formation assays were conducted to determine cell viability. Cell invasion was detected by using the transwell assay. The release of lactate dehydrogenase (LDH) was determined by the LDH detection assay. The protein expression levels of related genes were measured by western blotting and immunohistochemistry. The reactive oxygen species (ROS) level was detected by using a 2,7-dichlorodihydrofluorescein diacetate ROS Assay Kit. The in vivo effects of RB were evaluated in a xenograft mouse model. RB treatment reduced cell viability and invasion in a dose-dependent manner. Furthermore, RB also enhanced pyroptosis levels in A549 and H520 cells, as indicated by the increased release of LDH and pyroptosis-related proteins. Interestingly, we also found that the antiproliferative and antimetastatic effects of RB were alleviated by the blockade of pyroptosis using NLRP3 inhibitor MCC950. Further study demonstrated that RB induced pyroptosis in a caspase-1-dependent manner, as evidenced by the finding that VX765 effectively reversed the effects of RB on A549 and H520 cells. We also found that RB could trigger caspase-1-dependent pyroptosis through ROS-mediated NF-κB suppression. In summary, our findings provide a potential antitumor agent and a novel insight into the mechanism of RB treatment of NSCLC.