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[Display omitted] • Sialic acid inhibits LPS-induced inflammation in macrophage. • Sialic acid inhibits DSS-induced inflammation in mice. • Sialic acid exerts the protective effect by inhibiting MAPK-NF-κB/AP-1 signaling. • Sialic acid exerts the protective effect by modulating apoptosis. Edible bird's nest is a natural food tonic and thought to be many health benefits. Sialic acid is the main bioactive component contributing to the biological activity of edible bird's nest. This study aimed to clarify the effect and mechanism of sialic acid on ulcerative colitis through dextran sulfate sodium induced colitis model and lipopolysaccharide stimulated RAW264.7 cell inflammation. The results revealed that sialic acid significantly reduced inflammation and MAPK phosphorylation in vivo. In vitro , sialic acid markedly inhibited the productions of pro-inflammatory cytokine, MAPK pathway activation, and the transcriptional activities of NF-κB and AP-1. In addition, Bcl-2/Bax ratio was increased and the activation of Cyt-c, Caspase-9 and Caspase-3 were decreased remarkably by sialic acid, suggesting sialic acid could inhibit cell apoptosis. Taken together, sialic acid exerts protective effect by regulating MAPK-NF-κB/AP-1 signaling pathways and apoptosis, and it might be a potential candidate for the prevention of ulcerative colitis. [ABSTRACT FROM AUTHOR]

The present study was designed to detect the anti-depressant effects of paeonol and the possible mechanisms in the lipopolysaccharide-induced depressive-like behavior. Open-field test(OFT), tail suspension test(TST) and forced swimming test(FST) were used to evaluate the behavioral activity. The contents of 5-hydroxytryptamine (5-HT) and norepinephrine (NE) in mice hippocampus were determined by HPLC-ECD. Serum interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α levels were evaluated by enzyme-linked immunosorbent assay (ELISA). Our results showed that LPS significantly decreased the levels of 5-HT and NE in the hippocampus. LPS also reduced open-field activity, as well as increased immobility duration in FST and TST. Paeonol administration could effectively reverse the alterations in the concentrations of 5-HT, NE and reduce the IL-6 and TNF-α levels. Moreover, paeonol effectively downregulated brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB) and Nuclear factor-κB (NF-κB) in hippocampal. In conclusion, paeonol administration exhibited significant antidepressant-like effects in mice with LPS-induced depression. [ABSTRACT FROM AUTHOR]

Inflammation is a major factor affecting human health. Nuclear factor-kappa B (NF-κB) plays a vital role in the development of inflammation, and the promoters of most inflammatory cytokine genes have NF-κB-binding sites. Targeting NF-κB could be an exciting route for the prevention and treatment of inflammatory diseases. As important constituents of natural plants, lignans are proved to have numerous biological functions. There are growing pieces of evidence demonstrate that lignans have the potential anti-inflammatory activities. In this work, the type, structure and source of lignans and the influence on mitigating the inflammation are systematically summarized. This review focuses on the targeting NF-κB signaling pathway in the inflammatory response by different lignans and their molecular mechanisms. Lignans also regulate gut microflora and change gut microbial metabolites, which exert novel pathway to prevent NF-κB activation. Taken together, lignans target NF-κB with various mechanisms to inhibit inflammatory cytokine expressions in the inflammatory response. It will provide a scientific theoretical basis for further research on the anti-inflammatory effects of lignans and the development of functional foods. [ABSTRACT FROM AUTHOR]

Hesperidin, a kind of citrus bioflavonoid distributed in foods including grapefruits, oranges and lemons, has many pharmacological activities. This study was aimed to evaluate the anti-depressant-like effect of hesperidin on chronic unpredictable mild stress (CUMS)-induced mice. Depressive-like behavior was detected by the sucrose preference test (SPT), tail suspension test (TST) and forced swimming test (FST). A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was performed to assess the cell viability of corticosterone-induced PC12 cells. The serum, hippocampal and cell supernatant concentrations of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α were determined using enzyme-linked immunosorbent assay (ELISA) commercial kits. Furthermore, the protein expression levels of high-mobility group box 1 protein (HMGB1), receptor for advanced glycation end-products (RAGE)/NF-κB and brain-derived neurotrophic factor (BDNF)/tropomyosin-related kinase B (TrkB) pathway in the hippocampus and corticosterone-induced PC12 cells were detected by Western blot. Our results showed that hesperidin (100, 200 mg/kg) significantly relieved depressive-like behaviors, including decreased sucrose consumption in sucrose preference test (SPT), immobility in the forced swimming test (FST), tail suspension test, and locomotor activity in the open field test (OFT). Hesperidin reduced inflammatory cytokine levels by attenuating the HMGB1/RAGE/NF-κB signaling pathway and BDNF/TrkB pathway both in vivo and in vitro. In conclusion, hesperidin possessed efficient neuroprotective effects on depression, which was associated with neuroinflammation mediated by the HMGB1/RAGE/NF-κB and BDNF/TrkB pathways. [ABSTRACT FROM AUTHOR]

Baicalin (BA), a major polyphenol compound isolated from the extracts of Scutellaria radix, has been previously reported to ameliorate depressive-like behaviors in mice with chronic unpredictable mild stress (CUMS). However, its underlying antidepressant mechanisms remain unclear. This study was designed to confirm the antidepressant-like effects of BA on CUMS induced behavioral abnormalities in mice, and sought to explore the pharmacological mechanisms in vivo and in vitro. The CUMS procedure was carried out to induce depression in mice. Afterwards, the tail suspension test (TST), forced swim test (FST), and open field test (OFT) were performed within 24 h, then sucrose preference test (SPT) was conducted. Additionally, PC12 cells were pretreated with BA for 2 h, then further stimulated with corticosterone for 24 h. The levels of Interleukin-1β (IL-1β), IL-6 and Tumor Necrosis Factor-α (TNF-α) in serum, hippocampus homogenate and cell culture medium were determined using the enzyme-linked immunosorbent assay (ELISA) method. The protein expressions of inhibition of high mobility group box 1 protein (HMGB1)/Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) pathways in hippocampus and PC12 cells were detected. Our results showed that CUMS-treated mice presented notable depressive-like symptoms, such as decreased sucrose consumption, increased FST and TST immobility time. While BA (25, 50 mg/kg) significantly attenuated these changes. Besides, BA treatment considerably inhibited inflammatory cytokinesl (IL-1β, IL-6, TNF-α) levels in serum, hippocampus homogenate and cell culture medium. Western blot analysis indicated that BA inhibited the expressions of HMGB1, TLR4, and p-NF-κBp65 both in vivo and in vitro. In conclusion, the present study confirmed that BA possessed efficient antidepressant effects on depression, which was possibly related to the inhibition of HMGB1/TLR4/NF-κB pathways. [ABSTRACT FROM AUTHOR]