RA-XII exerts anti-oxidant and anti-inflammatory activities on lipopolysaccharide-induced acute renal injury by suppressing NF-κB and MAPKs regulated by HO-1/Nrf2 pathway

Acute kidney injury (AKI) is an abrupt loss of kidney function and severe AKI needs renal replacement therapeutic strategy and has high mortality. RA-XII is a natural cyclopeptide, isolated from the traditional Chinese medicine Rubia yunnanensis, exerting anti-inflammatory and anti-tumor activities. The present study aimed to explore the effects of RA-XII on LPS-induced ACI and the underlying molecular mechanism in TCMK-1?cells in vitro. The results indicated that RA-XII delayed the animal death caused by LPS in mice. The kidney histological changes were markedly attenuated by RA-XII. RA-XII also reduced the serum uric acid, creatinine, BUN and renal 8-OHdG. In addition, RA-XII suppressed LPS-induced oxidative stress in kidney, as evidenced by the up-regulation of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels, and the down-regulation of malondialdehyde (MDA) levels. Additionally, RA-XII enhanced heme oxygenase (HO)-1 and nuclear factor erythroid 2-related factor 2 (Nrf2) expressions in renal tissue sections. Further, RA-XII reduced the release of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), IL-6 and IL-18, in renal, which was linked to the inhibition of inhibitor of alpha/nuclear factor kappa B (IκBα/NF-κB) and mitogen-activated protein kinases (MAPKs) pathways. The in vitro study illustrated that the anti-inflammatory effects of RA-XII were partially reversed following Nrf2 and HO-1 inhibition. Together, these findings strongly suggested that RA-XII is a potential agent against acute kidney injury.     

Stress-induced phosphoprotein 1 restrains spinal cord ischaemia-reperfusion injury by modulating NF-κB signalling

Spinal cord injury (SCI), a major cause of disability, causes high global disease and economic burdens. Stress-induced phosphoprotein 1 (STIP1) has been identified to be involved in spinal cord ischaemia-reperfusion injury (SCII); however, the effect of STIP1 on SCII remains unclear until now. This study aimed to examine the role of STIP1 in SCII and unravel the possible mechanisms. Western blotting and immunohistochemical staining showed that STIP1 expression rapidly increased and then decreased in rat spinal cord following SCII treatment. Neurological function scoring, HE staining, immunohistochemical staining and Western blotting revealed that STIP1 overexpression alleviated SCII-induced motor dysfunction of hind limbs, neuronal loss and inflammation in spinal cord, and inhibited activity of nuclear factor kappa B (NF-κB) signalling in rats. Immunoprecipitation identified that STIP1 was co-located with Iba-1. In addition, STIP1 was found to ameliorate oxygen and glucose deprivation (OGD)-induced inflammation and activation of NF-κB signalling in mouse microglia BV2 cells, and STIP1 resulted in decrease of heat shock protein family A member 8 (HSPA8), increase of IκBβ expression and reduced binding of IκBβ to HSPA8 in BV2 cells. The results of the present study demonstrate that STIP1 alleviates ischaemia/reperfusion-induced neuronal injury and inflammation in rat spinal cord and mouse microglial cells by deactivating NF-κB signalling. These findings may provide novel insights for the clinical diagnosis and treatment of SCI.     

Pomegranate reverses methotrexate-induced oxidative stress and apoptosis in hepatocytes by modulating Nrf2-NF-κB pathways

The clinical efficacy of the widely used chemotherapeutic drug methotrexate (MTX) is limited due to its associated hepatotoxicity. Pomegranate polyphenols are of huge health benefits and known to possess remarkable antioxidant properties capable of protecting normal cells from various stimuli-induced oxidative stress and cell death. In this study, we explored the protective role of pomegranate fruit extract (PFE) in ameliorating MTX-induced hepatic damage. Male Swiss albino mice exposed to MTX (20 mg/kg body weight) exhibited distinct markers of toxicity such as increased activities of enzymes alanine transaminase, aspartate transaminase, lactate dehydrogenase and alkaline phosphatase and also increased oxidative stress in liver evidenced by increased ROS generation and lipid peroxidation. Decrease in reduced glutathione levels, superoxide dismutase, catalase, hepatic heme oxygenase 1 and NQO-1 activities were also observed. Tracing the signal transduction pathways, it was seen that MTX exposure significantly increased nuclear translocation of NF-κB coupled with increase in phosphorylated Iκ-B and down-regulation of NF-kappaB-dependent antiapoptotic protein Bcl-2. Treatment with MTX increased the expression of the apoptotic enhancer Rho/Cdc42 as well as the phosphorylation of SAPK/JNK. A shift in the Bax/Bcl-2 ratio towards apoptosis and increase in the caspase 3 level was also evident. Administration of PFE for 7 consecutive days before and after MTX challenge suppressed MTX-induced cell death, mitigated the injurious effects of MTX and offered protection against apoptosis. PFE was shown to reduce ROS generation in hepatocytes by activating the Nrf2-ARE pathway and inhibiting NF-κB as a consequence of which the antioxidant defense mechanism in the liver was up-regulated, thereby conferring protection against MTX-induced hepatotoxicity and apoptosis.     

Wogonin alleviates liver injury in sepsis through Nrf2-mediated NF-κB signalling suppression

Sepsis is a life-threatening organ dysfunction syndrome, and liver is a susceptible target organ in sepsis, because the activation of inflammatory pathways contributes to septic liver injury. Oxidative stress has been documented to participate in septic liver injury, because it not only directly induces oxidative genotoxicity, but also exacerbates inflammatory pathways to potentiate damage of liver. Therefore, to ameliorate oxidative stress is promising for protecting liver in sepsis. Wogonin is the compound extracted from the medicinal plant Scutellaria baicalensis Geogi and was found to exert therapeutic effects in multiple inflammatory diseases via alleviation of oxidative stress. However, whether wogonin is able to mitigate septic liver injury remains unknown. Herein, we firstly proved that wogonin treatment could improve survival of mice with lipopolysaccharide (LPS)- or caecal ligation and puncture (CLP)-induced sepsis, together with restoration of reduced body temperature and respiratory rate, and suppression of several pro-inflammatory cytokines in circulation. Then, we found that wogonin effectively alleviated liver injury via potentiation of the anti-oxidative capacity. To be specific, wogonin activated Nrf2 thereby promoting expressions of anti-oxidative enzymes including NQO-1, GST, HO-1, SOD1 and SOD2 in hepatocytes. Moreover, wogonin-induced Nrf2 activation could suppress NF-κB-regulated up-regulation of pro-inflammatory cytokines. Ultimately, we provided in vivo evidence that wogonin activated Nrf2 signalling, potentiated anti-oxidative enzymes and inhibited NF-κB-regulated pro-inflammatory signalling. Taken together, this study demonstrates that wogonin can be the potential therapeutic agent for alleviating liver injury in sepsis by simultaneously ameliorating oxidative stress and inflammatory response through the activation of Nrf2.     

Polysaccharides from Dicliptera chinensis ameliorate liver disturbance by regulating TLR-4/NF-κB and AMPK/Nrf2 signalling pathways

The purpose of this study was to alleviate liver disturbance by applying polysaccharides from Dicliptera chinensis (DCP) to act on the adenosine monophosphate–activated protein kinase/ nuclear factor erythroid 2-related factor 2 (AMPK/ Nrf2) oxidative stress pathway and the Toll-like receptor 4 (TLR-4)/ nuclear factor kappa-B (NF-κB) inflammatory pathway and to establish an in vivo liver disturbance model using male C57BL/6J and TLR-4 knockout (^−/−) mice. For this, we evaluated the expression levels of SREBP-1 and Nrf2 after silencing the expression of AMPK using siRNA technology. Our results show that with regard to the TLR-4/ NF-κB inflammatory pathway, DCP inhibits TLR-4, up-regulates the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), reduces the expression of phospho(p)-NF-κB and leads to the reduction of downstream inflammatory factors, such as tumour necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1β, thereby inhibiting the inflammatory response. Regarding the AMPK/ Nrf2 oxidative stress pathway, DCP up-regulates the expression of p-AMPK and Nrf2, in addition to regulating glucose and lipid metabolism, oxidative stress and ameliorating liver disturbance symptoms. In summary, our study shows that DCP alleviates liver disturbances by inhibiting mechanisms used during liver inflammation and oxidative stress depression, which provides a new strategy for the clinical treatment of liver disturbance.     

Phillyrin (KD-1) exerts anti-viral and anti-inflammatory activities against novel coronavirus (SARS-CoV-2) and human coronavirus 229E (HCoV-229E) by suppressing the nuclear factor kappa B (NF-κB) signaling pathway

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has extensively and rapidly spread in the world, causing an outbreak of acute infectious pneumonia. However, no specific antiviral drugs or vaccines can be used. Phillyrin (KD-1), a representative ingredient of Forsythia suspensa, possesses anti-inflammatory, anti-oxidant, and antiviral activities. However, little is known about the antiviral abilities and mechanism of KD-1 against SARS-CoV-2 and human coronavirus 229E (HCoV-229E).PurposeThe study was designed to investigate the antiviral and anti-inflammatory activities of KD-1 against the novel SARS-CoV-2 and HCoV-229E and its potential effect in regulating host immune response in vitro.MethodsThe antiviral activities of KD-1 against SARS-CoV-2 and HCoV-229E were assessed in Vero E6 cells using cytopathic effect and plaque-reduction assay. Proinflammatory cytokine expression levels upon infection with SARS-CoV-2 and HCoV-229E infection in Huh-7 cells were measured by real-time quantitative PCR assays. Western blot assay was used to determine the protein expression of nuclear factor kappa B (NF-κB) p65, p-NF-κB p65, IκBα, and p-IκBα in Huh-7 cells, which are the key targets of the NF-κB pathway.ResultsKD-1 could significantly inhibit SARS-CoV-2 and HCoV-229E replication in vitro. KD-1 could also markedly reduce the production of proinflammatory cytokines (TNF-α, IL-6, IL-1β, MCP-1, and IP-10) at the mRNA levels. Moreover, KD-1 could significantly reduce the protein expression of p-NF-κB p65, NF-κB p65, and p-IκBα, while increasing the expression of IκBα in Huh-7 cells.ConclusionsKD-1 could significantly inhibit virus proliferation in vitro, the up-regulated expression of proinflammatory cytokines induced by SARS-CoV-2 and HCoV-229E by regulating the activity of the NF-кB signaling pathway. Our findings indicated that KD-1 protected against virus attack and can thus be used as a novel strategy for controlling the coronavirus disease 2019.     

Allyl isothiocyanate attenuates oxidative stress and inflammation by modulating Nrf2/HO-1 and NF-κB pathways in traumatic brain injury in mice

Molecular Biology Reports - Traumatic brain injury (TBI) is the leading cause of mortality and morbidity in young adults and children in the industrialized countries; however, there are presently...     

Synergistic anti-inflammatory effects of silibinin and thymol combination on LPS-induced RAW264.7 cells by inhibition of NF-κB and MAPK activation

BackgroundCombination drug therapy has become an effective strategy for inflammation control. The anti‑inflammatory capacities of silibinin and thymol have each been investigated on its own, but little is known about the synergistic anti-inflammatory effects of these two compounds.PurposeThis study aims to investigate the synergistic anti-inflammatory effects of silibinin and thymol when administered in combination to lipopolysaccharide (LPS)-induced RAW264.7 cells.MethodsRAW264.7 cells were pre-treated with silibinin and thymol individually or in combination for 2 h before LPS stimulation. Cell viability was detected by the MTT assay. Nitric oxide (NO) production was measured by Griess reagent. Reactive oxygen species (ROS) was evaluated by 2’,7’-dichlorofluorescein-diacetate. ELISA was used to detect tumour necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Western blot was performed to analyse the protein expression of LPS-induced RAW264.7 cells.ResultsWe observed a synergistic anti-inflammatory effect of silibinin and thymol when administered in combination to LPS-induced RAW264.7 cells. Silibinin combined with thymol (40 μM and 120 μM respectively, with the molar ratio 1:3) had more potent effects on the inhibition of NO, TNF-α, and IL-6 than those exerted by individual administration of these compounds in LPS-induced RAW264.7 cells. The combination of silibinin and thymol (40 μM and 120 μM respectively, with the molar ratio 1:3) strongly inhibited ROS and cyclooxygenase-2 (COX-2). More importantly, the combination of silibinin and thymol (40 μM and 120 μM respectively, with the molar ratio 1:3) was also successful in inhibiting nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) activities. Our results suggest that the synergistic anti-inflammatory effects of silibinin with thymol were associated with the inhibition of NF-κB and MAPK signalling pathways.ConclusionThe combination of silibinin and thymol (40 μM and 120 μM, respectively, with the molar ratio 1:3) could inhibit inflammation by suppressing NF-κB and MAPK signalling pathways in LPS-induced RAW264.7 cells.     

Schisandra extract ameliorates arthritis pathogenesis by suppressing the NF-κB and MAPK signalling pathways

Schisandra chinensis is a medicinal plant used to treat various diseases. Extracts from the leaves or fruits of S. chinensis and their components are used in osteoarthritis (OA). The OA inhibitory effect of schisandrol A, one of its components, has been previously confirmed. We aimed to confirm the OA inhibitory effect of Schisandra (including components like schisandrol A) to identify why the inhibitory effect of the Schisandra extract is better. First, we investigated the effects of the Schisandra extract on OA as a potential therapeutic. Experimental OA was induced in a mouse model via destabilized medial meniscus surgery. The animals were orally administered the Schisandra extract; the inhibition of cartilage destruction was confirmed using histological analysis. In vitro analysis showed that the Schisandra extract attenuated osteoarthritic cartilage destruction by regulating IL-1β-induced MMP3 and COX-2 levels. The Schisandra extract inhibited IL-1β-induced degradation of IκB (NF-κB pathway) and IL-1β-induced phosphorylation of p38 and JNK (mitogen-activated protein kinase (MAPK) pathway). RNA-sequencing analysis showed that the Schisandra extract decreased the expression of IL-1β-induced MAPK and NF-κB signalling pathway-related genes more than schisandrol A alone. Therefore, Schisandra extract may be more effective than schisandrol A in preventing OA progression by regulating MAPK and NF-κB signalling.     

Centipeda minima extract exerts antineuroinflammatory effects via the inhibition of NF-κB signaling pathway

BackgroundCentipeda minima (L.) A.Br. (C. minima) has been used in traditional Chinese herbal medicine to treat nasal allergy, diarrhea, asthma and malaria for centuries. Recent pharmacological studies have demonstrated that the ethanol extract of C. minima (ECM) and several active components possess anti-bacterial, anti-arthritis and anti-inflammatory properties. However, the effects of ECM on neuroinflammation and the underlying mechanisms have never been reported.PurposeThe study aimed to examine the potential inhibitory effects of ECM on neuroinflammation and illustrate the underlying mechanisms.MethodsHigh performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was performed to qualify the major components of ECM; BV2 and primary microglial cells were used to examine the anti-inflammatory activity of ECM in vitro. To evaluate the anti-inflammatory effects of ECM in vivo, the mice were orally administrated with ECM (100, 200 mg•kg⁻¹•d⁻¹) for 2 days before cotreatment with LPS (2 mg•kg⁻¹•d⁻¹, ip) for an additional 3 days. The mice were sacrificed the day after the last treatment and the hippocampus was dissected for further experiments. The expression of inflammatory proteins and the activation of microglia were respectively detected by real-time PCR, ELISA, Western blotting and immunofluorescence.ResultsHPLC-MS/MS analysis confirmed and quantified seven chemicals in ECM. In BV2 and primary microglial cells, ECM inhibited the LPS-induced production of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), thus protecting HT22 neuronal cells from inflammatory damage. Furthermore, ECM inhibited the LPS-induced activation of NF-κB signaling pathway and subsequently attenuated the induction of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2), NADPH oxidase 2 (NOX2) and NADPH oxidase 4 (NOX4), leading to the decreased production of nitrite oxide, prostaglandin E₂ (PGE₂) and reactive oxygen species (ROS). In an LPS-induced neuroinflammatory mouse model, ECM was found to exert anti-inflammatory activity by decreasing the production of proinflammatory mediators, inhibiting the phosphorylation of NF-κB, and reducing the expression of COX2, iNOS, NOX2 and NOX4 in the hippocampal tissue. Moreover, LPS-induced microglial activation was markedly attenuated in the hippocampus, while ECM at a high dose possesses a stronger anti-inflammatory activity than the positive drug dexamethansone (DEX).ConclusionThese findings demonstrate that ECM exerts antineuroinflammatory effects via attenuating the activation of NF-κB signaling pathway and inhibiting the production of proinflammatory mediators both in vitro and in vivo. C. minima might become a novel phytomedicine to treat neuroinflammatory diseases.