Molecular mechanism underlying anti-inflammatory activities of lirioresinol B dimethyl ether through suppression of NF-κB and MAPK signaling in in vitro and in vivo models

Thymoquinone counteracts oxidative and inflammatory machinery in carrageenan-induced murine paw edema model

Thymoquinone (TQ) is an active constituent in Nigella sativa (black cumin) and is extensively reported for its distinguished antioxidant and anti-inflammatory bioactivities. Despite the local protective response of acute inflammation, it contributes to the development of various disease conditions such as cell death, organ damage, or carcinogenesis. Hence, in this study, the effects of orally administered TQ (50 mg/kg and 100 mg/kg) for 14 days against edema development, oxidative stress, and inflammation were investigated in paw edema induced by carrageenan in mice. Indomethacin (10 mg/kg) was used as a reference drug. The results revealed that TQ reduced the paw edema volume in a time-dependent manner, attenuated acetic acid-provoked writhing movements, and reduced xylene-triggered ear edema. Hematological findings revealed marked normalization of altered counts of WBCs, and platelets. Furthermore, paw tissue levels of malondialdehyde and nitric oxide showed marked decreases together with increases in nuclear factor erythroid 2-related factor 2, glutathione, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase after TQ administration. Additionally, TQ decreased pro-inflammatory mediators, such as interleukin-1 beta, tumor necrosis factor-alpha, interleukin-6, monocyte chemoattractant protein-1, C-reactive protein, myeloperoxidase, and nuclear factor kappa-B in the inflamed paw tissue. Moreover, appreciable decreases were recorded in cyclooxygenase-2 and its product prostaglandin E2 and the immune reaction of tumor necrosis factor-alpha in TQ-treated mice. Histopathological findings further validated the potential antiedematous, anti-inflammatory power of TQ in inflamed tissues. Conclusively, the results encourage the potent application of TQ to subside acute inflammatory events because of its striking antioxidant and anti-inflammatory properties in inflamed paw tissue.

Sulforaphane inhibits cytokine-stimulated chemokine and adhesion molecule expressions in human corneal fibroblasts: Involvement of the MAPK, STAT, and NF-κB signaling pathways

Chemokines and adhesion molecules are major inflammatory mediators of chronic and recurrent vernal keratoconjunctivitis (VKC). Sulforaphane (SFN) is a natural plant extract that is known to have anti-inflammatory and antioxidant properties. SFN is demonstrated to be effective against a variety of human diseases. The current investigation examines the effects and the molecular mechanisms of SFN on cytokine-induced human corneal fibroblasts (HCFs) expression of adhesion molecules and chemokines. HCFs were exposed to both interleukin (IL)-4 and tumor necrosis factor (TNF)-α in the absence or presence of SFN treatment. The levels of thymus- and activation-regulated chemokine (TARC) and eotaxin-1 in culture supernatants were evaluated using enzyme-linked immunosorbent assay (ELISA). Reverse transcription-polymerase chain reaction analysis (RT-PCR) enabled quantification of mRNA levels of vascular cell adhesion molecule (VCAM)-1, eotaxin-1, and TARC along with cytokine receptors. An immunoblotting assay was used to evaluate the activities of VCAM-1, nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs), signal transducer and activator of transcription factor (STAT)6 pathways, along with the expression of the cytokine receptors including IL-4 receptor (R)α, IL-13Rα1, TNFRI, as well as TNFRII. SFN inhibited TARC and eotaxin-1 release in HCFs stimulated by TNF-α and IL-4 in a manner dependent on dose and time. SFN suppressed transcriptions of TARC, eotaxin-1, and VCAM-1. Furthermore, the mRNA and protein expression levels of IL-4Rα, TNFRI, and TNFRII were also attenuated by SFN exposure, however, those of IL-13Rα1 remained unaffected. In addition, SFN downregulated the expression of VCAM-1 and the phosphorylation of MAPKs, IκBα, and STAT6. These results suggest that SFN inhibited cytokine-stimulated TARC, eotaxin-1 secretion as well as VCAM-1 expression in HCFs, with these effects likely occurring as a result of cytokine receptor inhibition and attenuation of MAPK, NF-κB, and STAT6 signaling. SFN may therefore have therapeutic potential in VKC treatment.

Dracocephalum moldavica Ethanol Extract Suppresses LPS-Induced Inflammatory Responses through Inhibition of the JNK/ERK/NF-κB Signaling Pathway and IL-6 Production in RAW 264.7 Macrophages and in Endotoxic-Treated Mice

The excessive synthesis of interleukin-6 (IL-6) is related to cytokine storm in COVID-19 patients. Moreover, blocking IL-6 has been suggested as a treatment strategy for inflammatory diseases such as sepsis. Sepsis is a severe systemic inflammatory response syndrome with high mortality. In the present study, we investigated the anti-inflammatory and anti-septic effects and the underlying mechanisms of Dracocephalum moldavica ethanol extract (DMEE) on lipopolysaccharide (LPS)-induced inflammatory stimulation in RAW 264.7 macrophages along with septic mouse models. We found that DMEE suppressed the release of inflammatory mediators NO and PGE₂ and inhibited both the mRNA and protein expression levels of iNOS and COX-2, respectively. In addition, DMEE reduced the release of proinflammatory cytokines, mainly IL-6 and IL-1β, in RAW 264.7 cells by inhibiting the phosphorylation of JNK, ERK and p65. Furthermore, treatment with DMEE increased the survival rate and decreased the level of IL-6 in plasma in LPS-induced septic shock mice. Our findings suggest that DMEE elicits an anti-inflammatory effect in LPS-stimulated RAW 264.7 macrophages and an anti-septic effect on septic mouse model through the inhibition of the ERK/JNK/NF-κB signaling cascades and production of IL-6.

α‑rhamnrtin‑3‑α‑rhamnoside exerts anti‑inflammatory effects on lipopolysaccharide‑stimulated RAW264.7 cells by abrogating NF‑κB and activating the Nrf2 signaling pathway

α-rhamnrtin-3-α-rhamnoside (ARR) is the principal compound extracted from Loranthus tanakae Franch. & Sav. However, its underlying pharmacological properties remain undetermined. Inflammation is a defense mechanism of the body; however, the excessive activation of the inflammatory response can result in physical injury. The present study aimed to investigate the effects of ARR on lipopolysaccharide (LPS)-induced RAW264.7 macrophages and to determine the underlying molecular mechanism. A Cell Counting Kit-8 assay was performed to assess cytotoxicity. Nitric oxide (NO) production was measured via a NO colorimetric kit. Levels of prostaglandin E2 (PGE₂) and proinflammatory cytokines, IL-1β and IL-6, were detected using ELISAs. Reverse transcription-quantitative (RT-q)PCR analysis was performed to detect the mRNA expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-6 and IL-1β in LPS-induced RAW246.7 cells. Western blotting, immunofluorescence and immunohistochemistry analyses were performed to measure the expression levels of NF-κB and nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway-related proteins to elucidate the molecular mechanisms of the inflammatory response. The results of the cytotoxicity assay revealed that doses of ARR ≤200 µg/ml exhibited no significant effect on the viability of RAW264.7 cells. The results of the Griess assay demonstrated that ARR inhibited the production of NO. In addition, the results of the ELISAs and RT-qPCR analysis discovered that ARR reduced the production of the proinflammatory cytokines, IL-1β and IL-6, as well as the proinflammatory mediators, PGE₂, iNOS and COX-2, in LPS-induced RAW264.7 cells. Immunohistochemical analysis demonstrated that ARR inhibited LPS-induced activation of TNF-associated factor 6 (TRAF6) and NF-κB p65 signaling molecules, while reversing the downregulation of the NOD-like receptor family CARD domain containing 3 (NLRC3) signaling molecule, which was consistent with the results of the western blotting analysis. Immunofluorescence results indicated that ARR reduced the increase of NF-κB p65 nuclear expression induced by LPS. Furthermore, the results of the western blotting experiments also revealed that ARR upregulated heme oxygenase-1, NAD(P)H quinone dehydrogenase 1 and Nrf2 pathway molecules. In conclusion, the results of the present study suggested that ARR may exert anti-inflammatory effects by downregulating NF-κB and activating Nrf2-mediated inflammatory responses, suggesting that ARR may be an attractive anti-inflammatory candidate drug.

The Anti-Inflammatory Effect of Trichilia martiana C. DC. in the Lipopolysaccharide-Stimulated Inflammatory Response in Macrophages and Airway Epithelial Cells and in LPS-Challenged Mice

A number of species of the genus Trichilia (Meliaceae) exhibit anti-inflammatory effects. However, the effect of Trichilia martiana C. DC. (TM) on lipopolysaccharide (LPS)-induced inflammation has not, to the best of our knowledge, yet been determined. Therefore, in the present study, the antiinflammatory effect of TM on LPS-stimulated RAW264.7 macrophages was evaluated. The ethanol extract of TM (TMEE) significantly inhibited LPS-induced nitric oxide (NO), prostaglandin 2 (PGE₂), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). TMEE also reduced the levels of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β and IL-6. The upregulation of mitogen-activated protein kinases (MAPKs) and NF-κB activation was revealed to be downregulated following TMEE pretreatment. Furthermore, TMEE was indicated to lead to the nucleus translocation of nuclear factor erythroid-derived 2-related factor 2 (Nrf2) and the expression of heme oxygenase-1 (HO-1). In H292 airway epithelial cells, the pretreatment of TMEE significantly downregulated the production of LPS-stimulated IL-1β, and TMEE was indicated to increase the expression of HO-1. In animal models exhibiting LPS-induced acute lung injury (ALI), treatment with TMEE reduced the levels of macrophages influx and TNF-α production in the bronchoalveolar lavage fluid (BALF) of ALI mice. Additionally, TMEE significantly downregulated the activation of ERK, JNK and IκB, and upregulated the expression of HO-1 in the lungs of ALI mice. In conclusion, the results of the current study demonstrated that TMEE could exert a regulatory role in the prevention or treatment of the endotoxin-mediated inflammatory response.

Risk of Postoperative Hyperalgesia in Adult Patients with Preoperative Poor Sleep Quality Undergoing Open-heart Valve Surgery

Purpose

Studies have reported that preoperative poor sleep quality could decrease the pain threshold in patients undergoing noncardiac surgery. However, the risk of postoperative hyperalgesia (HA) in cardiac surgery patients with preoperative poor sleep quality remains unclear.

Patients and Methods

We retrospectively collected clinical data from patients undergoing open-heart valve surgery between May 1 and October 31, 2019, in Fuwai Hospital (Beijing). We assessed preoperative sleep quality and postoperative pain severity using the Pittsburgh sleep quality index (PSQI) and numerical pain rating scale (NPRS), respectively. A PSQI of six or greater was considered to indicate poor sleep quality, and a NPRS of four or greater was considered to indicate HA. Multivariable logistic regression analysis was used to study the risk of postoperative HA in patients with preoperative poor sleep quality.

Results

We divided 214 eligible patients into two groups based on postoperative HA; HA group: n=61 (28.5%) and nonHA group: n=153 (71.5%). Compared with nonHA patients, patients with postoperative HA showed a higher percentage of history of smoking, 17 (11.1%) vs 15 (24.6%) and alcohol abuse, 5 (3.3%) vs 6 (9.8%), higher intraoperative dose of sufentanil (median, 1.02 vs 1.12 μg/kg/h), and longer duration of ventilation with tracheal catheter (median, 760 vs 934 min). Preoperative poor sleep quality was associated independently with an increased risk of postoperative HA (adjusted odds ratio [AOR]: 2.66; 95%CI: 1.31–5.39, P=0.007). Stratification by history of smoking revealed a stronger risk of postoperative HA in nonsmoking patients with preoperative poor sleep quality (AOR: 3.40; 95%CI: 1.51–7.66, P=0.003). No risk was found in patients who had history of smoking (AOR: 0.83; 95%CI: 0.14–4.75, P=0.832).

Conclusion

Preoperative poor sleep quality is an independent risk factor for postoperative HA in adult patients undergoing open-heart valve surgery who had no history of smoking.

Sulforaphane mitigates mast cell-mediated allergic inflammatory reactions in in silico simulation and in vitro models

Objectives: Sulforaphane, a major ingredient isolated from Brassica oleracea var. italica (broccoli), is known to exhibit anti-inflammatory, anti-cancer, and anti-diabetic effects. In this study, we employed an in vitro model of phorbol 12-myristate 13-acetate and a23187 (PMACI)-stimulated human mast cells (HMC-1 cells) to investigate the anti-allergic inflammatory effects and mechanisms of sulforaphane and Brassica oleracea var. italica extracts.Methods: Cytokine levels were measured by ELISA and quantitative real-time-PCR methods. Caspase-1 activity was determined by caspase-1 assay. Binding mode of sulforaphane within caspase-1 was determined by molecular docking simulation. Protein expression was determined by Western blotting.Results: Water extract of Brassica oleracea var. italica (WE) significantly reduced thymic stromal lymphopoietin (TSLP) secretion and caspase-1 activity on activated HMC-1 cells. In the molecular docking simulation and in vitro caspase-1 assays, sulforaphane regulated caspase-1 activity by docking with the identical binding site of caspase-1. Sulforaphane significantly inhibited the levels of inflammatory mediators including TSLP, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8 in a dose-dependent manner. Immunoblotting experiments revealed that sulforaphane and WE reduced translocation of NF-κBp65 into the nucleus and phosphorylation of IκBα in the cytosol. Furthermore, phosphorylation of mitogen-activated protein kinases (MAPK) was down-regulated by treatment with sulforaphane or WE.Conclusion: Our findings suggest that sulforaphane and WE have anti-allergic inflammatory effects by intercepting caspase-1/NF-κB/MAPKs signaling pathways.

Lirioresinol B dimethyl ether inhibits NF-κB and COX-2 and activates IκBα expression in CCl4-induced hepatic fibrosis

Background

Inflammation is one of the key components in the initiation and progression of hepatic diseases. If not treated, inflammation may cause cell dysplasia, and ultimately cancer. In the current study, we investigated the anti-inflammatory and anti-cancer activities of plant isolated compound Lirioresinol B Dimethyl Ether (LBDE) extracted from the seeds of Magnolia fargesii CHENG (Magnoliaceae) against HepG2 cells as well as in BALB/C male mice.

Methods

We assessed the antioxidant and anti-proliferative effects of plant compounds using DPPH assay and HepG2 cell lines. Carbon tetrachloride (CCl₄) and Diethylnitrosamine (DEN) were used to induce liver cell dysplasia followed by hepatocellular carcinoma (HCC) in BALB/C male mice for 12 weeks. We investigated the underlying mechanism by using histopathology and immunoblot experiments.

Results

Intraperitoneal injection of LBDE (50 mg/kg body weight/day) inhibited CCl₄-induced HCC. Free radical scavenging assay shows the strong anti-oxidant activity of LBDE. Western blot results show that LBDE down-regulated nuclear factor kappa B (NFκB) and cyclooxygenase (COX-2) by preventing the phosphorylation of I kappa B alpha (IκBα) in CCl₄ treated group. LBDE also improved liver function by decreasing Alkaline Phosphatase (ALP), aspartate aminotransferase (AST) and Alanine Aminotransferase (ALT) levels. Histopathology results revealed that LBDE decreased granulomas and express normal morphology of hepatocytes.

Conclusions

These preliminary results show that LBDE has the potential to inhibit CCl₄-induced liver cell dysplasia and prevents cancer development by regulating NFκB/COX-2 activation.

Effective fraction of Bletilla striata reduces the inflammatory cytokine production induced by water and organic extracts of airborne fine particulate matter (PM2.5) in vitro

BACKGROUND

Bletilla striata is a traditional Chinese medicine used to treat hemorrhage, scald, gastric ulcer, pulmonary diseases and inflammations. In this study, we investigated bioactivity of the effective fraction of B. striata (EFB) in reducing the inflammatory cytokine production induced by water or organic extracts of PM2.5.

METHODS

PM2.5 extracts were collected and analyzed by chromatographic system and inductively coupled plasma mass spectrometer. Cell viability was measured using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay, and cell supernatant was analyzed by flow cytometry, ELISA, and qRT-PCR in cultured mouse macrophage cell line RAW264.7 treated with EFB and PM2.5 extracts. Expressions of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathway were measured by Western blot.

RESULTS

PM2.5 composition is complex and the toxicity of PM2.5 extracts were not noticeable. The treatment of EFB at a wide dose-range of 0-40 μg/mL did not cause significant change of RAW264.7 cell proliferation. EFB pretreatment decreased the inflammatory cytokines in the macrophage. Further analysis showed that EFB significantly attenuated PM2.5-induced proinflammatory protein expression and downregulated the levels of phosphorylated NF-κBp65, inhibitor of kappa B (IκB)-α, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38.

CONCLUSIONS

Our study demonstrated the potential effectiveness of B. striata extracts for treating PM2.5-triggered pulmonary inflammation.