Anti-inflammatory effects of apigenin in lipopolysaccharide-induced inflammatory in acute lung injury by suppressing COX-2 and NF-kB pathway

Dietary Apigenin promotes lipid catabolism, thermogenesis, and browning in adipose tissues of HFD-Fed mice

Dietary Apigenin (AP), a natural flavonoid from plants, could alleviate high-fat diet (HFD) induced obesity and its complication. Nonetheless, the direct correlation between dietary AP and their effects in adipose tissues remained unclear. In this study, male C57BL/6 mice were fed with low-fat diet, HFD with or without 0.04% (w/w) AP for 12 weeks. Dietary AP ameliorated HFD induced body weight gain, glucose intolerance, and insulin resistance. Energy expenditure was increased with no influence on energy intake, which indicated us that AP prevented obesity by enhancing energy export. Interestingly, AP activated lipolysis (ATGL/FOXO1/SIRT1) without higher cycling free fatty acids (FFAs). FFAs were consumed by the upregulation of fatty acid oxidation (AMPK/ACC), thermogenesis, and browning (UCP-1, PGC-1α). Additionally, adipose tissue metabolic inflammation (NF-кB, MAPK) was also reduced by AP. Our study proposed that dietary AP could be explored as a new dietary strategy to combat obesity and related insulin resistance.

An Insight Into the Modulatory Effects and Mechanisms of Action of Phyllanthus Species and Their Bioactive Metabolites on the Immune System

Phyllanthus species (family; Euphorbiaceae) have been intensively studied for their immunomodulating effects due to their wide-ranging uses to treat immune-related diseases in indigenous medicine, which are primarily lack of scientific basis. The focuses of this review are on the significance of Phyllanthus species and their bioactive metabolites particularly corilagin (1), geraniin (2), gallic acid (3), phyllanthin (4), hypophyllanthin (5), ellagic acid (6), phyltetralin (7), niranthin (8), catechin (9), quercetin (10), astragalin (11), and chebulagic acid (12) in the modulation of both innate and adaptive immune systems through various mechanisms and their possible therapeutic benefits for treatment of immune-related diseases. We have compiled all significant findings published in the literature, and the data were analyzed critically to provide perspectives and directions for future research for the plants as a prospective source of novel immunomodulating agents. Various Phyllanthus species particularly Phyllanthus amarus, Phyllanthus emblica, Phyllanthus niruri, and Phyllanthus urinaria have been documented to possess significant immunomodulatory effects. However, the possible challenges encountered by the application of extracts of various Phyllanthus species and their bioactive constituents as immunomodulators need to be addressed. Most reports on the biological and pharmacological studies of the plants were based on crude extracts. The extracts were not chemically characterized, and the contributions of their chemical constituents to the bioactivities were not identified. The underlying mechanisms involved in the immunomodulatory effects of the Phyllanthus species were not indepthly studied due to limitations in terms of design, conduct, and interpretation. Extensive experimental and preclinical studies on the immunomodulating potential of Phyllanthus species should be carried out to provide sufficient data to prove that their traditional uses are inherently effective and safe and will allow clinical trials to be pursued for their further development as therapeutic agents to treat immune-related disorders.

Umbelliferone Alleviates Lipopolysaccharide-Induced Inflammatory Responses in Acute Lung Injury by Down-Regulating TLR4/MyD88/NF-κB Signaling

This study investigated the protective effect and underlying mechanism of action of umbelliferone (Umb) against lipopolysaccharide (LPS)-induced acute lung injury (ALI). An intragastric Umb injection prior to the administration of LPS dramatically decreased the wet/dry lung weight ratio, attenuated inflammatory cell infiltration in lung tissue, and reduced the LPS-induced production of inflammatory cytokines, including monocyte chemotactic protein-1(MCP-1), interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and IL-1β, in broncheoalveolar lavage fluid (BALF). In addition, Umb resulted in significant anti-oxidative effects as shown by decreased myeloperoxidase (MPO) and malondialdehyde (MDA) activity and increased superoxide dismutase (SOD) activity compared with the LPS group. Finally, the inhibitory effects of Umb on the expression of toll-like receptor 4 (TLR4)/myeloid differentiation protein 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway proteins were also measured. Our results clearly indicated that Umb exerted significant protective effects on LPS-induced ALI by inhibiting the activation of the TLR4/MyD88/NF-κB pathway.

Anti-inflammatory and analgesic potential of Tamarindus indica Linn. (Fabaceae): a narrative review

Chronic inflammation is one of the causes of a number of non-infectious diseases in the world. Over the years, Tamarindus indica has played fundamental roles in traditional medicine as an anti-inflammatory and analgesic drug. It is a commercialized biocompatible medicinal plant species with a wide range of therapeutic window and with suggested LD50 greater than 5000 mg kg⁻¹ body weight when administered to the Wistar rats. This review examined the anti-inflammatory and analgesic potential and mechanism of various extracts from T. indica pulp, leaves, seeds, stem bark, and roots. The preclinical studies provided strong pharmacological evidence for the anti-inflammatory and analgesic activities of the different parts of T. indica and this may be attributed to the various bioactive compounds in it including alkaloids, flavonoids, tannins, phenols, saponins, and steroids. The anti-inflammatory and analgesic effects of the extracts from the different parts of T. indica may be due to its ability to inhibit a number of biological processes including cyclooxygenase-2 (COX-2) expression, inducible nitric oxide synthase (iNOS), 5-lipoxygenase biosynthesis, and tumor necrosis factor-α. The analgesic activity of T. indica may also be through the activation of the opioidergic mechanism at both the peripheral and central levels. Although further pre-clinical studies still need to be conducted, these results demonstrated that T. indica has potent anti-inflammatory and analgesic activities and hence provides justification for its use in traditional medicine to treat body pain and other inflammatory related diseases including arthritis and offers a basis for future clinical studies and possible drug development.

Dexmedetomidine ameliorates LPS induced acute lung injury via GSK-3β/STAT3-NF-κB signaling pathway in rats

Acute lung injury (ALI) is a serious complication of sepsis and an important cause of death in intensive care. Studies have shown that DEX can inhibit inflammation. However, the anti-inflammatory effect and protective mechanism of DEX in lipopolysaccharide (LPS) induced ALI are still unclear. ALI model was established by intraperitoneal injection of LPS (10 mg/kg) in Sprague-Dawley (SD) male rats. Firstly, at 4, 6, 8, 12 and 24 h after LPS treatment, lung injury including pathologic histology, lung edema, and inflammation were detected. The optimal time point for lung injury was determined to be 12 h, at which time DEX was added to further test. Furthermore, STAT3 inhibitor (NSC74859) and GSK-3β inhibitor (SB216763) were added to verify the role of STAT3, GSK-3β and NF-κB in ameliorated ALI. Our results show that DEX pretreatment significantly decreased lung Wet-to-Dry weight (W/D) ratio and MPO activity and ameliorated LPS induced lung histopathological alterations. In addition, we confirmed that DEX can increased the phosphorylation of STAT3 and GSK-3β, and inhibit the phosphorylation of nuclear factor-κB (NF-κB) p65 in the inflammatory response induced by LPS. What's more, NSC74859 inhibited the phosphorylation of STAT3 and reversed the protect effect of DEX on LPS. SB216763 inhibited the phosphorylation of NF-κB and reversed the damage effect of LPS and plays the same anti-inflammatory effect as DEX. In summary, our data demonstrated that DEX can ameliorate ALI induced by LPS through GSK-3β/STAT3-NF-κB pathway.

Leukocyte immunoglobulin-like receptor B4 deficiency exacerbates acute lung injury via NF-κB signaling in bone marrow-derived macrophages

Acute lung injury (ALI) is an acute inflammatory disease. Leukocyte immunoglobulin-like receptor B4 (LILRB4) is an immunoreceptor tyrosine-based inhibitory motif (ITIM)-bearing inhibitory receptor that is implicated in various pathological processes. However, the function of LILRB4 in ALI remains largely unknown. The aim of the present study was to explore the role of LILRB4 in ALI. LILRB4 knockout mice (LILRB4 KO) were used to construct a model of ALI. Bone marrow cell transplantation was used to identify the cell source of the LILRB4 deficiency-aggravated inflammatory response in ALI. The effect on ALI was analyzed by pathological and molecular analyses. Our results indicated that LILRB4 KO exacerbated ALI triggered by LPS. Additionally, LILRB4 deficiency can enhance lung inflammation. According to the results of our bone marrow transplant model, LILRB4 regulates the occurrence and development of ALI by bone marrow-derived macrophages (BMDMs) rather than by stromal cells in the lung. The observed inflammation was mainly due to BMDM-induced NF-κB signaling. In conclusion, our study demonstrates that LILRB4 deficiency plays a detrimental role in ALI-associated BMDM activation by prompting the NF-κB signal pathway.

Protective effects of hesperetin on lipopolysaccharide-induced acute lung injury in a rat model

BACKGROUND

In this experimental study, we aimed to investigate the effects of hesperetin, a natural flavonoid, on a lipopolysaccharideinduced acute lung injury model in rats.

METHODS

Between March 2019 and May 2019, a total of 18 adult male Wistar albino rats, weighing approximately 250 to 300 g, were randomly divided into three groups as control, lipopolysaccharide, and lipopolysaccharide + hesperetin groups (n=6 in each group). The wet/dry weight ratio of lung tissue was determined. Histopathological changes were examined using light and scanning electron microscopy. Pulmonary nuclear factor-kappa beta, inducible nitric oxide synthase, and alpha-smooth muscle antigen activity were determined with indirect immunohistochemical methods. Pulmonary apoptosis was detected with the terminal deoxynucleotidyl transferase dUTP nick-end labeling method. Tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6, and interleukin-10 concentrations were measured with enzyme-linked immunosorbent assay.

RESULTS

Treatment with hesperetin significantly improved the architecture of lung tissue and reduced the wet/dry weight ratio, nuclear factor-kappa beta, inducible nitric oxide synthase, and alphasmooth muscle antigen expression, pulmonary apoptosis, and levels of proinflammatory cytokines.

CONCLUSION

Our study results suggest that hesperetin has a potent protective effect against lipopolysaccharide-induced acute lung injury in rats via suppression of the proinflammatory cytokine cascade, nuclear factor-kappa beta, signaling pathway activation, and apoptosis.

Baicalin alleviated APEC-induced acute lung injury in chicken by inhibiting NF-κB pathway activation

Bacterial pneumonia is a leading cause of death in the animal husbandry. Acute lung injury (ALI), most often seen as a part of systemic inflammatory process, characterized by progressive hypoxemia, edema, and neutrophil accumulation in the lung. Baicalin has been reported to inhibit inflammatory response, but its role in ALI remains unknown. The purpose of our study was to determine the protective effect and possible mechanism of baicalin against avian pathogenic Escherichia coli (APEC)-induced ALI in chicken. Chickens were conditioned with baicalin 1 week before intratracheally instilled with APEC. Then, chickens were sacrificed by CO₂ inhalation 12 h later and the lung tissues were collected for examining histopathological changes, wet/dry (W/D) ratio, myeloperoxidase (MPO) activity, levels of pro-inflammatory cytokines and activation of NF-κB signaling pathway. The results showed that pre-treatment of chickens with baicalin significantly alleviated the death rate, histopathological changes in lung tissues. The W/D ratio, MPO activity and production of cytokines, such as IL-1β, TNF-α, IL-6 of lung tissues were also decreased following treatment with baicalin. Furthermore, the mechanism responsible for these effects was attributed to the inhibitory effect of baicalin on nuclear factor-κB (NF-κB) signaling activation. These data thus support the application of baicalin as a potential medicine for the treatment of E. coli-induced ALI by regulating NF-κB signaling pathway.

Protective effects of the suppressed NF-κB/TLR4 signaling pathway on oxidative stress of lung tissue in rat with acute lung injury

The pathogenesis of acute lung injury (ALI) is characterized by lung inflammation and lung oxidative stress. The study was conducted in order to investigate the effect toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) exhibited on oxidative stress in ALI. After the rats had been assigned into different groups, arterial blood, white blood cell (WBC), lung permeability index (LPI), wet/dry (W/D) ratio, TLR4 and NF-κB expression and superoxide dismutase (SOD), myeloperoxidase (MPO), malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS) were examined. Afterward, the correlation between the levels of TLR4 and NF-κB was determined. Decreased levels of PaO₂ , SOD, MPO, and GSH accompanied by increased levels of PaCO₂ , WBC number, LPI and W/D ratio, MDA and ROS, as well as TLR4 and NF-κB expressions in the ALI, ALI + NF-κB inhibitor, and ALI + phosphate buffer saline groups were found. Inhibition of NF-κB resulted in increased PaO₂ and decreased PaCO₂ levels, WBC number, and LPI and W/D ratio. Decreased expression of NF-κB increased SOD, GSH, and MPO, but decreased MDA and ROS. We also found that NF-κB inhibition resulted in the improvement of ALI in rats. TLR4 and NF-κB expressions were negatively correlated with levels of SOD, MPO, and GSH, and positively correlated with MDA and ROS levels. In summary, our findings provided evidence that inhibition of the TLR4/NF-κB signaling pathway decreases oxidative stress, thereby improving ALI. As a result, NF-κB signaling pathway has shown potential as a therapeutic target in ALI therapy.

Apigenin Inhibits IL-31 Cytokine in Human Mast Cell and Mouse Skin Tissues

IL-31 is a recently discovered cytokine that is produced not only in T-cells but also in mast cells. It is strongly implicated to play a key role in inflammatory diseases and in the pathogenesis of itch in atopic dermatitis. Apigenin, a flavonoid of plant origin has numerous biological applications. In this study, we showed that apigenin modulates IL-31 mRNA, protein expression, and release in stimulated human mast (HMC-1) by inhibiting the phosphorylation activation of MAPK and NF-κB. To determine whether apigenin has similar effects in vivo, using Compound 48/80, we developed an atopic dermatitis itch model in mice and found an increase in IL-31 expression in the skin. We also revealed that apigenin prevents the infiltration and degranulation of mast cells and suppressed mRNA and protein expression of IL-31 in the skin of mice. These results provide a new suggestion of the potential applicability of apigenin for treatment of various inflammatory diseases and itch mediated by IL-31.

Cytotoxicity and apoptogenic properties of the standardized extract of Portulaca oleracea on glioblastoma multiforme cancer cell line (U-87): a mechanistic study

The traditional uses of Portulaca oleracea L. (PO) with anti-inflammatory and anti-cancer activity as well as antioxidants properties were expressed previously. Glioma is considered the most common primary brain tumor and its malignant form is the most lethal adult brain tumor, that glioblastoma covers about 50 % of glioma tumors. The present study was aimed to evaluate the cytotoxicity and apoptogenic effects of the hydro-ethanolic extract of PO on human glioblastoma cancer cell line (U-87) and the role of NF-κB. Cytotoxicity of the extract in the presence or absence of Vitamin C was evaluated using MTT assay, and the following hypotonic PI and SubG1 peak were performed. Moreover, the reactive oxygen species (ROS), the level of NF-κB protein and nitric oxide (NO) production were investigated. The extract had cytotoxicity and apoptogenic effects on U-87 cells in both the concentration and time-dependent manners. The mechanism of cytotoxicity and apoptosis induction of the extract at the first hours of incubation and low concentrations were dependent on ROS. However, the toxicity was replaced with NO pathway with time-lapse and higher concentrations. Results also indicated that the extract acts as an NF-κB inhibitor with concentration and time-dependent manners. The present study may suggest the anti-NF-κB activity of PO along with two upstream ROS and NO mechanisms. Furthermore, the extract as ethnobotanical may be used as adjunctive anti-cancer therapy against glioblastoma multiforme.

Alfalfa polysaccharide prevents H2O2-induced oxidative damage in MEFs by activating MAPK/Nrf2 signaling pathways and suppressing NF-κB signaling pathways

Alfalfa polysaccharide (APS) is a bioactive component extracted from alfalfa that exhibits potent antioxidant properties. However, the cellular and molecular mechanisms underlying these properties remain unclear. To explore the molecular mechanism by which APS exerts antioxidant effects, an H2O2-induced oxidative stress mouse embryonic fibroblast (MEF) model was established. Cell proliferation, antioxidant enzyme activity, immune cytokine expression, and related protein expression were examined in APS-supplemented or non-supplemented conditions. The results suggested that APS strengthened the antioxidative capacity of MEFs, increasing cell proliferation, superoxide dismutase activity (SOD), and the total antioxidant capacity (T-AOC). In addition, APS reduced the secretion of interleukin (IL)-6 and IL-8 as well as expression of the proinflammatory gene retinoic acid-inducible gene I (RIG-I). APS was also able to activate the mitogen-activated protein kinase (MAPK) pathway, which promoted the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) to the nucleus. However, expression of nuclear factor-κB (NF-κB) was decreased after APS treatment. Overall, these results suggest that APS relieves H2O2-induced oxidative stress in MEFs by activating MAPK/Nrf2 signaling and suppressing NF-κB signaling. To the best of our knowledge, this is the first study to link APS with MAPK/Nrf2, NF-κB and RIG-I, thus providing new perspectives regarding the mechanisms of the antioxidant activity of APS.

Resolvin D1 Promotes SIRT1 Expression to Counteract the Activation of STAT3 and NF-κB in Mice with Septic-Associated Lung Injury

Resolvin D1 (RvD1) is a novel endogenous docosahexaenoic acid (DHA)-derived lipid mediators, which possesses a dual role of anti-inflammation and promotes inflammation resolution. The aim of the present study was to assess the effects of RvD1 on cecal ligation and puncture (CLP) model of sepsis and explore the underlying mechanism. Six-to-eight-week-old male C57BL/6 mice were randomly divided into following three groups: sham-operated group (SO), CLP model group (CLP), and CLP+RvD1 group (RvD1). The SO group underwent the sham operation. The RvD1 groups were administered RvD1 (10-ng/g body weight) by penile vein injection, but the CLP groups were administered the same volume of vehicle (PBS) after CLP. We assessed the survival benefit of RvD1 in CLP-induced septic mice for 7 days. After 24 h, mice were sacrificed, bronchoalveolar lavage fluids (BALF) was collected for proinflammatory cytokines assay, and albumin assay and the lung tissues were harvested for histologic analysis, myeloperoxidase (MPO) activity and the expression of Sirtuin 1 (SIRT1), signal transducers, and activators of transcription 3 (STAT3), nuclear factor-κB (NF-κB), and mitogen-activated protein kinases (MAPKs). RvD1 treatment increased the survival time in mice with sepsis induced by CLP, reducing the MPO activity and albumin level at 24 h. The levels of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) in BALF were significantly decreased by RvD1. RvD1 promoted SIRT1 expression and suppressed the activation of NF-κB, STAT3, ERK, and p38 in lung tissues of septic mice. These results suggest that RvD1 may improve survival and attenuate the degree of lung inflammation reaction in mice with CLP by suppressing STAT3, NF-κB, ERK, and p38 expressions through a mechanism partly dependent on SIRT1.

miR-141 alleviates LPS-induced inflammation injury in WI-38 fibroblasts by up-regulation of NOX2

AIMS

The roles of miR-141 in various types of cancers and inflammatory bowel diseases are researched, whereas, little information about its function in lung inflammation is available. This study was designed to explore the effect of miR-141 on inflammation injury in WI-38 cells, possibly providing basis for targeted therapeutic strategy for treatment of infantile pneumonia.

MAIN METHODS

WI-38 cells were treated with LPS to construct cell model with inflammation injury. Expressions of miR-141 and NOX2 were altered by transfection assay and expressions of them were detected by qRT-PCR or Western blot. Cell viability and apoptosis were evaluated by CCK-8 assay and flow cytometry, respectively. The tested pro-inflammatory factors were analyzed by qRT-PCR and Western blot; and their productions were quantified by ELISA. Main proteins participating in regulation of apoptosis, p38 MAPK pathway and NF-κB pathway were analyzed by Western blot.

KEY FINDINGS

miR-141 was down-regulated in LPS-treated cells and elevating miR-141 level reduced inflammation extent of WI-38 cells by promoting viability, inhibiting apoptosis, and inhibiting production of tested pro-inflammatory cytokines. NOX2 was up-regulated by miR-141 overexpression. NOX2 silence impaired the cell-protective effect of miR-141. miR-141 inhibited LPS-induced activations of p38 MAPK and NF-κB pathways, which was also mediated by NOX2.

SIGNIFICANCE

miR-141 alleviated LPS-induced inflammation injury in WI-38 fibroblasts by up-regulating NOX2 and further inhibiting p38 MAPK and NF-κB pathways.

Identifying chondroprotective diet-derived bioactives and investigating their synergism

Osteoarthritis (OA) is a multifactorial disease and nutrition is a modifiable factor that may contribute to disease onset or progression. A detailed understanding of mechanisms through which diet-derived bioactive molecules function and interact in OA is needed. We profiled 96 diet-derived, mainly plant-based bioactives using an in vitro model in chondrocytes, selecting four candidates for further study. We aimed to determine synergistic interactions between bioactives that affected the expression of key genes in OA. Selected bioactives, sulforaphane, apigenin, isoliquiritigenin and luteolin, inhibited one or more interleukin-1-induced metalloproteinases implicated in OA (MMP1, MMP13, ADAMTS4, ADAMTS5). Isoliquiritigenin and luteolin showed reactive oxygen species scavenging activity in chondrocytes whereas sulforaphane had no effect and apigenin showed only a weak trend. Sulforaphane inhibited the IL-1/NFκB and Wnt3a/TCF/Lef pathways and increased TGFβ/Smad2/3 and BMP6/Smad1/5/8 signalling. Apigenin showed potent inhibition of the IL-1/NFκB and TGFβ/Smad2/3 pathways, whereas luteolin showed only weak inhibition of the IL-1/NFκB pathway. All four bioactives inhibited cytokine-induced aggrecan loss from cartilage tissue explants. The combination of sulforaphane and isoliquiritigenin was synergistic for inhibiting MMP13 gene expression in chondrocytes. We conclude that dietary-derived bioactives may be important modulators of cartilage homeostasis and synergistic relationships between bioactives may have an anti-inflammatory and chondroprotective role.

Epimedium sagittatum inhibits TLR4/MD-2 mediated NF-κB signaling pathway with anti-inflammatory activity

BACKGROUND

Epimedium sagittatum (Sieb.et Zucc.) Maxim., Ying-Yang-Huo in Chinese has been used as a traditional Chinese medicine and is deemed to "reinforce the kidney Yang". Previous studies showed that E. sagittatum could modulate the immune system and treat some chronic disease such as rheumatic arthritis, cardiovascular diseases and osteoporosis. The aim of this study is to evaluate the anti-inflammatory effects of ethyl acetate extracts (YYHs) of E. sagittatum and its mechanisms of action.

METHODS

In order to explore the composition of YYHs, YYHs was analyzed using high performance liquid chromatography-mass spectrometry-mass spectrometry (HPLC-MS/MS) and in comparison with reference standards. Anti-inflammatory model was established in LPS-induced RAW264.7 cells. The levels of nitric oxide (NO) were measured with the Griess reagent. Production of tumor necrosis factor-alpha (TNF-α) and interleukin-2 (IL-2) were measured by enzyme-linked immunosorbent assays (ELISA). In addition, expression of p-p65 protein and TLR4/MD-2 complex was detected by western blots and flow cytometric, respectively. Nuclear factor kappa B (NF-κB) nuclear translocation was observed by fluorescence microscope.

RESULTS

A total of eight compounds were identified, of which icariside II was the most abundant compound. YYHs (12.5-50 μg/mL) had no obvious cytotoxic effect on cells, and remarkably inhibited LPS-induced production of NO, TNF-α and IL-2 with a dose-dependent manner. Additionally, YYHs up-regulated expression of p-p65 and TLR4/MD-2 complex. Further research showed that YYHs significantly suppressed NF-κB p65 nuclear translocation.

CONCLUSION

In brief, YYHs contributed to the inhibition of LPS-induced inflammatory response through the TLR4/MD-2-mediated NF-κB pathway and may be a potential choice to combat inflammation diseases. It includes a schema of pathways at the end of the paper.

Apigenin reverses lung injury and immunotoxicity in paraquat-treated mice

Paraquat (PQ) induces acute lung injury (ALI) and immunotoxicity. Apigenin exerts anti-oxidant and anti-inflammatory properties. The purpose of this study was to investigate the possible protective effects of apigenin on PQ-induced ALI and immunotoxicity in mice. Female C57BL/6 mice received a single injection of PQ (50 mg/kg). Apigenin was given for 7 consecutive days starting 5 days before PQ exposure. The toxicity markers were evaluated in terms of weight loss, lung histopathology, oxidative stress, inflammation, and T cell functions after PQ exposure. Poisoned mice exhibited severe lung tissue lesions, inflammatory cell infiltration and the release of pro-inflammatory cytokines IL-6 and TNF-α. PQ administration increased the lung wet/dry ratios and lipid peroxidation by the increase of MDA levels and decreased anti-oxidase activity including SOD, GSH-PX, and CAT. While such effect on lung was reversed by apigenin. Importantly, PQ-induced immunotoxicity was also observed in a decrease of spleen weight, inhibition of T cell proliferation and T-cell secreting IL-2 from splenocytes. Further mechanism analysis found that PQ administration could decrease total splenocytes, CD4⁺ and CD8⁺ T cells, SOD, GSH-PX, and CAT activity, and increased the levels of MDA and the concentrations of pro-inflammatory cytokines IL-6 and TNF-α compared to control mice. However, apigenin treatment reversed PQ-induced immunotoxicity. In summary, all results suggest that apigenin has beneficial effects on PQ-induced ALI and immunotoxicity possibly, and it could be related, at least in part, to its ability in modulating inflammation and oxidative stress, although in-depth studies might be needed to fully understand the mechanism of action.

An Overview on the Anti-inflammatory Potential and Antioxidant Profile of Eugenol

The bioactive compounds found in foods and medicinal plants are attractive molecules for the development of new drugs with action against several diseases, such as those associated with inflammatory processes, which are commonly related to oxidative stress. Many of these compounds have an appreciable inhibitory effect on oxidative stress and inflammatory response, and may contribute in a preventive way to improve the quality of life through the use of a diet rich in these compounds. Eugenol is a natural compound that has several pharmacological activities, action on the redox status, and applications in the food and pharmaceutical industry. Considering the importance of this compound, the present review discusses its anti-inflammatory and antioxidant properties, demonstrating its mechanisms of action and therapeutic potential for the treatment of inflammatory diseases.

Salidroside protects LPS-induced injury in human thyroid follicular epithelial cells by upregulation of MiR-27a

AIMS

Hypothyroidism is a common endocrine disease without standard treatment. Salidroside (SAL) has various positive biological activities. In this study, experiments were performed to investigate whether SAL had protective effects on LPS-induced cell inflammatory injury.

MAIN METHODS

The human thyroid follicular epithelial cells (Nthy-ori 3-1) stimulated by LPS were treated with SAL and/or transfected with miR-27a inhibitor. Cell viability and cell apoptosis were detect by Cell Counting Kit-8 assay and flow cytometry, respectively. The expression of Cyclin D1 and apoptosis-related proteins, Notch proteins and NF-κB pathways related proteins were all measured by western blot. The expression of miR-27a and inflammatory chemokines MCP-1, IL-6 and TNF-α was examined by qRT-PCR. The protein weight of MCP-1, IL-6 and TNF-α was detected by ELISA.

KEY FINDINGS

LPS treatment induced cell injury by decreasing cell viability, and inducing cell apoptosis and inflammatory chemokines MCP-1, IL-6 and TNF-α. In addition, SAL alleviated LPS-induced cell injury by increasing cell viability, and decreasing cell apoptosis and inflammatory chemokines MCP-1, IL-6 and TNF-α. SAL upregulated miR-27a expression and further study showed that miR-27a downregulation impaired the protective effects of SAL. SAL downregulated the expression of Notch1/2, and phosphorylation of p65 and IκBα.

SIGNIFICANCE

SAL protects against LPS-induced injury in human thyroid follicular epithelial cells by upregulation of miR-27a. This process might be via inactivating Notch and NF-κB pathways.

Vitamin A pretreatment protects NO-induced bovine mammary epithelial cells from oxidative stress by modulating Nrf2 and NF-κB signaling pathways

It is known that physiological overproduction of nitric oxide (NO) contributes to oxidative stress and inflammation. Our published studies indicated that vitamin A (VA) reduces NO-induced oxidative stress in bovine mammary epithelial cells (BMECs) by increasing antioxidant enzyme activities. However, the precise mechanism is unclear. The present study was conducted to examine the protective effects of VA on NO-induced damage to BMECs in vitro using diethylenetriamine nitric oxide (DETA-NO) as the NO donor and to explore the intracellular signaling mechanisms of VA that involve nuclear factor erythroid 2-related factor (Nrf2) and nuclear factor kappa-B (NF-κB). Subconfluent BMECs were divided into 10 treatment groups with 6 replicates per treatment and were cultured with dimethyl sulfoxide (DMSO, vehicle negative control) or 0, 0.05, 0.1, 0.2, 0.5, 1, 2, 3, or 4 μg/mL of VA for 24 h and then incubated in the absence or presence of DETA-NO (1,000 μmol/liter) and VA for an additional 6 h. The results showed that exposure to DETA alone decreased cell proliferation compared with the negative control. Pretreatment with VA promoted the proliferation of BMECs, increased the activities of antioxidative enzymes including selenoprotein glutathione peroxidase (GPx) and thioredoxin reductase (TrxR) and their gene and protein expression but decreased NO and interleukin 1 (IL-1) contents in a quadratic manner (P < 0.05). In addition, the expression of mRNA and protein of factors that are related to NF-κB or Nrf2 signaling pathways in BMECs were regulated by VA in a quadratic dose-dependent manner; VA at a concentration of 1 μg/mL exhibited the strongest effect. Together, these results suggest that VA promotes antioxidant functions of BMECs by regulating the synthesis of selenoproteins including GPx and TrxR and by reducing concentrations of IL-1 and NO in vitro by modulating Nrf2 and NF-κB signaling pathways.

Melaleuca styphelioides Sm. Polyphenols Modulate Interferon Gamma/Histamine-Induced Inflammation in Human NCTC 2544 Keratinocytes

Melaleuca styphelioides, known as the prickly-leaf tea tree, contains a variety of bioactive compounds. The purposes of this study were to characterize the polyphenols extracted from Melaleuca styphelioides leaves and assess their potential antioxidant and anti-inflammatory effects. The polyphenol extracts were prepared by maceration with solvents of increasing polarity. The LC/MS-MS technique was used to identify and quantify the phenolic compounds. An assessment of the radical scavenging activity of all extracts was performed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) (ABTS⁺), and ferric reducing antioxidant power (FRAP) assays. The anti-inflammatory activity was determined on interferon gamma (IFN-γ)/histamine (H)-stimulated human NCTC 2544 keratinocytes by Western blot and RT-PCR. Compared to other solvents, methanolic extract presented the highest level of phenolic contents. The most frequent phenolic compounds were quercetin, followed by gallic acid and ellagic acid. DPPH, ABTS⁺, and FRAP assays showed that methanolic extract exhibits strong concentration-dependent antioxidant activity. IFN-γ/H treatment of human NCTC 2544 keratinocytes induced the secretion of high levels of the pro-inflammatory mediator inter-cellular adhesion molecule-1 (ICAM-1), nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor kappa B (NF-κB), which were inhibited by extract. In conclusion, the extract of Melaleuca styphelioides leaves is rich in flavonoids, and presents antioxidant and anti-inflammatory proprieties. It can be proposed as a useful compound to treat inflammatory skin diseases.

Ginsenoside Rh2 Ameliorates Lipopolysaccharide-Induced Acute Lung Injury by Regulating the TLR4/PI3K/Akt/mTOR, Raf-1/MEK/ERK, and Keap1/Nrf2/HO-1 Signaling Pathways in Mice

The anti-inflammatory effect of ginsenoside Rh2 (GRh2) has labeled it as one of the most important ginsenosides. The purpose of this study was to identify the anti-inflammatory and antioxidant effects of GRh2 using a lipopolysaccharide (LPS) challenge lung-injury animal model. GRh2 reduced LPS-induced proinflammatory mediator nitric oxide (NO), tumor necrosis factor-alpha, interleukin (IL)-1β, and anti-inflammatory cytokines (IL-4, IL-6, and IL-10) production in lung tissues. GRh2 treatment decreased the histological alterations in the lung tissues and bronchoalveolar lavage fluid (BALF) protein content; total cell number also reduced in LPS-induced lung injury in mice. Moreover, GRh2 blocked iNOS, COX-2, the phosphorylation of IκB-α, ERK, JNK, p38, Raf-1, and MEK protein expression, which corresponds with the growth of HO-1, Nrf-2, catalase, SOD, and GPx expression in LPS-induced lung injury. An in vivo experimental study suggested that GRh2 has anti-inflammatory effects, and has potential therapeutic efficacy in major anterior segment lung diseases.

The protective effects of Sauropus spatulifolius on acute lung injury induced by lipopolysaccharide

BACKGROUND

Sauropus spatulifolius Beille (named 'Long-Li-Ye' in China) is used to make 'herbal tea' to prevent pneumonia. This study aimed to evaluate the antioxidant activities in vitro and the protective effects of Long-Li-Ye on acute lung injury (ALI) induced by lipopolysaccharide (LPS).

RESULTS

The supernatant after ethanol addition to Long-Li-Ye water extract (LLYCSL) and the resin eluting fraction of LLYCSL (LLY40) showed strong antioxidant activities in vitro. LLYCSL and LLY40 could attenuate ALI via decreasing myeloperoxidase activity, increasing superoxide dismutase activity and decreasing the levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and IL-6. In addition, LLY40 could increase catalase activity, increase the levels of IL-10, IL-4 and IL-13 and decrease the TNF-α/IL-10 ratio.

CONCLUSION

Long-Li-Ye could be used as a natural antioxidant for food production and functional food or dietary supplementation for people with ALI. © 2018 Society of Chemical Industry.

Apigenin alleviates TGF-β1-induced nasal mucosa remodeling by inhibiting MAPK / NF-kB signaling pathways in chronic rhinosinusitis

Background

Chronic rhinosinusitis is involved in tissue remodeling of nasal mucosa such as nasal myofibroblast differentiation and extracellular matrix production. Apigenin (4’,5,7-trihydroxyflavone) is a bioflavonoid compound and has anti-tissue remodeling characteristics. The aims of this study were to evaluate the effect of apigenin on TGF-β1-induced myofibroblast differentiation and extracellular matrix accumulation and to determine the underlying mechanism.

Methods

Nasal fibroblasts and ex vivo nasal inferior turbinate tissues were stimulated with TGF-β1 with or without apigenin. The expression levels of α-SMA, fibronectin and collagen type I were determined by real-time PCR, western blot and immunocytochemical staining. Mitogen-activated protein kinase (MAPK) phosphorylation induced by TGF-β1 were determined by western blot analysis. The transcriptional activity of NF-κB was measured by luciferase assay. Migration effects of fibroblasts were evaluated by wound scratch and transwell migration assay. Contractile activity was determined by collagen gel contraction assay.

Results

The expression levels of α-SMA, fibronectin, and collagen type I significantly increased in TGF-β1-stimulated nasal fibroblasts. In TGF-β1-stimulated nasal fibroblasts, apigenin inhibited the expressions of α-SMA, fibronectin, and collagen type I. Inhibitors of MAPK (p-38, JNK) and NF-κB blocked the expression of α-SMA, fibronectin and collagen type I. Apigenin suppressed the activation of MAPK (p-38, JNK) and NF-κB induced by TGF-β1 treatment. Apigenin also inhibited the functional activity of fibroblasts by reducing the migration and collagen contractile activities.

Conclusions

These results suggests the possible use of apigenin as a chronic rhinosinusitis therapeutic agent which can suppress tissue remodeling in nasal mucosa.

Preventive effect of apigenin against isoproterenol-induced apoptosis in cardiomyoblasts

We investigated the effect of apigenin, a dietary flavonoid, on isoproterenol hydrochloride (ISO)-induced apoptotic signaling in cardiomyoblast H9C2 cells. The results showed that apigenin treatment (10 µM) prevented ISO (31.25 μM)-induced lipid peroxidative levels and antioxidants status in H9C2 cells. Furthermore, apigenin inhibited expression of inflammatory markers in ISO-treated cells. In addition, apigenin prevented ISO-induced DNA damage and apoptotic signaling through modulating the expression of Bax, caspase-3, -8 and -9, cytochrome c, and Fas proteins in H9C2 cells. It is concluded that apigenin prevents ISO-induced antioxidants depletion, oxidative DNA damage, inflammatory, and apoptotic signaling in H9C2 cells. Thus, the present results demonstrated that apigenin has a cardioprotective effect on cardiomyoblasts cells.

Supercritical anti-solvent fractionation for improving antioxidant and anti-inflammatory activities of an Achillea millefolium L. extract

Achillea millefolium L. is a plant widely used in traditional medicine. Nowadays, there is a growing concern about the study of its bioactive properties in order to develop food and nutraceutical formulations. Supercritical anti-solvent fractionation (SAF) of an A. millefollium extract was carried out to improve its antioxidant and anti-inflammatory activities. A selective precipitation of phenolic compounds was achieved in the precipitation vessel fractions, which presented an antioxidant activity twice than original extract, especially when fractionation was carried out at 10 MPa. The main phenolic components identified in this fraction were luteolin-7-O-glucoside, 3,5-dicaffeoylquinic acid, 6-hidroxyluteolin-7-O-glucoside and apigenin-7-O-glucoside. However, separator fractions presented higher anti-inflammatory activity than precipitation vessel ones, particularly at 15 MPa. This fact could be related to separator fractions enrichment in anti-inflammatory compounds, mainly camphor, artemisia ketone and borneol. Therefore, SAF produced a concentration of antioxidant and anti-inflammatory compounds that could be used as high-added valued ingredients.

Linarin prevents LPS‑induced acute lung injury by suppressing oxidative stress and inflammation via inhibition of TXNIP/NLRP3 and NF‑κB pathways

Acute lung injury (ALI) is an important cause of morbidity and mortality for critically ill patients, and linarin (LR) may be a potential treatment for ALI as it reportedly has antioxidant, anti-inflammatory and apoptotic-regulating activity. In the present study, the authors report that saline and LR (12.5, 25 and 50 mg/kg) were applied to male C57BL/6 mice via gavage. Then, mice were intratracheally injected with either saline or lipopolysaccharide (LPS). LR-pretreatment attenuated LPS-induced ALI and platelet activation and reduced CD41 expression levels and neutrophil platelet aggregates. Additionally, LPS-triggered pulmonary myeloperoxidase activity and neutrophil infiltration in lung tissues, and this was eliminated by LR dose-dependently. Furthermore, LPS-induced oxidative stress and pro-inflammatory cytokine release were downregulated by LR by inhibiting thioredoxin-interacting protein and nuclear factor-κB signaling pathways, including their downstream and upstream signals, such as xanthine oxidase, NLR family WHAT, pyrin domain-containing 3 (NLRP3), apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC), caspase-1, IκB kinase-α (IKK-α) and IκBα. Moreover, in LPS-induced mice, the mitogen-activated protein kinase pathway was inactivated by LR. In vitro, LR reduced LPS-induced inflammation and oxidative stress, which was linked to reduction of ROS. In conclusion, LR pretreatment may be protective against LPS-induced ALI.

Polydopamine nanoparticles for the treatment of acute inflammation-induced injury

Nanotechnology-mediated anti-inflammatory therapy is emerging as a novel strategy for the treatment of inflammation-induced injury. However, one of the main hurdles for these anti-inflammatory nano-drugs is their potential toxic side effects in vivo. Herein, we uncovered that polydopamine (PDA) nanoparticles with their structure and chemical properties similar to melanin, a natural bio-polymer, displayed a significant anti-inflammation therapeutic effect on acute inflammation-induced injury. PDA with enriched phenol groups functioned as a radical scavenger to eliminate reactive oxygen species (ROS) generated during inflammatory responses. As revealed by in vivo photoacoustic imaging with a H2O2-specific nanoprobe, PDA nanoparticles remarkably reduced intracellular ROS levels in murine macrophages challenged with either H2O2 or lipopolysaccharide (LPS). The anti-inflammatory capacity of PDA nanoparticles was further demonstrated in murine models of both acute peritonitis and acute lung injury (ALI), where diminished ROS generation, reduced proinflammatory cytokines, attenuated neutrophil infiltration, and alleviated lung tissue damage were observed in PDA-treated mice after a single dose of PDA treatment. Our work therefore presents the great promise of PDA nanoparticles as a biocompatible nano-drug for anti-inflammation therapy to treat acute inflammation-induced injury.

Phytochemicals as modulators of M1-M2 macrophages in inflammation

Macrophages are critical mediators of the innate immune response against foreign pathogens, including bacteria, physical stress, and injury. Therefore, these cells play a key role in the "inflammatory pathway" which in turn can lead to an array of diseases and disorders such as autoimmune neuropathies and myocarditis, inflammatory bowel disease, atherosclerosis, sepsis, arthritis, diabetes, and angiogenesis. Recently, more studies have focused on the macrophages inflammatory diseases since the discovery of the two subtypes of macrophages, which are differentiated on the basis of their phenotype and distinct gene expression pattern. Of these, M1 macrophages are pro-inflammatory and responsible for inflammatory signaling, while M2 are anti-inflammatory macrophages that participate in the resolution of the inflammatory process, M2 macrophages produce anti-inflammatory cytokines, thereby contributing to tissue healing. Many studies have shown the role of these two subtypes in the inflammatory pathway, and their emergence appears to decide the fate of inflammatory signaling and disease progression. As a next step in directing the pro-inflammatory response toward the anti-inflammatory type after an insult by a foreign pathogen (e. g., bacterial lipopolysaccharide), investigators have identified many natural compounds that have the potential to modulate M1 to M2 macrophages. In this review, we provide a focused discussion of advances in the identification of natural therapeutic molecules with anti-inflammatory properties that modulate the phenotype of macrophages from M1 to M2.

Toxicity against Drosophila melanogaster and antiedematogenic and antimicrobial activities of Alternanthera brasiliana (L.) Kuntze (Amaranthaceae)

Bioactive phytocompounds are studied by several bioactivities demonstrated, as their cytotoxic effects. The aim of this work was to evaluate the phytochemical profile, the toxic effect using the Drosophila melanogaster animal model and the anti-inflammatory and antimicrobial effect of the Alternanthera brasiliana (EEAB) ethanol extract. The phytochemical profile was performed using HPLC. The cytotoxic effect was evaluated in vivo using D. melanogaster. The anti-inflammatory effect was determined by neurogenic and antiedematogenic assays, and the antimicrobial activity was assayed using a microdilution method to determine the minimum inhibitory concentration (MIC) of the EEAB alone and in association with antibiotics. The main compound identified on the EEAB was luteolin (1.93%). Its cytotoxic effect was demonstrated after 24 h in the concentrations of 10, 20 and 40 mg/mL. The extract demonstrated an antiedematogenic effect, with a reduction of the edema between 35.57 and 64.17%. The MIC of the extract was ≥1.024 μg/mL, thus being considered clinically irrelevant. However, when the EEAB was associated with gentamicin, a synergism against all bacterial strains assayed was observed: Staphylococcus aureus (SA10), Escherichia coli (EC06) and Pseudomonas aeruginosa (PA24). Due to these results, the EEAB demonstrated a low toxicity in vivo and anti-inflammatory and synergistic activities. These are promising results, mainly against microbial pathogens, and the compounds identified can be a source of carbon backbones for the discovery and creation of new drugs.

Indirubin improves antioxidant and anti-inflammatory functions in lipopolysaccharide-challenged mice

Indirubin, a traditional Chinese medicine formulation from the Muricidae family, has been reported to exhibit abroad anti-cancer and anti-inflammation activities and mediate nuclear factor-κB (NF-κB) signal. Thus, this study aimed to investigate the protective effects of indirubin on LPS-induced acute lung injury and the potential mechanism in mice. The results showed that LPS treatment caused oxidative stress and inflammation in mice. Indirubin alleviated LPS-caused oxidative stress and inflammation via reducing MDA abundance and IL-1β and TNF-α expressions in mice. Meanwhile, indirubin improved lung NO production and inhibited NF-κB activation caused by LPS exposure. In conclusion, indirubin alleviated LPS-induced acute lung injury via improving antioxidant and anti-inflammatory functions, which might be associated with the NO and NF-κB signals.

Preventive Effects of Velvet Antler (Cervus elaphus) against Lipopolysaccharide-Induced Acute Lung Injury in Mice by Inhibiting MAPK/NF-κB Activation and Inducing AMPK/Nrf2 Pathways

Velvet antler (Cervus elaphus) is a typical traditional animal medicine. It is considered to have various pharmacological effects including stimulation of the immune system, increase in the physical strength, and enhancement of sexual function. This paper aims to investigate the aqueous extract of velvet antler (AVA) in the mouse models of LPS-induced ALI. Inhibition of NO, TNF-α, IL-1β, IL-6, and IL-10 productions contributes to the attenuation of LPS-induced lung inflammation by AVA. A 5-day pretreatment of AVA prevented histological alterations and enhanced antioxidant enzyme activity in lung tissues. AVA significantly reduced the material (total number of cells and proteins) in the BALF. Western blot analysis revealed that the expression of iNOS and COX-2 and phosphorylation of IκB-α and MAPKs proteins are blocked in LPS-stimulated macrophages as well as LPS-induced lung injury in mice. Consistent with this concept, the phosphorylation of CaMKKβ, LKB1, AMPK, Nrf2, and HO-1 was activated after AVA treatment. The results from this study indicate AVA has anti-inflammatory effects in vivo and AVA is a potential model for the development of health food. In addition, its pathways may be at least partially associated with inhibiting MAPK/NF-κB activation and upregulating AMPK/Nrf2 pathways and the regulation of antioxidant enzyme activity.

Resveratrol as a potential therapeutic drug for respiratory system diseases

Respiratory system diseases are common and major ailments that seriously endanger human health. Resveratrol, a polyphenolic phytoalexin, is considered an anti-inflammatory, antioxidant, and anticancer agent. Thanks to its wide range of biological activities, resveratrol has become a hotspot in many fields, including respiratory system diseases. Indeed, research has demonstrated that resveratrol is helpful to relieve pulmonary function in the general population. Meanwhile, growing evidence indicates that resveratrol plays a protective role in respiratory system diseases. This review aimed to summarize the main protective effects of resveratrol in respiratory system diseases, including its anti-inflammatory, antiapoptotic, antioxidant, antifibrotic, antihypertensive, and anticancer activities. We found that resveratrol plays a protective role in the respiratory system through a variety of mechanisms, and so it may become a new drug for the treatment of respiratory system diseases.

Protective effects of apigenin and myricetin against cisplatin-induced nephrotoxicity in mice

CONTEXT

Currently, the outcomes of the use of cisplatin in cancer therapy is limited by nephrotoxicity.

OBJECTIVE

This study aims to investigate the nephroprotective role of apigenin and myricetin against cisplatin-induced nephrotoxicity in mice.

MATERIALS AND METHODS

Adult female Wistar Albino mice were divided into eight groups (n = 8). Group I served as normal control. Groups II, III and IV received apigenin (3 mg/kg, i.p.), myricetin (3 mg/kg, i.p.) or their combination respectively, for seven days. Group V served as positive control group, received vehicles for seven days and cisplatin (7.5 mg/kg, i.p.) for three days starting at day five. Groups VI, VII and VIII received apigenin, myricetin or their combination, respectively for seven days as well as cisplatin injection for three days starting at day five. by the end of the experimental period, a biochemical study involving, nephrotoxicity markers [serum creatinine (Cr) and blood urea nitrogen (BUN)], apoptotic marker [caspase 3], inflammatory mediators [tumour necrosis factor alpha (TNF-α), interleukin 6 (IL-6), cyclooxygenase I and II (COXI, COXII)] and oxidative stress biomarkers [malondialdehyde (MDA), reduced glutathione (GSH) and catalase] was conducted. In addition, renal histopathological alterations were evaluated.

RESULTS

Apigenin, myricetin and their combination significantly reduced blood BUN, serum Cr, caspase-3TNF-α, IL-6, COXI and COXII, MDA levels and significantly increased GSH level and catalase activity parallel to, histopathological improvement in kidney tissues.

DISCUSSION AND CONCLUSION

Apigenin and myricetin exhibited a protective and promising preventive strategy against cisplatin-induced nephrotoxicity due to their antioxidant and anti-inflammatory effects.

Intravasation of SW620 colon cancer cell spheroids through the blood endothelial barrier is inhibited by clinical drugs and flavonoids in vitro

Mechanisms how colorectal cancer (CRC) cells penetrate blood micro-vessel endothelia and metastasise is poorly understood. To study blood endothelial cell (BEC) barrier breaching by CRC emboli, an in vitro assay measuring BEC-free areas underneath SW620 cell spheroids, so called "circular chemorepellent induced defects" (CCIDs, appearing in consequence of endothelial retraction), was adapted and supported by Western blotting, EIA-, EROD- and luciferase reporter assays. Inhibition of ALOX12 or NF-κB in SW620 cells or BECs, respectively, caused attenuation of CCIDs. The FDA approved drugs vinpocetine [inhibiting ALOX12-dependent 12(S)-HETE synthesis], ketotifen [inhibiting NF-κB], carbamazepine and fenofibrate [inhibiting 12(S)-HETE and NF-κB] significantly attenuated CCID formation at low μM concentrations. In the 5-FU-resistant SW620-R/BEC model guanfacine, nifedipine and proadifen inhibited CCIDs stronger than in the naïve SW620/BEC model. This indicated that in SW620-R cells formerly silent (yet unidentified) genes became expressed and targetable by these drugs in course of resistance acquisition. Fenofibrate, and the flavonoids hispidulin and apigenin, which are present in medicinal plants, spices, herbs and fruits, attenuated CCID formation in both, naïve- and resistant models. As FDA-approved drugs and food-flavonoids inhibited established and acquired intravasative pathways and attenuated BEC barrier-breaching in vitro, this warrants testing of these compounds in CRC models in vivo.

Thymol mitigates lipopolysaccharide-induced endometritis by regulating the TLR4- and ROS-mediated NF-κB signaling pathways

The purpose of this study was to investigate the effects of thymol on lipopolysaccharide (LPS)-induced inflammatory responses and to clarify the potential mechanism of these effects. LPS-induced mouse endometritis was used to confirm the anti-inflammatory action of thymol in vivo. RAW264.7 cells were used to examine the molecular mechanism and targets of thymol in vitro. In vivo, thymol markedly alleviated LPS-induced pathological injury, myeloperoxidase (MPO) activity, and the production of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in mice. Further studies were performed to examine the expression of the Toll-like receptor 4 (TLR4) -mediated nuclear factor-κB (NF-κB) pathway. These results showed that the expression of the TLR4-mediated NF-κB pathway was inhibited by thymol treatment. In vitro, we observed that thymol dose-dependently inhibited the expression of TNF-α, IL-1β, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW264.7 cells. Moreover, the results obtained from immunofluorescence assays also indicated that thymol dose-dependently suppressed LPS-induced reactive oxygen species (ROS) production. Silencing of TLR4 inhibited NF-κB pathway activation. Furthermore, H₂O₂ treatment increased the phosphorylation of p65 and IκBα, which were decreased when treated with N-acetyl cysteine or thymol. In conclusion, the anti-inflammatory effects of thymol are associated with activation of the TLR4 or ROS signaling pathways, contributing to NF-κB activation, thereby alleviating LPS-induced oxidative and inflammatory responses.