Anti-Inflammatory Activities of an Anti-Histamine Drug, Loratadine, by Suppressing TAK1 in AP-1 Pathway.

Loratadine is an anti-histamine routinely used for treating allergies. However, recent findings have shown that Loratadine may also have anti-inflammatory functions, while their exact mechanisms have not yet been fully uncovered. In this paper, we investigated whether Loratadine can be utilized as an anti-inflammatory drug through a series of in vitro and in vivo experiments using a murine macrophage cell line and an acute gastritis mouse model. Loratadine was found to dramatically reduce the expression of pro-inflammatory genes, including MMP1, MMP3, and MMP9, and inhibit AP-1 transcriptional activation, as demonstrated by the luciferase assay. Therefore, we decided to further explore its role in the AP-1 signaling pathway. The expression of c-Jun and c-Fos, AP-1 subunits, was repressed by Loratadine and, correspondingly, the expression of p-JNK, p-MKK7, and p-TAK1 was also inhibited. In addition, Loratadine was able to reduce gastric bleeding in acute gastritis-induced mice; Western blotting using the stomach samples showed reduced p-c-Fos protein levels. Loratadine was shown to effectively suppress inflammation by specifically targeting TAK1 and suppressing consequent AP-1 signaling pathway activation and inflammatory cytokine production.

Anti-Melanogenesis Effects of a Cyclic Peptide Derived from Flaxseed via Inhibition of CREB Pathway.

Linosorbs (Los) are cyclic peptides from flaxseed oil composed of the LO mixture (LOMIX). The activity of LO has been reported as being anti-cancer and anti-inflammatory. However, the study of skin protection has still not proceeded. In particular, there are poorly understood mechanisms of melanogenesis to LO. Therefore, we investigated the anti-melanogenesis effects of LOMIX and LO, and its activity was examined in mouse melanoma cell lines. The treatment of LOMIX (50 and 100 µg/mL) and LO (6.25-50 µM) suppressed melanin secretion and synthesis, which were 3-fold increased, in a dose-dependent manner, up to 95%. In particular, [1-9-NαC]-linusorb B3 (LO1) and [1-9-NαC]-linusorb B2 (LO2) treatment (12.5 and 25 µM) highly suppressed the synthesis of melanin in B16F10 cell lines up to 90%, without toxicity. LOMIX and LOs decreased the 2- or 3-fold increased mRNA levels, including the microphthalmia-associated transcription factor (MITF), Tyrosinase, tyrosinase-related protein 1 (TYRP1), and tyrosinase-related protein 2 (TYRP2) at the highest concentration (25 µM). Moreover, the treatment of 25 µM LO1 and LO2 inhibited the expression of MITF and phosphorylation of upper regulatory proteins such as CREB and PKA. Taken together, these results suggested that LOMIX and its individual LO could inhibit melanin synthesis via downregulating the CREB-dependent signaling pathways, and it could be used for novel therapeutic materials in hyperpigmentation.

Caragana rosea Turcz Methanol Extract Inhibits Lipopolysaccharide-Induced Inflammatory Responses by Suppressing the TLR4/NF-κB/IRF3 Signaling Pathways.

Caragana rosea Turcz, which belongs to the Leguminosae family, is a small shrub found in Northern and Eastern China that is known to possess anti-inflammatory properties and is used to treat fever, asthma, and cough. However, the underlying molecular mechanisms of its anti-inflammatory effects are unknown. Therefore, we used lipopolysaccharide (LPS) in RAW264.7 macrophages to investigate the molecular mechanisms that underlie the anti-inflammatory activities of a methanol extract of Caragana rosea (Cr-ME). We showed that Cr-ME reduced the production of nitric oxide (NO) and mRNA levels of iNOS, TNF-α, and IL-6 in a concentration-dependent manner. We also found that Cr-ME blocked MyD88- and TBK1-induced NF-κB and IRF3 promoter activity, suggesting that it affects multiple targets. Moreover, Cr-ME reduced the phosphorylation levels of IκBα, IKKα/ß and IRF3 in a time-dependent manner and regulated the upstream NF-κB proteins Syk and Src, and the IRF3 protein TBK1. Upon overexpression of Src and TBK1, Cr-ME stimulation attenuated the phosphorylation of the NF-κB subunits p50 and p65 and IRF3 signaling. Together, our results suggest that the anti-inflammatory activity of Cr-ME occurs by inhibiting the NF-κB and IRF3 signaling pathways.

Anti-inflammatory effect of Barringtonia angusta methanol extract is mediated by targeting of Src in the NF-κB signalling pathway.

CONTEXT: Among the plants in the genus Barringtonia (Lecythidaceae) used as traditional medicines to treat arthralgia, chest pain, and haemorrhoids in Indonesia, Barringtonia racemosa L. and Barringtonia acutangula (L.) Gaertn. have demonstrated anti-inflammatory activity in systemic inflammatory models. OBJECTIVE: The anti-inflammatory activity of Barringtonia angusta Kurz has not been investigated. We prepared a methanol extract of the leaves and stems of B. angusta (Ba-ME) and systemically evaluated its anti-inflammatory effects in vitro and in vivo. MATERIALS AND METHODS: RAW264.7 cells stimulated with LPS or Pam3CSK4 for 24 h were treated with Ba-ME (12.5, 25, 50, 100, and 150 µg/mL), and NO production and mRNA levels of inflammatory genes were evaluated. Luciferase reporter gene assay, western blot analysis, overexpression experiments, and cellular thermal shift assay were conducted to explore the mechanism of Ba-ME. In addition, the anti-gastritis activity of Ba-ME (50 and 100 mg/kg, administered twice per day for two days) was evaluated using an HCl/EtOH-induced gastritis mouse model. RESULTS: Ba-ME dose-dependently suppressed NO production [IC50 = 123.33 µg/mL (LPS) and 46.89 µg/mL (Pam3CSK4)] without affecting cell viability. Transcriptional expression of iNOS, IL-1ß, COX-2, IL-6, and TNF-α and phosphorylation of Src, IκBα, p50/105, and p65 were inhibited by Ba-ME. The extract specifically targeted the Src protein by binding to its SH2 domain. Moreover, Ba-ME significantly ameliorated inflammatory lesions in the HCl/EtOH-induced gastritis model. DISCUSSION AND CONCLUSIONS: The anti-inflammatory activity of Ba-ME is mediated by targeting of the Src/NF-κB signalling pathway, and B. angusta has potential as an anti-inflammatory drug.

Water Extract of Lotus Leaf Alleviates Dexamethasone-Induced Muscle Atrophy via Regulating Protein Metabolism-Related Pathways in Mice.

Muscle atrophy is an abnormal condition characterized by loss of skeletal muscle mass and function and is primarily caused by injury, malnutrition, various diseases, and aging. Leaf of lotus (Nelumbo nucifera Gaertn), which has been used for medicinal purposes, contains various active ingredients, including polyphenols, and is reported to exert an antioxidant effect. In this study, we investigated the effect of water extract of lotus leaf (LL) on muscle atrophy and the underlying molecular mechanisms of action. Amounts of 100, 200, or 300 mg/kg/day LL were administered to dexamethasone (DEX)-induced muscle atrophy mice for 4 weeks. Micro-computed tomography (CT) analysis revealed that the intake of LL significantly increased calf muscle volume, surface area, and density in DEX-induced muscle atrophy mice. Administration of LL recovered moving distance, grip strength, ATP production, and body weight, which were decreased by DEX. In addition, muscle damage caused by DEX was also improved by LL. LL reduced the protein catabolic pathway by suppressing gene expression of muscle atrophy F-Box (MAFbx; atrogin-1), muscle RING finger 1 (MuRF1), and forkhead box O (FoxO)3a, as well as phosphorylation of AMP-activated kinase (AMPK). The AKT-mammalian target of the rapamycin (mTOR) signal pathway, which is important for muscle protein synthesis, was increased in LL-administered groups. The HPLC analysis and pharmacological test revealed that quercetin 3-O-beta-glucuronide (Q3G) is a major active component in LL. Thus, Q3G decreased the gene expression of atrogin-1 and MuRF1 and phosphorylation of AMPK. This compound also increased phosphorylation levels of mTOR and its upstream enzyme AKT in DEX-treated C2C12 cells. We identified that LL improves muscle wasting through regulation of muscle protein metabolism in DEX-induced muscle atrophy mice. Q3G is predicted to be one of the major active phenolic components in LL. Therefore, we propose LL as a supplement or therapeutic agent to prevent or treat muscle wasting, such as sarcopenia.

Morinda citrifolia noni water extract enhances innate and adaptive immune responses in healthy mice, ex vivo, and in vitro.

Although Morinda citrifolia (noni) has long been used in traditional medicines for human diseases, its molecular and cellular mechanism of immunostimulatory ability to improve human health under normal healthy conditions is not fully elucidated. This study aimed to investigate the in vitro and in vivo immunostimulatory activity of M. citrifolia fruit water extract treated with enzymes (Mc-eWE). In vitro studies revealed that Mc-eWE stimulated the cells by inducing nitric oxide (NO) production and the expression of inflammatory cytokines, such as interleukin (IL)-1ß, IL-6, IL-12, tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ). The immunostimulatory activity was mediated by activation of NF-κB and AP-1. Ex vivo studies showed that Mc-eWE stimulated splenocytes isolated from mice by inducing NO production and expression of immunostimulatory cytokines and by downregulating the expression of the immunosuppressive cytokine IL-10 without cytotoxicity. In vivo demonstrated that Mc-eWE induced immunostimulation by modulating populations of splenic immune cells, especially by increasing the population of IFN-γ+ NK cells. Mc-eWE enhanced the expression of inflammatory genes and immunostimulatory cytokines and inhibited the expression of IL-10 in the mouse splenocytes and sera. Taken together, these results suggest that Mc-eWE plays an immunostimulatory role by activating innate and adaptive immune responses.

Hydroquinone suppresses IFN-ß expression by targeting AKT/IRF3 pathway.

Previous studies have demonstrated the role of hydroquinone (HQ), a hydroxylated benzene metabolite, in modulating various immune responses; however, its role in macrophage-mediated inflammatory responses is not fully understood. In this study, the role of HQ in inflammatory responses and the underlying molecular mechanism were explored in macrophages. HQ down-regulated the expression of interferon (IFN)-ß mRNA in LPS-stimulated RAW264.7 cells without any cytotoxicity and suppressed interferon regulatory factor (IRF)-3-mediated luciferase activity induced by TIR-domain-containing adapter-inducing interferon-ß (TRIF) and TANK-binding kinase 1 (TBK1). A mechanism study revealed that HQ inhibited IRF-3 phosphorylation induced by lipopolysaccharide (LPS), TRIF, and AKT by suppressing phosphorylation of AKT, an upstream kinase of the IRF-3 signaling pathway. IRF-3 phosphorylation is highly induced by wild-type AKT and poorly induced by an AKT mutant, AKT C310A, which is mutated at an inhibitory target site of HQ. We also showed that HQ inhibited IRF-3 phosphorylation by targeting all three AKT isoforms (AKT1, AKT2, and AKT3) in RAW264.7 cells and suppressed IRF-3-mediated luciferase activities induced by AKT in HEK293 cells. Taken together, these results strongly suggest that HQ inhibits the production of a type I IFN, IFN-ß, by targeting AKTs in the IRF-3 signaling pathway during macrophage-mediated inflammation.

The dietary flavonoid Kaempferol mediates anti-inflammatory responses via the Src, Syk, IRAK1, and IRAK4 molecular targets.

Even though a lot of reports have suggested the anti-inflammatory activity of kaempferol (KF) in macrophages, little is known about its exact anti-inflammatory mode of action and its immunopharmacological target molecules. In this study, we explored anti-inflammatory activity of KF in LPS-treated macrophages. In particular, molecular targets for KF action were identified by using biochemical and molecular biological analyses. KF suppressed the release of nitric oxide (NO) and prostaglandin E2 (PGE2), downregulated the cellular adhesion of U937 cells to fibronectin (FN), neutralized the generation of radicals, and diminished mRNA expression levels of inflammatory genes encoding inducible NO synthase (iNOS), TNF-α, and cyclooxygenase- (COX-) 2 in lipopolysaccharide- (LPS-) and sodium nitroprusside- (SNP-) treated RAW264.7 cells and peritoneal macrophages. KF reduced NF-κB (p65 and p50) and AP-1 (c-Jun and c-Fos) levels in the nucleus and their transcriptional activity. Interestingly, it was found that Src, Syk, IRAK1, and IRAK4 responsible for NF-κB and AP-1 activation were identified as the direct molecular targets of KF by kinase enzyme assays and by measuring their phosphorylation patterns. KF was revealed to have in vitro and in vivo anti-inflammatory activity by the direct suppression of Src, Syk, IRAK1, and IRAK4, involved in the activation of NF-κB and AP-1.

Immunotoxicological Effects of Aripiprazole: In vivo and In vitro Studies.

Aripiprazole (ARI) is a commonly prescribed medication used to treat schizophrenia and bipolar disorder. To date, there have been no studies regarding the molecular pathological and immunotoxicological profiling of aripiprazole. Thus, in the present study, we prepared two different formulas of aripiprazole [Free base crystal of aripiprazole (ARPGCB) and cocrystal of aripiprazole (GCB3004)], and explored their effects on the patterns of survival and apoptosis-regulatory proteins under acute toxicity and cytotoxicity test conditions. Furthermore, we also evaluated the modulatory activity of the different formulations on the immunological responses in macrophages primed by various stimulators such as lipopolysaccharide (LPS), pam3CSK, and poly(I:C) via toll-like receptor 4 (TLR4), TLR2, and TLR3 pathways, respectively. In liver, both ARPGCB and GCB3004 produced similar toxicity profiles. In particular, these two formulas exhibited similar phospho-protein profiling of p65/nuclear factor (NF)-κB, c-Jun/activator protein (AP)-1, ERK, JNK, p38, caspase 3, and bcl-2 in brain. In contrast, the patterns of these phospho-proteins were variable in other tissues. Moreover, these two formulas did not exhibit any cytotoxicity in C6 glioma cells. Finally, the two formulations at available in vivo concentrations did not block nitric oxide (NO) production from activated macrophage-like RAW264.7 cells stimulated with LPS, pam3CSK, or poly(I:C), nor did they alter the morphological changes of the activated macrophages. Taken together, our present work, as a comparative study of two different formulas of aripiprazole, suggests that these two formulas can be used to achieve similar functional activation of brain proteins related to cell survival and apoptosis and immunotoxicological activities of macrophages.

21-O-angeloyltheasapogenol E3, a novel triterpenoid saponin from the seeds of tea plants, inhibits macrophage-mediated inflammatory responses in a NF-κB-dependent manner.

21-O-Angeloyltheasapogenol E3 (ATS-E3) is a triterpenoid saponin recently isolated from the seeds of the tea tree Camellia sinensis (L.) O. Kuntze. ATS-E3 has several beneficial properties including anti-inflammatory, antidiabetic, antiatherosclerotic, and anticancer effects. Unlike other phenolic compounds isolated from tea plants, there are no studies reporting the pharmacological action of ATS-E3. In this study, we therefore aimed to explore the cellular and molecular inhibitory activities of ATS-E3 in macrophage-mediated inflammatory responses. ATS-E3 remarkably diminished cellular responses of macrophages such as FITC-dextran-induced phagocytic uptake, sodium nitroprusside- (SNP-) induced radical generation, and LPS-induced nitric oxide (NO) production. Analysis of its molecular activity showed that this compound significantly suppressed the expression of inducible NO synthase (iNOS), nuclear translocation of nuclear factor- (NF-) κB subunits (p50 and p65), phosphorylation of inhibitor of κB kinase (IKK), and the enzyme activity of AKT1. Taken together, the novel triterpenoid saponin compound ATS-E3 contributes to the beneficial effects of tea plants by exerting anti-inflammatory and antioxidative activities in an AKT/IKK/NF-κB-dependent manner.

Lancemaside A from Codonopsis lanceolata modulates the inflammatory responses mediated by monocytes and macrophages.

In this study, we aimed to examine the cellular and molecular mechanisms of lancemaside A from Codonopsis lanceolata (Campanulaceae) in the inflammatory responses of monocytes (U937 cells) and macrophages (RAW264.7 cells). Lancemaside A significantly suppressed the inflammatory functions of lipopolysaccharide- (LPS-) treated RAW264.7 cells by suppressing the production of nitric oxide (NO), the expression of the NO-producing enzyme inducible NO synthase (iNOS), the upregulation of the costimulatory molecule CD80, and the morphological changes induced by LPS exposure. In addition, lancemaside A diminished the phagocytic activity of RAW264.7 cells and boosted the neutralizing capacity of these cells when treated with the radical generator sodium nitroprusside (SNP). Interestingly, lancemaside A strongly blocked the adhesion activity of RAW264.7 cells to plastic culture plates, inhibited the cell-cell and cell-fibronectin (FN) adhesion of U937 cells that was triggered by treatment with an anti-ß1-integrin (CD29) antibody and immobilized FN, respectively. By evaluating the activation of various intracellular signaling pathways and the levels of related nuclear transcription factors, lancemaside A was found to block the activation of inhibitor of κB kinase (IKK) and p65/nuclear factor- (NF-) κB. Taken together, our findings strongly suggest that the anti-inflammatory function of lancemaside A is the result of its strong antioxidative and IKK/NF-κB inhibitory activities.

In vitro anti-cancer effects of beauvericin through inhibition of actin polymerization and Src phosphorylation.

BACKGROUND: Beauvericin (BEA) is a depsipeptide with antimicrobial, anti-inflammatory, and anti-cancer activities isolated from Beauveria bassiana. However, little is understood on its anti-cancer activities and mechanism. PURPOSE: Aim of this study was to explore the anti-cancer activity of BEA and its underlying molecular mechanism to provide a theoretical basis for its role as a candidate natural drug in cancer diseases. STUDY DESIGN: Various cancer cells such as C6 glioma, U251, MDA-MB-231, HeLa, HCT-15, LoVo cells, and HEK293T cells were used to the anti-cancer activity of BEA. METHODS: To evaluate the anti-cancer activity of BEA, cell viability test (MTT assay), morphological change check, confocal microscopy, actin polymerization assay, flow cytometry, and Western blotting analysis. To check the target enzyme of BEA, overexpression and site-directed mutagenesis was employed. RESULTS: BEA inhibited the viability of cancer cells including C6, MDA-MB-231, HeLa, HCT-15, LoVo, and U251 cells. Treatment of BEA in C6 glioma cells induced cell membrane blebbing and apoptosis. Caspase-3 and -9 were dose-dependently activated by BEA, and the mRNA expression of Bcl-2 was inhibited by BEA. According to confocal microscopy, actin polymerization and actin-actin interaction were interrupted by BEA in C6 cells. BEA regulated the apoptosis of C6 cells depending on the protein phosphorylation of Src and Signal transducer and activator of transcription (STAT3). Moreover, c-terminal amino acids in Src directly interacted with BEA in C6 cells, and the binding of Src and BEA suppressed the kinase activity of Src. CONCLUSIONS: These results suggest that BEA may be a critical candidate or substitute drug for cancer treatment via suppression of the Src/STAT3 pathway.

20(S)-Protopanaxadiol from Panax ginseng Induces Apoptosis and Autophagy in Gastric Cancer Cells by Inhibiting Src.

20(S)-protopanaxadiol (PPD), a metabolite of Panax ginseng, has multiple pharmacological properties. However, the effects of PPD against human gastric cancer have not been elucidated. Our purpose in this study was to investigate if PPD has anticancer effects against human gastric cancer in vitro. Cell viability, migration, clone formation, and invasion were assessed to explore the effects of PPD on cancer cells. PI and annexin V staining as well as immunoblotting were employed to determine if PPD-induced apoptosis and autophagy of MKN1 and MKN45 cells. The target of PPD was identified using immunoblotting, overexpression analysis, and flow cytometric analysis. PPD exhibited significantly suppressed cell viability, migration, colony formation, and invasion. Phosphorylation of Src and its down-stream effectors were inhibited by PPD. PPD-enhanced apoptosis and autophagy in a dose- and time-dependent manner by inhibiting Src. Collectively, our results demonstrate that PPD induces apoptosis and autophagy in gastric cancer cells in vitro by inhibiting Src.

Tumor-suppressive functions of protein lysine methyltransferases.

Protein lysine methyltransferases (PKMTs) play crucial roles in histone and nonhistone modifications, and their dysregulation has been linked to the development and progression of cancer. While the majority of studies have focused on the oncogenic functions of PKMTs, extensive evidence has indicated that these enzymes also play roles in tumor suppression by regulating the stability of p53 and ß-catenin, promoting α-tubulin-mediated genomic stability, and regulating the transcription of oncogenes and tumor suppressors. Despite their contradictory roles in tumorigenesis, many PKMTs have been identified as potential therapeutic targets for cancer treatment. However, PKMT inhibitors may have unintended negative effects depending on the specific cancer type and target enzyme. Therefore, this review aims to comprehensively summarize the tumor-suppressive effects of PKMTs and to provide new insights into the development of anticancer drugs targeting PKMTs.

Korean Red Ginseng Relieves Inflammation and Modulates Immune Response Induced by Pseudo-Type SARS-CoV-2.

Few studies have reported the therapeutic effects of Korean red ginseng (KRG) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the positive effects of KRG on other viruses have been reported and the effects of KRG on pulmonary inflammatory diseases have also been studied. Therefore, this study investigated the therapeutic effects of KRG-water extract (KRG-WE) in a pseudo-type SARS-CoV-2 (PSV)-induced lung injury model. Constructing the pseudovirus, human angiotensin-converting enzyme 2 (hACE2) transgenic mice were infected via intranasal injection that had been orally administered with KRG-WE for six weeks. After 7-days post infection (dpi), the antiviral effects of KRG-WE were confirmed, followed by real-time polymerase chain reaction (PCR), western blot analysis, flow cytometric analysis, and an enzyme-linked immunoassay (ELISA). KRG-WE significantly inhibited an increase in immunoglobulin caused by PSV. Furthermore, KRG-WE effectively suppressed alveolar macrophages (AMs) inside the lungs and helped normalize the population of other immune cells. In addition, virus-induced gene expression and inflammatory signals such as nuclear factor-kappa B and other upstream molecules were downregulated. Moreover, KRG-WE also normalized gene expression and protein activity in the spleen. In conclusion, KRG-WE reduced AMs, normalized the immune response, and decreased the expression of inflammatory genes and activation of signaling pathway phosphorylation, thereby exhibiting anti-inflammatory effects and attenuating lung damage.

Protection of c-Fos from autophagic degradation by PRMT1-mediated methylation fosters gastric tumorigenesis.

Both AP-1 and PRMT1 are vital molecules in variety of cellular progresssion, but the interaction between these proteins in the context of cellular functions is less clear. Gastric cancer (GC) is one of the pernicious diseases worldwide. An in-depth understanding of the molecular mode of action underlying gastric tumorigenesis is still elusive. In this study, we found that PRMT1 directly interacts with c-Fos and enhances AP-1 activation. PRMT1-mediated arginine methylation (mono- and dimethylation) of c-Fos synergistically enhances c-Fos-mediated AP-1 liveliness and consequently increases c-Fos protein stabilization. Consistent with this finding, PRMT1 knockdown decreases the protein level of c-Fos. We discovered that the c-Fos protein undergoes autophagic degradation and found that PRMT1-mediated methylation at R287 protects c-Fos from autophagosomal degradation and is linked to clinicopathologic variables as well as prognosis in stomach tumor. Together, our data demonstrate that PRMT1-mediated c-Fos protein stabilization promotes gastric tumorigenesis. We contend that targeting this modification could constitute a new therapeutic strategy in gastric cancer.

Antiphotoaging and Skin-Protective Activities of Ardisia silvestris Ethanol Extract in Human Keratinocytes.

Ardisia silvestris is a traditional medicinal herb used in Vietnam and several other countries. However, the skin-protective properties of A. silvestris ethanol extract (As-EE) have not been evaluated. Human keratinocytes form the outermost barrier of the skin and are the main target of ultraviolet (UV) radiation. UV exposure causes skin photoaging via the production of reactive oxygen species. Protection from photoaging is thus a key component of dermatological and cosmetic products. In this research, we found that As-EE can prevent UV-induced skin aging and cell death as well as enhance the barrier effect of the skin. First, the radical-scavenging ability of As-EE was checked using DPPH, ABTS, TPC, CUPRAC, and FRAP assays, and a 3-(4-5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assay was used to examine cytotoxicity. Reporter gene assays were used to determine the doses that affect skin-barrier-related genes. A luciferase assay was used to identify possible transcription factors. The anti-photoaging mechanism of As-EE was investigated by determining correlated signaling pathways using immunoblotting analyses. As-EE had no harmful effects on HaCaT cells, according to our findings, and As-EE revealed moderate radical-scavenging ability. With high-performance liquid chromatography (HPLC) analysis, rutin was found to be one of the major components. In addition, As-EE enhanced the expression levels of hyaluronic acid synthase-1 and occludin in HaCaT cells. Moreover, As-EE dose-dependently up-regulated the production of occludin and transglutaminase-1 after suppression caused by UVB blocking the activator protein-1 signaling pathway, in particular, the extracellular response kinase and c-Jun N-terminal kinase. Our findings suggest that As-EE may have anti-photoaging effects by regulating mitogen-activated protein kinase, which is good news for the cosmetics and dermatology sectors.

BN82002 alleviated tissue damage of septic mice by reducing inflammatory response through inhibiting AKT2/NF-κB signaling pathway.

BN82002 is well-known as an inhibitor of the CDC25 phosphatase. However, it was recently reported that BN82002 also selectively suppressed AKT2 and reduced inflammatory responses in lipopolysaccharide (LPS)-stimulated macrophage-like RAW264.7 cells. Therefore, in this study, we evaluated the alleviating efficacy of BN82002 in sepsis in vivo. BN82002 (50 µM) suppressed the mRNA levels of cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 in LPS-treated peritoneal macrophages without cytotoxicity. The septic in vivo mouse model was established on the basis of the endotoxin model using poly(I:C) (10 mg/kg) and LPS (54 mg/kg). In histological analysis, peritoneal injection of BN82002 (20 mg/kg) significantly reduced lung, kidney, and liver damage. Lung edema and serum alanine transaminase (ALT), aspartate transaminase (AST), TNF-α, IL-1ß, and nitric oxide (NO) levels also were decreased by BN82002 (20 mg/kg). In addition, BN82002 (20 mg/kg) suppressed the mRNA levels of TNF-α in lung and liver tissues. Gene expression levels of IL-1ß and IL-6 were decreased in lung, kidney, and liver in the BN82002 (20 mg/kg) group. Furthermore, p-AKT2 and p-IκBα levels were reduced by BN82002 (20 mg/kg). Finally, all septic mice died 7 days after poly(I:C)/LPS-injection, whereas 4 mice in the BN82002 (20 mg/kg) group, survived strongly suggesting that BN82002 reduces sepsis mortality. In conclusion, we verified that pre-treatment with BN82002 protects against tissue damage and increases survival by inhibiting AKT2-NF-κB signaling in septic mice. These results suggest that BN82002 could be utilized in the treatment of sepsis.

p38-dependent c-Jun degradation contributes to reduced PGE2 production in sodium orthovanadate-treated macrophages.

In particular, the phenomenon of c-Jun degradation within the inflammatory response has not yet been fully analyzed. In order to verify this, we investigated LPS-stimulated murine macrophages pre-treated with sodium orthovanadate (SO) in order to uncover the regulatory mechanisms of the MAPKs which regulate c-Jun degradation within the inflammatory response. Through our study, we found that SO suppressed the production of prostaglandin E2 (PGE2) and the expression of COX-2 in LPS-stimulated RAW264.7 cells. Additionally, SO decreased total c-Jun levels, without altering the amount of mRNA, although the phospho-levels of p38, ERK, and JNK were strongly enhanced. Through the usage of selective MAPK inhibitors, and knockdown and overexpression strategies, p38 was revealed to be a major MAPK which regulates c-Jun degradation. Further analysis indicates that the phosphorylation of p38 is a determinant for c-Jun degradation, and is sufficient to induce ubiquitination-dependent c-Jun degradation, recovered through MG132 treatment. Therefore, our results suggest that the hyperphosphorylation of p38 by SO contributes to c-Jun degradation, which is linked to the suppression of PGE2 secretion in inflammatory responses; and thus, finding drugs to increase p38 activity could be a novel strategy for the development of anti-inflammatory drugs. [BMB Reports 2022; 55(8): 389-394].

Phosphatase inhibition by sodium orthovanadate displays anti-inflammatory action by suppressing AKT-IKKß signaling in RAW264.7 cells.

Sodium orthovanadate (Na3VO4) is an inhibitor of phosphatases that acts as a phosphate analog and is being developed as an anti-diabetes drug. Phosphatases play important roles in inflammatory signal pathways by modulating the removal of phosphate moieties of key signaling proteins. However, the role of protein phosphatases on the inflammatory response has not been fully established. In this study, we investigated how phosphatases can control the inflammatory response using Na3VO4 in LPS-stimulated RAW264.7 cells and explored the molecular mechanisms by NO assay, mRNA analysis, immunoblotting analysis, kinase assay, luciferase reporter gene assay, and mutation strategy. Na3VO4 decreased the release of nitric oxide (NO) and suppressed the expression of pro-inflammatory genes at the transcriptional level, without cytotoxicity. The translocation of nuclear factor (NF)-κB subunits into the nucleus and the level of p-IκBα were reduced by Na3VO4, as was IKKß activity. Na3VO4 inhibited NF-κB-Luc activity under AKT1/2 and IKKß overexpression. However, the inhibitory effect of Na3VO4 against NF-κB-Luc was not observed in the group overexpressing both AKT2 and IKKß-M10, a mutant in which the 10 serine residues in the autophosphorylated region of the C-terminal were replaced with alanine. Na3VO4 directly decreased the activity of protein phosphatase 1α (PP1α) and protein phosphatase 2 A (PP2A) by 95%. Phosphatase inhibition by Na3VO4 also selectively suppressed AKT-IKKß signaling by directly blocking the phosphatase activity of PP1 and PP2A, consequently down-regulating NF-κB and inflammatory gene expression. Therefore, these results suggest that vanadium compounds including Na3VO4 can be developed as anti-inflammatory drugs.