Inhibition of lipopolysaccharide-inducible nitric oxide synthase, TNF-alpha and COX-2 expression by sauchinone effects on I-kappaBalpha phosphorylation, C/EBP and AP-1 activation

A novel TGR5 agonist Sauchinone ameliorates IMQ induced murine psoriasis by regulating macrophage polarization

INTRODUCTION

G-protein-coupled bile acid receptor (TGR5) is a member of G-protein-coupled receptor (GPCR) superfamily that participates in regulating macrophage polarization and resolving inflammatory diseases. Sauchinone is Saururus chinensis derived natural product with anti-inflammatory activity. Still, whether Sauchinone could regulate macrophage polarization and its direct target remain to be explored.

OBJECTIVES

This study aims to demonstrate the direct target of Sauchinone, its influences on macrophage polarization and its pharmacological actions on imiquimod (IMQ) induced mouse psoriasis model.

METHODS

We detected the TGR5 agonistic activity of Sauchinone in mouse/human TGR5/ cAMP response elements (CRE)/HEK293 stable cell lines and verified its direct effect on mouse/human macrophages by Cellular thermal shift assay (CETSA) and by examining downstream CREB phosphorylation. Afterwards, we discovered the activity of Sauchinone on regulating macrophage M1/M2 polarization in Bone marrow-derived macrophages (BMDM) by detecting M1/M2 markers through Enzyme-linked immunosorbent assay (ELISA), Real-time polymerase chain reaction (RT-qPCR), Western blot and Fluorescence-activated cell sorting (FACS). We further utilized macrophages derived from Tgr5-/- mice or introduced TGR5 specific inhibitor, TGR5 si-RNA and PKA inhibitor to determine whether Sauchinone regulated macrophage polarization through TGR5. We then prepared Sauchinone cream formulation to disclose its pharmacological action in IMQ induced mouse psoriasis model and used FACS and immunofluorescence to verify its action on macrophage polarization in psoriatic skin. Moreover, we tested the protective actions of Sauchinone cream in IMQ treated Tgr5-/- mice to verify that Sauchinone alleviated psoriasis in TGR5 dependent manner.

RESULTS

Sauchinone is a novel TGR5 agonist without human/mouse species selectivity. Sauchinone rectified macrophage M1 polarization through activating TGR5. Topical use of Sauchinone cream ameliorated IMQ induced psoriasis and regulated macrophage polarization in psoriatic skins. Sauchinone cream alleviated psoriasis in TGR5 dependent manner.

CONCLUSION

Our work identified Sauchinone as a novel TGR5 agonist that could ameliorate IMQ induced murine psoriasis by regulating macrophage polarization.

Benzoxanthenone Lignans Related to Carpanone, Polemanone, and Sauchinone: Natural Origin, Chemical Syntheses, and Pharmacological Properties

Medicinal plants from the genus Saururus are commonly used to treat inflammatory pathologies. They contain numerous bioactive compounds, notably the polycyclic lignan sauchinone from the species Saururus chinensis. An in-depth analysis of benzoxanthenone lignans related to sauchinone, and the analogous products carpanone and polemannones, has been carried out. The review reports the product's isolation, biosynthetic pathway, and chemical strategies to synthesize benzoxanthenones via liquid- and solid-phase syntheses. The metabolic and pharmacokinetic properties of sauchinone are discussed. At the pharmacological level, sauchinone is a potent blocker of the production of pro-inflammatory mediators, such as nitric oxide and prostaglandin E2, and an efficient antioxidant agent. The properties of sauchinone can be exploited to combat multiple pathologies, such as liver injuries, renal dysfunction, osteoarthritis, inflammatory bowel disease, ulcerative colitis, and cancers. The capacity of the natural product to inhibit tumor cell proliferation and to reduce migration/invasion of cancer cells and the development of metastases is underlined, together with the regulation of the epithelial-mesenchymal transition and immune checkpoints. Altogether, the review offers a complete survey of the chemical and biochemical properties of sauchinone-type benzoxanthenones.

Rheumatoid arthritis-recent advances in pathogenesis and the anti-inflammatory effect of plant-derived COX inhibitors

The majority of people with autoimmune disorders, including those with rheumatoid arthritis, osteoarthritis, and tendonitis report pain, stiffness, and inflammation as major contributors to their worse quality of life in terms of overall health. Of all the available treatment options, COX inhibitors are the ones that are utilized most frequently to ease the symptoms. Various signaling cascades have been reported to be involved in the pathogenesis of rheumatoid arthritis which includes JAK/STAT, MAPK, and NF-kB signaling pathways, and several allopathic inhibitors (tofacitinib and baricitinib) have been reported to target the components of these cascades and have received approval for RA treatment. However, the prolonged use of these COX inhibitors and other allopathic drugs can pose serious health challenges due to their significant side effects. Therefore, searching for a more effective and side effect-free treatment for rheumatoid arthritis has unveiled phytochemicals as both productive and promising. Their therapeutic ability helps develop potent and safe drugs targeting immune-inflammatory diseases including RA. Various scientific databases were used for searching articles such as NCBI, SpringerLink, BioMed Central, ResearchGate, Google Scholar, Scopus, Nature, Wiley Online Library, and ScienceDirect. This review lists various phytochemicals and discusses their potential molecular targets in RA treatment, as demonstrated by various in vitro, in vivo (pre-clinical), and clinical studies. Several pre-clinical and clinical studies suggest that various phytochemicals can be an alternative promising intervention for attenuating and managing inflammation-associated pathogenesis of rheumatoid arthritis.

DhHP-6 alleviates inflammation and reduces vascular permeability by eliminating reactive oxygen species

Inflammation is a defensive immune response to external stimuli. However, uncontrolled inflammation may cause potential damage to the host. Therefore, timely control of uncontrolled inflammation is particularly important. Previous studies have found that small molecules with antioxidant activity, such as peroxidase mimic enzymes, can inhibit the development of inflammation. DhHP-6 is a new peptide mimic of peroxidase previously designed by our laboratory. Here, we explored its anti-inflammatory activity in vitro and in vivo. Our results showed that treatment with DhHP-6 significantly reduced the production of reactive oxygen species (ROS), NO, IL-6, and TNF-α in RAW264.7 cells induced by lipopolysaccharides (LPS); in addition, it also blocked the phosphorylation of extracellularly regulated kinase 1 and 2 (ERK1/2) and ribosomal s6 kinase 1 (RSK1), thereby blocking the phosphorylation and degradation of IκBα, and inhibiting the nuclear translocation of p65. Interestingly, treatment with DhHP-6 blocked the phosphorylation of ERK1/2 and myosin light chain kinase (MLCK) in HUVECs induced by LPS. Finally, we found that DhHP-6 treatment significantly reduced the infiltration of immune cells in balloon model rats. Therefore, we believe that DhHP-6 is a potent inhibitor of inflammation.

Fermentation of Abelmoschus manihot Extract with Halophilic Bacillus licheniformis CP6 Results in Enhanced Anti-Inflammatory Activities

Microbial fermentation provides a valorization strategy, through biotransformation, to convert plant-derived raw materials into health-promoting agents. In this study, we have investigated the antioxidative activity of Abelmoschus manihot fermented with various Bacillaceae strains from specific environments and demonstrated the anti-inflammatory effects of Bacillus licheniformis CP6 fermented A. manihot extract (FAME) in lipopolysaccharide (LPS)-stimulated Raw264.7 macrophages. Of 1500 bacteria isolated from various specific environments, 47 extracellular protease- and amylase-producing strains with qualified presumption safety status, belonging to the family Bacillaceae, were selected for A. manihot fermentation. Among them, strain CP6, a halophilic bacterium isolated from Tongyeong seawater in Korea and identified as B. licheniformis, showed the highest antioxidant activity. In particular, FAME exerted anti-inflammatory effects on LPS-stimulated Raw264.7 macrophages. Consequently, FAME had a potent inhibitory effect on nitric oxide (NO) production in LPS-stimulated macrophages, without cytotoxicity. Moreover, FAME downregulated LPS-induced pro-inflammatory mediator and enzyme levels in LPS-induced Raw264.7 cells, including IL-1β, IL-6, TNF-α, iNOS, and COX-2, compared to levels when cells were incubated in A. manihot extract (IAME). Further detailed characterization indicated that FAME suppresses inflammation by blocking NF-κB via IKK phosphorylation inhibition and IκB-α degradation and by downregulating NO production, and inflammatory mediators also decreased NF-κB translocation. Furthermore, FAME inhibited LPS-stimulated activation of MAPKs, including ERK1/2, JNK, and p38, compared to that with either IAME. Therefore, we suggest that FAME could be used for inflammation-related disorders.

Anti-inflammatory and antioxidant activities of methanol extract of Piper betle Linn. (Piper betle L.) leaves and stems by inhibiting NF-κB/MAPK/Nrf2 signaling pathways in RAW 264.7 macrophages

Oxidative stress and chronic inflammation are closely linked to various diseases. However, previous studies have demonstrated that plant extracts could prevent and alleviate these adverse outcomes. Piper betle Linn. (Piper betle L.) is a cosmopolitan plant that belongs to the Piperaceae family, whose leaves are edible and possess several health benefits. This study sought to characterize the anti-inflammatory and antioxidant effects of a methanol extract of Piper betle L. leaves and stems (MPBLLS). MPBLLS was found to have a dose-dependent radical scavenging effect, as demonstrated by the 2,2-diphenyl-1-picrylhydrazyl assay. Additionally, MPBLLS inhibited the lipopolysaccharide (LPS)-stimulated production of nitric oxide and prostaglandin E₂ by reducing the expression of inducible nitric oxide synthase and cyclooxygenase-2 in RAW 264.7 macrophages without affecting cell viability. Furthermore, our findings suggested that the inhibitory effects of MPBLLS on pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-1β, and interleukin-6 were due to the inhibition of the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways in LPS-treated RAW 264.7 macrophages. MPBLLS and hydroxychavicol, a major constituent of MPBLLS, suppressed LPS-induced translocation of NF-κB p65 from cytoplasm to nucleus. Interestingly, MPBLLS increased nuclear factor erythroid 2-related factor 2 (Nrf2) protein levels and transcription levels of Nrf2 target genes in a dose-dependent manner. Collectively, our findings suggest that MPBLLS could serve as a basis for the development of novel orally-administered therapies due to its inhibitory effects on oxidative and inflammatory stress. DATA AVAILABILITY: The data presented in this study are available on request from the corresponding author.

Carrageenophyte Kappaphycus malesianus Inhibits Microglia-Mediated Neuroinflammation via Suppression of AKT/NF-κB and ERK Signaling Pathways

Neuroinflammation is an inflammatory response in any part of the central nervous system triggered by the activation of microglia and astrocytes to produce proinflammatory cytokines in the brain. However, overproduction of proinflammatory cytokines further contributes to the development of neurodegenerative disorders. Red seaweed, Kappaphycus malesianus, is a predominant carrageenophyte commercially cultivated in Semporna, Sabah, Malaysia. It is an important source of raw material for kappa-carrageenan productions in the food, pharmaceutical and cosmetics industries. However, no studies have been conducted focusing on the antineuroinflammatory effects of K. malesianus. The aim of the present study was to investigate the effect of the antineuroinflammatory activity of K. malesianus extracts (ethyl acetate, ethanol and methanol) on lipopolysaccharide-stimulated BV2 microglia and the underlying mechanisms involved in the regulation of neuroinflammatory pathways. Extract with the most promising antineuroinflammatory activity was analyzed using liquid chromatography-mass spectrometry (LC-MS). Our results show that methanol extract has a convincing antineuroinflammatory effect by suppressing both AKT/NF-κB and ERK signaling pathways to inhibit the expression of all proinflammatory cytokines without causing a cytotoxicity effect. LC-MS analysis of methanol extract revealed two compounds: prosopinine and eplerenone. Our findings indicated that metabolites of K. malesianus are potent antineuroinflammatory agents with respect to prevention of neurological disorders.

Lignans as Pharmacological Agents in Disorders Related to Oxidative Stress and Inflammation: Chemical Synthesis Approaches and Biological Activities

Plant lignans exhibit a wide range of biological activities, which makes them the research objects of potential use as therapeutic agents. They provide diverse naturally-occurring pharmacophores and are available for production by chemical synthesis. A large amount of accumulated data indicates that lignans of different structural groups are apt to demonstrate both anti-inflammatory and antioxidant effects, in many cases, simultaneously. In this review, we summarize the comprehensive knowledge about lignan use as a bioactive agent in disorders associated with oxidative stress and inflammation, pharmacological effects in vitro and in vivo, molecular mechanisms underlying these effects, and chemical synthesis approaches. This article provides an up-to-date overview of the current data in this area, available in PubMed, Scopus, and Web of Science databases, screened from 2000 to 2022.

Importance of Gedunin in Antagonizing Rheumatoid Arthritis via Activating the Nrf2/ARE Signaling

Objective

This study assessed the anti-arthritic effect and protection of Gedunin (GDN) on joint tissues and revealed the possible mechanism in suppressing rheumatoid arthritis (RA).

Methods

LPS-induced macrophages and TNF-α-stimulated synovial fibroblasts (MH7A) or IL-1β-stimulated primary rheumatoid arthritis synovial fibroblasts (RASFs) were used to evaluate the antiinflammatory effect of GDN. In addition, CIA-induced arthritis was employed here to evaluate the anti-arthritic effect. MTT and BRDU assays were utilized to evaluate the cell viability and proliferation, Q-PCR was conducted to detect the mRNA expression of cytokines, FACS was adopted to monitor ROS production, while western blotting (WB) and siRNA interference were applied in confirming the anti-arthritic effects of GDN via the Nrf2 signaling. Results. In vitro, cell viability was inhibited in macrophages and MH7A cells, but not in RASFs; but the proliferation of RASFs was significantly suppressed in time- and dose-dependent manners. GDN suppressed cytokine levels in LPS-stimulated macrophages and TNF-α-stimulated MH7A cells or RASFs. GDN suppressed ROS expression. Furthermore, GDN treatment notably dose-dependently decreased the mRNA and protein expression of iNOS in LPS-induced macrophages. sip62 interference results showed that GDN cause the less expression of HO-1 and Keap1 and also fail to inhibit cytokines after sip62 interference. In vivo, GDN effectively inhibited paw swelling, arthritis score, and arthritis incidence and cytokines.

Conclusions

Our study suggested that GDN exhibited strong antagonistic effect on arthritis both in vitro and in vivo via activation of Nrf2 signaling. Our work will provide a promising therapeutic strategy for RA.

Anti-Inflammatory and Immunoregulatory Action of Sesquiterpene Lactones

Sesquiterpene lactones (SL), characterized by their high prevalence in the Asteraceae family, are one of the major groups of secondary metabolites found in plants. Researchers from distinct research fields, including pharmacology, medicine, and agriculture, are interested in their biological potential. With new SL discovered in the last years, new biological activities have been tested, different action mechanisms (synergistic and/or antagonistic effects), as well as molecular structure–activity relationships described. The review identifies the main sesquiterpene lactones with interconnections between immune responses and anti-inflammatory actions, within different cellular models as well in in vivo studies. Bioaccessibility and bioavailability, as well as molecular structure–activity relationships are addressed. Additionally, plant metabolic engineering, and the impact of sesquiterpene lactone extraction methodologies are presented, with the perspective of biological activity enhancement. Sesquiterpene lactones derivatives are also addressed. This review summarizes the current knowledge regarding the therapeutic potential of sesquiterpene lactones within immune and inflammatory activities, highlighting trends and opportunities for their pharmaceutical/clinical use.

The bioactivity and applications of pomegranate peel extract: A review

Pomegranate peel (PP) is a by-product in the processing of pomegranate products, which is usually discarded as a waste. However, a large number of researches have shown that pomegranate peel extract (PPE) is rich in a variety of phenolic substances, among which ellagic acid (EA), as one of the main active components, has significant biological activities, such as anti-oxidation, anti-tumor, anti-inflammatory, neuroprotection, anti-viral, and anti-bacterial. We analyzed the mechanism of EA's biological activity, and discussed its application in the food industry, for instance, food preservation, food additives, and functional foods. Combined with the research status of PPE, we discussed the limitations and development potential of PPE, in order to provide theoretical reference and scientific basis for the development and utilization of pomegranate by-products. PRACTICAL APPLICATIONS: Pomegranate peel (PP), the inedible part of the fruit, is usually treated as waste. In recent years, researchers have been committed to exploring various bioactive ingredients in PP and exploring its potential benefits to human health, which has far-reaching significance. In this paper, the chemical constituents of polyphenols in PP were reviewed, mainly focusing on the biological activity and mechanism of ellagic acid (EA). We reviewed the applications and invention patents of pomegranate peel extract (PPE) in food field, including food preservation, food additive, and functional foods, providing reference for the recycling and reuse of PP.

Anti-Inflammatory Activity and Mechanism of Cryptochlorogenic Acid from Ageratina adenophora

Ageratina adenophora is an invasive plant known for its toxicity to livestock. Current research on this plant has shifted from toxicity prevention to the beneficial utilization of plant resources. This study was performed to investigate the effects and mechanisms of cryptochlorogenic acid (CCGA) isolated from Ageratina adenophora on the inflammatory responses induced by lipopolysaccharide (LPS) in RAW264.7 cells. RAW264.7 cells were pretreated with CCGA (200, 100, and 50 μg/mL) and subsequently stimulated with LPS (1 μg/mL) for 16 h. The cytotoxicity of CCGA was tested using the Cell Counting Kit (CCK8). The mechanism of action of CCGA in attenuating inflammation was also identified using enzyme-linked immunosorbent assay (ELISA), quantitative reverse transcription-polymerase chain reaction, and Western blot. The results showed that CCGA had a maximal safe concentration of 200 mg/mL. Moreover, CCGA reduced the level of nitric oxide (NO) and iNOS in LPS-induced RAW264.7 cells (p < 0.01). In addition, CCGA reduced the levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-8) and cyclooxygenase-2 (COX-2) in LPS-induced RAW264.7 cells at both the mRNA and protein levels (p < 0.01). CCGA prevented the activation of nuclear factor-kappa B (NF-kB) in LPS-induced RAW264.7 cells via the inhibition of IKK and IκB phosphorylation and the degradation of IκB proteins (p < 0.01). This finding indicated that CCGA isolated from A. adenophora may be a potential candidate for the treatment of inflammation-related diseases.

Luteolin-3'-O-Phosphate Inhibits Lipopolysaccharide-Induced Inflammatory Responses by Regulating NF-κB/MAPK Cascade Signaling in RAW 264.7 Cells

Luteolin (LT), present in most plants, has potent anti-inflammatory properties both in vitro and in vivo. Furthermore, some of its derivatives, such as luteolin-7-O-glucoside, also exhibit anti-inflammatory activity. However, the molecular mechanisms underlying luteolin-3′-O-phosphate (LTP)-mediated immune regulation are not fully understood. In this paper, we compared the anti-inflammatory properties of LT and LTP and analyzed their molecular mechanisms of action; we obtained LTP via the biorenovation of LT. We investigated the anti-inflammatory activities of LT and LTP in macrophage RAW 264.7 cells. We confirmed from previously reported literature that LT inhibits the production of nitric oxide and prostaglandin E₂, as well as the expression of inducible NO synthetase and cyclooxygenase-2. In addition, expressions of inflammatory genes and mediators, such as tumor necrosis factor-α, interleukin-6, and interleukin-1β, were suppressed. LTP showed anti-inflammatory activity similar to LT, but better anti-inflammatory activity in all the experiments, while also inhibiting mitogen-activated protein kinase and nuclear factor-kappa B more effectively than LT. At a concentration of 10 μM, LTP showed differences of 2.1 to 44.5% in the activity compared to LT; it also showed higher anti-inflammatory activity. Our findings suggest that LTP has stronger anti-inflammatory activity than LT.

Sauchinone inhibits the proliferation, migration and invasion of breast cancer cells by suppressing Akt-CREB-MMP13 signaling pathway

Sauchinone, a lignan isolated from Saururus chinenesis, is known to exhibit anti-inflammatory and anti-oxidant effects. Recently, sauchinone has been reported to inhibit the growth of various cancer cells, but its effects on breast cancer cells remain poorly understood. In the present study, we investigated the effects of sauchinone on the growth of breast cancer cells along with the underlying molecular mechanisms. Our results show that sauchinone treatment markedly inhibited the proliferation, migration, and invasion of breast cancer cells. Sauchinone reduced the phosphorylation of Akt, ERK, and CREB increased by transforming growth factor-β (TGF-β). In particular, sauchinone treatment suppressed the expression of matrix metalloproteinase (MMP)-13 (MMP13) by regulating the Akt-CREB signaling pathway. Sauchinone was less effective in inhibiting cell migration in Mmp13-knockdown cells than in control cells, suggesting that MMP13 may be a novel target for sauchinone. Our study suggests that sauchinone inhibits the growth of breast cancer cells by attenuating the Akt-CREB-MMP13 pathway. In addition, the targeted inhibition of MMP13 by sauchinone represents a promising approach for the treatment of breast cancer.

Synergistic inhibitory effects of the oxyresveratrol and dacarbazine combination against melanoma cells

Various therapies have been developed to target malignant melanoma, which is associated with a high mortality rate worldwide. Although dacarbazine (DTIC) is employed for treating melanoma, it is associated with several side effects. Hence, patients with melanoma are co-treated with additional drugs to mitigate the side effects of DTIC. In the present study, synergistic therapeutic effects of the DTIC/oxyresveratrol (ORT) combination were examined using the human malignant melanoma WM-266-4 cell line. Treatment with ORT and DTIC inhibited the proliferation of WM-266-4 cells. Compared with those in the ORT- and DTIC-treated groups, the proportion of cells arrested at the S phase, as well as apoptotic rates, were increased in the ORT and DTIC co-treatment group. In WM-266-4 cells, synergistic proliferation-inhibitory activities of the ORT/DTIC combination were assessed based on cell viability and migration, antioxidant capacity, cytokine production, cell cycle arrest, apoptotic rate and protein expression through WST-1 assay, wound healing assay, flow cytometry and western blotting. Furthermore, the expression levels of proteins, including NOTCH, involved in the pathogenesis of solid cancers, such as melanoma, were examined. Overall, the ORT/DTIC combination synergistically promoted cell cycle arrest at the S phase and the apoptosis of WM-266-4 cells. Thus, this combination treatment may serve as a novel therapeutic strategy for treating malignant melanoma.

Sauchinone Blocks Ethanol Withdrawal-Induced Anxiety but Spares Locomotor Sensitization: Involvement of Nitric Oxide in the Bed Nucleus of the Stria Terminalis

Both the positive (manifested by locomotor sensitization) and negative (withdrawal symptoms) reinforcing effects of ethanol (EtOH) involve central nitric oxide (NO) signaling. Sauchinone (a bioactive lignan in Saururus chinensis) has been shown to improve methamphetamine-induced behavioral and neurochemical changes via the NO signaling pathway. Thus, this study evaluated the effects of sauchinone on locomotor sensitization and anxiety during EtOH withdrawal (EtOHW). Male adult Sprague-Dawley rats were treated with 1.5 g/kg/day of EtOH (20%, vol/vol) via intraperitoneal injection for 28 days, followed by a 3-day withdrawal. During withdrawal, the rats were given intragastric sauchinone (2.5, 7.5, or 25 mg/kg/day) once a day. EtOH locomotor sensitization was determined by challenging EtOHW rats with 0.75 g/kg EtOH, while EtOHW-induced anxiety was assessed using the elevated plus maze (EPM). None of the three doses of sauchinone affected EtOH locomotor sensitization. However, in the EPM, treatment of EtOHW rats with sauchinone at 7.5 or 25 mg/kg/day increased both the number of entries into and the time spent in the open arms. Moreover, the two doses of sauchinone inhibited the oversecretion of plasma corticosterone during EtOHW. In the bed nucleus of the stria terminalis (BNST), EtOHW increased NO production, enhanced gene and protein expression of both inducible nitric oxide synthase (iNOS) and neuronal NOS (nNOS), and also elevated protein levels of corticotropin-releasing factor, which were all inhibited by 25 mg/kg/day sauchinone. In an in vitro experiment, sauchinone (3, 10, and 30 μM) inhibited H₂O₂-stimulated nNOS protein expression in neuronal PC12 cells. Finally, intra-BNST infusion of sodium nitroprusside, a NO donor, after sauchinone (25 mg/kg/day) administration, abolished its expected anxiolytic effect. Taken together, these results indicate that sauchinone attenuates anxiety-like behavior in rats during EtOHW but spares EtOH locomotor sensitization, and the anxiolytic effect is mediated via the NO signaling pathway in the BNST.

Inhibitory Effects of Porphyra tenera Extract on Oxidation and Inflammatory Responses

Porphyra tenera (laver) has long been a popular and traditional seaweed food in Korea, Japan, and China. Historically, it was known as a marine medicinal herb to treat hemorrhoids and cholera morbus in Donguibogam. We investigated the effects of P. tenera extract (PTE) for its antioxidant and anti-inflammatory activities. These activities were measured using assays for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) radical scavenging and its superoxide dismutase- (SOD-) like activity, and through the inhibitory production of inflammatory mediators (prostaglandin E₂ (PGE₂), NO, tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6)) in lipopolysaccharide- (LPS-) stimulated Raw 264.7 cells. The antioxidant assay results showed that PTE displayed DPPH radical scavenging activity (46.44%), NO radical scavenging activity (67.14%), and SOD-like activity (80.29%) at a concentration of 5 mg/mL. In the anti-inflammatory assays, treatment with PTE (1 mg/mL) significantly inhibited expression levels of LPS-induced COX-2 and iNOS, as well as the production of PGE₂, NO, TNF-α, and IL-6. These results show that PTE has antioxidant and anti-inflammatory properties and provide scientific evidence to explain the antioxidative and anti-inflammatory properties of PTE.

Anti-inflammatory effects of Fritillaria thunbergii Miquel extracts in LPS-stimulated murine macrophage RAW 264.7 cells

The aim of the present study was to demonstrate that Fritillaria thunbergii Miquel extract exerts anti-inflammatory and antioxidant effects on lipopolysaccharide-stimulated RAW 264.7 cells. To confirm the inhibitory effect of ethyl acetate fraction of FTM (EAFM) on inflammation, the expression of nitric oxide (NO) and inflammatory cytokines was assessed by performing ELISA. Expression of intracellular mRNA and protein was confirmed by reverse transcription PCR and western blotting. In addition, the anti-inflammatory and anti-oxidant mechanisms of NF-κB, MAPK and heme oxygenase-1 (HO-1) were also investigated. EAFM significantly inhibited the expression of inflammatory factors including NO, IL-6 and TNF-α at non-toxic concentrations. EAFM also inhibited the mRNA and protein expression of inducible nitric oxide synthase in a concentration-dependent manner, but did not alter the expression of cyclooxygenase-2. Pre-treatment with EAFM inhibited the nuclear translocation of NF-κB, and suppressed the phosphorylation of ERK and JNK. In addition, EAFM induced 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity and an increase in the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and HO-1. The results indicated that EAFM inhibited the expression of pro-inflammatory cytokines by inhibiting ERK/JNK phosphorylation and NF-κB translocation. EAFM also exerted antioxidant effects via Nrf2/HO-1 stimulation. Collectively, the results of the present study indicated that EAFM may be a valuable alternative for the treatment of a variety of inflammatory diseases.

Immunomodulatory Properties of a γ-Aminobutyric Acid-Enriched Strawberry Juice Produced by Levilactobacillus brevis CRL 2013

Gamma-aminobutyric acid (GABA) plays a key role in mammals as the major inhibitory neurotransmitter of the central nervous system. Although GABA may not be able to cross the human blood-brain barrier, it was approved as a food ingredient because of its benefits to the host after oral administration including anti-hypertensive, anti-depressant and anti-inflammatory activities. Considering the current trend toward the development of new functional and natural products and that microbial fermentation is one of the most promising methods to produce this non-protein amino acid, the in situ production of GABA through fermentation of strawberry and blueberry juices by the efficient GABA producer strain, Levilactobacillus brevis (formerly known as Lactobacillus brevis) CRL 2013, was evaluated. A high GABA production (262 mM GABA) was obtained after fermenting strawberry juice supplemented with yeast extract for 168 h, being GABA yield significantly higher in strawberry juices than in the blueberry ones. Thus, GABA-enriched fermented strawberry juice (FSJ) was selected to carry out in vivo and in vitro studies. The in vitro functional analysis of the GABA-enriched FSJ demonstrated its ability to significantly decrease the expression of cox-2 gene in LPS stimulated RAW 264.7 macrophages. In addition, in vivo studies in mice demonstrated that both, L. brevis CRL 2013 and the GABA-enriched FSJ were capable of reducing the levels of peritoneal, intestinal and serum TNF-α, IL-6, and CXCL1, and increasing IL-10 and IFN-γ in mice exposed to an intraperitoneal challenge of LPS. Of note, the GABA-enriched FSJ was more efficient than the CRL 2013 strain to reduce the pro-inflammatory factors and enhance IL-10 production. These results indicated that the CRL 2013 strain exerts anti-inflammatory effects in the context of LPS stimulation and that this effect is potentiated by fermentation. Our results support the potential use of L. brevis CRL 2013 as an immunomodulatory starter culture and strawberry juice as a remarkable vegetable matrix for the manufacture of GABA-enriched fermented functional foods capable of differentially modulating the inflammatory response triggered by TLR4 activation.

Cohousing-mediated microbiota transfer from milk bioactive components-dosed mice ameliorate colitis by remodeling colonic mucus barrier and lamina propria macrophages

Human milk oligosaccharides (HMOs) and milk fat globule membrane (MFGM) are highly abundant in breast milk, and have been shown to exhibit potent immunomodulatory effects. Yet, their role in the gut microbiota modulation in relation to colitis remains understudied. Since the mixtures of fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS) perfectly mimic the properties and functions of HMOs, the combination of MFGM, FOS, and GOS (CMFG) has therefore been developed and used in this study. Here, CMFG were pre-fed to mice for three weeks to investigate its preventive effect on dextran sodium sulfate (DSS) induced colitis. Moreover, CMFG-treated and vehicle-treated mice were cohoused to further elucidate the preventive role of the gut microbiota transfer in colitis. At the end of the study, 16S rDNA gene amplicon sequencing, short-chain fatty acids (SCFAs) profiling, transcriptome sequencing, histological analysis, immunofluorescence staining and flow cytometry analysis were conducted. Our results showed that CMFG pre-supplementation alleviated DSS-induced colitis as evidenced by decreased disease activity index (DAI) score, reduced body weight loss, increased colon length and mucin secretion, and ameliorated intestinal damage. Moreover, CMFG reduced macrophages in the colon, resulting in decreased levels of IL-1β, IL-6, IL-8, TNF-α, and MPO in the colon and circulation. Furthermore, CMFG altered the gut microbiota composition and promoted SCFAs production in DSS-induced colitis. Markedly, the cohousing study revealed that transfer of gut microbiota from CMFG-treated mice largely improved the DSS-induced colitis as evidenced by reduced intestinal damage and decreased macrophages infiltration in the colon. Moreover, transfer of the gut microbiota from CMFG-treated mice protected against DSS-induced gut microbiota dysbiosis and promotes SCFAs production, which showed to be associated with colitis amelioration. Collectively, these findings demonstrate the beneficial role of CMFG in the gastrointestinal diseases, and further provide evidence for the rational design of effective prophylactic functional diets in both animals and humans.

Sauchinone Protects Renal Mesangial Cell Dysfunction against Angiotensin II by Improving Renal Fibrosis and Inflammation

Abnormal and excessive growth of mesangial cells is important in the pathophysiologic processes of diabetes-associated interstitial fibrosis and glomerulosclerosis, leading to diabetic nephropathy, which eventually turns into end-stage renal disease. Sauchinone, a biologically-active lignan isolated from aerial parts of Saururus chinensis, has anti-inflammatory and anti-viral activities effects on various cell types. However, there are no studies reporting the effects of sauchinone on diabetic nephropathy. The present study aims to investigate the role of sauchinone in mesangial cell proliferation and fibrosis induced by angiotensin II, as well as the underlying mechanisms of these processes. Human renal mesangial cells were induced by angiotensin II (AngII, 10 μM) in the presence or absence of sauchinone (0.1-1 μM) and incubated for 48 h. In this study, we found that AngII induced mesangial cell proliferation, while treatment with sauchinone inhibited the cell proliferation in a dose-dependent manner. Pre-treatment with sauchinone induced down-regulation of cyclins/CDKs and up-regulation of CDK inhibitor, p21, and p27kip1 expression. In addition, AngII-enhanced expression of fibrosis biomarkers such as fibronectin, collagen IV, and connective tissue growth factor (CTGF), which was markedly attenuated by sauchinone. Sauchinone also decreased AngII-induced TGF-β1 and Smad-2, Smad-3, and Smad-4 expression. This study further revealed that sauchinone ameliorated AngII-induced mesangial inflammation through disturbing activation of inflammatory factors, and NLRP3 inflammasome, which is composed of the NLRP3 protein, procaspase-1, and apoptosis-associated speck-like protein containing a CARD (ASC). Moreover, pretreatment of sauchinone inhibited NF-κB translocation and ROS production in AngII-exposed mesangial cells. These data suggest that sauchinone has a protective effect on renal proliferation, fibrosis and inflammation. Therefore, sauchinone might be a potential pharmacological agent in prevention of AngII-induced renal damage leading to diabetic nephropathy.

Sec-O-glucosylhamaudol suppressed inflammatory reaction induced by LPS in RAW264.7 cells through inhibition of NF-κB and MAPKs signaling

As a major bioactive compound from the Saposhnikovia divaricata (Turcz.) Schischk, sec-O-glucosylhamaudol (SOG), has been reported to have anti-nociceptive activity and high 5-lipoxygenase (5-LOX) activity. Nevertheless, the mechanism of the potential anti-inflammatory effects of SOG is unclear. The anti-inflammatory impacts of SOG in RAW 264.7 cell lines stimulated by LPS were explored in the present study. It was found that SOG dose-dependently reduced the emergence of inflammation cytokines, such as IL-6 and TNF-α in Raw264.7 murine macrophages stimulated by LPS. Real-time PCR assay demonstrated the SOG dose-dependently inhibited transcription of these cytokines as well. In addition, it was also found that NF-κB activation and MAPKs phosphorylation including p38, JNK and ERK1/2 induced by LPS were suppressed by SOG. Due to its anti-inflammatory activity, our results suggest that SOG might have therapeutic effects on inflammatory disease, such as acute lung injury or rheumatoid arthritis.

Inhibitory Mechanisms of Water Extract of Oplopanax elatus on Lipopolysaccharide-Induced Inflammatory Responses in RAW 264.7 Murine Macrophage Cells

OBJECTIVE

To study the anti-inflammatory action and cellular mechanism of Oplopanax elatus.

METHODS

A hot water extract of OE (WOE) was prepared and a major constituent, syringin, was successfully isolated. Its content in WOE was found to be 214.0 µg/g dried plant (w/w). Their anti-inflammatory activities were examined using RAW 264.7 macrophages and a mouse model of croton oil-induced ear edema.

RESULTS

In lipopolysaccharide (LPS)-treated RAW 264.7 cells, a mouse macrophage cell line, WOE was found to significantly and strongly inhibit cyclooxygenase-2 (COX-2)-induced prostaglandin E₂ (PGE₂) production [half maximal inhibitory concentration (IC₅₀)=135.2 µg/mL] and inducible nitric oxide synthase (iNOS)-induced NO production (IC₅₀=242.9 µg/mL). In the same condition, WOE was revealed to inhibit NO production by down-regulating iNOS expression, mainly by interrupting mitogen activated protein kinases (MAPKs)/activator protein-1 (AP-1) pathway. The activation of all three major MAPKs, p38 MAPK, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase, was inhibited by WOE (50-300 µg/mL). On the other hand, WOE reduced PGE₂ production by inhibiting COX-2 enzyme activity, but did not affect COX-2 expression levels. In addition, WOE inhibited the production of proinflammatory cytokines such as interleukin-6 and tumor necrosis factor-α. In croton oil-induced ear edema in mice, oral administration of WOE (50-300 mg/kg) dose-dependently inhibited edematic inflammation.

CONCLUSION

Water extract of OE exhibited multiple anti-inflammatory action mechanisms and may have potential for treating inflammatory disorders.

A Review of Traditional Uses, Phytochemistry, and Pharmacological Properties of the Genus Saururus

The genus Saururus, belonging to Saururaceae, contains two species, S. cernuus L. and S. chinensis (Lour) Baill. with common utilization in traditional medicine from Asia to North America for the treatment of edema, beriberi, jaundice, leucorrhea, urinary tract infections, hypertension, hepatitis diseases, and tumors. An extensive review of literature was made on traditional uses, phytochemistry, and ethnopharmacology of Saururus using ethno-botanical books, published articles, and electronic databases. The 147 of chemical constituents have been isolated and identified from S. cernuus and S. chinensis, and lignans, flavonoids, alkaloids, anthraquinones, saponins, and phenols are the major constituents. Various pharmacological investigations in many in vitro and in vivo models have revealed the potential of the genus Saururus with anti-inflammatory, antitumor, anti-oxidant, hepatoprotective, antimelanogenic, lipid-lowering, and bone protective activities, supporting the rationale behind numerous of its traditional uses. Due to the noteworthy pharmacological properties, Saururus can be a better option for new drug discovery. Data regarding many aspects of this plant such as toxicology, pharmacokinetics, quality-control measures, and the clinical value of the active compounds is still limited which call for additional studies.

Role of natural products in mitigation of toxic effects of methamphetamine: A review of in vitro and in vivo studies

OBJECTIVE

Methamphetamine (METH) increases dopamine, norepinephrine and serotonin concentrations in the synaptic cleft, and induces hyperactivity. The current management of acute METH poisoning relies on supportive care and no specific antidote is available for treatment. The main objective of this review was to present the evidence for effectiveness of the herbal medicine in alleviating the adverse effects of METH abuse.

MATERIALS AND METHODS

Literature search was performed using the following electronic databases: MEDLINE, Scopus, PubMed and EMBASE.

RESULTS

Plant-derived natural products ginseng and sauchinone reduced METH-induced hyperactivity, conditioned place preference and neurological disorder. Garcinia kola decreased METH-induced hepatotoxicity, raised METH lethal dose, and restored the METH-impaired cognitive function. Repeated administration of baicalein resulted in attenuation of acute binge METH-induced amnesia via dopamine receptors. Activation of extracellular-regulated kinase in the hypothalamus by levo-tetrahydropalmatine facilitated the extinction of METH-induced conditioned place preference and reduced the hyperactivity. Other herbal medicine from various parts of the world were also discussed including hispidulin, silymarin, limonene, resveratrol, chlorogenic acid and barakol.

CONCLUSION

Based on the current study, some natural products such as ginseng and levo-tetrahydropalmatine are promising candidates to treat METH abuse and poisoning. However, clinical trials are needed to confirm these finding.

Deacetyl Ganoderic Acid F Inhibits LPS-Induced Neural Inflammation via NF-κB Pathway Both In Vitro and In Vivo

Microglia mediated neuronal inflammation has been widely reported to be responsible for neurodegenerative disease. Deacetyl ganoderic acid F (DeGA F) is a triterpenoid isolated from Ganoderma lucidum, which is a famous edible and medicinal mushroom used for treatment of dizziness and insomnia in traditional medicine for a long time. In this study the inhibitory effects and mechanisms of DeGA F against lipopolysaccharide (LPS)-induced inflammation both in vitro and in vivo were investigated. On murine microglial cell line BV-2 cells, DeGA F treatment inhibited LPS-triggered NO production and iNOS expression and affected the secretion and mRNA levels of relative inflammatory cytokines. DeGA F inhibited LPS-induced activation of the NF-κB pathway, as evidenced by decreased phosphorylation of IKK and IκB and the nuclear translocation of P65. In vivo, DeGA F treatment effectively inhibited NO production in zebrafish embryos. Moreover, DeGA F suppressed the serum levels of pro-inflammatory cytokines, including TNF-α and IL-6 in LPS-stimulated mice model. DeGA F reduced inflammatory response by suppressing microglia and astrocytes activation and also suppressed LPS-induced NF-κB activation in mice brains. Taken together, DeGA F exhibited remarkable anti-inflammatory effects and promising therapeutic potential for neural inflammation associated diseases.

Effects of dichloromethane Sarcophyton spp. extract on the lipopolysaccharide-induced expression of nuclear factor-kappa B and inducible nitric oxide synthase in mice

BACKGROUND AND AIM

The soft coral genus Sarcophyton is a source of cembraneterpen. Sarcophyton is reported to have anti-inflammatory properties, with the ability to reduce the expression of inducible nitric oxide synthase (iNOS) and inhibit nuclear factor-kappa B (NF-κB) activation. This study aimed to investigate the efficacy of dichloromethane (DCM) extracts of soft coral Sarcophyton spp. to inhibit the expression of NF-κB and iNOS induced by lipopolysaccharide (LPS).

MATERIALS AND METHODS

Crude extracts of Sarcophyton spp. were macerated with DCM (1:3 v/v) for 24 h. Thirty-six Balb/c mice were divided into six treatment groups, namely, normal control (without LPS induction), negative control (LPS induction 4 mg/mL), comparative control (LPS+Dexamethasone 6 mg/kg), and 3 concentration groups extract (LPS+50, 125, and 250 mg/kg). The expression of NF-κB and iNOS was measured in each treatment group.

RESULTS

Flow cytometry analysis showed that the relative number of NF-κB+ cells increased (18.38±1.24%) in LPS-induced mice compared with normal mice (13.24±1.15%). The Sarcophyton spp. DCM extracts decreased the relative number of NF-κB+ cells (125 mg/kg: 13.96±0.84%). Immunohistochemical analysis with ImmunoMembrane showed that LPS induction in mice increased iNOS expression when compared to normal mice. The Sarcophyton spp. DCM extracts reduced iNOS expression (especially at 125 mg/kg).

CONCLUSION

DCM extracts of Sarcophyton spp. inhibited the activation of NF-κB, resulting in suppressed iNOS expression, which directly inhibits NO production.

Identification of an IKKβ inhibitor for inhibition of inflammation in vivo and in vitro

Targeting on the IKKβ to discover anti-inflammatory drugs has been launched for ten years, due to its predominant role in canonical NF-κB signaling. In the current study, we identified a novel IKKβ inhibitor, ellipticine (ELL), an alkaloid isolated from Ochrosia elliptica and Rauvolfia sandwicensis. We found that ELL reduced the secretion and mRNA expression of TNF-α and IL-6 and decreased the protein expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in bone marrow derived macrophages (BMDMs) stimulated with LPS. In coincided with the results, ELL suppressed PGE2 and NO production in BMDMs. Underlying mechanistic study showed that ELL inhibited IκBα phosphorylation and degradation as well as NF-κB nuclear translocation, which was attributed to suppression of IKKα/β activation. Furthermore, kinase assay and binding assay results indicated that ELL inhibited IKKβ activity via directly binding to IKKβ and in turn resulted in suppression of NF-κB signaling. To identify the binding sites of ELL on IKKβ, IKKβC46A plasmid was prepared and the kinase assay was performed. The results demonstrated that the inhibitory effect of ELL on IKKβ activity was impaired in the mutation, implying that anti-inflammatory effect of ELL was partially attributed to binding on cysteine 46. Furthermore, ELL up-regulated LC3 II expression and reduced p62 expression, suggesting that autophagy induction contributed to the anti-inflammatory effect of ELL as well. In coincided with the in vitro results, ELL increased the survival and antagonized the hypothermia in the mice with LPS-induced septic shock. Consistently, ELL reduced TNF-α and IL-6 production in the serum of the mice treated with LPS. Collectively, our study provides evidence that ELL is an IKKβ inhibitor and has potential to be developed as a lead compound for treatment inflammatory diseases in the future.

Anti-Inflammatory Effects of Formononetin 7-O-phosphate, a Novel Biorenovation Product, on LPS-Stimulated RAW 264.7 Macrophage Cells

Biorenovation is a microbial enzyme-catalyzed structural modification of organic compounds with the potential benefits of reduced toxicity and improved biological properties relative to their precursor compounds. In this study, we synthesized a novel compound verified as formononetin 7-O-phosphate (FMP) from formononetin (FM) using microbial biotransformation. We further compared the anti-inflammatory properties of FMP to FM in lipopolysaccharide (LPS)-treated RAW264.7 macrophage cells. We observed that cell viabilities and inhibitory effects on LPS-induced nitric oxide (NO) production were greater in FMP-treated RAW 264.7 cells than in their FM-treated counterparts. In addition, FMP treatment suppressed the production of proinflammatory cytokines such as prostaglandin-E₂ (PGE₂), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in a dose-dependent manner and concomitantly decreased the mRNA expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). We also found that FMP exerted its anti-inflammatory effects through the downregulation of the extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and nuclear factor kappa B (NF-κB) signaling pathways. In conclusion, we generated a novel anti-inflammatory compound using biorenovation and demonstrated its efficacy in cell-based in vitro assays.

Antileishmanial activity and ultrastructural changes of related tetrahydrofuran dineolignans isolated from Saururus cernuus L. (Saururaceae)

Objective

This work describes the isolation of anti-Leishmania amazonensis metabolites from Saururus cernuus (Saururaceae). Additionally, ultrastructural changes in promastigotes were evidenced by electron microscopy.

Methods

The MeOH extract from the leaves of S. cernuus was subjected to bioactivity-guided fractionation. Anti-L. amazonensis activity of purified compounds was performed in vitro against promastigote and amastigote forms.

Key findings

Bioactivity-guided fractionation of the MeOH extract from the leaves of S. cernuus afforded two related tetrahydrofuran dineolignans: threo,threo-manassantin A (1) and threo,erythro-manassantin A (2). Compounds 1 and 2 displayed activity against promastigotes (EC50 of 35.4 ± 7.7 and 17.6 ± 4.2 μm, respectively) and amastigotes (EC50 of 20.4 ± 1.9 and 16.0 ± 1.1 μm, respectively), superior to that determined for the positive control miltefosine (EC50 of 28.7 ± 3.5 μm). Reduced cytotoxicity for host cells was observed for both compounds. Additionally, ultrastructural changes in promastigotes leading to an alteration of structural morphology were observed, as evidenced by electron microscopy. Furthermore, these compounds altered the morphology and physiology of the plasmatic membrane of L. amazonensis.

Conclusions

The obtained results indicated that dineolignans 1 and 2 could be considered as a scaffold for the design of novel and selective drug candidates for the treatment of leishmaniasis.

Anti-inflammatory Effects of a Sesquiterpene Lactone Extract from Chicory (Cichorium intybus L.) Roots

A chicory root extract rich in sesquiterpene lactones significantly reduced inflammation in two animal models. In a rat paw edema model, chicory extract at 50 and 100 mg/kg significantly reduced inflammation by 58 and 76%, respectively, 24 h after carrageenan injection. In a mouse collagen induced arthritis model, chicory extract (200 mg/kg) reduced paw edema by 71% while the extract was being administered, and 31% 48 h after extract administration was discontinued. Two possible modes of action were investigated, pro-inflammatory gene expression and nitric oxide production by LPS-elicited macrophages. Chicory root extract down-regulated COX-2, TNF-α, IL1β, and iNOS expression and reduced nitric oxide production in a dose dependant manner. Several compounds were isolated from the chicory extract and tested in vitro to confirm activity. Dihydrolactucopicrin and 8-deoxylactucin showed particularly high nitric oxide inhibitory activity (IC50 = 13 μM for both). Dihydrolactucopicrin also was shown to down-regulate pro-inflammatory gene expression. These data demonstrate that chicory extracts rich in sesquiterpene lactones have potent anti-inflammatory activity with potential therapeutic use.

Intracellular Signaling Mechanisms Involved in the Biological Effects of the Xanthophyll Carotenoid Astaxanthin to Prevent the Photo-aging of the Skin in a Reactive Oxygen Species Depletion-independent Manner: The Key Role of Mitogen and Stress-activated Protein Kinase 1

In the first review, we summarized the biological effects of the xanthophyll carotenoid astaxanthin (AX) to prevent UV-induced cutaneous inflammation, abnormal keratinization, pigmentation, and wrinkling in a manner independent of the depletion of reactive oxygen species. In this manuscript, we review what is known about the intracellular signaling mechanisms that are involved in those effects in keratinocytes and in melanocytes. Our research has characterized the intracellular stress signaling mechanism(s) that are involved in the up-regulated expression of genes encoding cyclooxygenase (COX2), interleukin (IL)-8, granulocyte macrophage colony stimulatory factor (GM-CSF), and transglutaminase (TGase)1 in UVB-exposed keratinocytes as well as in the stimulated transcription and/or translation of melanogenic factors, including microphthalmia-associated transcription factor (MITF), in stem cell factor (SCF)-treated melanocytes. The results reveal that while the expression of COX2, IL-8, GM-CSF, and TGase1 stimulated by UVB is due to effects primarily via the NFκB pathway, that stimulation can be abrogated by specifically interrupting the p38/MSK1/NFκBp65Ser276 axis. Further, the stimulation of melanogenesis by SCF can be inhibited by disrupting the phosphorylation of MSK1 via the p38, MSK1, CREB, and MITF axis. The sum of these findings provides new evidence for the interruption of ROS depletion independent-signaling by antioxidants.

Tetrahydrobenzochromene Synthesis Enabled by a Deconjugative Alkylation/Tsuji-Saegusa-Ito Oxidation on Knoevenagel Adducts

A modular and practical route to versatile cyano-1,3-dienes by a sequence involving deconjugative alkylation and "Tsuji-Saegusa-Ito oxidation" is reported. In this letter, the versatility of the products is also explored, including a route to benzochromene scaffolds common to many natural products.

Combination of EPA with Carotenoids and Polyphenol Synergistically Attenuated the Transformation of Microglia to M1 Phenotype Via Inhibition of NF-κB

Microglia activation toward the M1 phenotype has been reported to contribute to the neurodegenerative processes and cognition alterations due to the release of pro-inflammatory mediators and cytokines. The aim of the present research was to assess the effectiveness of free fatty acids omega-3 preparations: eicosapentaenoic acid (EPA) or/and docosahexaenoic acid (DHA), carotenoids and phenolics combinations, in inhibiting the release of inflammatory mediators from activated microglia. Preincubation of BV-2 microglia cells with each of the FFAs omega-3 preparations in a range of 0.03-2 μM together with Lyc-O-mato^® (0.1 μM), Carnosic acid (0.2 μM) with or without Lutein (0.2 μM), 1 h before addition of lipopolysaccharide (LPS) for 16 h caused a synergistic inhibition of nitric oxide (NO) production with a rank order of EPA > Ropufa (EPA/DHA 2/1) > Krill (EPA/DHA 1.23/1). The optimal inhibitory combinations of EPA (0.125 μM) with the phytonutrients caused a synergistic inhibition of prostaglandin E₂ (PGE₂) release, IL-6 secretion, superoxide and NO production and prevention of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) upregulation and elevated CD40 expression in microglia exposed to LPS or interferon-γ (IFN-γ), representing infection or inflammation, respectively. The presence of the combination caused a synergistic increase in the release of the anti-inflammatory cytokine IL-10. The inhibitory effects by the combinations of EPA with the phytonutrients were mediated by the inhibition of the redox-sensitive NF-κB activation and detected by its phosphorylated p-65 on serine 536 in microglia stimulated by either LPS or IFN-γ. In addition, phosphorylated CREB on serine 133 which was shown to be involved in the induction of iNOS was inhibited by the combinations in stimulated cells. In conclusion, the results suggest that low concentrations of EPA with the phytonutrients are very efficient in inhibiting the transformation of microglia to M1 phenotype and may prevent cognition deficit.

7-deacetylgedunin suppresses inflammatory responses through activation of Keap1/Nrf2/HO-1 signaling

Macrophages play a critical role in a variety of inflammatory diseases. Activation of Keap1/Nrf2/HO-1 signaling results in inactivation of macrophages and amelioration of inflammatory and autoimmune conditions. Hence, discovery for the activators of Keap1/Nrf2/HO-1 signaling has become a promising strategy for treatment inflammatory diseases. In the current study, the anti-inflammatory potential of 7-deacetylgedunin (7-DGD), a limonin chemical isolated from the fruits of Toona sinensis (A. Juss.) Roem, was intensively examined in vivo and in vitro for the first time. Results showed that 7-DGD alleviated mice mortality induced by LPS. Mechanistic study showed that 7-DGD suppressed macrophage proliferation via induction of cell arrest at the G0/G1 phase. Furthermore, 7-DGD inhibited iNOS expression, which is correlated with the increases of NQO1, HO-1 and UGT1A1 mRNA expression as well as HO-1 protein expression level in the cells. More importantly, 7-DGD markedly decreased Keap1 expression, promoted p62 expression, and facilitated Nrf2 translocation and localization in the nucleus of macrophages, and in turn up-regulates these anti-oxidant enzymes expression, eventually mediated anti-inflammatory effect. Collectively, 7-DGD suppresses inflammation in vivo and in vitro, indicating that the compound is valuable for further investigation as an anti-inflammatory agent in future.

Inhibitory effect of Gardenblue blueberry (Vaccinium ashei Reade) anthocyanin extracts on lipopolysaccharide-stimulated inflammatory response in RAW 264.7 cells

Blueberries are a rich source of anthocyanins, which are associated with health benefits contributing to a reduced risk for many diseases. The present study identified the functional Gardenblue blueberry (Vaccinium ashei Reade) anthocyanin extracts (GBBAEs) and evaluated their capacity and underlying mechanisms in protecting murine RAW 264.7 cells from lipopolysaccharide (LPS)-stimulated inflammation in vitro. Enzyme-linked immunosorbent assay (ELISA) kit results showed that GBBAEs significantly inhibited the production of nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-6 (IL-6), IL-1β, and interferon-γ (INF-γ). Real-time polymerase chain reaction (PCR) analysis indicated that the mRNA expression levels of IL-6, IL-1β, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and cyclooxygenase 2 (COX-2) were suppressed in LPS-stimulated RAW 264.7 cells. Additionally, Western blot analysis was used to evaluate the relative protein expression levels of COX-2 and nuclear factor-κB p65 (NF-κBp65). All these results suggested the potential use of GBBAEs as a functional food for the treatment of inflammatory diseases.

Macrophage-stimulating activities of newly isolated complex polysaccharides from Parachlorella kessleri strain KNK-A001

Our previous studies demonstrated that the microalga Parachlorella kessleri (KNK-A001) has immunostimulatory activities, which were observed as an increase in natural killer (NK) cell activity in mice after intraperitoneal injection or as a protective effect on a virus-infected model shrimp after oral administration. In this study, we attempted to gain insight into the constituent substances of KNK-A001 that are responsible for the immunostimulatory activity. First, we obtained five polysaccharide fractions from KNK-A001 by DEAE anion exchange chromatography. Among the fractions, F5 showed the most potent induction of nitric oxide (NO) secretion in RAW264.7 cells, and both mRNA and protein expression levels of inducible NO synthase (iNOS) were increased in F5-treated RAW264.7 cells. A significant increase in the nuclear translocation of the p65 subunit of nuclear factor-kappa B (NF-κB) was observed in F5-treated RAW264.7 cells. F5 also induced the secretion of tumor necrosis factor (TNF)-α in RAW264.7 cells. Analysis using mitogen-activated protein (MAP) kinase inhibitors suggested that c-Jun N-terminal kinase (JNK) and p38 MAP kinase were mainly involved in F5-induced NO and TNF-α productions. The compositional analysis of F5 identified the main constituents as galactose, glucose, galacturonic acid, and mannose. Gel-filtration analysis suggested that molecular mass of F5 was approximately 400kDa.

Leaves of Raphanus sativus L. Shows Anti-Inflammatory Activity in LPS-Stimulated Macrophages via Suppression of COX-2 and iNOS Expression

Raphanus sativus L. (RS) is a cruciferous vegetable that is widely consumed in Korea. The anticancer activity of leaves of RS (RSL) extract has been investigated; however, no studies focused on its anti-inflammatory effects. Therefore, the aim of the current study was to evaluate the anti-inflammatory effects of RSL extract. In brief, RSL powder was fractionated into n-hexane, chloroform, ethyl acetate, n-butanol, and water-soluble fractions. Lipopolysaccharide (LPS)-stimulated RAW264.7 cells were treated with each fraction for initial screening. It was found that the chloroform fraction significantly inhibited nitric oxide release in LPS-stimulated RAW264.7 cells with a half maximal inhibitory concentration value of 196 μg/mL. In addition, the mRNA and protein expression levels of inducible nitric oxide synthase, measured using reverse transcriptase-polymerase chain reaction and western blotting, respectively, were reduced in a concentration-dependent manner. Moreover, the inflammatory cyclooxygenase-2 enzyme expression decreased. Furthermore, the expression of nuclear factor-kappa B (NF-κB), the key regulator of the transcriptional activation of the inflammatory cytokine genes, was reduced by the RSL chloroform fraction. Therefore, the results of our study suggest that RSL exhibits anti-inflammatory effects in LPS-stimulated macrophages via NF-κB inactivation.

Cyclooxygenase-2 facilitates dengue virus replication and serves as a potential target for developing antiviral agents

Cyclooxygenase-2 (COX-2) is one of the important mediators of inflammation in response to viral infection, and it contributes to viral replication, for example, cytomegalovirus or hepatitis C virus replication. The role of COX-2 in dengue virus (DENV) replication remains unclear. In the present study, we observed an increased level of COX-2 in patients with dengue fever compared with healthy donors. Consistent with the clinical data, an elevated level of COX-2 expression was also observed in DENV-infected ICR suckling mice. Using cell-based experiments, we revealed that DENV-2 infection significantly induced COX-2 expression and prostaglandin E₂ (PGE₂) production in human hepatoma Huh-7 cells. The exogenous expression of COX-2 or PGE₂ treatment dose-dependently enhanced DENV-2 replication. In contrast, COX-2 gene silencing and catalytic inhibition sufficiently suppressed DENV-2 replication. In an ICR suckling mouse model, we identified that the COX-2 inhibitor NS398 protected mice from succumbing to life-threatening DENV-2 infection. By using COX-2 promoter-based analysis and specific inhibitors against signaling molecules, we identified that NF-κB and MAPK/JNK are critical factors for DENV-2-induced COX-2 expression and viral replication. Altogether, our results reveal that COX-2 is an important factor for DENV replication and can serve as a potential target for developing therapeutic agents against DENV infection.

Saurolactam Inhibits Proliferation, Migration, and Invasion of Human Osteosarcoma Cells

Osteosarcoma is a common type of malignant bone tumor with features of osteoid formation or osteolytic lesions of bone. New therapeutic approaches are urgently needed since it lacks response to chemotherapeutic treatments. Saurolactam, a natural compound isolated from the aerial portions of Saururus chinensis, was reported to have an anti-inflammatory activity. Here, we demonstrate that saurolactam shows anti-cancer activity against human osteosarcoma cells. Saurolactam treatment inhibited proliferation of human osteosarcoma cell lines MG-63 and HOS and decreased colony formation in soft agar in a dose-dependent manner. Intraperitoneal administration of saurolactam at 25 mg/kg of body weight for 21 days dramatically inhibited the growth of MG-63 xenografts in nude mice. Flow cytometric analysis indicated that saurolactam treatment (20 μM) led to G1 cell cycle arrest and induced apoptosis in these two cell lines. Western analysis suggested that saurolactam treatment resulted in a reduction of Akt/PKB, phospho-Ser473-Akt, c-Myc, and S-phase kinase-associated protein 2 (Skp2) in MG-63 and HOS osteosarcoma cells. Akt overexpression significantly abolished saurolactam-induced decrease in protein and phosphorylation levels of Akt, c-Myc, and Skp2 protein levels, implying that Akt inactivation was a causal mediator of saurolactam-induced inhibition of c-Myc and Skp2. Moreover, Skp2 overexpression in MG-63 cells partly abolished the growth inhibition induced by saurolactam. Saurolactam treatment repressed migration and invasion ability, and Skp2 overexpression significantly blocked these inhibitory effects of saurolactam in MG-63 Cells. The present study indicates that saurolactam might represent a new promising agent to improve osteosarcoma treatment.

Cheongsangbangpung-tang ameliorated the acute inflammatory response via the inhibition of NF-κB activation and MAPK phosphorylation

Background

Cheongsangbangpung-tang (CBT) is a traditional herbal formula used in Eastern Asia to treat heat-related diseases and swellings in the skin. The present study was conducted to evaluate the anti-inflammatory effects of cheongsangbangpung-tang extract (CBTE) both in vitro and in vivo.

Methods

The in vitro effects of CBTE on the lipopolysaccharide (LPS)-induced production of inflammation-related proteins were examined in RAW 264.7 cells. The levels of nitric oxide (NO) were measured with the Griess reagent. Inflammatory cytokines and prostaglandin E₂ (PGE₂) were detected using the enzyme-linked immunosorbent assay (ELISA) method. Inflammation-related proteins were detected by Western blot. The effect of CBTE on acute inflammation in vivo was evaluated using carrageenan (CA)-induced paw oedema. To evaluate the anti-inflammatory effect, paw oedema volume, thickness of the dorsum and ventrum pedis skin, number of infiltrated inflammatory cells, and number of COX-2-, iNOS-immunoreactive cells were measured.

Results

In an in vitro study, CBTE inhibited the production of NO and PGE₂ and also decreased the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) activity, interleukin (IL)-1β, IL-6 and tumuor necrosis factor-α. In LPS-activated macrophages, nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinase (MAPK) signalling is a pivotal pathway in the inflammatory process. These plausible molecular mechanisms increased the phosphorylation of I-κBα, while the activation of NF-κB and the phosphorylation of MAPK by LPS were blocked by CBTE treatment. In our in vivo study, a CA-induced acute oedematous paw inflammation rat model was used to evaluate the anti-inflammatory effect of CBTE. CBTE significantly reduced the increases in paw swelling, skin thicknesses, infiltrated inflammatory cells and iNOS-, COX-2 positive cells induced by CA injection.

Conclusions

Based on these results, CBTE should favourably inhibit the acute inflammatory response through modulation of NF-κB activation and MAPK phosphorylation. Furthermore, the inhibition of CBTE in rat paw oedema induced by CA is considered to be clear evidence that CBTE may be a useful source to treat inflammation.