Mediators In RAW264 Research Articles

Multidirectional Effects of Terpenoids from Sorbus intermedia (EHRH.) PERS Fruits in Cellular Model of Benign Prostate Hyperplasia.

Benign prostatic hyperplasia (BPH) is a common urological disease affecting aging men. Its pathogenesis is regarded as complex and multifactorial, with sex hormones and inflammation as key contributory factors. In the current study, we investigated the anti-BPH potential of terpenoids present in the fruits of Sorbus intermedia (EHRH.) PERS. Not only the effects on testosterone-stimulated normal prostate epithelial PNT2 cells, namely suppression of 5-α-reductase activity, PSA secretion, and cell proliferation, were determined but also the inhibitory activity on heat-induced protein denaturation, hyaluronidase, as well as IL-6, TNF-α, and NO release in LPS-treated macrophages. Sorbus terpenoids significantly inhibited 5-α-reductase activity and reduced PSA secretion in PNT2 cells, reversing the stimulatory effect of testosterone. PNT2 cell proliferation was also found to be attenuated. Subsequently, all compounds reduced the release of pro-inflammatory mediators in RAW 264.7 cells. In addition, ursolic acid (UA) and its aldehyde (UAL) were the most potent hyaluronidase inhibitors of all compounds, with IC50 values of 225.75 µg/mL and 369.77 µg/mL, respectively. For better understanding and interpretation of the overall effect of Sorbus terpenoids on different aspects of BPH pathogenesis and development, cluster analysis was applied.

Polyphenols from the Peels of Punica granatum L. and Their Bioactivity of Suppressing Lipopolysaccharide-Stimulated Inflammatory Cytokines and Mediators in RAW 264.7 Cells via Activating p38 MAPK and NF-κB Signaling Pathways.

Punica granatum L. (Punicaceae) is a popular fruit all over the world. Owning to its enriched polyphenols, P. granatum has been widely used in treating inflammation-related diseases, such as cardiovascular diseases and cancer. Twenty polyphenols, containing nine unreported ones, named punicagranins A–I (1–9), along with eleven known isolates (10–20), were obtained from the peels. Their detailed structures were elucidated based on UV, IR, NMR, MS, optical rotation, ECD analyses and chemical evidence. The potential anti-inflammatory activities of all polyphenols were examined on a lipopolysaccharide (LPS)-induced inflammatory macrophages model, which indicated that enhancing nitric oxide (NO) production in response to inflammation stimulated in RAW 264.7 cells was controlled by compounds 1, 3, 5–8, 10, 11, 14 and 16–20 in a concentration-dependent manner. The investigation of structure–activity relationships for tannins 6–8 and 12–20 suggested that HHDP, flavogallonyl and/or gallagyl were key groups for NO production inhibitory activity. Western blotting indicated that compounds 6–8 could down-regulate the phosphorylation levels of proteins p38 MAPK, IKKα/β, IκBα and NF-κB p65 as well as inhibit the levels of inflammation-related cytokines and mediators, such as IL-6, TNF-α, iNOS and COX-2, at the concentration of 30 μM. In conclusion, polyphenols are proposed to be the potential anti-inflammatory active ingredients in P. granatum peels, and their molecular mechanism is likely related to the regulation of the p38 MAPK and NF-κB signaling pathways.

Magnoliae flos Downregulated Lipopolysaccharide-Induced Inflammatory Responses via NF-κB/ERK-JNK MAPK/STAT3 Pathways.

Background Magnoliae flos is the dried flower bud of Magnolia biondii and related plants. It has been used as a medicinal herb for the treatment of rhinitis, sinusitis, and sinus headaches. Nevertheless, the effects of Magnoliae flos in microbial infection or sepsis remain unclear. In this study, we investigated the anti-inflammatory effects of Magnoliae flos water extract (MF) in lipopolysaccharide- (LPS-) induced septic mice and LPS-stimulated RAW264.7 macrophages. Results We found that MF reduced the mortality of LPS-challenged mice. Enzyme immunoassays and reverse transcription polymerase chain reaction analysis revealed that MF administration attenuated mRNA expression and protein production of proinflammatory mediators, including cyclooxygenase 2, inducible nitric oxide synthase, tumor necrosis factor-α, and interleukin-6. In parallel to these results in mice, pretreatment with MF suppressed the LPS-induced production of proinflammatory mediators in RAW264.7 macrophages. In addition, we found that MF exerted its suppressive effects by inhibiting the activation of the mitogen-activated protein kinase, nuclear factor-κB, and signal transducer and activator of transcription pathways at the protein level. Conclusion MF could be a potential therapeutic agent for regulating excessive inflammatory responses in sepsis.

Extract of Pinus densiflora needles suppresses acute inflammation by regulating inflammatory mediators in RAW264.7 macrophages and mice

Context Pinus densiflora Siebold & Zucc. (Pinaceae) needle extracts ameliorate oxidative stress, but research into their anti-inflammatory effects is limited. Objective To investigate antioxidant and anti-inflammatory effects of a Pinus densiflora needles (PINE) ethanol extract in vitro and in vivo. Materials and methods We measured levels of reactive oxygen species (ROS), superoxide dismutase (SOD) and inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW264.7 cells at various PINE concentrations (25, 50 and 100 μg/mL; but 6.25, 12.5 and 25 μg/mL for interleukin-1β and prostaglandin E2 (PGE2)). Thirty ICR mice were randomized to six groups: vehicle, control, PINE pre-treatment (0.1, 0.3 and 1 mg/left ear for 10 min followed by arachidonic acid treatment for 30 min) and dexamethasone. The posttreatment ear thickness and myeloperoxidase (MPO) activity were measured. Results PINE 100 μg/mL significantly decreased ROS (IC50, 70.93 μg/mL, p < 0.01), SOD (IC50, 30.99 μg/mL, p < 0.05), malondialdehyde (p < 0.01), nitric oxide (NO) (IC50, 27.44 μg/mL, p < 0.01) and tumour necrosis factor-alpha (p < 0.05) levels. Interleukin-1β (p < 0.05) and PGE2 (p < 0.01) release decreased significantly with 25 μg/mL PINE. PINE 1 mg/ear inhibited LPS-stimulated expression of cyclooxygenase-2 and inducible NO synthase in RAW264.7 macrophages and significantly inhibited ear oedema (36.73–15.04% compared to the control, p < 0.01) and MPO activity (167.94–105.59%, p < 0.05). Discussion and conclusions PINE exerts antioxidant and anti-inflammatory effects by inhibiting the production of inflammatory mediators. Identified flavonoids such as taxifolin and quercetin glucoside can be attributed to effect of PINE.

Mosloflavone-Resveratrol Hybrid TMS-HDMF-5z Exhibits Potent In Vitro and In Vivo Anti-Inflammatory Effects Through NF-κB, AP-1, and JAK/STAT Inactivation.

TMS-HDMF-5z is a hybrid of the natural products mosloflavone and resveratrol. It was discovered to show potent inhibitory effects against lipopolysaccharide (LPS)-induced production of inflammatory mediators in RAW 264.7 macrophages. However, its mechanism of action is unknown. Hence this study aimed to demonstrate and explore in vitro and in vivo anti-inflammatory effects of TMS-HDMF-5z and its mechanism of action employing RAW 264.7 macrophages and carrageenan-induced hind paw edema. This work revealed that TMS-HDMF-5z suppressed the LPS-induced inducible nitric-oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein, mRNA, and promoter binding levels and tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6, and interferon-β (IFN-β) at the mRNA expression in RAW 264.7 macrophages. The results showed that TMS-HDMF-5z reduced the transcription and DNA binding activities of nuclear factor-κB (NF-κB) through inhibiting nuclear translocation of p65 and phosphorylation of κB inhibitor α (IκBα), IκB kinase (IKK), and TGF-β activated kinase 1 (TAK1). Additionally, TMS-HDMF-5z attenuated the LPS-induced transcriptional and DNA binding activities of activator protein-1 (AP-1) by suppressing nuclear translocation of phosphorylated c-Fos, c-Jun, and activating transcription factor 2 (ATF2). TMS-HDMF-5z also reduced the LPS-induced phosphorylation of Janus kinase 1/2 (JAK1/2), signal transducers and activators of transcription 1/3 (STAT1/3), p38 mitogen-activated protein kinase (MAPK), and MAPK-activated protein kinase 2 (MK2). In rats, TMS-HDMF-5z alleviated carrageenan-induced hind paw edema through the suppressing iNOS and COX-2 via NF-κB, AP-1, and STAT1/3 inactivation. Collectively, the TMS-HDMF-5z-mediated inhibition of NF-κB, AP-1, and STAT1/3 offer an opportunity for the development of a potential treatment for inflammatory diseases.

New steroidal alkaloids with anti-inflammatory and analgesic effects from Veratrum grandiflorum

Ethnopharmacological relevance“Li-Lu”, the roots and rhizomes of Veratrum grandiflorum (Melianthiaceae), has been historically used as a traditional folk medicine for the treatment of wrist pain, fractures, sores, and inflammation in Yunnan Province, China. However, the anti-inflammatory and analgesic studies of this plant have seldom reported. Aim of the studyTo evaluate the anti-inflammatory and analgesic properties related to the traditional usage of V. grandiflorum both in vitro and in vivo, and further explore the accurate bioactive compounds from the medicinal plant. Materials and methodsPhytochemical investigation was carried out by chromatographic methods and their structures were established based on extensive spectra and comparison with corresponding data in the reported literatures. Anti-inflammatory activities were assessed by the suppression of lipopolysaccharide-activated inflammatory mediators in RAW 264.7 macrophage cells in vitro. Furthermore, anti-inflammatory and analgesic effects were evaluated based on carrageenan-induced paw edema and acetic acid-stimulated writhing in mice. ResultsThe methanol extract (ME) of V. grandiflorum significantly alleviated the paw edema caused by carrageenan and the writhing numbers induced by acetic acid. Subsequent phytochemical investigation led to isolated of 21 steroidal alkaloids, including seven new compounds, veragranines C–I (1–7). Anti-inflammatory test indicated that steroidal alkaloids could decrease the expression of cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), and tumor necrosis factor α (TNF-α) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells at a concentration of 5.0 μg/ml in vitro, comparable to DXM. Moreover, five new steroidal alkaloids (2, 4, 5, 6, and 7) and two major steroidal alkaloids (9 and 13) significantly decreased the numbers of writhing in mice at the doses of 0.5 and/or 1.0 mg/kg (p < 0.01/0.05), roughly comparable to Dolantin™ at 10.0 mg/kg. ConclusionsThe investigation supported the traditional use of V. grandiflorum and provided new steroidal alkaloids as potent analgesic agents.

C19 Benzylisoquinoline Alkaloid with Unprecedented Architecture from Hypecoum erectum.

Hyperectumine (1), the first C19 benzylisoquinoline alkaloid with a complicated ring system, was isolated from Hypecoum erectum and structurally characterized. Its biosynthetic origin should involve a hybrid pattern of C8 + C8 + C1 + C2, from which a C17 benzylisoquinoline alkaloid might be further attacked by a malonamic acid and undergo decarboxylation and cyclization to produce 1. Compound (-)-1 exhibited moderate anti-inflammatory activity via suppression of LPS-activated inflammatory mediators in RAW 264.7 macrophage cells.

A Novel Para-Amino Salicylic Acid Magnesium Layered Hydroxide Nanocomposite Anti-Tuberculosis Drug Delivery System with Enhanced in vitro Therapeutic and Anti-Inflammatory Properties.

IntroductionMycobacterium tuberculosis infections are associated with severe local inflammatory reactions, which may be life-threatening and lead to tuberculosis pathogenesis and associated complications. Inorganic nanolayers have been vastly exploited for biomedical applications (especially in drug delivery) because of their biocompatible and biodegradable nature with the ability to release a drug in a sustained manner. Herein, we report a new nanodelivery system of inorganic nanolayers based on magnesium layered hydroxides (MgLH) and a successfully intercalated anti-tuberculosis drug para-aminosalicylic acid (PAS).MethodsThe designed anti-tuberculosis nanodelivery composite, MgLH-PAS, was prepared by a novel co-precipitation method using MgNO3 as well MgO as starting materials.ResultsThe designed nano-formulation, PAS-MgLH, showed good antimycobacterial and antimicrobial activities with significant synergistic anti-inflammatory effects on the suppression of lipopolysaccharide (LPS) stimulated inflammatory mediators in RAW 264.7 macrophages. The designed nano-formulation was also found to be biocompatible with human normal lung cells (MRC-5) and 3T3 fibroblast cells. Furthermore, the in vitro release of PAS from PAS-MgLH was found to be sustained in human body simulated phosphate buffer saline (PBS) solutions of pH 7.4 and pH 4.8.DiscussionThe results of the present study are highly encouraging for further in vivo studies. This new nanodelivery system, MgLH, can be exploited in the delivery of other drugs and in numerous other biomedical applications as well.

Improved immune-enhancing activity of egg white protein ovotransferrin after enzyme hydrolysis.

Ovotransferrin (OTF), an egg protein known as transferrin family protein, possess strong antimicrobial and antioxidant activity. This is because OTF has two iron binding sites, so it has a strong metal chelating ability. The present study aimed to evaluate the improved immune-enhancing activities of OTF hydrolysates produced using bromelain, pancreatin, and papain. The effects of OTF hydrolysates on the production and secretion of pro-inflammatory mediators in RAW 264.7 macrophages were confirmed. The production of nitric oxide (NO) was evaluated using Griess reagent and the expression of inducible nitric oxide synthase (iNOS) were evaluated using quantitative real-time polymerase chain reaction (PCR). And the production of pro-inflammatory cytokines (tumor necrosis factor [TNF]-α and interleukin [IL]-6) and the phagocytic activity of macrophages were evaluated using an ELISA assay and neutral red uptake assay, respectively. All OTF hydrolysates enhanced NO production by increasing iNOS mRNA expression. Treating RAW 264.7 macrophages with OTF hydrolysates increased the production of pro-inflammatory cytokines and the phagocytic activity. The production of NO and pro-inflammatory cytokines induced by OTF hydrolysates was inhibited by the addition of specific mitogen-activated protein kinase (MAPK) inhibitors. In conclusion, results indicated that all OTF hydrolysates activated RAW 264.7 macrophages by activating MAPK signaling pathway.

Aspilia africana C. D. Adams inhibits the production of lipopolysaccharide-induced inflammatory mediators in murine macrophage RAW264.7 cells by suppressing the NF-κB and PI3K/Akt pathways

Aspilia africana C. D. Adams (A. africana) is used in African folk medicine as a wound healing remedy. In this study, the potential anti-inflammatory effects of A. africana were investigated in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The cytotoxicity of A. africana was assessed in RAW264.7, human embryonic kidney 293, and HaCaT cells using the WST-1 assay. The results indicated that concentrations up to 400 μg/mL were safe for all cell lines studied. Further analyses, such as the nitric oxide (NO) assay, quantitative reverse transcription polymerase chain reaction (qRT-PCR), and western blotting, were performed to evaluate the anti-inflammatory potential of A. africana. The results of NO analysis showed that A. africana inhibited NO production, while the results of western blot analysis showed that the expression levels of important inflammatory enzymes, such as inducible nitric oxide synthase and cyclooxygenase-2, and pro-inflammatory cytokines (tumor necrosis factor-α, interleukin [IL]-6, and IL-1β) were significantly suppressed by A. africana. The results also demonstrated that A. africana prevents the activation of the nuclear factor κB (NF-κB) and phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathways by inhibiting phosphorylated (p)-p65 NF-κB, p-Akt, p-IκBα, and p-PI3K. qRT-PCR analysis revealed that A. africana affects the expression of pro-inflammatory cytokines at the gene level. The results of this study showed that A. africana prevents the production of inflammatory mediators in RAW264.7 cells stimulated with LPS by regulating the NF-κB and PI3K/Akt signaling pathways.

Tuna blood inhibits lipopolysaccharide-induced inflammatory mediators in RAW264.7 macrophages

Background: This study aimed to evaluate the anti-inflammation effects of the freeze-dried tuna whole blood (FTB), and freeze-dried tuna blood cell (FTC) in LPS-induced RAW264.7 cells.Methods: The RAW264.7 cells were pre-administered with FTB and FTC at different concentrations for 2 h and then stimulated with lipopolysaccharide (LPS) for 24 h. The production of reactive oxygen species (ROS), nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) in RAW 264.7 cells were then determined.Results: The results showed that only FTB remarkably abolished LPS-induced ROS in RAW264.7 cells. FTB and FTC significantly decreased LPS-induced NO which IC50 values of FTB and FTC after 24 h were 78.58 and 22.47 μg/mL, respectively. TNF-α and IL-1β secretion were abolished by FTB and FTC in LPS-stimulated macrophages which IC50 values of both FTB and FTC after 24 h were more than 25 μg/mL, respectively. However, the efficacy of FTC against inflammatory mediators was due to cytotoxic effects on RAW 264.7 cells.Conclusion: Tuna whole blood potentially inhibits inflammation through modulating the synthesis of several mediators and cytokines associated with the development of inflammation. These findings suggest a role of tuna blood on anti-inflammatory activity.Keywords: Anti-inflammatory activity, RAW 264.7 cells, red blood cell, tuna blood, waste utilization

Influence of acid treatment on flavonoid content and biological activity in tartary buckwheat grains and its application for noodles

Acid treatment is one of the most effective methods to convert flavonoid glycosides into their aglycones. In this study, the impacts of acid treatment of tartary buckwheat grains on the flavonoid composition and biological activities of tartary were investigated. The results indicated that acid treatment allowed the deglycosylation of rutin to quercetin in buckwheat grains, contributing to the enhancement of their antioxidant activity. Furthermore, as compared to the non-treated sample, acid-treated buckwheat grain samples showed stronger inhibition on tert-butyl hydroperoxide mediated the formation of intracellular reactive oxygen species in HepG2 cells, reduction in lipid accumulation and the related adipogenic transcription factors in 3T3-L1 cells, and reduction in inflammatory mediators in RAW 264.7 cells. Upon application to noodles making, noodles supplemented with acid-treated tartary buckwheat flours, which had weakened gluten strength and a low degree of gelatinization, displayed significantly improved antioxidant activity. These findings suggest that acid-treated buckwheat flours can be used to improve the health benefits of buckwheat products.

Inhibitory Effects on Oral Microbial Activity and Production of Lipopolysaccharides-Induced Pro-Inflammatory Mediators in Raw264.7 Macrophages of Ethanol Extract of Perilla flutescens (L.) Britton

Other SectionsAbstractIntroductionMaterials and MethodsResultsDiscussionConflict of interestEthical approvalAuthor contributionsReference

Anti-Inflammatory Activity of Kurarinone Involves Induction of HO-1 via the KEAP1/Nrf2 Pathway.

Kurarinone, a flavonoid isolated from the roots of Sophora flavescens, was suggested to exert potent antioxidant and immunosuppressive effects. However, the underlying mechanisms remain unclear. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor that regulates the antioxidant defense system with anti-inflammatory activity. In the present study, we demonstrated that kurarinone activated Nrf2 and increased the expression of antioxidant enzymes, including heme oxygenase-1 (HO-1). Mechanistically, kurarinone downregulated the expression of kelch-like ECH-associated protein 1 (KEAP1), subsequently leading to the activation of Nrf2. Kurarinone also inhibited the expression of the inflammatory cytokine, interleukin (IL)-1β, and inducible nitric oxide synthase (iNos) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The overexpression of HO-1 suppressed the LPS-induced production of inflammatory mediators in RAW264.7 cells, and the immunosuppressive effects of kurarinone were partially inhibited by a treatment with Tin Protomorphyrin IX (TinPPIX), an inhibitor of HO-1. These results indicate that kurarinone activates the KEAP1/Nrf2 pathway to induce HO-1 expression, thereby exerting immunosuppressive effects.

Suppression of Inflammatory Mediators by Ethanol Extracts of &lt;i&gt;Pennisetum purpureum &lt;/i&gt;S. (Napiergrass Taishigrass no. 2) in Activated RAW 264.7 Macrophages

Napiergrass Taishigrass no. 2 (NT2) is a new hybrid of napiergrass (Pennisetum purpureum S.), and is commonly added as an ingredient in bioorganic energy soup, a plant-based drink which is thought to have health-promoting effects. Thus, NT2 is hypothesized to possess biological functions. In this study, we explored the effects of NT2 ethanol extracts on in vitro antioxidant activities and on modulation of immune mediators in RAW 264.7 macrophages. Results showed that ethanol extracts contained significant amount of polyphenols and chlorophylls, and possessed in vitro ferric-reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidative activities. The ethanol extracts did not show immunomodulatory activities in macrophages without lipopolysaccharide (LPS, 100 ng/ml) treatment, but significantly suppressed the LPS-stimulated production of inflammatory mediators, including nitric oxide (NO), interleukin (IL)-6, and tumor necrosis factor (TNF)-α, and such effects were associated with decreased expression of inducible NO synthase (iNOS) protein and cluster of differentiation 14 (CD14) mRNA, suggesting that NT2 has anti-inflammatory activities. On the other hand, the extracts increased matrix metalloproteinase (MMP)-9 activity, but showed no effects on Toll-like receptor (TLR) expression. In conclusion, ethanol extracts of NT2 possessed in vitro antioxidative activities and exhibited anti-inflammatory activities by decreasing NO, IL-6, and TNF-α production in association with decreased CD14 mRNA expression in LPS-induced RAW 264.7 macrophages, indicating its potential roles on health promotion and prentive effects against chronic diseases and such effects were and it’s in vitro antioxidant activities, suggesting its potential roles on health promotion.

Immune-enhancing activity of Hydrangea macrophylla subsp. serrata leaves through TLR4/ROS-dependent activation of JNK and NF-κB in RAW264.7 cells and immunosuppressed mice

Abstract In this study, we investigated the immune-enhancing activity of water extracts from Hydrangea macrophylla subsp. serrata (WE-HML). WE-HML increased cell viability and production of immunomodulators, which contributed to activating phagocytic activity in RAW264.7 cells. Inhibition of JNK and NF-κB reduced the production of immunomodulators by WE-HML. ROS inhibition suppressed the production of immunomodulators, and the activation of JNK and NF-κB signaling by WE-HML. TLR4 inhibition attenuated the production of immunomodulators, and activation of JNK and NF-κB signaling by WE-HML. In the immunosuppressed mouse model, WE-HML increased the spleen index, the levels of the cytokines, the numbers of white blood cells, lymphocytes, and neutrophils. However, WE-HML inhibited LPS-mediated overproduction of pro-inflammatory mediators in RAW264.7 cells, which indicated that WE-HML may have anti-inflammatory activity under excessive inflammatory conditions. Taken together, WE-HML may be considered to have immune-enhancing activity and expected to be used as a potential immune-enhancing agent.

Panax quinquefolius (North American ginseng) cell suspension culture as a source of bioactive polysaccharides: Immunostimulatory activity and characterization of a neutral polysaccharide AGC1

In this study, we propose the use of a plant tissue culture-based system for the production of polysaccharides with consistent chemical characteristics and reduced endotoxin content. Polysaccharides were isolated from suspension cultures of Panax quinquefolius (American ginseng), a widely used medicinal herb. A neutral fraction, AGC1, purified by anion exchange and size exclusion chromatography, displayed immunostimulatory activity in vitro and ex vivo. AGC1 (average molecular weight: 5.2kDa) was predominantly composed of galactose (>60%) along with the presence of several other neutral sugars such as arabinose, xylose, glucose, mannose and rhamnose in minor amounts. The major glycosidic linkages were found to be 3-Galp (48.5%), 3,6-Galp (10.2%), t-Galp (5.2%), 6-Galp (4.4%), 4-Glcp (5.7%), 4-Arap/5-Araf (4.0%) and t-Araf (4.5%). AGC1 significantly (p<0.05) stimulated the expression of a range of proinflammatory mediators in RAW 264.7 murine macrophages such as IL-6, TNF-α, MCP-1 and GM-CSF. Additionally, AGC1 treatment of RAW 264.7 cells stimulated NOS2 gene expression, leading to increased levels of iNOS and downstream NO. Consistent with this, AGC1 was able to act as an immunostimulant in primary murine splenocytes, enhancing cell proliferation, as well as NO and TNF-α production. Our results also indicate the partial role of NF-κB pathway in the immunostimulatory response.

Expression of a stress-responsive gene cluster for mycosporine-2-glycine confers oxidative stress tolerance in Synechococcus elongatus PCC7942.

Mycosporine-like amino acids (MAAs) are a class of well-documented UV-screening compounds produced by taxonomically diverse organisms. Extensive studies revealed that a rare MAA, mycosporine-2-glycine (M2G), possesses unique biological activities and functions. M2G is not only a potent antioxidant, but also suppresses protein glycation in vitro, and production of inflammatory mediators in RAW 264.7 macrophages. The present study evaluates vital functions of M2G in a heterologous expression system. The stress-sensitive fresh water cyanobacterium Synechococcus elongatus PCC7942, carrying a M2G biosynthetic gene cluster, was generated. The M2G-expressing cells were more tolerant to H2O2-induced oxidative stress than the wild type, with a half-maximal inhibitory concentration (IC50) value of 2.3±0.06 mM. Transcriptional analysis revealed that all M2G biosynthetic genes were highly up-regulated under oxidative stress. Further, expression of vital genes in the cellular antioxidant defense system, including sodB, cat and tpxA were modulated and up-regulated. Elevated M2G was detected under oxidative stress as well as salt stress treatments. This study provides insight into the molecular and cellular effects of the M2G biosynthetic gene cluster, contributing to understanding of the mechanism behind physiological plasticity under this heterologous expression system.

Design, synthesis and biological evaluation of alantolactone derivatives as potential anti-inflammatory agents

While screening for potential anti-inflammatory natural product scaffolds, alantolactone (1) was found to attenuate LPS-induced pro-inflammatory mediators in RAW264.7 macrophage cells. In this regard, a series of 17 novel thiol derivatives of 1 has been synthesized and evaluated as inhibitors of pro-inflammatory mediators viz. NO (nitric oxide), IL-6 (interleukin-6), and TNF-α (tumor necrosis factor-α) in LPS-treated RAW264.7 macrophage cells (In vitro) and female Balb/C mice (in vivo). In vitro, the best inhibition potencies were obtained with compounds 3, 4, 6, and 18, which were selected for further in vivo testing. The results of in vivo studies revealed that compounds 3, 6, and 18 are comparable to that of the parent molecule 1 on the inhibition of TNF-α and IL-6 release, whereas compound 4 was identified as the most potent inhibitor of cytokines IL-6 (69.49%) and TNF-α (66.12%) as compared with 1 at dose 10 mg/kg. Taken together, our results suggest that thiol analogs of 1 have therapeutic potential and could be further explored for potential anti-inflammatory activity.

Expression of Concern: Aldose reductase mediates the lipopolysaccharide-induced release of inflammatory mediators in RAW264.7 murine macrophages

Aldose Reductase Mediates the Lipopolysaccharide-induced Release of Inflammatory Mediators in RAW264.7 Murine MacrophagesJournal of Biological ChemistryVol. 281Issue 44PreviewAbnormal production of inflammatory cytokines and chemokines is a key feature of bacterial endotoxin, lipopolysaccharide (LPS)-induced inflammation, and cytotoxicity; however, the mechanisms regulating production of inflammatory markers remain unclear. Herein, we show that inhibition of the aldehyde-metabolizing enzyme aldose reductase (AR; AKR1B3) modulates NF-κB-dependent activation of inflammatory cytokines and chemokines in mouse serum, liver, heart, and spleen. Pharmacological inhibition or small interfering RNA ablation of AR prevented the biosynthesis of tumor necrosis factor-α, interleukin 1β, interleukin-6, macrophage-chemoattractant protein-1, and cyclooxygenase-2 and prostaglandin E2 in LPS-activated RAW264.7 murine macrophages. Full-Text PDF Open Access VOLUME 281 (2006) PAGES 33019–33029 The publisher of the Journal of Biological Chemistry is issuing an Expression of Concern to inform readers that credible concerns have been raised regarding some of the data and conclusions in the article listed above. The Journal of Biological Chemistry will provide additional information as it becomes available.