Oxidative Distress Induces Wnt/ß-Catenin Pathway Modulation in Colorectal Cancer Cells: Perspectives on APC Retained Functions.

Colorectal cancer (CRC) is a multistep process that arises in the colic tissue microenvironment. Oxidative stress plays a role in mediating CRC cell survival and progression, as well as promoting resistance to therapies. CRC progression is associated with Wnt/ß-Catenin signaling dysregulation and loss of proper APC functions. Cancer recurrence/relapse has been attributed to altered ROS levels, produced in a cancerous microenvironment. The effect of oxidative distress on Wnt/ß-Catenin signaling in the light of APC functions is unclear. This study evaluated the effect of H2O2-induced short-term oxidative stress in HCT116, SW480 and SW620 cells with different phenotypes of APC and ß-Catenin. The modulation and relationship of APC with characteristic molecules of Wnt/ß-Catenin were assessed in gene and protein expression. Results indicated that CRC cells, even when deprived of growth factors, under acute oxidative distress conditions by H2O2 promote ß-Catenin expression and modulate cytoplasmic APC protein. Furthermore, H2O2 induces differential gene expression depending on the cellular phenotype and leading to favor both Wnt/Catenin-dependent and -independent signaling. The exact mechanism by which oxidative distress can affect Wnt signaling functions will require further investigation to reveal new scenarios for the development of therapeutic approaches for CRC, in the light of the conserved functions of APC.

Valproic acid alters nitric oxide status in neurulating mouse embryos.

The molecular bases of the teratogenic effects elicited by valproic acid (VPA) are not fully defined. It was previously shown that inhibition of nitric oxide (NO) synthesis is associated with an enhancement of the teratogenic effects of VPA, while amplification of NO signal by sildenafil prompted a dose-dependent reduction of VPA-induced neural tube defects. In this study, for the first time, the effect of VPA on the NO synthesis was evaluated in mouse embryos during early organogenesis. On gestation day 8, ICR-CD1 mice received 600 mg/kg of VPA. Eight and 24 h later embryos were collected and analyzed for NO synthase (NOS) isoform expression, and for molecular mechanisms involved in their modulation. As main finding, in utero embryonic exposure to VPA determined a time-dependent shift of NOS isoforms expression, with a down regulated expression and activity of constitutive NOS (cNOS) and an increased expression and activity of inducible NOS (iNOS). The teratological relevance of this information remains to be established.

Short ELF-EMF Exposure Targets SIRT1/Nrf2/HO-1 Signaling in THP-1 Cells.

Extremely low frequency electromagnetic fields (ELF-EMFs) have been known to modulate inflammatory responses by targeting signal transduction pathways and influencing cellular redox balance through the generation of oxidants and antioxidants. Here, we studied the molecular mechanism underlying the anti-oxidative effect of ELF-EMF in THP-1 cells, particularly with respect to antioxidant enzymes, such as heme oxygenase-1 (HO-1), regulated transcriptionally through nuclear factor E2-related factor 2 (Nrf2) activation. Cells treated with lipopolysaccharides (LPS) were exposed to a 50 Hz, 1 mT extremely low frequency electromagnetic fields for 1 h, 6 h and, 24 h. Our results indicate that ELF-EMF induced HO-1 mRNA and protein expression in LPS-treated THP-1 cells, with peak expression at 6 h, accompanied with a concomitant migration to the nucleus of a truncated HO-1 protein form. The immunostaining analysis further verified a nuclear enrichment of HO-1. Moreover, ELF-EMF inhibited the protein expressions of the sirtuin1 (SIRT1) and nuclear factor kappa B (NF-kB) pathways, confirming their anti-inflammatory/antioxidative role. Pretreatment with LY294002 (Akt inhibitor) and PD980559 (ERK inhibitor) inhibited LPS-induced Nrf2 nuclear translocation and HO-1 protein expression in ELF-EMF-exposed cells. Taken together, our results suggest that short ELF-EMF exposure exerts a protective role in THP-1 cells treated with an inflammatory/oxidative insult such as LPS, via the regulation of Nrf-2/HO-1 and SIRT1 /NF-kB pathways associated with intracellular glutathione (GSH) accumulation.

Anti-Migratory Effects of 4'-Geranyloxyferulic Acid on LPS-Stimulated U937 and HCT116 Cells via MMP-9 Down-Regulation: Involvement of ROS/ERK Signaling Pathway.

Matrix metalloproteinases (MMPs) play a crucial role in tumor angiogenesis, and metastasis. 4'-geranyloxyferulic acid (GOFA) has anti-tumor and anti-inflammatory proprieties. Herein, we aimed to determine whether this compound affects cell survival, invasion, and migration through reactive oxygen species (ROS)-mediated MMPs activation of extracellular signal-regulated kinases (ERKs) and p38 signaling in lymphocytic histiocytoma (U937) and colorectal cancer (HCT116) cells. We observed that lipopolysaccharide (LPS) stimulated U937 and HCT116 cells presented abnormal cell proliferation and increased metalloproteinase (MMP-9) activity and expression. Non-cytotoxic doses of GOFA blunted matrix invasive potential by reducing LPS-induced MMP-9 expression and cell migration via inhibiting ROS/ ERK pathway. GOFA also attenuated apoptosis and cell senescence. Our findings indicate that GOFA, inhibiting cancer cell proliferation and migration, could be therapeutically beneficial to prevent tumor metastasis.

Modulation of Apoptotic Cell Death and Neuroprotective Effects of Glutathione-L-Dopa Codrug Against H2O2-Induced Cellular Toxicity.

The L-3,4-dihydroxyphenylalanine (LD) is the gold standard drug currently used to manage Parkinson's disease (PD) and to control its symptoms. However, LD could cause disease neurotoxicity due to the generation of pro-oxidant intermediates deriving from its autoxidation. In order to overcome this limitation, we have conjugated LD to the natural antioxidant glutathione (GSH) to form a codrug (GSH-LD). Here we investigated the effect of GSH-LD on H2O2-induced cellular toxicity in undifferentiated and differentiated lymphoma U-937 and dopaminergic neuroblastoma SH-SY5Y cell lines, used respectively as models to study the involvement of macrophages/microglia and dopaminergic neurons in PD. We analyzed the effect of GSH-LD on apoptosis and cellular oxidative stress, both considered strategic targets for the prevention and treatment of neurodegenerative diseases. Compared to LD and GSH, GSH-LD had a stronger effect in preventing hydrogen peroxide (H2O2) induced apoptosis in both cell lines. Moreover, GSH-LD was able to preserve cell viability, cellular redox status, gluthation metabolism and prevent reactive oxygen species (ROS) formation, in a phosphinositide 3-kinase (PI3K)/kinase B (Akt)-dependent manner, in a neurotoxicity cellular model. Our findings indicate that the GSH-LD codrug offers advantages deriving from the additive effect of LD and GSH and it could represent a promising candidate for PD treatment.

Modulation of CAT-2B-Mediated l-Arginine Uptake and Nitric Oxide Biosynthesis in HCT116 Cell Line Through Biological Activity of 4'-Geranyloxyferulic Acid Extract from Quinoa Seeds.

Chenopodium quinoa Wild is a "pseudocereal" grain which attracts a lot of attention in the scientific community as it has a positive effect on health. Here, we investigate the presence of biologically active O-prenylated phenylpropanoids in the ethanol extract of commercially available quinoa seeds. We claim that 4'-Geranyloxyferulic acid (GOFA) was the only phytochemical product found that belongs to quinoa's group secondary metabolites. We studied the changes in the oxidative and inflammatory status of the cellular environment in HCT 116 cell line processed with quinoa extract and its component GOFA; the implementation was done through the analysis of the antioxidant enzymes (SOD and CAT), the pro-inflammatory components (iNOS, IL-6 and TNF-α), and the products of intermediary metabolism (ONOO-, O2-). Moreover, the l-arginine uptake was proposed as a target of the tested compounds. We demonstrated that the GOFA, through a decrease of the CAT-2B expression, leads to a reduction of the l-arginine uptake, downregulating the harmful iNOS and restoring the altered redox state. These results propose a new molecular target involved in the reduction of the critical inflammatory process responsible for the cancer progression.

Chelating and antioxidant properties of l-Dopa containing tetrapeptide for the treatment of neurodegenerative diseases.

Neurodegenerative diseases share a common pathogenetic mechanism involving aggregation and deposition of misfolded proteins, oxidative stress, metal dyshomeostasis, and glutamate exicitotoxicity, which lead to progressive dysfunction of central nervous system (CNS). A potential strategy to counteract these deleterious events at neuronal level is represented by the employment of a novel class of multi-target therapeutic agents that selectively and simultaneously hit these targets In this paper, we report the metal binding and antioxidant properties of a novel metal-protein attenuating peptide, GSH-LD, a tetrapeptide obtained by linking glutathione, a well-known antioxidant tripeptide, to L-Dopa. Results demonstrated that GSH-LD possesses chelating capabilities in order to selectively target the excess of metals without interfere with metal-containing antioxidant enzymes. Moreover, antioxidant assays revealed a large contribution of GSH-LD to restore the antioxidant defences of damaged neuronal cells.

Biological Effect of Licochalcone C on the Regulation of PI3K/Akt/eNOS and NF-κB/iNOS/NO Signaling Pathways in H9c2 Cells in Response to LPS Stimulation.

Polyphenols compounds are a group molecules present in many plants. They have antioxidant properties and can also be helpful in the management of sepsis. Licochalcone C (LicoC), a constituent of Glycyrrhiza glabra, has various biological and pharmacological properties. In saying this, the effect of LicoC on the inflammatory response that characterizes septic myocardial dysfunction is poorly understood. The aim of this study was to determine whether LicoC exhibits anti-inflammatory properties on H9c2 cells that are stimulated with lipopolysaccharide. Our results have shown that LicoC treatment represses nuclear factor-κB (NF-κB) translocation and several downstream molecules, such as inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Moreover, LicoC has upregulated the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/endothelial nitric oxide synthase (eNOS) signaling pathway. Finally, 2-(4-Morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride (LY294002), a specific PI3K inhibitor, blocked the protective effects of LicoC. These findings indicate that LicoC plays a pivotal role in cardiac dysfunction in sepsis-induced inflammation.

Quantitative profiling of 4'-geranyloxyferulic acid and its conjugate with l-nitroarginine methyl ester in mononuclear cells by high-performance liquid chromatography with fluorescence detection.

Oxyprenylated natural products were shown to exert in vitro and in vivo remarkable anti-cancer and anti-inflammatory effects. This paper describes a rapid, selective, and sensitive HPLC method with fluorescence detection for determination of 4'-geranyloxyferulic acid (GOFA) and its conjugate with l-nitroarginine methyl ester (GOFA-L-NAME) in mononuclear cells. Analytes were extracted from cells using methanol and eluted on a GraceSmart RP18 analytical column (250×4.6mm i.d., 5µm particle size) kept at 25°C. A mixture of formic acid 1% in water (A) and methanol (B) were used as mobile phase, at a flow-rate of 1.2mL/min in gradient elution. A fluorescence detector (excitation/emission wavelength of 319/398nm for GOFA and GOFA-L-NAME), was used for the two analytes. Calibration curves of GOFA and GOFA-L-NAME were linear over the concentration range of 1.0-50µg/mL, with correlation coefficients (r2)≥0.9995. Intra- and inter-assay precision do not exceed 6.8%. The accuracy was from 94% to 105% for quality control samples (2.0, 25.0 and 40µg/mL). The mean (RSD%) extraction recoveries (n=5) for GOFA and GOFA-L-NAME from spiked cells at 2.0, 25.0 and 40.0µg/mL were 92.4±1.5%, 94.7±0.9% and 93.8±1.1%, for GOFA and 95.3±1.2%, 94.8±1.0% and 93.9±1.3%, for GOFA-L-NAME. The limits of detection and quantification were 0.3µg/mL and 1.0µg/mL for GOFA and GOFA-L-NAME. This method was successfully applied to measure GOFA and GOFA-L-NAME concentrations in a mononuclear cells.

The NF-kB regulates the SHP-1 expression in monocytes in congestive heart failure.

It has been shown that functional recovery of patients with acute congestive heart failure (ACHF) after treatment with conventional drugs (CD) is mediated by suppression of inflammation in peripheral blood mononuclear cells. Here, we analyzed gene expression profiles of monocytes from symptomatic ACHF patients (NYHA Class III-IV) before and after pharmacological treatment with CD. The treatment was associated with selective down-regulation of "TNFR signaling" and pro-inflammatory mediators CCL5, MIP-1α receptor, CD14, ITGAM, and significant up-regulation of "TNFR signaling" as evidenced by increase in anti-inflammatory factors including NF-kBIA, TNFAIP3 and SHP-1. In monocyte TNF-alpha-stimulated there is a down-regulation of the phosphatase SHP-1 which induces a significant activation of TAK-1/IKK/NF-kB signaling. These findings suggest that the therapeutic impact of CD treatment in symptomatic ACHF includes negative regulation of the NF-kB signaling in monocytes and the improvement of the SHP-1 activity.

New Approach in Translational Medicine: Effects of Electrolyzed Reduced Water (ERW) on NF-κB/iNOS Pathway in U937 Cell Line under Altered Redox State.

It is known that increased levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) can exert harmful effects, altering the cellular redox state. Electrolyzed Reduced Water (ERW) produced near the cathode during water electrolysis exhibits high pH, high concentration of dissolved hydrogen and an extremely negative redox potential. Several findings indicate that ERW had the ability of a scavenger free radical, which results from hydrogen molecules with a high reducing ability and may participate in the redox regulation of cellular function. We investigated the effect of ERW on H2O2-induced U937 damage by evaluating the modulation of redox cellular state. Western blotting and spectrophotometrical analysis showed that ERW inhibited oxidative stress by restoring the antioxidant capacity of superoxide dismutase, catalase and glutathione peroxidase. Consequently, ERW restores the ability of the glutathione reductase to supply the cell of an important endogenous antioxidant, such as GSH, reversing the inhibitory effect of H2O2 on redox balance of U937 cells. Therefore, this means a reduction of cytotoxicity induced by peroxynitrite via a downregulation of the NF-κB/iNOS pathway and could be used as an antioxidant for preventive and therapeutic application. In conclusion, ERW can protect the cellular redox balance, reducing the risk of several diseases with altered cellular homeostasis such as inflammation.

A Novel Biological Role of α-Mangostin in Modulating Inflammatory Response Through the Activation of SIRT-1 Signaling Pathway.

Several studies have shown that xanthones obtained from Garcinia Mangostana (GM) have remarkable biological activities. α-mangostin (α-MG) is the main constituent of the fruit hull of the GM. Several findings have suggested that SIRT-1, a nuclear histone deacetylase, could influence cellular function by the inhibition of NF-kB signaling. ROS can inhibit SIRT-1 activity by initiating oxidative modifications on its cysteine residues, and suppression of SIRT-1 enhances the NF-κB signaling resulting in inflammatory responses. The goals of the present study were to evaluate the quantity of α-MG in the methanolic extract of GM (Vithagroup Spa) and to investigate the activity of this xanthone in U937 cell line and in human monocytes from responsive to inflammatory insult analyzing the possible changes on the activation of SIRT-1 protein via NF-Kb. Cells were treated with the methanolic extract of GM and/or LPS. The chromatographic separation of α-MG was performed by an HPLC analysis. EX 527, a specific SIRT-1 inhibitor, was used to determine if SIRT-1/NfkB signaling pathway might be involved in α-MG action on cells. Our results show that α-MG inhibits p65 acetylation and down-regulates the pro-inflammatory gene products as COX-2, iNOS via SIRT-1 activation. Cells treated with EX 527 showed an up-regulation of NFkB acetylation and an over expression of inducible enzymes and their product of catalysis (NO and PGE2). These results suggest that α-MG may be useful for the development of alternative pharmacological strategies aimed at reducing the inflammatory process. J. Cell. Physiol. 231: 2439-2451, 2016. © 2016 Wiley Periodicals, Inc.

Verbascoside down-regulates some pro-inflammatory signal transduction pathways by increasing the activity of tyrosine phosphatase SHP-1 in the U937 cell line.

Polyphenols are the major components of many traditional herbal remedies, which exhibit several beneficial effects including anti-inflammation and antioxidant properties. Src homology region 2 domain-containing phosphatase-1 (SHP-1) is a redox sensitive protein tyrosine phosphatase that negatively influences downstream signalling molecules, such as mitogen-activated protein kinases, thereby inhibiting inflammatory signalling induced by lipopolysaccharide (LPS). Because a role of transforming growth factor ß-activated kinase-1 (TAK1) in the upstream regulation of JNK molecule has been well demonstrated, we conjectured that SHP-1 could mediate the anti-inflammatory effect of verbascoside through the regulation of TAK-1/JNK/AP-1 signalling in the U937 cell line. Our results demonstrate that verbascoside increased the phosphorylation of SHP-1, by attenuating the activation of TAK-1/JNK/AP-1 signalling. This leads to a reduction in the expression and activity of both COX and NOS. Moreover, SHP-1 depletion deletes verbascoside inhibitory effects on pro-inflammatory molecules induced by LPS. Our data confirm that SHP-1 plays a critical role in restoring the physiological mechanisms of inducible proteins such as COX2 and iNOS, and that the down-regulation of TAK-1/JNK/AP-1 signalling by targeting SHP-1 should be considered as a new therapeutic strategy for the treatment of inflammatory diseases.

Synthesis of a novel cyclic prodrug of S-allyl-glutathione able to attenuate LPS-induced ROS production through the inhibition of MAPK pathways in U937 cells.

A novel cyclic prodrug of S-allyl-glutathione (CP11), obtained by using an acyloxy-alkoxy linker, was estimated for its pharmacokinetic and biological properties. The stability of CP11 was evaluated at pH 1.2, 7.4, in simulated fluids with different concentrations of enzymes, and in human plasma. The anti-inflammatory ability of CP11 was assessed in U937 cells, an immortalized human monocyte cell line. Results showed that CP11 is stable at acidic pH showing a possible advantage for oral delivery due to the longer permanence in the stomach. Having a permeability coefficient of 2.49 × 10(-6) cm s(-1), it was classified as discrete BBB-permeable compound. Biological studies revealed that CP11 is able to modulate inflammation mediated by LPS in U937 cells preventing the increase of ROS intracellular levels through interaction with the MAPK pathway.

Effect of erythropoietin on primed leucocyte expression profile.

Resistance to erythropoietin (EPO) affects a significant number of anaemic patients with end-stage renal disease. Previous reports suggest that inflammation is one of the major independent predictors of EPO resistance, and the effects of EPO treatment on inflammatory mediators are not well established. The aim of this study was to investigate EPO-induced modification to gene expression in primary cultured leucocytes. Microarray experiments were performed on primed ex vivo peripheral blood mononuclear cells (PBMCs) and treated with human EPO-α. Data suggested that EPO-α modulated genes involved in cell movement and interaction in primed PBMCs. Of note, EPO-α exerts anti-inflammatory effects inhibiting the expression of pro-inflammatory cytokine IL-8 and its receptor CXCR2; by contrast, EPO-α increases expression of genes relating to promotion of inflammation encoding for IL-1ß and CCL8, and induces de novo synthesis of IL-1α, CXCL1 and CXCL5 in primed cells. The reduction in MAPK p38-α activity is involved in modulating both IL-1ß and IL-8 expression. Unlike the induction of MAPK, Erk1/2 activity leads to upregulation of IL-1ß, but does not affect IL-8 expression and release. Furthermore, EPO-α treatment of primed cells induces the activation of caspase-1 upstream higher secretion of IL-1ß, and this process is not dependent on caspase-8 activation. In conclusion, our findings highlight new potential molecules involved in EPO resistance and confirm the anti-inflammatory role for EPO, but also suggest a plausible in vivo scenario in which the positive correlation found between EPO resistance and elevated levels of some pro-inflammatory mediators is due to treatment with EPO itself.

Astaxanthin treatment confers protection against oxidative stress in U937 cells stimulated with lipopolysaccharide reducing O2- production.

Recently, astaxanthin (ASTA) studies have focused on several biological functions such as radical scavenging, singlet oxygen quenching, anti-carcinogenesis, anti-diabetic, anti-obesity, anti-inflammatory, anti-melanogenesis, and immune enhancement activities. In this study, we investigated the potential role protective of ASTA, an antioxidant marine carotenoid, in restoring physiological conditions in U937 cells stimulated with LPS (10 µg/ml). Our results show that pre-treatment with ASTA (10 µM) for 1 h attenuates the LPS-induced toxicity and ROS production. The beneficial effect of ASTA is associated with a reduction intracellular O2 (-) production by restoring the antioxidant network activity of superoxide dismutase (SOD) and catalase (CAT), which influence HO-1 expression and activity by inhibiting nuclear translocation of Nrf2. We accordingly hypothesize that ASTA has therapeutic properties protecting U937 cells from LPS-induced inflammatory and oxidative stress.

A glutathione derivative with chelating and in vitro neuroprotective activities: synthesis, physicochemical properties, and biological evaluation.

Metal-ion dysregulation and oxidative stress have been linked to the progressive neurological decline associated with neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Herein we report the synthesis and chelating, antioxidant, and in vitro neuroprotective activities of a novel derivative of glutathione, GS(HQ)H, endowed with an 8-hydroxyquinoline group as a metal-chelating moiety. In vitro results showed that GS(HQ)H may be stable enough to be absorbed unmodified and arrive intact to the blood-brain barrier, that it may be able to remove Cu(II) and Zn(II) from the Aß peptide without causing any copper or zinc depletion in vivo, and that it protects SHSY-5Y human neuroblastoma cells against H2 O2 - and 6-OHDA-induced damage. Together, these findings suggest that GS(HQ)H could be a potential neuroprotective agent for the treatment of neurodegenerative diseases in which a lack of metal homeostasis has been reported as a key factor.

Analysis of genomic methylation level using micellar electrokinetic chromatography with UV detection.

Analytical methods for quantification of 5'-methylcytosine in genomes are important tools to investigate epigenetic changes in gene expression during development, differentiation, aging, or cancer. Here, we report a novel genomic methylation content assay based on enzymatic hydrolysis of DNA and MEKC separation of 5'-deoxyribonucleoside monophosphates (dNMP) using the cationic surfactant CTAB as pseudostationary phase. Calf Thymus DNA was used during method development to determine electrophoretic parameters and electrolyte composition for a complete separation between 2'-deoxycytosine-5'-monophosphate and 2'-deoxy-5'-methylcytosine 5'-monophosphate (d5mCMP). Methylated and not methylated oligonucleotides were used to confirm the identity of each peak and evaluate analytical parameters of the method. The LOD of the method was found to be 12.5 pmol/µL for d5mCMP.

Novel aminobenzyl-acetamidine derivative modulate the differential regulation of NOSs in LPS induced inflammatory response: role of PI3K/Akt pathway.

BACKGROUND: Previous reports suggest that NO may contribute to the pathophysiology of septic shock. Recently, we have synthesized and characterized a series of benzyl- and dibenzyl derivative of N-(3-aminobenzyl)acetamidine, a potent and selective inhibitor of iNOS, in vitro assay. We evaluated the molecular mechanisms by which these compounds are involved in the regulation of NOSs expression. METHODS: H9c2 cells were stimulated with lipopolysaccharide (LPS) in the presence or absence of acetamidine-derivative. The NOSs mRNA and protein, and activation of signaling pathways (Akt and NF-κB) were assayed. RESULTS: The induction of endotoxic shock in H9c2 with LPS caused an increase of inducible NOS and a down-regulation of constitutive NOS. The molecular mechanism involved in the modulation of NOSs expression in H9c2 cells upon LPS stimulation resulted in the modification of the redox state responsible for NF-kB nuclear translocation via NIK -IKKα/ß-IkBα, simultaneously to the inactivation of the PI3K/Akt pathway. The compounds acted as an anti-inflammatory modulator. CONCLUSION: These results suggest that LPS regulates the opposite NOS expression in H9c2 cells by modifying the redox state of these cells responsible for the NF-kB nuclear translocation via NIK-IKKα/ß-IkBα, simultaneous to the inactivation of the PI3K/Akt pathway. The new molecule acts as an anti-inflammatory modulator in LPS-induced inflammation in H9c2 cells by the restoration of eNOS and nNOS expressions, mechanistically involving the PI3K/Akt pathway. GENERAL SIGNIFICANCE: This study delineates the underlying mechanisms of opposite NOSs expression in H9c2 cells stimulated with LPS.

Licocalchone-C extracted from Glycyrrhiza glabra inhibits lipopolysaccharide-interferon-γ inflammation by improving antioxidant conditions and regulating inducible nitric oxide synthase expression.

The genus Glycyrrhiza consists of about 30 species, amoung these, G. glabra is the source of several phenolic compounds, known as flavonoids, such as licoagrodin, licoagrochalcones, licoagroaurone and licochalcone C, kanzonol Y, glyinflanin B and glycyrdione A, which have shown various pharmacological activities, including antitumor, antiparasitic, antileishmanial, anti-ulcer and antioxidative effects. Among these compounds, licochalcone C was isolated but its biology has not been fully examined. In our study we reproduced an inflammatory state by treating THP-1 (human myelomonocytic leukaemia) cells with pro-inflammatory stimuli, such as LPS and IFN-γ and we investigated the possible antioxidant activity of licochalcone C at a concentration of 50 µM. Our results show that treatment with licochalcone C attenuates the LPS-IFN-γ-induced inflammatory response by significantly decreasing the expression and activity of iNOS via NFκB (nuclear factor kappa-B), by influencing extracellular O2⁻ production, and by modulating the antioxidant network activity of SOD (superoxide dismutase), CAT (catalase) and GPx (glutathione peroxidase) activity. Based on these results we hypothesize that Licochalcone C has antioxidant properties since it reduces the production of superoxide radicals and consequently reduces the activity of iNOS.