Lorenza Speranza

Antiinflammatory effects in THP-1 cells treated with verbascoside

Verbascum thapsus commonly known as ‘mullein’ is part of a large family of Scrophulariaceae consisting of more than 360 species. From antiquity Verbascum thapsus has been used as a medicinal herb, it contains diverse polysaccharides, iroid glycosides, flavonoids, saponins, volatile oils and phenylentanoids. Inducible nitric oxide synthase (iNOS) represents one of the three isoforms that produce nitric oxide using L‐arginine as a substrate in response to an increase in superoxide anion activated by NF‐kB. It is implicated in different pathophysiological events and its expression increases greatly during an inflammatory process, due to oxidative stress and the activation of the enzymes of the antioxidant network such as SOD, CAT and GPx.

Marine carotenoids and cardiovascular risk markers.

Marine carotenoids are important bioactive compounds with physiological activities related to prevention of degenerative diseases found principally in plants, with potential antioxidant biological properties deriving from their chemical structure and interaction with biological membranes. They are substances with very special and remarkable properties that no other groups of substances possess and that form the basis of their many, varied functions and actions in all kinds of living organisms. The potential beneficial effects of marine carotenoids have been studied particularly in astaxanthin and fucoxanthin as they are the major marine carotenoids. Both these two carotenoids show strong antioxidant activity attributed to quenching singlet oxygen and scavenging free radicals. The potential role of these carotenoids as dietary anti-oxidants has been suggested to be one of the main mechanisms for their preventive effects against cancer and inflammatory diseases. The aim of this short review is to examine the published studies concerning the use of the two marine carotenoids, astaxanthin and fucoxanthin, in the prevention of cardiovascular diseases.

Novel phytonutrient contributors to antioxidant protection against cardiovascular disease

The associations linking endothelial inflammation, endothelial oxidative stress, and atherogenesis and the potential for dietary phytonutrients to decrease the impact of these associations were assessed. A detailed literature review was conducted and summarized. A large body of scientific evidence describes the interactions among endothelial inflammation, endothelial oxidative stress, and atherogenesis. A growing body of research indicates that several dietary phytonutrients (astaxanthin, lycopene, lutein, and glabridin) can decrease the risk for atherosclerosis by decreasing endothelial inflammation and oxidative stress. The consumption of foods or dietary supplements that provide astaxanthin, lycopene, lutein, and glabridin can ameliorate endothelial inflammation and oxidative stress, retard atherogenesis, and decrease the risk for atherogenic cardiovascular disease.

Astaxanthin Treatment Reduced Oxidative Induced Pro-Inflammatory Cytokines Secretion in U937: SHP-1 as a Novel Biological Target

It has been suggested that oxidative stress activates various intracellular signaling pathways leading to secretion of a variety of pro-inflammatory cytokines and chemokines. SHP-1 is a protein tyrosine phosphatase (PTP) which acts as a negative regulator of immune cytokine signaling. However, intracellular hydrogen peroxide (H2O2), generated endogenously upon stimulation and exogenously from environmental oxidants, has been known to be involved in the process of intracellular signaling through inhibiting various PTPs, including SHP-1. In this study, we investigated the potential role of astaxanthin, an antioxidant marine carotenoid, in re-establishing SHP-1 negative regulation on pro-inflammatory cytokines secretion in U-937 cell line stimulated with oxidative stimulus. ELISA measurement suggested that ASTA treatment (10 µM) reduced pro-inflammatory cytokines secretion (IL-1β, IL-6 and TNF-α) induced through H2O2, (100 µM). Furthermore, this property is elicited by restoration of basal SHP-1 protein expression level and reduced NF-κB (p65) nuclear expression, as showed by western blotting experiments.

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.

Extremely low frequency electromagnetic field and wound healing: implication of cytokines as biological mediators.

Wound healing is a highly coordinated and complex process involving various cell types, chemical mediators and the surrounding extracellular matrix, resulting in a tightly orchestrated re-establishment of tissue integrity by specific cytokines. It consists of various dynamic processes including a series of overlapping phases: inflammation, proliferation, re-epithelialization and remodeling. One of the underlying mechanisms responsible for the disturbances in wound healing is an out-of-control inflammatory response that can cause pathological consequences, such as hypertrophic scars, keloids or chronic wounds and ulcers. Recently, several reports have evaluated the effects of extremely low frequency electromagnetic fields (EMFs) on tissue repair. In particular, the data analysis supports an anti-inflammatory effect of EMFs by the modulation of cytokine profiles that drive the transition from a chronic pro-inflammatory state to an anti-inflammatory state of the healing process. In this review, we focus on the effect of EMFs on skin wound healing showing emerging details of the anti-inflammatory effects of EMFs, with a view to cytokines as candidate biomarkers. Molecular clarification of the mechanisms involved in the modulation of inflammatory factors following exposure to EMFs will provide a better understanding of the cellular responses induced by EMFs and a potential, additional treatment in non-responding, chronic wounds.

Vascular Endothelial Growth Factor (VEGF), Mast Cells and Inflammation

Vascular endothelial growth factor (VEGF) is one of the most important inducers of angiogenesis, therefore blocking angiogenesis has led to great promise in the treatment of various cancers and inflammatory diseases. VEGF, expressed in response to soluble mediators such as cytokines and growth factors, is important in the physiological development of blood vessels as well as development of vessels in tumors. In cancer patients VEGF levels are increased, and the expression of VEGF is associated with poor prognosis in diseases. VEGF is a mediator of angiogenesis and inflammation which are closely integrated processes in a number of physiological and pathological conditions including obesity, psoriasis, autoimmune diseases and tumor. Mast cells can be activated by anti-IgE to release potent mediators of inflammation and can also respond to bacterial or viral antigens, cytokines, growth factors and hormones, leading to differential release of distinct mediators without degranulation. Substance P strongly induces VEGF in mast cells, and IL-33 contributes to the stimulation and release of VEGF in human mast cells in a dose-dependent manner and acts synergistically in combination with Substance P. Here we report a strong link between VEGF and mast cells and we depict their role in inflammation and immunity.

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.

Activity of matrix metallo proteinases (MMPs) and the tissue inhibitor of MMP (TIMP)-1 in electromagnetic field-exposed THP-1 cells.

Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) are the main determinants of tissue remodeling in both physiological and pathological processes. Metabolic processes, which generate oxidants and antioxidants can be influenced by environmental factors such as electromagnetic fields (EMF). We analyzed the effects of EMF on the activity and expression of MMPs in THP‐1 cells. Cells were exposed to a 50 Hz, 1 mT EMF for 24 h and incubated with or without LPS. Our data indicate that THP‐1 cells exposed to EMF causes a reduction of anti‐oxidant enzyme activity and an enhancement of nitrogen intermediates involving the iNOS pathway. We then analyzed the role of nitration of TIMP‐1 in increasing the activity of MMPs in EMF exposed cells. Molecular modeling tools were employed to identify the most plausible sites in the active conformation of TIMP‐1; at least two protein sites, Y120 and Y38 and/or Y72 were identified. Reactive nitrogen species (RNS) may affect protein targets, such as TIMP‐1, which are crucial for the regulation of MMP activities by oxidation of sulfydryl groups, or by nitration of tyrosine residues. These results may suggest a pathway connecting an imbalance of MMPs and their cognate inhibitor TIMP‐1. J. Cell. Physiol. 227: 2767–2774, 2012.

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/β-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/β-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.