Alessandra Luini

Antioxidant and cytoprotective properties of infusions from leaves and inflorescences of Achillea collina Becker ex Rchb.

Plants are the main source of molecules with antioxidant and radical scavenging properties that aid the natural defence systems of cells and may be involved in the preservation of human health, particularly preventing all the physiopathological conditions where oxidative damage is a hallmark. Achillea collina Becker ex Rchb. is a medicinal plant of the Achillea millefolium aggregate (yarrow) traditionally used, particularly in mountain areas, as an infusion or alcohol extract for its digestive, antiinflammatory, analgesic, antipyretic and wound healing properties. The aim of this study was to investigate the antioxidant capacity and cytoprotective activity against oxidative stress of infusions obtained from the leaves and inflorescences of Achillea collina Becker ex Rchb., assessed by chemical (free radical scavenging activity by DPPH and Folin Ciocalteu assay) and biological assays (in vitro model of cytotoxicity and lipid peroxidation in PC12 cells line). Infusions of leaves had the highest antioxidant properties and cytoprotective activity. The antioxidant capacity was significantly correlated with the total phenolic content but not with the cytoprotective profile. Achillea collina Becker ex Rchb. has good antioxidant and cytoprotective properties, suggesting further investigations on its chemical composition and potential health value, particularly for traditionally prepared infusions of leaves. Copyright

The Essential Oil of Bergamot Stimulates Reactive Oxygen Species Production in Human Polymorphonuclear Leukocytes

Bergamot (Citrus aurantium L. subsp. bergamia) essential oil (BEO) is used in folk medicine as an antiseptic and anthelminthic and to facilitate wound healing. Evidence indicates that BEO has substantial antimicrobial activity; however its effects on immunity have never been examined. We studied the effects of BEO on reactive oxygen species (ROS) production in human polymorphonuclear leukocytes (PMN) and the role of Ca2+ in the functional responses evoked by BEO in these cells. Results show that BEO increased intracellular ROS production in human PMN, an effect that required the contribution of extracellular (and, to a lesser extent, of intracellular) Ca2+. Bergamot essential oil also significantly increased ROS production induced by the chemotactic peptide N‐formyl‐Met‐Leu‐Phe and reduced the response to the protein kinase C activator phorbol myristate acetate. In conclusion, this is the first report showing the ability of BEO to increase ROS production in human PMN. This effect could both contribute to the activity of BEO in infections and in tissue healing as well as underlie an intrinsic proinflammatory potential. The relevance of these findings for the clinical uses of BEO needs careful consideration. Copyright

Increased expression of dopamine receptors in synovial fibroblasts from patients with rheumatoid arthritis: inhibitory effects of dopamine on interleukin-8 and interleukin-6.

Observations in both animal models of arthritis and patients with rheumatoid arthritis (RA) suggest a role for dopamine and its receptors in RA. Because synovial fibroblasts (SFs) contribute to inflammation and joint destruction in RA, the aim of this study was to investigate dopaminergic pathways in SFs obtained from patients with RA and, for comparison, in SFs from patients with osteoarthritis (OA) undergoing knee joint replacement surgery.

Isoflavone content and estrogenic activity of different batches of red clover (Trifolium pratense L.) extracts: An in vitro study in MCF-7 cells

The estrogenicity of different batches of red clover (Trifolium pratense L., Fabaceae; RCL) extracts and its relationship with the isoflavone content were assessed by measuring MCF-7 cell proliferation by flow cytometry and propidium iodide staining. RCL extracts were compared to estradiol (E2) and to the main RCL isoflavones biochanin A, daidzein, genistein and formononetin. Isoflavone content in the extracts was assayed by HPLC. E2 and isoflavones increased MCF-7 proliferation in a concentration-dependent fashion, with the following potency order: E2>>>genistein>biochanin A=daidzein>formononetin. Extracts increased MCF-7 proliferation with different potencies, which in four out of five extracts correlated with the ratios 5,7-dihydroxyisoflavones/7-hydroxyisoflavones. The efficacy of all extracts increased with decreasing genistein contents. A solution containing the main isoflavones at the average concentration of RCL extracts increased MCF-7 proliferation with higher potency and steeper concentration-response curve. The effects of E2, of RCL extracts and of the isoflavone solution were inhibited by the estrogen receptor antagonist 4-hydroxytamoxifen. Flow cytometric analysis of MCF-7 proliferation is a suitable bioassay for the estrogenicity of RCL extracts, thus expanding the characterization of individual batches beyond assessment of chemical composition and contributing to improved standardization of quality and activity.

Adrenergic modulation of migration, CD11b and CD18 expression, ROS and interleukin-8 production by human polymorphonuclear leukocytes

ObjectivesAdrenergic modulation of immunity has been extensively characterized, however, few information exist regarding polymorphonuclear leukocytes (PMN), despite their key role in immunity and inflammation. We investigated the effect of adrenergic agents on human PMN migration, CD11b and CD18 expression, reactive oxygen species (ROS) and interleukin (IL)-8 production, and on adrenoceptor (AR) expression.MethodsMigration was measured by the Boyden chamber assay, CD11b/CD18 expression was assessed by flow cytometry, intracellular ROS were detected by spectrofluorimetry, and IL-8 was quantitated by standard ELISA assay. AR mRNA levels were measured by real-time PCR and PMN morphology was studied by scanning electron microscopy.ResultsAdrenaline(A), noradrenaline and the β-AR agonist isoprenaline reduced N-formyl-Met-Leu-Phe (fMLP)-induced migration, CD11b/CD18 expression, and ROS production, without affecting IL-8. The effect of A on CD11b was antagonized by yohimbine and propranolol, and increased by prazosin. The effect on ROS production was completely abolished by propranolol. PMN expressed α1A-, α1B-, α1D-, α2A-, α2C-, β1-, β2-, and β3-AR mRNA. A prevented fMLP-induced morphological changes of PMN.ConclusionsAdrenergic agents reduced PMN responses mainly through β-AR, although α-AR may contribute at least to CD11b expression. AR-operated pathways in PMN should be investigated in disease conditions and in the response to therapeutic agents.

NET amyloidogenic backbone in human activated neutrophils

Activated human neutrophils produce a fibrillar DNA network [neutrophil extracellular traps (NETs)] for entrapping and killing bacteria, fungi, protozoa and viruses. Our results suggest that the neutrophil extracellular traps show a resistant amyloidogenic backbone utilized for addressing reputed proteins and DNA against the non‐self. The formation of amyloid fibrils in neutrophils is regulated by the imbalance of reactive oxygen species (ROS) in the cytoplasm. The intensity and source of the ROS signal is determinant for promoting stress‐associated responses such as amyloidogenesis and closely related events: autophagy, exosome release, activation of the adrenocorticotrophin hormone/α‐melanocyte‐stimulating hormone (ACTH/α‐MSH) loop and synthesis of specific cytokines. These interconnected responses in human activated neutrophils, that have been evaluated from a morphofunctional and quantitative viewpoint, represent primitive, but potent, innate defence mechanisms. In invertebrates, circulating phagocytic immune cells, when activated, show responses similar to those described previously for activated human neutrophils. Invertebrate cells within endoplasmic reticulum cisternae produce a fibrillar material which is then assembled into an amyloidogenic scaffold utilized to convey melanin close to the invader. These findings, in consideration to the critical role played by NET in the development of several pathologies, could explain the structural resistance of these scaffolds and could provide the basis for developing new diagnostic and therapeutic approaches in immunomediated diseases in which the innate branch of the immune system has a pivotal role.

Characterization of human leukocyte-HUVEC adhesion: Effect of cell preparation methods

OBJECTIVE Sample manipulation to obtain isolated granulocytes represents a key, and often necessary, step in the in vitro studies. We investigated by the means of flow cytometry and microscopic techniques (both optical microscopy [OM] and scanning electron microscopy [SEM]), the granulocyte-endothelium adhesion and the role of sample manipulation. METHODS By means of a co-culture method, we have analysed the adhesion of human leukocytes, originated from two different blood samples (fresh venous blood [FB] and buffy coat [BC]), to the human umbilical venous endothelial cell (HUVEC) monolayer. Cultured HUVEC were analysed for adhesion molecule expression by means of flow cytometry, while the morphological changes were evaluated by means of SEM. Cell adhesion was evaluated by means of flow cytometry and both OM and SEM. RESULTS HUVEC expressed under resting conditions the adhesion molecules ICAM-1, VCAM-1 and E-selectin and their expression was upregulated by stimulation with TNF-α (0.1-10ng/ml) as well as with LPS (1μg/ml). SEM analysis showed that stimulation with both stimuli profoundly affect cell morphology. Flow cytometric evaluation of cell adhesion showed that the ability of cells to adhere to HUVEC monolayer was quite different in the two preparations, with the lowest adhesion for FB in all the cell subsets analysed. Finally, isolated granulocytes were able to adhere to HUVEC monolayer more than cells identified in FB or BC and the adhesion was increased during activation of HUVEC with 10ng/ml of TNF-α. CONCLUSION Our data showed that cell manipulation necessary for the isolation of specific immune cells from whole blood profoundly affect the ability of these cells to adhere to the HUVEC monolayer although their functional properties remain unchanged.

β2‐Adrenoceptors inhibit neutrophil extracellular traps in human polymorphonuclear leukocytes

This study tests the hypothesis that in isolated human polymorphonuclear leukocytes (PMN) adrenergic ligands can affect neutrophil extracellular trap (NET) formation. We have previously shown that, in PMN, adrenaline (A), through the activation of adrenergic receptors (AR), reduces stimulus‐dependent cell activation; we have, therefore, planned to investigate if AR are involved in NET production. PMN were obtained from venous blood of healthy subject. The ability of adrenergic ligands to affect reactive oxygen species (ROS) production, NET production, and cell migration was investigated in cells cultured under resting conditions or after activation with N‐formyl‐methionyl‐leucyl‐phenylalanine (fMLP), LPS, or IL‐8. Stimuli‐induced NET production measured as ROS, microscopic evaluation, and elastase production was reverted by A and this effect was blocked by the selective β2–AR antagonist ICI‐118,551. The stimulus‐induced ROS generation and migration was prevented by A and by isoprenaline (ISO), and these effects were counteracted only by ICI‐118,551 and not by the other two selective ligands for the β1 and β3–AR. Finally, the presence of the β–ARs on PMN was confirmed, by means of microscopy and flow cytometry. The data of the present study suggest that adrenergic compounds, through the interaction of mainly β2–AR, are able to affect neutrophil functions. These data are suggestive of a possible therapeutic role of β2–AR ligands (in addition to their classical use), promoting the possible therapeutic relevance of adrenergic system in the modulation of innate immunity proposing their possible use as anti‐inflammatory drugs.

Strong activation of dopamine pathway in synovial fibroblasts from rheumatoid arthritis patients

270 Opioid and alcohol action: The role of brain and spinal cord innate immune signalling M.R. Hutchinson , Y. Wu , L. Liu , S. Phipps , K.C. Rice , J.K. Coller , L.R. Watkins , A.A. Somogyi a a University of Adelaide, Pharmacology, Level 5, Medical School North, Frome Rd, Adelaide, SA 5005, Australia b University of Queensland, Australia c National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism National Institutes of Health, USA d University of Colorado at Boulder, USA Opioids and alcohol have been used and abused for several millennia. Until recently, it was believed that their actions were mediated almost exclusively by neuronal mechanisms within the central nervous system (CNS). Recent developments in pharmacology and basic neuroscience have implicated non-neuronal, immune-related mechanisms in the functional response to these drugs. Data will be presented showing that in mice, opioid and alcohol administration causes proinflammatory activation of glia and that this drug-induced glial activation occurs in a Toll-Like Receptor 4 dependent fashion. Importantly, behavioural drug actions are also altered. Morphine-induced TLR4 signalling opposes acute analgesia, whilst increasing reward and dependence. Interestingly, using three strains of in-bred mice with differing opioid sensitivity we demonstrated that the extent of morphine-induced hippocampal IL-1 expression and the degree of TLR4-induced IL-1 release from splenocytes of these strains correlated significantly with the degree of opioid dependence. Alcohol sleep time and motor impairments were significantly reduced when TLR4 signalling was inhibited using novel pharmacological agents or genetic knockout mice. ‘‘In cell” flow cytometric data suggest that ERK phosphorylation is a key mediator of the TLR4-induced drug signal. The sum of these data supports the hypothesis that TLR4 is critical to drug action and hence is a possible target to improve the clinical efficacy of opioids and increasing the safety of opioid and alcohol use. doi:10.1016/j.bbi.2010.07.060