Gábor Eros

Anti-inflammatory effects of phosphatidylcholine in neutrophil leukocyte-dependent acute arthritis in rats

We investigated the effects of exogenous phosphatidylcholine (PC) and non-steroidal diclofenac supplementation on polymorphonuclear cell influx in carrageenan-induced arthritis in rats. The microcirculatory consequences were evaluated by a novel method developed for direct intravital microscopic observation of the synovial membrane. Arthritis was induced by injection of a mixture of 2% lambda-carrageenan and 4% kaolin into the knee joints and the animals were treated orally with PC (150 mg/kg twice daily), sodium diclofenac (0.5mg/kg twice daily) or saline vehicle. Intravital videomicroscopy was used to investigate the leukocyte-endothelial interactions directly in the synovial membrane at 6h after the challenge. The inflammation-induced thermal and mechanical secondary hyperalgesic reactions were assessed at 24h, and the knee volume changes at 48h after the insult. The development of arthritis was accompanied by a significant increase in the number of adherent leukocytes in the synovial postcapillary venules, but this increase was reduced significantly (by approximately 40%) by PC, and slightly (by 22%) by diclofenac treatment. The perivascular infiltration of the neutrophil leukocytes and the intercellular adhesion molecule-1 (ICAM-1) expressions were reduced only by PC treatment. The significant decrease (45%) in the thermal nociceptive latency, the 3-fold increase in the mechanical touch sensitivity and the knee cross-sectional area (which was increased by 35% by the arthritis induction) were significantly ameliorated by both treatments. The present study demonstrated the anti-inflammatory effects of PC in experimental arthritis. The therapeutic potential may be linked to the reduction of neutrophil leukocyte-mediated microcirculatory inflammatory reactions.

Anti-Inflammatory Action of a Phosphatidylcholine, Phosphatidylethanolamine and N-Acylphosphatidylethanolamine-Enriched Diet in Carrageenan-Induced Pleurisy

Background/Aims: Phosphatidylcholine (PC)-derived choline exhibits anti-inflammatory properties in stress conditions. Phosphatidylethanolamine (PE) and N-acylphosphatidylethanolamines (NAPEs) are endogenous bioactive phospholipids linked to the PC and endocannabinoid metabolisms. We hypothesized that an increased dietary input of PC, PE and NAPE may interfere with leukocyte reactions and thus decreases the inflammatory activation. Methods: CFLP mice were fed with a control diet or with a diet supplemented with 1% PC, 0.4% PE and 0.1% NAPE for 7 days before the induction of pleurisy with carrageenan. Pleural leukocyte migration, pulmonary mast cell degranulation (Alcian blue-safranin O staining), and the activities of inducible nitric oxide synthase, xanthine oxidoreductase and myeloperoxidase were determined in lung tissue biopsies. Results: The carrageenan-induced inflammatory response was characterized by pulmonary leukocyte infiltration, mast cell degranulation and significantly increased inducible nitric oxide synthase and xanthine oxidoreductase activities (by 82 and 60%, respectively). Treatment of mice with acetylsalicylic acid or with dietary PC + PE + NAPE supplementation significantly decreased the leukocyte reaction, and suppressed the activity of the pulmonary proinflammatory enzymes. Conclusion: This study confirms a potential for dietary PC + PE + NAPE supplementation to influence events crucial for the remission of acute inflammation. PC + PE + NAPE administration could possibly be a novel preventive or pharmacotherapeutic option in inflammatory pathologies.

Protective effects of a phosphatidylcholine-enriched diet in lipopolysaccharide-induced experimental neuroinflammation in the rat.

Our goal was to characterize the neuroprotective properties of orally administered phosphatidylcholine (PC) in a rodent model of systemic inflammation. Sprague-Dawley rats were killed at 3 h, 1 day, 3 days, or 7 days after i.p. administration of lipopolysaccharide (LPS) to determine the plasma levels of tumor necrosis factor &agr; (TNF-&agr;) and interleukin 6 cytokines. The control group and one group of LPS-treated animals were nourished with standard laboratory chow, whereas another LPS-treated group received a special diet enriched with 1% PC for 5 days before the administration of LPS and thereafter during the 7-day observation period. Immunohistochemistry was performed to visualize the bromodeoxyuridine and doublecortin-positive neuroprogenitor cells and Iba1-positive microglia in the hippocampus, whereas the degree of mucosal damage was evaluated on ileal and colon biopsy samples after hematoxylin-eosin staining. The activities of proinflammatory myeloperoxidase and xanthine-oxidoreductase and the tissue nitrite/nitrate (NOx) level were additionally determined, and the cognitive functions were monitored via Morris water maze testing. The inflammatory challenge transiently increased the hippocampal NOx level and led to microglia accumulation and decreased neurogenesis. The intestinal damage, mucosal myeloperoxidase, xanthine-oxidoreductase, and NOx changes were less pronounced, and long-lasting behavioral alterations were not observed. Phosphatidylcholine pretreatment reduced the plasma TNF-&agr; and hippocampal NOx changes and prevented the decreased neurogenesis. These data demonstrated the relative susceptibility of the brain to the consequences of transient peripheral inflammatory stimuli. Phosphatidylcholine supplementation did not reduce the overall extent of peripheral inflammatory activation, but efficiently counteracted the disturbed hippocampal neurogenesis by lowering circulating TNF-&agr; concentrations.

Microcirculatory changes in the canine oesophageal mucosa during experimental reflux oesophagitis: Comparison of the effects of acid and bile

Background: The response of the oesophageal microcirculation to luminal damaging agents may play an important role in reflux‐induced mucosal injury. We characterized the microcirculatory consequences of exposure to bile with or without hydrochloric acid, and determined the changes in the constitutive nitric oxide synthase and inducible nitric oxide synthase activities in a canine model of acute reflux oesophagitis. Methods: Group 1 served as a saline‐treated control, while groups 2–4 were exposed for 3 h to bile alone, to hydrochloric acid, or to bile + hydrochloric acid, respectively. The mucosal microcirculation was observed continuously by means of intravital videomicroscopy with an orthogonal polarization spectral imaging technique. Myeloperoxidase, constitutive and inducible nitric oxide synthase activities were measured via tissue biopsies, while the degree of mucosal damage was evaluated histologically. Results: Bile evoked deep tissue damage and leucocyte accumulation in the mucosa and muscle layer. The capillary red blood cell velocity and the relative vessel area increased significantly (P < 0.05). The constitutive NO synthase activity was decreased, and the inducible NO synthase activity was increased significantly. In the hydrochloric acid‐treated group the functional capillary density decreased, the mucosal damage was less severe, the constitutive NO synthase activity did not change, whereas the inducible NO synthase activity was increased significantly. The constitutive NO synthase activity did not change after the bile + hydrochloric acid treatment either. Conclusion: Reflux components induce characteristic microcirculatory alterations. The structural damage and leucocyte invasion are accompanied by bile‐induced constitutive NO synthase inhibition when hydrochloric acid production is suppressed.

Antiirritant properties of polyols and amino acids.

Background: Antiirritants are used in cosmetic products to prevent or to treat skin irritations that arise during daily life. Data were published earlier on the efficacy of the best‐known humectant, glycerol, in reducing irritation. Objective: The aim of the present study was to examine the effects of different polyols (including glycerol, xylitol, and mannitol) and the amino acids taurine and glycine on sodium lauryl sulfate (SLS)‐induced skin irritation. Methods: Healthy adult volunteers were patch‐tested with 0.1% SLS in the presence or absence of one or another polyol or amino acid. Skin reactions were evaluated via measurements of transepidermal water loss (TEWL). Results: Glycerol and xylitol significantly suppressed the SLS‐induced increase in TEWL, whereas mannitol had no effect on the SLS‐induced skin irritation. Taurine also inhibited the SLS‐induced increase in TEWL, but glycine was not effective in reducing the SLS‐induced irritative response. Conclusion: Similar to the action of the well‐known antiirritant glycerol, SLS‐induced skin irritation is suppressed by xylitol and taurine. These results suggest that these agents might also be effective in preventing irritative dermatitis.

A novel murine model for the in vivo study of transdermal drug penetration

Enhancement of the transdermal penetration of different active agents is an important research goal. Our aim was to establish a novel in vivo experimental model which provides a possibility for exact measurement of the quantity of penetrated drug. The experiments were performed on SKH-1 hairless mice. A skin fold in the dorsal region was fixed with two fenestrated titanium plates. A circular wound was made on one side of the skin fold. A metal cylinder with phosphate buffer was fixed into the window of the titanium plate. The concentration of penetrated drug was measured in the buffer. The skin fold was morphologically intact and had a healthy microcirculation. The drug appeared in the acceptor buffer after 30 min, and its concentration exhibited a continuous increase. The presence of ibuprofen was also detected in the plasma. In conclusion, this model allows an exact in vivo study of drug penetration and absorption.

Acrylamide, acrylic acid and N-isopropylacrylamide hydrogels as osmotic tissue expanders.

Background and Aim: Osmotically active tissue expanders allow the harvesting of soft tissue for reconstruction after different injuries. However, their expansion properties could be improved. Thus, our goal was to examine the in vivo applicability of acrylamide (AAm), acrylic acid (AAc) and N- isopropylacrylamide (NIPAAm) hydrogels. Materials and Methods: Cylinders of AAm, AAc and NIPAAm hydrogels were implanted under the skin of rats in the dorsal region. The diameter and the length of the cylinders were measured daily. After removal of the hydrogels, their mass and rheological properties were determined. Further, biopsies were taken from the adjacent tissue for histological analysis. Results: The hydrogels reached the peak of swelling by the end of the 2nd postoperative week. The wet mass of the removed cylinders was 25 times their dry mass prior to implantation. NIPAAm polymers exhibited the most favourable visco-elastic properties, with the highest tendency to retain their preformed shape. The histological analysis revealed serious tissue damage when the AAc devices were used, whereas the AAm and NIPAAm did not result in such lesions. Conclusion: In view of its mechanical and biological properties, NIPAAm hydrogel seems to be the most appropriate of these materials for application in plastic and reconstructive surgery.

A Review of Electroporation-based Antitumor Skin Therapies and Investigation of Betulinic Acid-loaded Ointment

BACKGROUND Electrochemotherapy is a novel treatment for cutaneous and subcutaneous tumors utilizing the combination of electroporation and chemotherapeutic agents. Since tumors have an increasing incidence nowadays as a result of environmental and genetic factors, electrochemotherapy could be a promising treatment for cancer patients. OBJECTIVE The aim of this article is to summarize the novel knowledge about the use of electroporation for antitumor treatments and to present a new application of electrochemotherapy with a well-known plant derived antitumor drug betulinic acid. For the review we have searched the databases of scientific and medical research to collect the available publications about the use of electrochemotherapy in the treatment of various types of cancer. METHOD By the utilization of the available knowledge, we investigated the effect of electroporation on the penetration of a topically applied betulinic acid formulation into the skin by ex vivo Raman spectroscopy on hairless mouse skin. RESULTS Raman measurements have demonstrated that the penetration depth of betulinic acid can be remarkably ameliorated by the use of electroporation, so this protocol can be a possibility for the treatment of deeper localized cancer nodules. Furthermore, it proved the influence of various treatment times, since they caused different spatial distributions of the drug in the skin. CONCLUSION The review demonstrates that electrochemotherapy is a promising tool to treat different kinds of tumors with high efficiency and with only a few moderate adverse effects. Moreover, it presents a non-invasive method to enhance the penetration of antitumor agents, which can offer novel prospects for antitumor therapies.

Contents Vol. 22, 2009

N. Ahmad, Madison, Wisc. P. Altmeyer, Bochum C. Antoniou, Athens H. Bachelez, Paris J.M. Baron, Aachen E. Benfeldt, Hellerup E. Berardesca, Rome D.R. Bickers, New York, N.Y. I. Bogdan Allemann, Zürich K. De Paepe, Brussels P. Elsner, Jena A. Farkas, Szeged A. Giannetti, Modena M.W. Greaves, London R.H. Guy, Bath J. Hadgraft , London E.M. Jackson, Bonney Lake, Wash. Y. Kawakubo, Chiba H.-C. Korting, Munich J. Krutmann, Düsseldorf R. Neubert, Halle D.R. Roop, Aurora, Colo. T. Ruzicka, Munich M. Schäfer-Korting, Berlin S. Seidenari, Modena B. Shroot, San Antonio, Tex. J. Wohlrab, Halle S. Yamamoto, Hiroshima Journal of Pharmacological and Biophysical Research