3-nitrotyrosine and caffeic-acid-phenethyl-ester

Excessive free radical production by immune cells has been linked to cell death and tissue injury during sepsis. Peroxynitrite is a short-lived oxidant and a potent inducer of cell death that has been identified in several pathological conditions. Caffeic acid phenethyl ester (CAPE) is an active component of honeybee products and exhibits antioxidant, anti-inflammatory, and immunomodulatory activities. The present study examined the ability of CAPE to scavenge peroxynitrite in RAW 264.7 murine macrophages stimulated with lipopolysaccharide/interferon-γ that was used as an in vitro model. Conversion of 123-dihydrorhodamine to its oxidation product 123-rhodamine was used to measure peroxynitrite production. Two mouse models of sepsis (endotoxemia and cecal ligation and puncture) were used as in vivo models. The level of serum 3-nitrotyrosine was used as an in vivo marker of peroxynitrite. The results demonstrated that CAPE significantly improved the viability of lipopolysaccharide/interferon-γ-treated RAW 264.7 cells and significantly inhibited nitric oxide production, with effects similar to those observed with an inhibitor of inducible nitric oxide synthase (1400W). In addition, CAPE exclusively inhibited the synthesis of peroxynitrite from the artificial substrate SIN-1 and directly prevented the peroxynitrite-mediated conversion of dihydrorhodamine-123 to its fluorescent oxidation product rhodamine-123. In both sepsis models, CAPE inhibited cellular peroxynitrite synthesis, as evidenced by the absence of serum 3-nitrotyrosine, an in vivo marker of peroxynitrite. Thus, CAPE attenuates the inflammatory responses that lead to cell damage and, potentially, cell death through suppression of the production of cytotoxic molecules such as nitric oxide and peroxynitrite. These observations provide evidence of the therapeutic potential of CAPE treatment for a wide range of inflammatory disorders.

Topics: Animals; Caffeic Acids; Cells, Cultured; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Free Radical Scavengers; Interferon-gamma; Lipopolysaccharides; Macrophage Activation; Macrophages; Male; Mice, Inbred BALB C; Nitric Oxide; Peroxynitrous Acid; Phenylethyl Alcohol; Sepsis; Tyrosine

Cardioplegic arrest remains the method of choice for myocardial protection in cardiac surgery. Caffeic acid phenethyl ester (CAPE) prevents lipid peroxidation induced by ischemia-reperfusion injury and has a potent antioxidant property. We investigated the advantages of CAPE supplemented cardioplegic solution (St. Thomas' Hospital cardioplegic solution No.: 2) on the antioxidant defense system of myocardium against ischemia-reperfusion injury.. Isolated rat hearts were mounted on a nonrecirculating type of Langendorff apparatus. The hearts were arrested for 60 min with cardioplegic solution given at 20-min intervals and then reperfused for 15 min. The hearts were divided into three groups. Cold saline (0.9%, 4 degrees C) in group 1, St. Thomas' Hospital solution in group 2 and CAPE added St. Thomas' Hospital solution in group 3 were used as the cardioplegic solution. Krebs-Henseleit buffer solution was used for reperfusion. The tissues were examined biochemically for oxidative stress.. Significant differences among the three groups existed in tissue myeloperoxidase (MPO), catalase (CAT), Na+-K+ ATPase activity and in the concentrations of malonydealdehyde (MDA) and 3-nitrotyrosine (3-NT). Group 2 showed significant changes in MPO (P = 0.04), Na+-K+ ATPase enzyme activity (P = 0.02) and the levels of MDA (P = 0.004) and 3-NT (P = 0.01) in comparison with group 1. Group 3 efficiently reduced MDA levels (P = 0.004) and also led to significant decrease in levels of MPO (P = 0.006), 3-NT (P = 0.01) and Na+-K+ ATPase activity (P = 0.01) and increase in the level of CAT (P = 0.004) in comparison with group 1. Significant changes were also found in the levels of MDA (P = 0.03), MPO (P = 0.04) and CAT (P = 0.009) in comparison between groups 2 and 3.. We demonstrated that the administration of CAPE into cardioplegic solutions improves the antioxidant defense system of rat heart during the ischemia-reperfusion injury.

Topics: Animals; Antioxidants; Caffeic Acids; Cardioplegic Solutions; Catalase; Free Radical Scavengers; Heart; In Vitro Techniques; Male; Malondialdehyde; Myocardial Reperfusion Injury; Peroxidase; Phenylethyl Alcohol; Rats; Rats, Wistar; Sodium-Potassium-Exchanging ATPase; Tyrosine

Ischemia-reperfusion (IR) is characterized by microvascular disfunction and this involves both direct effected organ and remote organ by systemic inflammatory response. These remote effects of IR are most frequently observed in the lung and cardiovascular system. In this study we aim to determine lung damage which induced IR, and endothelial and microvascular disfunction using nitrosative markers. Previous studies suggest that caffeic acid phenethyl ester (CAPE) has some antioxidant effects. Therefore, we also investigated whether it has a role associated with nitric oxide during IR condition. Twenty-two adult male Wistar rats were divided into three groups: control (n= 7), IR (n= 7), and CAPE + IR (n= 8). 8 h IR period was performed on right hindlimb in the IR and the CAPE with IR group. In the CAPE with IR group, animals received CAPE 10 microM 1 h before the reperfusion. At the end of the reperfusion period, blood, bronchoalveolar lavage (BAL) and lung tissue were obtained, and were used for biochemical and histopathological examination. There was a significantly elevation in serum nitrate, BAL MPO, and leukocyte infiltration in the lung in the IR group compared to the CAPE + IR group. But, serum nitrite and lung 3-NT levels were not different between these groups. While nitrate (p< 0.0001), MPO (p< 0.0001) and leukocyte infiltration (chi2= 27.163, p= 0.0001), reduce by using CAPE before reperfusion, tissue 3-NT levels did not change. In conclusion, peripheral IR leads to systemic inflammatory responses and endothelial disfunction-induced NO production, and these harmful effects may reduced by CAPE.

Topics: Animals; Bronchoalveolar Lavage Fluid; Caffeic Acids; Capillary Permeability; Cytokines; Hindlimb; Lung; Male; Malondialdehyde; Neutrophil Infiltration; NF-kappa B; Phenylethyl Alcohol; Rats; Rats, Wistar; Reperfusion Injury; Respiratory Distress Syndrome; Tourniquets; Tyrosine