Effects of caffeic acid phenethyl ester on lipopolysaccharide-induced lung injury in rats.

Extracts of propolis, a natural beehive product, have been known for centuries to have a variety of beneficial medical properties, among which their anti-inflammatory effect is a major one. Caffeic acid phenethyl ester (CAPE), an active propolis component, has antimicrobial, anti-inflammatory, antioxidant, carcinostatic and immunomodulatory properties. In this study, we aimed to investigate the efficacy of CAPE in endotoxin-induced lung injury in rats. Lung injury was induced by a footpad injection of lipopolysaccharide (LPS). In the treatment group, 10 micromol kg(-1) CAPE was injected intraperitoneally immediately after LPS injection. At 24 h after LPS and/or CAPE injection, blood and lung tissue specimens were collected. MDA levels and MPO activity in serum and lung tissue, serum total antioxidant levels, lung tissue Na(+)/K(+) ATP-ase activity and histopathological evaluation were determined to assess the efficacy of CAPE treatment. CAPE was found to be efficient in reducing inflammation and lung tissue damage induced by LPS in rats.

Effects of N-acetylcysteine on oxidant-antioxidant balance in oleic acid-induced lung injury.

The antioxidant and anti-inflammatory properties of N-acetylcysteine has been documented in many experimental lung injury models. Because intravenous injection of oleic acid induces histopathologic changes similar to those seen in human acute lung injury or acute respiratory distress syndrome, the authors evaluated the effects of N-acetylcysteine (NAC) on oxidative stress and lung damage in an oleic acid (OA)-induced lung injury model. Thirty-five rats were divided into 5 groups as sham, NAC, OA, pre-OA-NAC, and post-OA-NAC. Lung damage was induced by intravenous administration of oleic acid. Pre-OA-NACgroup received intravenous (IV) N-acetylcysteine 15 minutes before oleic acid infusion and post-OA-NAC group received IV N-acetylcysteine 2 hours after oleic acid infusion. In both of the N-acetylcysteine treatment groups, blood and tissue samples were collected 4 hours after oleic acid infusion, independent from the time of N-acetylcysteine infusion. In other groups, blood and tissue samples were collected 4 hours after ethanol, NAC, or OA infusions. Serum myeloperoxidase activity, total antioxidant capacity, malondialdehyde levels, and lung tissue Na+ - K+ ATPase activity were measured and light microscopic analyses of lung specimens were performed. The administration of N-acetylcysteine significantly restored Na+ - K+ ATPase activity and total antioxidant capacity levels and ameliorated lung architecture. N-acetylcysteine has been shown to have some attenuating effects in experimental animal studies. However, further investigations are necessary to suggest N-acetylcysteine as a treatment agent in critically ill patients with lung injury.