The effect of L-theanine on the oxidant-antioxidant balance in serum and lung tissue in experimentally induced sepsis in rats

Sepsis induces lung injury and respiratory distress syndrome and is therefore potentially fatal. L-theanine (LT), an amino acid found in tea, is a bioactive compound with an important antioxidant, anti-inflammatory, and antifibrotic properties. The purpose of this study was to evaluates whether, LT exhibits protective effects against lung tissue damage by determining its effect on oxidative stress, inflammation and mineral levels in an experimental model of cecal ligation and perforation (CLP)-induced sepsis in rats. Rats were randomly divided into three groups (n=6): sham, CLP, and CLP+LT. LT was administered intraperitoneally (750 mg/kg) in two equal doses immediately and 12 h after surgery. Malondialdehyde (MDA), advanced protein oxidation product (AOPP), myeloperoxidase (MPO), total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and ischemia modified albumin (IMA) values were determined spectrophotometrically. Serum elements (Na, K, Mg, Ca, and Fe), albumin, glucose, triglyceride, and lactate levels were determined using an autoanalyzer. Lung tissues were also examined histopathologically. Treatment of septic rats with LT significantly reduced oxidative stress and inflammation in lung tissues and serum. LT also increased albumin and Na levels and reduced triglyceride levels in serum. In conclusion, LT treatment may exhibit a preventive effect against sepsis-induced lung injury by reducing oxidative stress and inflammation, and by regulating osmotic balance.