Mustafa Zerin

The effect of melatonin on bleomycin-induced pulmonary fibrosis in rats

The present investigation was designed to determine the protective effects of melatonin against bleomycin (BLM)‐induced oxidant lung toxicity. Wistar‐albino rats were divided into four groups: saline (SA, 0.4 mL/animal), 1% ethanol‐saline (ALC, 0.4 mL/animal), bleomycin sulphate (BLM, 10 mg/kg), or bleomycin sulphate + melatonin (BLM, 10 mg/kg + MLT, 10 mg/kg). All injections were given intraperitoneally (i.p.), twice weekly for a period of 3 wk (a total of seven injections for each group). Twenty‐five days after BLM treatment, pulmonary fibrosis was assessed as hydroxyproline content in lung homogenates. Findings show that BLM‐induced pulmonary injury resulted in increases in bronchoalveolar lavage fluid (BALF) biomarkers including total protein, lactate dehydrogenase (LDH), glutathione‐peroxidase (GSH‐Px), superoxide dismutase (SOD), and catalase (CAT). Additionally, the levels of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation (LPO), were also increased in BALF. Conversely, the level of glutathione (GSH) was reduced in BALF of BLM‐treated rats. Melatonin provided protection against BLM‐induced pulmonary fibrosis by suppressing oxidative stress. It abolished BLM‐stimulated LPO and reversed the imbalance between oxidants and antioxidants in the BALFs. Results thus indicate that melatonin inhibits BLM‐induced lung toxicity associated with oxidative damage.

Effects of intraperitoneally injected selenium and vitamin E in rats anesthetized with halothane

Halothane, commonly used for anesthetizing humans and animals, is one of the most important volatile anesthetics and may cause the formation of free radicals during its biotransformation. Free radicals may lead to degeneration of liver cells. Vitamin E and glutathione peroxidase (GSH-Px) containing selenium are two natural antioxidants, and these may protect the cellular lipid and lipoproteins against oxidative damage caused by free radicals. Therefore, the purposes of the present study were to investigate the probable protective effects of intraperitoneally administered Se and vitamin E on liver enzymes and to determine some other hematological parameters in the halothane anesthesia of rats. All rats were randomly divided into five groups. The first group was used as a control, and physiological saline (0.9%) was intraperitoneally injected into these animals as a placebo. The second group was used as an anesthesia control group and was only anesthetized with halothane for two hours. The third group received intraperitoneally administered Se (Na2SeO3, 0.3 mg/200 g body weight), the fourth group vitamin E (dl-alpha-tocopheryl acetate, 100 mg/kg body weight), and the fifth group a Se plus vitamin E combination (Na2SeO3, 0.3 mg/200 g body weight + dl-alpha-tocopheryl acetate, 100 mg/kg body weight). The activities of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase, triglycerides, erythrocyte counts, the packet-cell volume, hemoglobin concentrations and neutrophyle rates significantly increased (p < 0.05 to p < 0.01) after halothane anesthesia and returned to near control levels after Se, vitamin E and Se plus vitamin E injections. The values of cholesterol, total protein, white blood cell counts and lymphocyte rates significantly decreased (p < 0.05 to p < 0.01) in the anesthesia control group. However, the levels of albumin, total bilirubin, creatinine, the mean corpuscular volume, the mean corpuscular hemoglobin, and the mean corpuscular hemoglobin concentration were not statistically influenced. In conclusion, we have determined that halothane anesthesia affected some liver enzymes and some other biochemical and hematological parameters. Se, vitamin E and their combination may prevent the increase of liver enzymes after halothane anesthesia. Based upon these results, Se and vitamin E may play an important role in the indication of hepatic cellular injury produced by halothane.