Protective effects of melatonin and ß-d-glucan against liver injury in rats - a comparative study.

OBJECTIVES: The aim of this study was to investigate the possible protective effects of melatonin and ß-d-glucan against ischemia-reperfusion (IR) injury in rats. MATERIAL AND METHODS: Forty rats were randomly divided into 5 groups, each consisting of 8 animals, as follows. Sham group [S], IR group [C], IR + ß-Glucan group [ß], IR + melatonin group [MLT], IR + melatonin + ß-Glucan group [MLT + ß]. The rats in the C, ß, MLT and MLT + ß groups were subjected to IR for 60 min each. Melatonin (10 mg∙kg⁻¹) was intraperitoneally injected for a single dose 30 min before IR. ß-Glucan (50 mg∙kg⁻¹âˆ™day⁻¹) was orally administered for 10 days to rats. All of the rats were killed on day 11, and histological changes in the liver and tissue levels of oxidants and antioxidants were evaluated. RESULTS: Malondialdehyde [MDA] level were significantly higher in the C group compared to the S group (p = 0.007). MDA level were significantly higher in the ß group compared to the MLT and MLT + ß groups (p =0.007). Tissue antioxidant markers (superoxide dismut ase [SOD], glutathione-peroxidase [GPx], and catalase [CAT]) were significantly lower in the C group than the S group (p < 0.05). SOD levels were simply not significant in the ß group compared to the MLT and MLT + ß groups. CAT and GPx activities were significantly higher in the ß group compared to the MLT and MLT + ß groups (p = 0.004).The histological damage ameliorated in ß, MLT and MLT + ß groups compared to C group.

Effects of benzo(a)pyrene and ethanol on oxidative stress of brain, lung tissues and lung morphology in rats.

Ethanol and benzo(a)pyrene cause lipid peroxidation either by producing the reactive oxygen species or decreasing the activities of antioxidant enzymes that lead to cellular damage and cellular dysfunction. In this study, we investigated both physiological and histological changes in lung and physiological changes in brain after the administration of benzo(a)pyrene and ethanol both separately and together. Male Sprague Dawley rats were divided into four groups, each containing seven rats as follows: Group I (control), group II (benzo(a)pyrene, [B(a)P]), group III ([B(a)P] + ethanol (EtOH)) and group IV (EtOH). Superoxide dismutase (SOD) activity, levels of glutathione(GSH), malondialdehyde (MDA) as well as histological examinations were evaluated to demonstrate the damages in lung and brain tissues following the administration of [B(a)P] and EtOH. SOD activities of lung and brain tissues in group II and group III decreased significantly, compared to that in group I and group IV, respectively. GSH levels of both the lung and brain tissues in the experimental groups were lower when compared to the control group. MDA levels of lung tissues in group II and III were significantly higher than that in the control group. Moreover, MDA levels in the brain tissues of all the experimental groups were higher than that in the control group, but these values were only significantly higher in group II and IV. In the second study group, [B(a)P] administration resulted in lung damage. On the other hand, lung tissue of the third experimental group showed moderate damage, and lung tissues of the fourth group was less severely damaged. [B(a)P] and EtOH administration alone or together caused changes in the GSH, MDA levels and SOD enzyme activity in the lung and brain tissues. We also noted that [B(a)P] and EtOH caused different degrees of histological changes.