EBSELEN PROTECTS AGAINST OXIDATIVE AND MORPHOLOGICAL EFFECTS OF HIGH CONCENTRATION CHRONIC TOLUENE EXPOSURE ON RAT SCIATIC NERVES

Protective effects of caffeic acid phenethyl ester and thymoquinone on toluene induced liver toxicity

Toluene is an organic solvent that is toxic to humans. Caffeic acid phenethyl ester (CAPE) and thymoquinone (TQ) exhibit antioxidant and antitoxic effects. We investigated the protective effects of CAPE and TQ on toluene induced hepatotoxicity. Wistar albino rats were divided into seven groups of eight. The animals were injected intraperitoneally (i.p.) with 0.1 ml/10 g/day corn oil (control I), 0.1 ml/10 g/day corn oil + 2 ml/kg/day 10% ethanol (control II), 20 mg/kg/day TQ dissolved in 0.1 ml/10 g corn oil (TQ), 10 µmol/kg/day CAPE dissolved in 10% ethanol (CAPE), 500 mg/kg/day toluene (T), toluene and TQ together (T + TQ), or toluene and CAPE together (T + CAPE). All rats were sacrificed on day 15. Liver samples were obtained for histological analysis. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured to evaluate liver function. Liver sections from the control I and TQ groups exhibited normal histology. Sections from the T group exhibited sinusoid dilation, hemorrhage, vacuolization and necrosis. TQ and CAPE protected against toluene induced histopathological changes. AST and ALT levels were increased significantly in T group compared to both control groups. CAPE decreased significantly the toluene induced increase in AST and ALT levels, while TQ did not. CAPE and TQ exhibited some antitoxic and hepato-protective effects on toluene induced liver damage.

Effects of Acute Toluene Toxicity on Different Regions of Rabbit Brain

The acute phase effects of toluene on the brain have been investigated in this study using rabbit brain via histopathological, immunohistochemical, and biochemical methods. A total of 20 male rabbits were used as control and experimental groups. Moreover, nerve growth factor (NGF), tumor necrosis factor-alpha (TNF-alpha), dopamine (DA), and glial fibrillary acidic protein (GFAP) tests were performed in order to designate the severity of the biochemical damage. In the biochemical evaluation of the prefrontal cortex, hippocampus, hypothalamus, substantia nigra, and entorhinal cortex, the TNF-alpha levels in the brain were found to be significantly higher than in the control group. Levels of dopamine, secreted from the substantia nigra, nerve growth factor (NGF) developed from the hippocampal neurons, and GFAP, secreted from astrocyte cells, were detected to be significantly lower in the toluene-administration group than in the control group (p < 0.05). In addition, areas of focal vacuolar degeneration (abscess formation), gliosis, and perivascular demyelination, many pyknotic cells and necrosis were observed. In the toluene-administration group compared to the control group, distinct excessive expansions of the blood vessels and severe degeneration in the structure of cells and also dispersed cell borders were observed. Furthermore, abnormal malformations of the nuclei structure of the oligodendrocyte cells were seen. Bodies of the sequential neurons of the hippocampus in the toluene-administration group were distinctly structurally damaged compared to the control group. In addition, cytoplasm of the cortex cell showed serious immune reactivity in the experimental group.

Predicting disease onset in clinically healthy people

Virtually all human disease is induced by oxidative stress. Oxidative stress, which is caused by toxic environmental exposure, the presence of disease, lifestyle choices, stress, chronic inflammation or combinations of these, is responsible for most disease. Oxidative stress from all sources is additive and it is the total oxidative stress from all sources that induces the onset of most disease. Oxidative stress leads to lipid peroxidation, which in turn produces Malondialdehyde. Serum malondialdehyde level is an additive parameter resulting from all sources of oxidative stress and, therefore, is a reliable indicator of total oxidative stress which can be used to predict the onset of disease in clinically asymptomatic individuals and to suggest the need for treatment that can prevent much human disease.

The protective effects of caffeic acid phenethyl ester against toluene-induced nephrotoxicity in rats

Caffeic acid phenethyl ester (CAPE) has antioxidant and anti-inflammatory properties. The aim of this study is to examine the negative effects of toluene on kidney tissues and functions and to investigate the protective effects of CAPE against toluene-induced nephrotoxicity in rats. A total of 21 male Wistar rats were divided into three groups of equal number in each. The rats in group I were the controls. Toluene was intraperitoneally injected into the rats in group II with a dose of 500 mg/kg. Rats in group III received CAPE daily while exposed to toluene. After 14 days of experimental period, all rats were killed by decapitation. Enzymatic activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) and malondialdehyde (MDA) levels were studied in the rat kidneys. Blood urea nitrogen (BUN) and serum creatinine levels were measured for renal function. The CAT and SOD enzyme activities and serum creatinine levels were significantly increased in rats treated with toluene when compared with the controls. But GSH-Px activity, MDA, and BUN levels showed statistically nonsignificant changes. However, increased CAT and SOD enzyme activities and decreased serum creatinine levels were detected in the rats that received CAPE while exposed to toluene. The GSH-Px activity and MDA and BUN levels in the same group did not show statistically significant changes. The results of our study demonstrated that toluene damages kidney tissue and is a nephrotoxic substance. CAPE was able to prevent the renal damage as antioxidant, antitoxic, and nephroprotective agent.