ABSTRACT
Tocotrienol, a multipotent nutraceutical with antioxidative, anti-inflammatory and neuroprotective properties, could be used to maintain the cognitive functions even in the presence of neurotoxicants. Oral supplementation of two doses of tocotrienol was used during the three doses of ethanol exposure (comparable with low-to-moderate doses of alcohol consumption in human), and learning, retention, and utilisation of navigation performances were evaluated and correlated with the level of oxidative stress markers in cerebral regions. Rats received ethanol exposure for 4 weeks and tocotrienol supplementation for 4 weeks of ethanol exposure and continued for 2 more weeks. The significant decrement in weight gain during the experimentation was observed only in the groups receiving the highest amount of ethanol exposure (0.6 mg/kg body weight). Only the group exposed to ethanol at 0.4 mg/kg bw demonstrated alterations in acquisition time and post-48 h retention time of Morris water maze navigation task. Significant influences of ethanol exposure and tocotrienol supplementation were observed in the probe test using the Morris water maze. The correlation between oxidative stress parameters of cerebral regions and probe test did not provide any significant information; however, indicated that investigated domains of cognition most likely were associated with frontal cortex and temporal cortex functions.
ABSTRACT
Tocotrienols are members of vitamin E family present in low concentrations and possess high antioxidant activity. Consumption of ethanol is a common problem and induces oxidative stress. In this study, we evaluated the effect of tocotrienol against ethanol-induced oxidative stress. Male albino Wistar rats were divided into two sets; one set of rats were exposed with low to moderate doses of ethanol for 4 weeks, while another set was exposed to tocotrienol orally (10 mg/day) in addition to the ‘low to moderate doses of ethanol for 4 weeks’. Oxidative stress parameters, like levels of reduced glutathione and lipid peroxidation, activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase were determined in serum before the initiation of treatment protocol and at the end of 2nd and 4th week of treatment. Serum levels of superoxide and peroxide handling capacities were also calculated in those three time points. Tocotrienol-treated rats showed statistically significant enhancement in reduced glutathione level, glutathione peroxidase and glutathione reductase activities. Glutathione-dependent superoxide and peroxide handling capacity of those rats were found to be higher. The current study suggests that the tocotrienol-induced protection against the oxidative stress is most likely mediated by glutathione-based system.