Oxidative stress characterized by an imbalance in the production and degradation of radical species has been implicated in the onset and progression of several diseases. The efficacy of antioxidants acting via the inhibition of radical chain reactions, scavenging of free radicals, direct donation of electrons to radical species and chelation of metal ions have been reported to attenuate the oxidative process. Vitamin E is an effective antioxidant and its hydrophobic nature and membrane permeability offer some benefits to application and bioavailability. This chapter highlights the following; structural differences in the vitamin family, biosynthesis in plants and the native biological role, antioxidant mechanisms of vitamin E, an overview of the prophylactic action of vitamin E as well as the effect on the oxidative process in some diseases.

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The continued use of potassium bromate in some food and cosmetic products in Nigeria against regulatory provision has continually exposed Nigerians to its deleterious effect. The mechanism of bromate induced damage in the liver and kidney is through oxidative stress. Phytochemicals have antioxidant capacity and have gained research interest in the management of oxidative stress. In this study, the effect of the ethanol extract of Aframomum angustifolium seed on kidney and liver damage induced by exposure to an acute dose of potassium bromate was measured using appropriate biomarkers. Eighteen male Wistar rats, randomly divided into 3 groups were used for the study. Group I (normal control) received distilled H2O; Group II (positive control) received 400 mg/kgbw bromate once while Group III (test) received same acute dose as Group II but thereafter treated with an oral dose of ethanol extract (750 mg/kgbw) for 10days. Half the populations of each group were sacrificed on day 3 while the remaining was sacrificed on day 10 of treatment. Liver and kidney tissues as well as blood samples were collected for analysis. Biochemical parameters; malondialdehyde, creatinine, electrolytes (Na+ and K+) concentration as well as catalase, alanine aminotransferase and alkaline phosphatase activities were measured using standard spectrophotometric procedures. In the kidney tissue, malondialdehyde concentration increased significantly in all groups from day 3 to day 10 but was highest in Group II. A similar trend was observed in the liver tissue but only group III increased significantly. Catalase activity was inhibited in Group II in both kidney and liver tissues and was significantly lower than test group. Serum Na+ decreased and K+ increased respectively but Group III were comparable to the Group I. Creatinine concentration increased in all groups but was highest in Group II though it was not significant. ALP activity was significantly higher (p<0.05) in Group III on day 3 compared to Group I but was not significantly different (p>0.05) on day 10. The results of this study suggests that ethanol extract of Aframomum angustifolium seeds can accelerate the in vivo repair of bromate induced hepato- and reno- toxicity in Wistar rats. Keywords: Aframomum angustifolium, bromate toxicity, malondialdehyde, antioxidant, phytochemicals.

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