Research ArticleEffect of Indigofera tinctoria on β-amyloid (25-35) mediated Alzheimer's disease in mice: Relationship to anti-oxidant activity
BJP
IntroductionOxidative stress has been implicated as a major cause of neurotoxicity in a number of neurodegenerative disorders including Alzheimer's disease. Oxidative damage in Alzheimer's disease may be a direct result of amyloid beta (AP). Markers of oxidative DNA damage, including mitochondrial DNA damage, have been localized to amyloid plaque affected areas in the Alzheimer's disease brain (Mecocci et al., 1994); the generation of lipid peroxidation products and the lipo peroxidation of membranes is also noted in amyloid plaques (Matsuoka et al., 2001).The mechanism of AP mediated oxidative stress may be direct or indirect, functionality of mitochondrial electron transport chain (ETC) is particularly susceptible to inhibition by AP, which is a major source of reactive oxygen species (ROS) within the cell and may therefore represent an indirect source of oxidative stress. Alternatively, AP can cause neurotoxicity by direct production of ROS (Behl et al., 1992), the mechanism which is directly related to biometal dyshomeostasis as evident in the brain of Alzheimer's disease (Lovell et al., 1998). Cell culture studies have provided further support for AP-ROS production as a potential mechanism for AP mediated neurodegeneration (Huang et al., 1999). The constant assault of oxidative stress during the aging process contributes towards neurodegeneration in Alzheimer's disease (Bush, 2003).Indigofera tinctoria Linn (Fabaceae) is an evergreen shrub native to entire India, especially in Southern India (Santapav and Henry, 1994). The entire plant is a stimulant, alternative and purgative. It is used in the treatment of liver and spleen enlargements. Root of the plant is used to cure hepatitis and urinary complications. The dried whole plant is used in phobia, delusion and disturbed mental states (Khare, 2007;
AbstractThe oxidative stress reducing effect of methanol extract of Indigofera tinctoria leaves (250 and 500 mg/kg) was investigated on β-amyloid (25-35) peptideinduced Alzheimer's disease in mice. All the anti-oxidant enzymes (superoxide dismutase, catalase, glutathione peroxide and glutathione reductase) in brain were reduced significantly (p<0.001) in the β-amyloid peptide injected group, whereas lipid peroxidation was increased significantly (p<0.001). The reduced enzyme level were restored significantly (p<0.01; p<0.001) by the administration of extract at the tested dose levels. A significant (p<0.001) reduction in lipid peroxidation was observed in the groups of animals administered with extract. Histopathological sections of the hippocampal region showed the extent of neuronal loss and its restoration upon administration of extract. Treatment with extract at the tested doses moderately prevented the neuronal loss.
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