Ameliorative Effect of Palm Oil in Aluminum Lactate Induced Biochemical and Histological Implications in Rat Brain.

α-Tocotrienol is one of the major constituents of palm oil. It is a well-known antioxidant and cholesterol-lowering neuroprotectant. To prevent the initiation of Alzheimer's like symptoms, much attention has been shifted to the major role played by antioxidants. Previous epidemiological reports correlate the increasing incidence of developing Alzheimer's disease (AD), to the aluminum (Al) content in drinking water. Al, being a ubiquitous element, has a long history of being particularly reactive towards multiple aspects of neurobiology. So, the current study examines the effect of Al-induced behavioral, biochemical, and histopathological changes in rat brain; and the ameliorative effect of palm oil in reducing the resulting neurotoxicity. The experimental design consisted of 4 groups: control group which received rodent chow diet and water ad libitum; Al group received aluminum lactate (50 mg/kg bw); Al + palm oil group was administered with Al (50 mg/kg bw) and palm oil (60 mg/kg bw); and palm oil group received palm oil (60 mg/kg bw). Al was given by oral gavage once daily for 6 weeks and palm oil was administered intraperitoneally. After 6 weeks of supplementation, Al + palm oil group showed significantly lower malondialdehyde (MDA) content, but higher superoxide dismutase (SOD), catalase (CAT), GST, and GPx activity as compared to Al group. Al group has significantly higher level of MDA content, but lower SOD, CAT, GST, and GPx activity as compared to control group. In conclusion, this study suggested that palm oil was effective in preventing the Al-induced brain damage in rats.

Neuroprotective Role of Lazaroids Against Aluminium Chloride Poisoning.

Aluminium (Al) is neurotoxic primarily because of its interference with biological enzymes in key mechanisms of metabolic pathways. Mitochondria being a major site of reactive oxygen species (ROS) production, it seems that the oxidative damage to mitochondrial proteins may underlie the pathogenesis of Al induced neurodegeneration. The present study investigates the effectiveness of the anti-oxidant property of lazaroids (U-74500A), a known lipid peroxidation inhibitor as neuroprotective agent against Al induced neurotoxicity. Al chloride was administered orally at a dose level of 100 mg/kg body wt/day in water and U-74500A was administered at a dose of 0.25 mg/kg body wt i.p. in citrate buffer for a period of 8 weeks on alternate days. Following Al exposure there was a significant increase in lipid peroxidation (LPO), ROS levels and reduction in the activity of mitochondrial complexes in all the three regions of rat brain, i.e., cerebral cortex, mid brain, and cerebellum. This decrease in the activities of electron transport complexes in turn affected the ATP synthesis and ATP levels adversely in the mitochondria. These alterations were also depicted in the histology which shows signs of hypoxia, paucity of neurons in cortical region and loosening of fibers in the white matter. U-74500A co-administration was able to restore alterations in the LPO, ROS levels as well as all the three mitochondrial complexes and caspase expression. Therefore, it is suggested that 21-aminosteroids (lazaroids), by attenuating LPO and mitochondrial dysfunction, holds a promise as an agent that can potentially reduce Al-induced adverse effects in brain.

Stress proteins and glial cell functions during chronic aluminium exposures: protective role of curcumin.

Involved in the ongoing debate is the speculation that aluminium is somehow toxic for neurons. Glial cells cope up to protect neurons from this toxic insult by maintaining the glutathione homeostasis. Of late newer and newer roles of glial cells have been depicted. The present work looks into the other regulatory mechanisms that show the glial cells response to pro-oxidant effects of aluminium exposure. In the present investigation we have evaluated the inflammatory responses of the glial cells as well as HSP70-induction during aluminium exposure. Further, the protective role of curcumin is also evaluated. Aluminium was administered by oral gavage at a dose level of 100 mg/kg b.wt/day for a period of 8 weeks. Curcumin was administered i.p. at a dose of 50 mg/kg b.wt./day on alternate days. Enhanced gene and protein expression of HSP70 in the glial fractions of the aluminium exposed animals as compared to the corresponding neuronal population. Aluminium exposure resulted in a significant increase in the NF-κB and TNF-α expression suggesting inflammatory responses. In the conjunctive treatment group of aluminium and curcumin exposure marked reduction in the gene and protein expression of NF-κB and TNF-α was observed. This was further reflected in histopathological studies showing no evidence of inflammation in conjunctive group as compared to aluminium treatment. From the present study, it can be concluded that curcumin has a potential anti-inflammatory action and can be exploited in other toxicological conditions also.

Curcumin attenuates aluminum-induced oxidative stress and mitochondrial dysfunction in rat brain.

Aluminum is neurotoxic both in animals and human beings primarily because of its interference with biological enzymes in key mechanisms of metabolic pathways. Mitochondrial dysfunction is one such mechanism that has been implicated in the pathogenesis of neurodegenerative diseases like Alzheimer's disease. Aluminum toxicity is very closely related to Alzheimer's disease. We evaluated the potentials of curcumin, a known cytoprotectant, against neurotoxic consequences of aluminum that acts through a wide range of mechanisms. Curcumin has been reported to be an antioxidant, and it is this property that is widely held to be responsible for its protective effects in tissue. Aluminum was administered by oral gavage at a dose level of 100 mg/kg body wt/day for a period of 8 weeks. Curcumin was administered in conjunction with aluminum at a dose of 50 mg/kg of body wt i.p. for a period of 8 weeks on alternate days. The effects of different treatments were studied on oxidative phosphorylation and reduced glutathione of different regions of rat brain. The study indicates reduced activity of NADH dehydrogenase (complex I), succinic dehydrogenase (complex II), and cytochrome oxidize (Complex IV) in all the three regions of rat brain, i.e., cerebral cortex, mid brain, and cerebellum. Curcumin supplementation to aluminum-treated rats was able to normalize significantly the activities of all the three mitochondrial complexes as well as reduced glutathione content in all the three regions of brain which were altered following aluminum treatment. We conclude that curcumin, by attenuating oxidative stress, as evident by hypoxia in histological observations and mitochondrial dysfunction holds a promise as an agent that can potentially reduce aluminum-induced adverse effects in brain.