Oxidative stress may play a key role in Alzheimer's disease (AD) neuropathology. Pomegranates (石榴 Shí Liú) contain very high levels of antioxidant polyphenolic substances, as compared to other fruits and vegetables. Polyphenols have been shown to be neuroprotective in different model systems. Here, the effects of the antioxidant-rich pomegranate fruit grown in Oman on brain oxidative stress status were tested in the AD transgenic mouse. The 4-month-old mice with double Swedish APP mutation (APPsw/Tg2576) were purchased from Taconic Farm, NY, USA. Four-month-old Tg2576 mice were fed with 4% pomegranate or control diet for 15 months and then assessed for the influence of diet on oxidative stress. Significant increase in oxidative stress was found in terms of enhanced levels of lipid peroxidation (LPO) and protein carbonyls. Concomitantly, decrease in the activities of antioxidant enzymes was observed in Tg2576 mice treated with control diet. Supplementation with 4% pomegranate attenuated oxidative damage, as evidenced by decreased LPO and protein carbonyl levels and restoration in the activities of the antioxidant enzymes [superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione (GSH), and Glutathione S transferase (GST)]. The activities of membrane-bound enzymes [Na+ K+-ATPase and acetylcholinesterase (AChE)] were altered in the brain regions of Tg2576 mouse treated with control diet, and 4% pomegranate supplementation was able to restore the activities of enzymes to comparable values observed in controls. The results suggest that the therapeutic potential of 4% pomegranate in the treatment of AD might be associated with counteracting the oxidative stress by the presence of active phytochemicals in it.

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Oxidative stress may play a key role in Alzheimer's disease (AD) neuropathology. Changes in the oxidative stress, antioxidants, and membrane-bound enzymes were investigated in the cerebral cortex and hippocampus of AD transgenic mice model after long-term dietary supplementation of date palm fruits from Oman. The 4-month-old mice with double Swedish APP mutation (APPsw/Tg2576) were purchased from Taconic Farm, NY, USA; mice were fed two different doses of dates (such as 4 and 2%) or control diet for 15 months and then assessed for the influence of diet on oxidative stress. Significant increase in oxidative stress in terms of enhanced levels of lipid peroxidation (LPO) and protein carbonyls and parallel decrease in the activity of antioxidant enzymes were observed in control diet-treated Tg2576 AD mice. Dates (4 and 2%) treated APPsw/Tg2576 AD mice exhibited significantly attenuated oxidative damage, evidenced by decreased LPO and protein carbonyl levels and restoration in the activities of the antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione, and glutathione reductase). The activities of membrane-bound enzymes (Na(+), K(+)-ATPase and acetyl cholinesterase) were altered in control diet-treated APPsw/Tg2576 AD mice brain regions. Meanwhile, both the percentages of date supplementation were able to restore the activity of enzymes to comparable values observed in controls. In summary, we have shown that chronic dietary supplementation of date palm fruits grown in Oman showed possible beneficial effects concomitant with oxidative stress reduction and increased antioxidant enzymes in AD transgenic mice model. These results warrant further exploration of how anti-reactive oxygen species properties of dates offer such beneficial effects on the AD-like brain.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is an environmental toxin which selectively induces oxidative damage and mitochondrial and proteasomal dysfunctions to dopaminergic neurons in the substantia nigra leading to Parkinsonian syndrome in animal models and humans. MPTP is one of the most widely used in vitro models to investigate the pathophysiology of Parkinson's disease (PD) and, screen for novel therapeutic compounds that can slow down or ameliorate this progressive degenerative disease. We investigated the therapeutic effect of pomegranate juice extracts (PJE), Helow, Malasi, Qusum, and Hamadh against MPTP-induced neurotoxicity in primary human neurons by examining extracellular LDH activity, intracellular NAD+ and ATP levels, and endogenous antioxidant levels including lipid peroxidation products, catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, and reduced glutathione (GSH) levels. MPTP induced a reduction in SOD and GPx activities and intracellular NAD+, ATP, and GSH levels parallel to an increase in extracellular LDH and CAT activities, although lipid peroxidation was not altered. We report that helow and malasi can ameliorate MPTP-induced neurotoxicity by attenuating the observed changes in redox function to a greater extent than qusum and hamedh. Selected PJE varieties may exhibit properties which may be of therapeutic value to slow down age-related degeneration and neurodegeneration in particular.

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