Antioxidant and neuroprotective properties of Mediterranean oils: Argan oil, olive oil, and milk thistle seed oil

Argan, olive, and milk thistle seed oils are characterized by high levels of tocopherols, mainly α-tocopherol. They are also rich in oleic acid (C18:1 n-9) and linoleic acid (C18:2 n-6) and contain small quantities of several polyphenols. As tocopherols and polyphenols have antioxidant properties and are able to cross the blood-brain barrier, it is suggested that argan, olive, and milk thistle seed oils could be useful in the prevention of neurodegenerative disorders since these are characterized by an enhancement of oxidative stress leading to neurodegeneration. This hypothesis is supported by the antioxidant properties of these oils determined by different assays KRL (Kit Radicaux Libres), FRAP (ferric-reducing antioxidant power), and DPPH [2,2-diphenyl-1-picryl-hydrazyl)] and by cytoprotective properties of these oils which are able to prevent major side effects associated with oxysterols-induced neurodegeneration such as oxidative stress, mitochondrial dysfunction, and cell death of nerve cells.