Ageing and Oxidative Stress: a Role for Dolicol in the Antioxidant Machinary of Cell Membranes?

Dolichol is a polyprenol compound broadly distributed in membranes, biosynthetized by the general isoprenoid pathway from acetate via mevalonate and farnesyl pyrophosphate. Dolichol lays inside the membrane between the two leaflets of the lipid bilayer very close to the tail of phospholipid fatty acids. No definite catabolic pathways for this molecule have yet been identified. Evidence is produced that dolichol levels increase dramatically with increasing age; that anti-ageing caloric restriction retards this age-associated change; that dolichol may act as a radical scavenger of peroxidized lipids belonging to the cell membranes. In view of the polyunsaturated fatty acids (PUFA), dolichol and Vitamin E location and stechiometry, it is proposed that molecules might interact each-other to form a highly matched free-radical-transfer chain, whose malfunctioning might be involved in statin toxicity and neurodegenerative diseases.