Role of calorie restriction in alleviation of age-related morphological and biochemical changes in sciatic nerve

• We investigate the effect of aging on peripheral nerves.
• We detect histopathological changes in aged peripheral nerves.
• The possible underlined oxidative stress in peripheral nerves with aging.
• Calorie restriction protects the peripheral nerves against aging changes.

BackgroundAging is associated with structural, functional and biochemical alterations in the nervous system. Calorie restriction (CR) was found to retard most physiological indices of aging.ObjectivesThis work aimed to investigate the effect of CR on age-related changes in sciatic nerves.Materials and methodsThirty male albino rats aged 1 month were equally divided into three groups; Group I [control adult-ad libitum AL]: fed a regular diet and sacrificed at the age of 6 months, group II (aged-AL group): fed a regular diet AL and sacrificed at the age of 18 months, and group III (aged CR) fed a 40% calorie restricted diet and sacrificed at the age of 18 months. Rats were anesthetized and sciatic nerves were processed for light, electron microscope and morphometric studies. Oxidative stress in sciatic nerves was investigated by estimation of lipid perioxidation by product malondialdehyde (MDA) tissue level and antioxidant enzyme; superoxide dismutase activity (SOD).ResultsThe aged (AL) sciatic nerves appeared disorganized, with thick perineurium and increased collagen fibers associated with decreased g-ratio. Abnormal myelin forms were seen as outfolded myelin loops, thin denuded myelin, splitting of myelin into myelin figures and interlamellar vacuoles. Schwann cells revealed vacuolated cytoplasm. There was also significant increase in MDA level and a significant decrease in SOD activity in comparison to control adult (AL). Apparent structural and histomorphological improvement were noticed after CR in aged rats.ConclusionAging caused structural and biochemical alterations in sciatic nerves with alleviating effect of calorie restriction on such effects.