The structure of the optic nerve after the administration of interferon α-2a in adult male albino rats and the role of α-lipoic acid supplementation

Abstract

Introduction Interferon alpha (IFN-α) therapy is used considerably in Egypt because of a high prevalence rate of chronic hepatitis C virus infection. α-Lipoic acid (ALA) has been found to play a neuroprotective role in many insults. The aim of this study is to observe the histological structure of the optic nerve of rats after an injection of IFN-α and to determine the role of ALA supplementation. Materials and methods Forty adult male albino rats were divided equally into four groups. Group I served as the control group. Group II included rats that received ALA alone (100mg/kg/day, intraperitoneally). Group III included rats that received IFN-α alone (100000 IU/kg/three times/week, intraperitoneally). Group IV included rats that received both IFN-α and ALA. After 8 weeks, the optic nerves were extirpated and processed for light and electron microscope examination. Results Optic nerves of the group that received IFN-α showed nerve damage manifested as axonal damage and changes in the myelin sheath. Neuroglia showed vacuolation in their cytoplasm and heterochromatic nuclei. Morphometric and statistical analyses showed a significant increase in the surface area of positive glial fibrillary acidic protein astrocytes, indicating reactive astrogliosis. Blood capillaries were distorted with ill-defined walls and protrusion of the endothelial cells into their lumina. These changes were limited by concomitant ALA supplementation with IFN-α. Conclusion IFN-α exerted a deleterious effect on the histological structure of the optic nerve in rats and ALA supplementation minimized these effects.