Inflammation and Oxidative Stress in Young and Aged Rats after Acute Homocysteine Administration

Abstract

Introduction: Hyperhomocysteinemia plays an etiologic role in homocystinuria, neurodegenerative and cardiovascular diseases. Potential mechanisms involved in the degenerative diseases of aging include: oxidative stress, endothelial dysfunction and inflammation. Aim: In the present study we evaluated the effect of acute administration of homocysteine (Hcy), at a level similar to that found in homocystinuria, on biochemical markers of inflammation (such as IL-6) and of oxidative stress (such as gluthathione peroxidase - GPx). Material and Method: The study was performed on 40 young and older Wistar rats. IL-6 serum level was quantified by a high-sensitivity enzyme-linked immunoabsorbent assay (ELISA) method and the activity of whole blood GPx was measured using a commercially available Randox kit. Results: Our results showed that Hcy administration increased the pro-inflammatory cytokine IL-6 in young rats (p<0.3) and decreased IL-6 level in older rats (p<0.008), when compared to the control group. GPx activity was found to increase with age (587.07 U/gHb versus 847.5 U/gHb, p<0.001). Two hours after Hcy administration, GPx activity was found to decrease, but not in a statistically significant manner. The difference between GPx activities in Hcy treated groups remains statistically significant (p<0.01) in the younger group, compared to older group (556.62 U/gHb versus 748.38 U/gHb). Conclusion: Our results indicate the existence of a correlation between hyperhomocysteinemia, proinflammatory state and oxidative stress, illustrated by the direct dependence of whole blood GPx activities on the increasing age.