Impaired Antioxidant Defense and Enhanced Lipid Peroxidation in Osteoporosis: Evaluation of Sod, Cat, Gsh, Gpx, Mda, and Nitric Oxide

Abstract

Objective: To examine the status of antioxidant defense enzymes (SOD, CAT, GSH, GPx), and oxidative stress biomarkers (MDA, NO) in postmenopausal females with osteoporosis.

Materials & Methods: 73 clinically diagnosed osteoporotic females were recruited for the study with a comparison of 20 healthy females of similar ages. Serum samples were obtained during the fasting period and analyzed by standard spectrophotometric, colorimetric and enzymatic methods of superoxide dismutase (SOD), catalase (CAT), glutathione (GHS), glutathione peroxidase (GPx), malondialdehyde (MDA) and nitric oxide (NO). One-way ANOVA was used to analyze data and p values < 0.05 were considered statistically significant.

Results: Osteoporotic patients exhibited significantly depleted antioxidant defenses: SOD (0.12±0.10 vs. 0.47±0.16 nmol/mL), CAT (0.78±0.49 vs. 4.13±0.80 μmol/mol), GSH (2.39±0.97 vs. 9.88±1.16 mg/dL), and GPx (0.21±0.07 vs. 0.63±0.32 IU/mL; all p < 0.001). Conversely, lipid peroxidation and nitrosative stress markers were markedly elevated: MDA (3.81±0.95 vs. 1.34±0.30 nmol/mL) and NO (15.62±1.62 vs. 11.28±1.34 μmol/L; both p < 0.001).

Conclusion: There is a significant decrease of the antioxidant defense system and increase in lipid peroxidation in osteoporosis. The marked reduction in SOD, CAT, GSH and GPx levels along with the increased levels of MDA and NO highlight that oxidative stress is an important mediator of bone resorption. The use of targeted antioxidant modulation could be a promising strategy for adjunctive treatment.