The Effect of Melatonin on Oxidative Biomarkers (MDA,SOD,GSH) in Patients with Stable Angina

Abstract

Objective: To investigate the relationship between change in oxidative stress markers and change in angina symptom burden and sleep quality in patients with stable angina given adjunctive melatonin therapy.

Study Design: Randomized, quadruple blind, placebo-controlled Study
Place and Duration of Study: This study was conducted at the College of Pharmacy, University of Thi-Qar, Iraq from 1st February 2026 to 30th April 2026

Methods: One hundred patients were enrolled, among them 55 patients taking melatonin 5 mg once daily at night and 45 taking placebo, in addition to usual anti-anginal treatment. Oxidative stress markers were malondialdehyde, superoxide dismutase and glutathione. Clinical measures were the number of angina episodes per week, angina severity, short-acting nitrate use, and Pittsburgh Sleep Quality Index.

Results: In the melatonin group, malondialdehyde decreased from 4.82±0.91 to 3.79±0.81 μmol/L, while superoxide dismutase increased from 6.21±1.15 to 7.15±1.20 U/mL and glutathione from 38.7±6.5 to 44.8±7.1
μmol/L. Weekly angina episodes decreased from 3.4±1.7 to 1.3±1.1, short acting nitrate use from 3.0±1.8 to 1.0±1.1 doses/week, and Pittsburgh Sleep Quality Index from 9.1±3.0 to 6.2±2.7.

Conclusion: Favourable changes in oxidative stress biomarkers, particularly reduced malondialdehyde and increased glutathione, were associated with improved angina symptoms and sleep quality.