Oxidative stress plays a key role in the development of chronic pulmonary complications of sulfur mustard (SM). Curcuminoids are polyphenols with documented safety and antioxidant activity. The present study aimed to investigate the efficacy of short-term supplementation with curcuminoids (co-administered with piperine to enhance the bioavailability of curcuminoids) in alleviating systemic oxidative stress and clinical symptoms, and improvement of health-related quality of life (HRQoL) in subjects suffering from chronic pulmonary complications due to SM exposure who are receiving standard respiratory treatments. Eighty-nine subjects were recruited to this randomized double-blind placebo-controlled trial, being randomly allocated to either curcuminoids (1500 mg/day) + piperine (15 mg/day) combination (n = 45) or placebo (n = 44) for a period of 4 weeks. High-resolution computed tomography suggested the diagnosis of bronchiolitis obliterans in all subjects. Efficacy measures were changes in serum levels of reduced glutathione (GSH) and malonedialdehyde (MDA). The severity and frequency of respiratory symptoms and HRQoL were also assessed using St. George respiratory Questionnaire (SGRQ) and COPD Assessment Test (CAT) indices. Serum levels of GSH were increased whilst those of MDA decreased by the end of trial in both groups. Likewise, there were significant improvements in the total as well as subscale (symptoms, activity and impact) SGRQ and CAT scores in both groups. However, comparison of magnitude of changes revealed a greater effect of curcuminoids-piperine combination compared to placebo in elevating GSH, reducing MDA and improving CAT and SGRQ (total and subscale) scores (p < 0.001). Regarding the promising effects of curcuminoids on the measures of systemic oxidative stress, clinical symptoms and HRQoL, these phytochemicals may be used as safe adjuvants in patients suffering from chronic SM-induced pulmonary complications who are receiving standard treatments.
Keywords: antioxidant; lipid peroxidation; lung; mustard gas; randomized controlled trial.