Serum nitric oxide in chronic Chagas disease: a scoping review

Nitric oxide (NO) plays a complex role in the pathophysiology of chronic Chagas disease (CD), contributing to both host defense and tissue damage. Thus, understanding its clinical implications may support therapeutic strategies. The objective of this scoping review was to map and synthesize the available evidence on the clinical impact of serum NO levels in individuals with chronic CD. A scoping review was conducted following PRISMA-ScR guidelines, in which a systematic search of PubMed, Scopus, and Web of Science was performed. The inclusion criteria were studies that quantified NO or its synthetizing enzymes (NOS) in individuals with chronic CD irrespective of the publication year or the language. Studies that did not assess the levels of NO, its metabolites or NOS, in addition to in vivo and in vitro experimental studies, were excluded. The findings from this scoping review showed that individuals with chronic CD have high serum NO levels, suggesting that excessive production of this marker may lead to oxidative stress and play a role in the pathophysiological process associated with cardiac and digestive complications. Combined therapies using antiparasitic drugs with antioxidants have shown a greater reduction in NO levels compared to conventional drug therapy, indicating a potential to reduce oxidative damage and consequently slow disease progression. Nonetheless, additional studies at various disease stages are necessary to confirm the effectiveness of this approach.