The role of melatonin on radiation-induced pneumonitis and lung fibrosis: A systematic review

Purpose: Pneumonitis and lung fibrosis, as the most common compliances of lung irradiation, can affect the quality of life. The use of radio-protective agents can ameliorate these injuries. This study aimed to review the potential protective role of melatonin in the treatment of radiation-induced Pneumonitis and lung fibrosis. Methods: The current systematic study was conducted based on PRISMA guidelines to identify relevant literature on the effect of melatonin on radiation-induced pneumonitis and lung fibrosis in the electronic databases of Web of Science, Embase, PubMed, and Scopus up to January 2021. Eighty-one articles were screened in accordance with the inclusion and exclusion criteria of the study. Finally, eight articles were included in this systematic review. Results: The finding showed that the lung irradiation-induced pneumonitis and lung fibrosis. The co-treatment with melatonin could alleviate these compliances through its anti-oxidant and anti-inflammatory actions. Melatonin through upregulation of some enzymes such as catalase, superoxide dismutase, glutathione, NADPH oxidases 2 and 4, dual oxidases 1 and 2, and also downregulation of malondialdehyde reduced oxidative stress following lung radiation. Moreover, melatonin through its anti-inflammatory effects, can attenuate the increased levels of nuclear factor kappa B, tumor necrosis factor alpha, transforming growth factor beta 1, SMAD2, interleukin (IL)-4, IL-4 receptor-a1 (IL4ra1), and IL-1 beta following lung radiation. The histological damages induced by ionizing radiation were also alleviated by co-treatment with melatonin. Conclusion: According to the obtained results, it was found that melatonin can have anti-pneumonitis and antifibrotic following lung irradiation.

Automated summary

According to the study, melatonin can play a protective role in treating radiation-induced pneumonitis and lung fibrosis by alleviating oxidative stress and inflammation. This is achieved through melatonin's upregulation of enzymes and downregulation of inflammatory markers, ultimately reducing histological damages caused by ionizing radiation.