NPPB and persistent fetal circulation syndrome: Additionally, melatonin administration was associated with earlier weaning from mechanical ventilation (MV) and respiratory support, shorter hospital stays, lower levels of serum high-mobility group box-1 (HMGB1) protein, and N-terminal pro-B-type natriuretic peptide (NT-proBNP).<h4>Conclusion</h4>Melatonin can enhance LV function in PPHN, likely through its cardioprotective and antioxidative mechanisms.