BACKGROUND: Sleep deprivation resulting from night shifts, is a major cause of burnout among physicians. Exogenous melatonin may improve sleep quality in night-shift workers. The study aims to compare the effectiveness of melatonin versus placebo on sleep efficiency in emergency medicine (EM) residents. METHODS: A randomized, double-blind, replicated crossover trial was performed on EM residents. This study consisted of 4 phases within a month with intervention periods of 2 nights and washouts of 6 days. In our study, EM residents had nine-hour shifts on 6 consecutive days, 2 mornings, 2 evenings and 2 nights and then 2 days off. At the end of shifts' cycle, 24 EM residents were given 3 mg melatonin or placebo (12 in each arm of the study) for 2 consecutive nights after the second night shift with crossover to the other arm after a six-day off drug. This crossover intervention was repeated for two more another time. Finally, we created 48 cases and comparisons in each arm. Different items related to sleep quality were assessed and compared both within the same group and between the two groups. RESULTS: In the melatonin group, daytime sleepiness (calculated by Karolinska Sleep Scale) had a significant reduction after taking the second dose of drug (P=0.003) but the same result was not observed when comparing the 2 groups. Mood status (calculated by Profile of Mood States) showed no remarkable difference between the 2 groups. CONCLUSION: Melatonin might have a limited benefit on sleep quality in EM residents working night shifts.

Peroxisome proliferator-activated receptor (PPAR) is a transcriptional coactivator that binds to a diverse range of transcription factors. PPAR coactivator 1 (PGC-1) coactivators possess an extensive range of biological effects in different tissues, and play a key part in the regulation of the oxidative metabolism, consequently modulating the production of reactive oxygen species, autophagy, and mitochondrial biogenesis. Owing to these findings, a large body of studies, aiming to establish the role of PGC-1 in the neuromuscular system, has shown that PGC-1 could be a promising target for therapies targeting neuromuscular diseases. Among these, some evidence has shown that various signaling pathways linked to PGC-1 are deregulated in muscular dystrophy, leading to a reduced capacity for mitochondrial oxidative phosphorylation and increased reactive oxygen species (ROS) production. In the light of these results, any intervention aimed at activating PGC-1 could contribute towards ameliorating the progression of muscular dystrophies. PGC-1 is influenced by different patho-physiological/pharmacological stimuli. Natural products have been reported to display modulatory effects on PPAR activation with fewer side effects in comparison to synthetic drugs. Taken together, this review summarizes the current knowledge on Duchenne muscular dystrophy, focusing on the potential effects of natural compounds, acting as regulators of PGC-1.