Effects of photobiomodulation on inflammatory factors during skeletal muscle regeneration: A systematic review with meta‐analysis of animal studies

Skeletal muscle injury is a common sports injury and photobiomodulation (PBM) therapy has been recognized as a potential treatment for it. However, the optimal intervention timing for PBM to suppress inflammatory factor expression during muscle regeneration remains unclear. The study is a systematic review with meta-analysis to summarize the effect of PBM on the expression levels of inflammatory factors during skeletal muscle regeneration in animals. The PubMed, Cochrane Library, Scopus, and Web of Science databases were searched to obtain the studies about the effects of PBM on the inflammatory factors during muscle regeneration in animals. Two authors independently extracted the data, and the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) tool was used to assess the risk of bias for the included studies. Review manager 5.4 software was used to analyze the data, and subgroup and sensitivity analyses were performed. A total of 18 studies were included in this study. The results show that PBM treatment reduces levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 during skeletal muscle regeneration, especially in the early stage of skeletal muscle injury (6 and 12 h), but its effects on IL-4 and IL-10 need to be validated in higher-quality studies. In conclusion, PBM therapy primarily reduces inflammatory factor levels in the early stage of skeletal muscle injury, thereby accelerating skeletal muscle regeneration.