The effects of L-thyroxine and its association with physical exercise decrease the inflammation in an acute lung injury model

Acute lung injury (ALI) is an inflammatory disease with a high incidence and prevalence that can lead to death. While L-thyroxine is widely used as a synthetic hormone in the treatment of hypothyroidism, its effects on inflammatory processes are not fully understood. Physical exercise, recommended for the general population, serves as an ally in treating various pathologies. Due to this and the lack of understanding of how L-thyroxine affects the immune response, coupled with the well-known benefits of exercise, this study aimed to evaluate L-thyroxine’s effects on lipopolysaccharide-induced inflammation and its combination with exercise in ALI. We assessed L-thyroxine’s effects on RAW 264.7 cells exposed to LPS and its association with exercise in a mouse ALI model. Pre-treatment with L-thyroxine demonstrated a decrease in the production of reactive oxygen species ( P < 0.01) and the expression of pro-inflammatory genes and proteins ( P < 0.05). In ALI, pre-treatment with L-thyroxine, either alone or combined with exercise, reduced the cell influx ( P < 0.01) and the release of inflammatory cytokines ( P < 0.05), in addition to mitigating lung damage caused by LPS ( P < 0.01). However, combining L-thyroxine with exercise did not enhance its anti-inflammatory effect.