Pulsed ultrasound associated with gold nanoparticle gel reduces oxidative stress parameters and expression of pro-inflammatory molecules in an animal model of muscle injury

Animals were divided in nine groups: sham (uninjured muscle); muscle injury without treatment; muscle injury + DMSO; muscle injury + GNP; muscle injury + DMSO + GNP; muscle injury + TPU; muscle injury + TPU + DMSO; muscle injury + TPU + GNP; muscle injury + TPU + DMSO + GNP. The ROS production was determined by concentration of superoxide anion, modulation of antioxidant defenses was determined by the activity of superoxide dismutase, catalase and glutathione peroxidase enzymes, oxidative damage determined by formation of thiobarbituric acid-reactive substance and protein carbonyls. The levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were measured as inflammatory parameters.Compared to muscle injury without treatment group, the muscle injury + TPU + DMSO + GNP gel group promoted a significant decrease in superoxide anion production and lipid peroxidation levels (p < 0.050). It also showed a significant decrease in TNF-α and IL-1β levels (p < 0.050) when compared to muscle injury without treatment group.Our results suggest that TPU + DMSO + GNP gel presents beneficial effects on the muscular healing process, inducing a reduction in the production of ROS and also the expression of pro-inflammatory molecules.Muscle contusion usually results from a direct blunt impact and is frequently associated with contact sports. Muscle contusion results from microscopic muscle fiber and capillary disruption with resultant microhemorrhage dissecting between the torn fibers and the remaining viable muscle fibers [1]. Muscle injury typically initiates a rapid and sequential invasion of muscle by inflammatory cell populations that can persist for days to weeks, while muscle repair, regeneration, and growth occur [2].Many studies have demonstrated that muscle injury induces an increased generation of Reactive Oxidative Species (ROS), which alters intracellular oxidant-antioxidant balance in favour of the former and can result in oxidative damage of traumatized muscl