Effect of Phonophoresis and Copaiba Oil on Oxidative Stress Biomarkers after Skeletal Muscle Injury in Rats

The objective of this study was to analyze the effectiveness of phonophoresis with copaiba oil gel, in comparison to therapeutic pulsed ultrasound alone or topical application of copaiba oil gel, on oxidative stress after a traumatic muscle injury. Forty male Wistar rats were divided into five groups: control, muscle injury, therapeutic pulsed ultrasound (TPU), copaiba oil gel (CO) and TPU plus CO. TPU and CO application occurred at 2, 12, 24, 48, 72 and 96 h after injury. The gastrocnemius muscle was injured by mechanical trauma. Malondialdehyde (a lipoperoxidation marker) and superoxide dismutase and catalase (antioxidant enzymes) were assessed 98 h after muscle injury. All were elevated in the muscle injury group. There was a significant difference among treatment groups favoring TPU plus CO for reducing malondialdehyde levels, but all treatments reduced superoxide dismutase and catalase activity, with no between-groups difference. In conclusion, phonophoresis—the application of TPU plus CO—was superior to TPU or CO alone for reducing lipoperoxidation. Phonophoresis, TPU alone and CO were all effective in decreasing antioxidant enzyme activity after a traumatic skeletal muscle injury.