Topical application of (S)-(-)-limonene is as effective as phonophoresis for improving oxidative parameters of injured skeletal muscle in rats.

The aim of this study is to investigate the effects of limonene, alone or associated with therapeutic ultrasound, on oxidative stress following skeletal muscle injury. Thirty male Wistar rats were divided into 5 groups: CTR-control, MI-muscle injury without treatment, TPU-therapeutic pulsed ultrasound alone, TPU + LIM-phonophoresis with 5% limonene, and LIM-5% limonene applied topically. Muscle injury was induced by a mechanical abrupt impact over gastrocnemius muscle. The animals were treated in the following intervals: 2, 12, 24, 48, 72, and 96 h after injury. Blood and gastrocnemius samples were collected 98 h after lesion for data analysis. Creatine kinase (CK) and lactate dehydrogenase (LDH) activity, lipid peroxidation (TBARS) levels, catalase (CAT), and superoxide dismutase (SOD) activity were assessed. CK (p = 0.01), SOD activity (p < 0.01), and TBARS levels (p < 0.01) were increased after injury. There was no effect on LDH levels in any group. Phonophoresis (TABRS p < 0.01; SOD p = 0.01), TPU alone (TBARS p < 0.01; SOD p = 0.01), and LIM alone (TBARS p < 0.01; SOD p < 0.01) reduced TBARS levels and SOD activity after muscle injury. There was no change for CAT activity after injury. Only phonophoresis reduced CK activity after injury (p < 0.01). There was no difference between phonophoresis, TPU alone and LIM alone groups for TBARS, SOD, CAT, and LDH. Limonene alone and TPU alone were effective in reducing oxidative stress parameters after skeletal muscle injury. Only phonophoresis decreased CK activity. Skeletal muscle injury increases reactive oxidative species (ROS) levels and muscle proteins activity as creatine kinase (CK) and lactate dehydrogenase (LDH). Five percent limonene, alone or associated with therapeutic pulsed ultrasound, exhibited reduction of CK, superoxide dismutase (SOD) and catalase (CAT) activity, and lipid peroxidation markers (TBARS). Graphical abstract.

Effect of Pulsed Therapeutic Ultrasound and Diosmin on Skeletal Muscle Oxidative Parameters.

Cyclodextrins (CDs) have been widely used as a promising alternative in the formation of inclusion complexes with poorly soluble molecules. From this perspective, the present study aimed to study the inclusion complexes of diosmin in ß-cyclodextrin, chemically quantify the diosmin-in-gel preparation and analyze the stability of the gels. Furthermore, we evaluated the effect of therapeutic pulsed ultrasound (TPU) in association with the gel-diosmin complex on the parameters of muscle damage and oxidative stress in rats. Serum creatine kinase (CK) levels were used as an indicator of skeletal muscle injury. Lipid peroxidation (thiobarbituric acid-reactive substances [TBARS]) and superoxide dismutase and catalase activities were used as indicators of oxidative stress. The results obtained indicated that the inclusion complex obtained by co-evaporation had the highest complexation efficiency and stability; there was no change in the features of diosmin on incorporation into the Carbopol gel. Additionally, a significant (p <0.05) decrease was observed in CK levels (TPU plus gel-diosmin: 178.4 ± 85.3 U/L) relative to the untreated group (527.8 ± 46.1 U/L). Levels of TBARS were lower in the TPU plus gel-diosmin group (0.008 ± 0.0004 nmol malondialdehyde/mg protein, p <0.05) compared with the untreated group (0.081 ± 0.011 nmol malondialdehyde/mg protein, p <0.05, n = 6). Catalase activity did not statistically significantly differ between the treatment groups, and superoxide dismutase activity was lower in the diosmin-treated group (0.320 ± 0.11 U/mg protein) compared with the untreated group (0.983 ± 0.40 U/mg protein). These results suggest that TPU in association with the diosmin-gel complex is effective in reducing muscle damage and oxidative stress after mechanical trauma.