Greice Itamaro Heiden

Resistance training (RT) can help with injury recovery and the healing process. Still, high-intensity exercise can cause ischemia and reperfusion, resulting in exacerbated production of reactive oxygen species and oxidative stress. This study aimed to evaluate the effects of RT with progressive loads on markers of tissue damage and oxidative stress in rats subjected to skin lesions. Forty male Wistar rats were used, divided into four groups (n = 10): Control (CG): no intervention; Sedentary Injury (SHAM): subjected to injury, no training; Training + Injury 1 (G1): injury after one week of training; Training + Injury 2 (G2): injury followed by training. The protocol consisted of climbing a vertical ladder three times a week, 48 h apart, using progressive loads (50%, 65%, and 80%). After euthanasia, markers of tissue damage (CK, LDH, ALT, AST), oxidative stress (MDA/TBARS, SH, uric acid), and histological analysis of collagen deposition in the injured tissue were assessed. Groups G1 and G2 showed a significant increase (p < 0.0001) in CK, LDH, ALT, and AST levels compared to GC and SHAM. Oxidative stress markers, such as MDA and SH, were also elevated in the G1 and G2 groups (p < 0.0001). Uric acid concentrations increased significantly in the exercised groups compared to the controls (p < 0.0001). Histology revealed an inflammatory infiltrate and disorganized collagen fibers in the SHAM group, while G1 and G2 showed tissue with greater cellular maturity and organization. Although RT induced muscle damage and an increase in pro-oxidant markers, it also favored cellular organization and scar tissue quality.

Background/Objectives: Wound healing relies on a coordinated process with the participation of different mediators. Natural products are a source of active compounds with healing potential. Isoorientin is a natural flavone recognized as having several pharmacological properties, such as anti-inflammatory effects, making it a potential treatment for wounds. We investigated the effect of isoorientin on the healing of excisional skin wounds. Methods: Male Swiss mice were subjected to the induction of excisional skin wounds (6 mm diameter) and treated with a vehicle (2% dimethyl sulfoxide in propylene glycol) or 2.5% isoorientin applied topically once a day for 14 days. The wound area was measured on days 0, 3, 7, and 14. Histopathological analyses were performed on the cicatricial tissue after 14 days. The myeloperoxidase activity and the interleukin-1β, tumoral necrosis factor (TNF)-α, and interleukin-6 concentrations were determined on the third day. Results: We observed that 3 days after the topical application of isoorientin, the lesion area was significantly smaller when compared to those of the vehicle (p < 0.01) and control (p < 0.05) groups. No difference was observed after 7 and 14 days of induction. Despite this, on day 14, histological analysis of cicatricial tissue from the animals treated with isoorientin showed reduced epidermal thickness (p < 0.001) and increased collagen deposition (p < 0.001). These effects were accompanied by decreased myeloperoxidase activity and interleukin-1β concentration on the third day of induction, without alteration in TNF-α and interleukin-6. Conclusions: The treatment with isoorientin promoted better tissue repair in excisional wounds in mice, which may be linked to the modulation of the early inflammatory response.