Laser phototherapy improves early stage of cutaneous wound healing of rats under hyperlipidic diet

Abstract

The aim of this study was to evaluate the influence of laser photobiomodulation in cutaneous healing of rats under a hyperlipidic diet. Forty-eight Wistar Albinus rats, weaned, received standard diet (SD) or hyperlipidic diet (HD) for 20 weeks. The groups were divided into SD rats and HD rats, SD-irradiated rats (LSD), and HD-irradiated rats (LHD). Standard cutaneous wound (1 cm(2)) was created on the dorsum of each rat. The irradiation started immediately after surgery and every 48 h for 7 or 14 days (λ660 nm, 40 mW, 6 J/cm(2), ϕ 0,04 cm(2), CW), when they were killed under deep anesthesia. The specimens were removed, routinely processed, stained with hematoxylin/eosin (H/E), and evaluated by light microscopy. Rats fed with hyperlipidic diet had greater intensity in the inflammatory process and prolonged hyperemia. At day 7, the intensity of inflammation was reduced in LSD and LHD groups when compared to their control groups, SD (p = 0.002) and HD (p = 0.02). There was an increase in fibroblast proliferation and collagen deposition, especially in the LHD group. At day 14, the HD group presented more intensive hyperemia than the SD group. It can be concluded that the hyperlipidic diet modified the inflammation pattern in wound healing and that laser light has a positive biomodulative effect on the healing process only in early stages.

Estudo comparativo de diferentes protocolos de irradiação com laser de baixa potência para a reparação tecidual de excisões realizadas em dorso de ratos não diabéticos e diabéticos induzidos por estreptozotocina

“…Entretanto, sabe-se também que além de todas as ações da PBMT supracitadas (reparo clínico mais rápido, maior porcentagem de re-epitelização, e maior maturação do epitélio), outra ação importante dessa terapia é a modulação do processo inflamatório, o qual exerce papel importante no processo de reparação tecidual, principalmente em uma condição de hiperglicemia crônica (140,(162)(163)(164)(165).…”