Low-level laser therapy in experimental model of collagenase-induced tendinitis in rats: effects in acute and chronic inflammatory phases

A variety of treatments for tendinopathies is currently used or has been trialed. However, in fact, there is a remarkably little evidence that any conventional therapies are effective. in the last years, low-level laser therapy (LLLT) has been showing interesting results in inflammatory modulation in different musculoskeletal disorders, but the optimal parameters and mechanisms behind these effects are not fully understood. the aim of this study is to investigate if the LLLT modulates the acute and chronic phase of collagenase-induced tendinitis in rat by interfering in mRNA expression for matrix metalloproteinases (MMP13 and MMP1), vascular endothelial growth factor (VEGF), and anti-inflammatory mediator (interleukin (IL)-10). for such, tendinitis was induced by collagenase injection in male Wistar rats. Animals were treated with LLLT (780 nm, potency of 22 mW, 107 mW/cm(2), energy density of 7.5 J/cm(2), and energy delivered of 1.54 J) with different number of treatments in accordance with the inflammatory phase analyzed. LLLT was able to modulate mRNA gene expression of IL-10, VGEF, MMP1, and MMP13 both in acute than in chronic inflammatory phase (p < 0.05). Our results suggest that LLLT with parameters employed in the present study was able to modulate IL-10, VEGF, MMP1, and MMP13 mRNA gene expression both in acute than in chronic tendon inflammation. However, further studies are needed to establish optimal parameters for LLLT.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Nove de Julho Univ UNINOVE, Post Grad Program Rehabil Sci, BR-01504001 São Paulo, BrazilNove de Julho Univ UNINOVE, Post Grad Program Biophoton Appl Hlth Sci, BR-01504001 São Paulo, BrazilUniv Camilo Castelo Branco, Ctr Biomed Engn, Sao Jose Dos Campos, SP, BrazilVale Jequitinhonha & Mucuri Fed Univ, Dept Phys Therapy, Diamantina, MG, BrazilFed Univ São Paulo UNIFESP, Sao Jose Dos Campos, SP, BrazilFed Univ São Paulo UNIFESP, Sao Jose Dos Campos, SP, BrazilFAPESP: 2011/05890-9FAPESP: 2012/02087-3Web of Scienc

Effects of low-intensity non-coherent light therapy on the inflammatory process in the calcaneal tendon of ovariectomized rats

The aim of this experimental study was to investigate the effects of low-intensity light-emitting diode (LED) phototherapy on the inflammatory process in the calcaneal tendon of ovariectomized rats (OVX) through the involvement of the inflammatory mediators interleukin (IL)-6, IL-10, and tumor necrosis factor-alpha (TNF-alpha). Thirty-five female Wistar rats were divided into 4 groups: 3 groups of OVX rats totaling 30 rats (untreated OVX rats [OVX injury group], treated OVX rats [OVX LED group], and control OVX rats subgroups existed based on the sampling times, which were 3, 7, and 14 days) and 1 group of non-OVX rats (not OVX n = 5). Tendon injury was induced by trauma using a 208-g mass placed at 20 cm from the right tendon of each animal with energy of 0.70 J. The animals were treated 12 h after tendonitis with LED therapy and every 48 h thereafter until euthanasia (at 3, 7, or 14 days). The tendons were dissected and stored in liquid nitrogen at -196 A degrees C, thawed only at the time of immunoenzymatic testing (ELISA). Groups treated with LED showed a decrease in the number of pro-inflammatory cells, IL-6, and TNF-alpha (p < 0.05), and an increase in IL-10 (p < 0.05) when compared to the not OVX group (p < 0.05). It was concluded that low-intensity LED treatment using the parameters and wavelength of 945 nm in the time periods studied reduced the release of IL-6 and TNF-alpha and increased the release of IL-10, thereby improving the inflammatory response in OVX rats.Multi Radiance Medical (Solon, OH, USA)Univ Nove Julho, Postgrad Program Biophoton, Appl Hlth Sci, UNINOVE, Sao Paulo, SP, BrazilUniv Nove Julho, Postgrad Program Rehabil Sci, UNINOVE, BR-01504001 Sao Paulo, SP, BrazilFed Univ Goias UFG, Dept Vet Med, Jatai, Go, BrazilUniv Fed Sao Paulo Unifesp, Inst Sci & Technol ICT, Sao Jose Dos Campos, SP, BrazilInstitute of Science and Technology - ICT- Federal University of São Paulo-UnifespSão José dos Campos, BrazilWeb of Scienc