Anti-inflammatory effects of low-level light emitting diode therapy on achilles tendinitis in rats

✍ Scribed by Murilo Xavier; Débora Rodrigues David; Renato Aparecido de Souza; Arthur Nascimento Arrieiro; Humberto Miranda; Eduardo Tadeu Santana; José Antonio Silva Jr.; Miguel Angel Castillo Salgado; Flávio Aimbire; Regiane Albertini

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 176 KB
• Volume: 42
• Category: Article
• ISSN: 0196-8092
• DOI: 10.1002/lsm.20896

✦ Synopsis

Abstract

Background and Objectives

The present study investigated the effects of low‐level light emitting diode (LED) therapy (880 ± 10 nm) on inflammatory process in a experimental model of Achilles tendinitis induced by collagenase.

Study Design/Materials and Methods

Fifty‐six male Wistar were separated into seven groups (n = 8), three groups in the experimental period of 7 days and four groups in the experimental period of 14 days, the control group (CONT), tendinitis group (TEND), LED therapy group (LEDT) for both experimental periods, and LED therapy group 7th to 14th day (LEDT delay) for 14 days experimental period. The LED parameters was 22 mW CW of optical output power, distributed in an irradiation area of 0.5 cm^2^, with an irradiation time of 170 seconds, the applied energy density was 7.5 J/cm^2^ in contact. The therapy was initiated 12 hours after the tendinitis induction, with a 48‐hour interval between the irradiations. The histological analysis and inflammatory mediators were quantified.

Results

Our results showed that LED decreases the inflammatory cells influx and mRNA expression to IL‐1β, IL‐6, tumor necrosis factor‐α (TNF‐α) in both phase, and cyclooxygenase‐2 (COX‐2) just in initial phase (P < 0.05).

Conclusion

Our results suggest that the anti‐inflammatory therapy with low‐power LED (880 nm) enhanced the tissue response in all groups. We can conclude that the LED was able to reduce signs of inflammation in collagenase‐induced tendinitis in rats by reducing the number of inflammatory cells and decrease mRNA expression of cytokines. Lasers Surg. Med. 42:553–558, 2010. © 2010 Wiley–Liss, Inc.