Effects of laser therapy on cytokines in rats with oxazolone induced ulcerative colitis

Abstract

Objective To explore the effects and molecular mechanisms of laser therapy on serum and colon tumor necrosis factor α （TNF-α） , interleukin-6 （IL-6） and interleukin-10 （IL-10） in rats with oxazolone induced ulcerative colitis （UC）. Methods Thirty adult male SD rats were randomly divided into four groups： a normal group （n=6）, a UC model group （n=8）, a400 mWlaser treatment group （n=8） and a200 mWlaser treatment group （ n = 8）. Odified oxazolone sensitization was used to induce UC models in the rats. The AsA1Ga semiconductor laser used in the treatment had a power of 200 mW or 400 mW. The therapy lasted for 10 days with daily 10 min sessions. The rats were sacrificed after treatment and enzyme-linked immunosorbent assay （ELISA） was used to measure IL- 6, IL- 10 and TNF-α in serum and ulcer tissues in all groups. Results Compared with the normal group, the weights of the UC model rats were significantly lower, and they had severe mucoid bloody stool. TNF-α and IL-6 levels in serum and colon tissues increased significantly and IL-10 decreased significantly, so the UC model was successfully established. After laser treatment, body weight gain and stool moderation in rats were observed, in the 400 mW group, and average TNF-α and IL-6 levels in both serum and colon tissue decreased significantly. IL-10 in- creased significantly, close to the level of the normal group. In the 200 mW group, serum TNF-α and IL-6 levels were significantly lower, and IL-6 in the colon tissue was reduced significantly. TNF-α did not lessen significantly, and serum and colon tissue IL-10 levels did not improve significantly compared with the model group. Conclusions 400 mW AsAIGa semiconductor laser irradiation can effectively regulate cytokines after oxazolone induced UC in rats in two ways. It reduces pro-inflammatory cytokines and increases the level of anti-inflammatory eytokines. This may imply one of the underlying molecular mechanisms of low energy laser treatment of UC. Key words: Ulcerative colitis; Lasers; Cytokines