Methodological study of photobiomodulation anti-edematous effects on carrageenan-induced inflammation on zebrafish

Abstract

The anti-inflammatory action of Photobiomodulation (PBM) is one of its most reproducible effects in vivo. New models to study PBMeffects and to investigate light dosimetry may bring different perspectives on the field. Based on the importance of establishing new experimental models and the advantages of using zebrafish for screening new drugs with potential anti-inflammatory effects the present investigation evaluated the effect of PBM on carragenan-induced abdominal edema in zebrafish. Thirty Danio rerio (± 1 g) zebrafish were randomly divided into five aquariums with 0.25L of water to establish three treatments: T1 - Naive non-treated; T2 – Saline 0.9%-injected; T3 - carrageenan-injected (CG) 3.5% in the coelomic cavity. T4 –injected (CG) 3.5% and treated with a diode laser λ=808nm, 50mWand 0.5J T5 –same parameters with 1J and T6 -1.5J. Abdominal volumes were measured by a caliper and the area was calculated 4 hours post-indu ction. Four hours after edema induction the results revealed an increase in the abdominal area of fish injected with CG 3.5% compared to negative control. The animals injected with CG and treated with PBM exhibited a reduction in abdominal edema in a dose-dependent manner. The 0.5J energy did not present a significant reduction compare do control (p=0.18), the 1J and 1.5J groups presented a significant difference (p=0.027 and p=0.005 respectively). The 1.5J group was not different from negative control (T2) p=0.37. The present study identified that zebrafish may represent a good model to investigate PBM effects and the response was dose dependent.