Interleukin-10 and collagen type II immunoexpression are modulated by photobiomodulation associated to aerobic and aquatic exercises in an experimental model of osteoarthritis

The aim of this study was to compare the effects of photobiomodulation (PBM) associated with an aerobic and an aquatic exercise training on the degenerative process related to osteoarthritis (OA) in the articular cartilage in rats. Fifty male Wistar rats were randomly divided into 5 groups: OA control group (CG), OA plus aerobic training group (AET), OA plus aquatic training group (AQT), OA plus aerobic training associated with PBM group (AETL), OA plus aquatic training associated with PBM group (AQTL). The aerobic training (treadmill; 16 m/min; 50 min/day) and the aquatic training (water jumping; 50–80% of their body mass) started 4 weeks after the surgery and they were performed 3 days/week for 8 weeks. Moreover, PBM was performed after the physical exercise trainings on the left joint. Morphological characteristics and immunoexpression of IL-10, TGF-β, and collagen type I (Col I) and II (Col II) of the articular cartilage were evaluated. The results showed that all the treated groups (exercise and PBM) presented less intense signs of degradation (measured by histopathological analysis and OARSI grade system). Additionally, aerobic and aquatic exercise training rats (associated or not with PBM) showed increased IL-10 (AET p = 0.0452; AETL p = 0.03; AQTL p = 0.0193) and Col II (AET p = 0.012; AQT p = 0.0437; AETL p = 0.0001; AQTL p = 0.0001) protein expression compared to CG. Furthermore, a statistically higher TGF-β expression was observed in AET ( p = 0.0084) and AETL ( p = 0.0076) compared to CG. These results suggest that PBM associated with aerobic and aquatic exercise training were effective in mediating chondroprotective effects and maintaining the integrity of the articular tissue in the knees of OA rats.