The effect of low-level laser to apoptosis of chondrocyte and caspases expression, including caspase-8 and caspase-3 in rabbit surgery-induced model of knee osteoarthritis

The purpose of this study was to observe the effect of 810-nm low-level laser to apoptosis of chondrocyte and related proteins, including caspase-3 and caspase-8, in rabbit surgery-induced model of knee osteoarthritis. A total of 24 New Zealand White rabbits were randomly assigned into 3 groups: test group, model group, and normal group. The rabbits in test group and model group received anterior cruciate ligament transection in the right knee. Six weeks after transection, the rabbits in test group were given 10-session 810-nm laser illumination. Eight weeks after transection, all animal were killed. Modified Mankin Score was made for histological assessment. The caspases expressions and chondrocytes apoptosis were tested using the immunohistochemistry and TUNEL assessment, respectively. The modified Mankin Score of test group was significantly lower than model group (P < 0.01) and higher than normal group (P < 0.01). The caspase-8 expression of test group was lower than model group and higher than normal group, but no significant difference was found (P > 0.05). This study revealed that the 810-nm low-level laser can improve cartilage structure, prevent articular cartilage degradation and significantly decrease the expression of caspase-3 in this surgery-induced OA model. Further studies are needed.