title: Effects of low-level laser therapy on joint pain, synovitis, anabolic, and catabolic factors in a progressive osteoarthritis rabbit model.
abstract: The aim of this study was to investigate the effect of low-level laser therapy (LLLT) on short-term and long-term joint pain, synovitis, anabolic, and catabolic factors in the cartilage of a rabbit model with progressive osteoarthritis (OA) induced by anterior cruciate ligament transection (ACLT). A total of 160 New Zealand white rabbits were randomly assigned into two groups (ACLT group and LLLT group). All rabbits received ACLT surgery, and 2-, 4-, 6-, and 8-week treatment after the surgery, with 20 rabbits being tested biweekly over every study period. The LLLT group received LLLT with a helium-neon (He-Ne) laser (830 nm) of 1.5 J/cm(2) three times per week, and the ACLT group received placebo LLLT with the equipment switched off. Long-term and short-term pain was tested via weight-bearing asymmetry; synovitis was assessed histologically; and knee joint cartilage was evaluated by gross morphology, histology, and gene expression analysis of anabolic and catabolic factors. The histological assessment of pain and synovitis showed that at least 6-week intermittent irradiation of LLLT could relief knee pain and control synovium inflammation. Gross morphologic inspection and histological evaluation showed that 6 weeks of LLLT could decrease cartilage damage of medical femoral condyle and 8 weeks of LLLT could decrease cartilage damage of medical and lateral femoral condyles and medical tibial plateau. Gene expression analysis revealed two results: At least 6 weeks of LLLT could decrease production of catabolic factors, for example, interleukin 1β (IL-1β), inducible nitric oxide synthase (iNOS), and MMP-3, and slow down the loss of anabolic factors, mainly TIMP-1. Eight weeks of LLLT treatment could slow down the loss of collagen II, aggrecan, and anabolic factors, mainly transforming growth factor beta (TGF-β). The study suggests that LLLT plays a protective role against cartilage degradation and synovitis in rabbits with progressive OA by virtue of the regulation of catabolic and anabolic factors in the cartilage.
authors.affiliation: Rehabilitation Medicine Center of West China Hospital, Sichuan University, ChengDu, People's Republic of China, wangpu0816@qq.com.
authors.forename: Pu
authors.initials: P
authors.lastname: Wang
authors.forename: Chuan
authors.initials: C
authors.lastname: Liu
authors.forename: Xiaotian
authors.initials: X
authors.lastname: Yang
authors.forename: Yujing
authors.initials: Y
authors.lastname: Zhou
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Wei
authors.forename: Qiaodan
authors.initials: Q
authors.lastname: Ji
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Chengqi
authors.initials: C
authors.lastname: He
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000378:metabolism; D018771:Arthralgia / Q000532:radiotherapy*; D002356:Cartilage / Q000528:radiation effects; D002358:Cartilage, Articular / Q000528:radiation effects*; D019902:Chondrocytes / Q000528:radiation effects; D004195:Disease Models, Animal; D018450:Disease Progression; D005269:Femur / Q000473:pathology / Q000528:radiation effects; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007719:Knee Joint / Q000378:metabolism / Q000528:radiation effects; D028022:Low-Level Light Therapy / Q000379:methods*; D010003:Osteoarthritis / Q000532:radiotherapy*; D059408:Pain Management; D011817:Rabbits; D013585:Synovitis / Q000532:radiotherapy*; D013977:Tibia / Q000528:radiation effects; D016474:Weight-Bearing