Effects Of Melatonin On Expression Of BFGF And IL-1β In Articular Cartilage Of Rat With Osteoarthritis

Objective To investigate the effect of intra-articular injection of melatonin on the articular cartilage injury in the rats with osteoarthritis by observing the expression of bFGF and IL-1β.Methods A total of40rats were randomly divided into four groups (each group with10rats):Group A was control group, group B was osteoarthritis group, group C was pinealectomy group established on the basic of osteoarthritis, and group D was treatment group made on the basic of group C. After establishing the animal models for a week, the rats in group D were injected with0.2ml20mg/ml melatonin solution in left knuckle articular cavity accordingly four times a week for four weeks. After the last melatonin injection, rats of the group of A,B,C were received the test of the level of serum melatonin from apex cordis drawing blood by ELASA respectively. All groups of rats were killed to draw the tissue from left cartilage of femoral condyle for gross observation, observation of histology and immunohistochemical staining.Results The surface of articular cartilage was smooth and elastic and the chondrocytes arranged regularly in group A rats while those in group B and C rats were rough, lackluster and disorder, in addition, the phenomenons of chondromalacia and subchondral bone exposure exist in group B and C rats. But the injury of articular cartilage in group C rats was more serious. In group D rats, the injury of articular cartilage was alleviated in contrast to the group B and C rays. According to the immunohistochemical staining results, the expression of IL-1β in articular cartilage in group D rats was significantly lower than group C and group B (P<0.05), the expression of bFGF in articular cartilage in group D rats was significantly higher than group C and group B (P<0.05).Conclusion The progress of cartilage defects could be delayed by intra-articular injection of melatonin. The mechanism of cartilage repair might be related to the up-regulation of anabolic factor of bFGF and down-regulation of catabolic factors of IL-1β.