An investigation of the effects of melatonin administration on biochemical parameters in rats with experimental cartilage damage

Objective:  This study was intended to show the effects of melatonin (MEL) in the treatment of cartilage damage in a rat model as a novel field of application. Materials and Methods: Male Sprague Dawley rats aged 3-4 months were assigned into four groups of six rats each. Group I represented the sham group. In groups 2, 3, and 4, the right knee medial meniscus was surgically destabilized. MEL was administered to groups 3 and 4 twice a week at dosages of 0.4 μg/ml and 4 μg/ml, respectively. The application continued for four weeks. Histological examinations, imaging studies [computed tomography and magnetic resonance imaging], and biochemical tests [cartilage and bone turnover markers (COMP and CTX-I)] were performed. Results: The application of MEL initiated regeneration in the damaged areas. However, cartilage repair was not observed in areas with experimental cartilage damage without MEL application. MEL-treated rats had higher T2 scores compared to Group 1 in the median femoral condyle at the 12th week (p<0.05). Serum COMP and CTX-I levels at 12 weeks were significantly higher in Group 2 compared to Group 1 (p<0.05). Serum COMP and CTX-I levels at 12 weeks were lower in groups 3 and 4, but were also significantly higher than in Group 1 (p<0.05). Conclusion: We recommend MEL therapy for diseases related to cartilage damage. MEL seems to exert its therapeutic effect on cartilage damage through its antioxidant properties.