The healing effects of L-carnitine and spongostan on cartilage defect in rat model

Abstract

Purpose: We aimed to determine the effect of L-carnitine and spongostan on cartilage healing in an experimental animal model with a full-thickness cartilage defect. Methods: In the study 32 Sprague–Dawley rats were divided into four groups in equal numbers. A cartilage defect with a diameter of 1 mm and a depth of 3 mm was created in the femoral intercondylar region of rats in groups A, B, and C. Group A received no treatment in the defective area. Group B received treatment with spongostan. Group C received treatment with spongostan soaked in L-carnitine. Group D served as the healthy control group. The rats were euthanized 6 weeks after the treatment. Histological evaluation of the condyles was done with the modified Mankin scoring. Results: In the histopathological imaging of the cartilage structure, it was observed that in group A, there was complete disorganization and cellular structure was completely absent up to the subchondral bone. In group B, moderate structural improvement, partially intact appearance in border integrity and mostly diffuse hypercellularity were observed. In group C, a near-normal healing, a completely intact appearance in boundary integrities and normal or hypercellularity in cellular structure were observed. The total score of the modified Mankin decreases numerically from A to D. There was no statistically significant difference observed between the A-B (p = 0.176), C-D (p = 0.145), and C-B (p = 0.580) groups, while significant differences were detected between the A–C (p = 0.004), B–D (p = 0.007), and A–D (p = 0.000) groups. Conclusion: It has been known that mitochondrial activity is reduced in the osteoarthritis, and as a result, decrease in cellular activity occurs with ATP synthesis. For this reason, we found that L-carnitine, which we expect to stimulate cell proliferation by stimulating ATP synthesis, makes a positive contribution to cartilage healing, as expected. It has been found that combining spongostan with L-carnitine for the treatment of cartilage healing, instead of applying spongostan alone, provides near-normal healing.