Fig. 1

Histological examination of leptin-induced cartilage and healthy cartilage. Safranin O−/fast green−/hematoxylin-stained midsagittal sections of knee joints of rats in the control group (a), leptin-induced group at 4 weeks (b) and leptin-induced group at 8 weeks (c). Articular cartilage tissue in leptin-induced group lost glycosaminoglycans not only in the superficial zone but also down deep in the middle zone. Original magnification × 40. (d-e) OARSI score was obtained to quantify the severity of cartilage degradation. Data are presented as a box and whisker diagram. Upper and lower bars represent maximum and minimum. Edges of the box represent the first quartile, median and third quartile. The line in the middle represents the median. NS = Not significant; MTP = medial tibial plateau; MFC = medial femoral condyle. P values calculated by one-way analysis of variance followed by Scheffe’s test