Figure 5.

Effects of ligustilide (LIG) on the JNK and p38 mitogen‐activated protein kinase (MAPK) pathways in cartilage chondrocytes in vivo. (A) Apoptotic chondrocytes in the rat articular cartilage were detected by TUNEL staining (original magnification 400 ×). Immunohistochemical analyses of p‐activating transcription factor 2 (ATF2), p‐JNK and p‐p38 MAPK expression were determined in each group (original magnification 400 × and zoom‐in areas magnification 800 ×) 10 weeks after anterior cruciate ligament transection together with medial menisci resection (ACLT + MMx) surgery or sham operation. (B) The percentage of apoptotic chondrocytes in articular cartilage was calculated. (C‐E) The ratios of immunoreactive positive cells of p‐ATF2, p‐JNK and p‐p38 MAPK were analysed. Each column represented mean ± SEM (n = 5). ***P < 0.001 vs the sham‐operated group; ^# P < 0.05, ^## P < 0.01 and ^### P < 0.001 vs the osteoarthritis‐induced group