| Objective To investigate the impact of crocin on the apoptosis of chondrocytes in rats with knee osteoarthritis (KOA) by regulating Hippo/Yes-associated protein (YAP) signaling pathway. Methods SD rats were separated into CK group, Model group, low-dose crocin group (crocin-L group, 10 mg/kg), high-dose crocin group (crocin-H group, 40 mg/kg), celecoxib group (CLCX group, 10 mg/kg), crocin-H+VTPF (YAP inhibitor) group (40 mg/kg+10 mg/kg), 12 in each group. the changes in thermal pain threshold and tenderness threshold of rats were observed and recorded; ELISA detect the levels of matrix metalloproteinase (MMP)-3, MMP-13, interleukin (IL)-1β, and IL-6 in rat serum; HE staining detect the pathological changes of rat cartilage tissue and Mankin score was performed; TUNEL staining detect apoptosis of rat chondrocytes; the expression of Bcl2 related X protein (Bax), aspartate specific cysteine proteinase-3 (Caspase-3), p-YAP and YAP protein were detected by immunohistochemistry and Western blot. Results Compared with CK group, the thermal pain threshold, tenderness threshold and p-YAP protein expression were decreased, and the cartilage tissue was severely damaged, the MMP-3, MMP-13, IL-1β, IL-6 levels, Mankin score, chondrocyte apoptosis rate, Bax, Caspase-3, YAP protein expressions increased in the Model group (P<0.05); compared with Model group, the corresponding indicators in the crocin-L group, crocin-H group and CLCX group had the opposite trends (P<0.05); VTPF attenuated the inhibitory effect of high-dose crocin on chondrocyte apoptosis in KOA rats. Conclusion Crocin may inhibit the apoptosis of chondrocytes in KOA rats by activating the Hippo/YAP signaling pathway. |