Objective: To explore the effects of Achyranths Bidentatae Radix(AB) extracts on monosodium iodoacetate (MIA)-induced injury in rat chondrocytes. Method: Chondrocytes were isolated from the knee joints of Sprague-Dawley rats by using enzymatic digestion. The experiment was divided into 5 groups:the normal group

the model group (4 μmol · L-1 MIA)

the low-

medium-and high-dose AB extract groups (10

30

100 mg · L-1). The viability of chondrocytes was detected by MTT assay. The morphology change of chondrocytes was detected by Hoechst 33258 method. The activity of Caspase-3 chondrocytes was measured by spectrophotometry. The activation of AKT and down-stream molecules including Bax

Bcl-2 was assayed by Western Blot. Result: Compared with the normal group

the viability of chondrocytes declined

chondrocytes nucleus shrivel or cracking occurred

the activity of Caspase-3 and the level of Bax protein raised

the level of Bcl-2 protein and phosphorylation of AKT declined in the model group (P<0.01). Compared with the model group

the viability and morphology of chondrocytes were restored

the expression of Bax was inhibited in the medium-and high-dose AB extract groups (P<0.01). Moreover

the activity of Caspase-3 was inhibited

the expression of Bcl-2 and the phosphorylation of AKT were promoted in the low-

medium-and high-dose AB extract groups (P<0.01). Conclusion: These results suggested AB extract exerted anti-apoptosis effect on MIA-induced rat chondrocytes

which might be related to PI3K/AKT signal pathway.