Objective: To observe the effects of Platycodonis Radix combined with Cnidii Fructus-Psoraleae Fructus on C-X-C chemokine ligand 12 (CXCL12)-C-X-C chemokine receptor 4 (CXCR4) axis in nude mice with bone metastasis of breast cancer. Method: The model of bone metastasis of breast cancer in nude mice were established by left ventricle injection of MDA-MB-231BO cells. The modeled mice were treated with traditional Chinese medicine decoction ‘Cnidii Fructus 1.28 g -Psoraleae Fructus 1.28 g’

‘Cnidii Fructus 1.28 g-Psoraleae Fructus 1.28 g -Platycodonis Radix 0.32 g’ and ‘Cnidii Fructus 1.28 g-Psoraleae Fructus 1.28 g-Cyathulae Radix 0.32 g’. After the interventions

the nude mice models were observed for the effects of the treatment methods on upper limb and lower limb bone metastasis damages and degree of bone metastases

CXCL12 and CXCR4 mRNA expressions and protein expressions in bone metastasis lesions of upper and lower limbs were detected by RT-PCR and Western blot. Result: Cnidii Fructus-Psoraleae Fructus had certain inhibitory effects on bone metastasis degree

bone damage degree of upper limb and lower limb

as well as CXCL12 and CXCR4 gene expressions in bone metastases tissues (P<0.05). The upward medicinal guide drug Platycodonis Radix can enhance the inhibitory effect of Cnidii Fructus-Psoraleae Fructus on bone metastasis degree

bone damage degree of upper limb

as well as mRNA and protein expressions of CXCL12 and CXCR4 in bone metastasis tissues (P<0.05). The downward medicinal guide drug Achyranthes had no obvious effects on the above indexes. Conclusion: Platycodonis Radix can enhance the therapeutic effect of Cnidii Fructus-Psoraleae Fructuson in nude mice with bone metastasis of breast cancer

and the mechanism may be associated with the enhancing effect of Cnidii Fructus-Psoraleae Fructus on down-regulating the mRNA and protein expressions of CXCL12 and CXCR4 in bone metastasis lesions of upper limb.