Antinociceptive Effects of Shenling Baizhu through PI3K-Akt-mTOR Signaling Pathway in a Mouse Model of Bone Metastasis with Small-Cell Lung Cancer

Shenling Baizhu additive powder (SLBZ-AP), a formulation of a variety of natural medicinal plants, has clinical efficacy in treating cancers in previous studies. We explored the effect of SLBZ-AP in bone metastasis of lung cancer (BMLC) mice, and the possible mechanism involved was further investigated in the present study. Mice model of BMLC was made and treated with SLBZ-AP. Pain behavioral tests were performed to explore the effect on BMLC-induced pain in mice. TUNEL staining was used to investigate apoptosis. The mRNA expression of markers in the PI3K/Akt/mTOR pathway was measured by qPCR, and protein expression was detected by western blotting and immunohistochemistry analysis. SLBZ-AP relieved BMLC-induced pain and prolonged animals' survival, promoted cell apoptosis in the marrow from the tibia of BMLC mice, and inhibited mRNA and protein expression of AKT, mTOR, P70S6, and VEGF, as well as protein expression of p-AKT, p-mTOR, p-P70S6, and VEGF upregulation in the marrow of tibia induced by BMLC, an effect which was similar to rapamycin. Our results suggested that SLBZ-AP may have antinociceptive effect and prolong survival of BMLC mice at least partially by inhibiting cell proliferation and promoting apoptosis through the PI3K/Akt/mTOR signaling pathway. SLBZ-AP may be a potential candidate for BMLC therapy.