The A549/DDP cells at logarithmic growth phase were divided into control group （without drug intervention）， APS groups （ given 25， 50， 100， 200， and 400 mg·L^－1 APS）， DDP groups （given 2， 4， 8， 16， and 32 mg·L^－1 DDP） and APS+DDP groups （given 100 mg·L^－1 APS and 2， 4， 8， 16， 32 mg·L^－1 DDP）. After the cells were treated for 24 h， the inhibitory rates of proliferation of the A549/DDP cells in various groups were detected by CCK-8 method and the half inhibitory concentration （IC₅₀） was caluculated. The A549/DDP cells were divided into control group （without drug intervention）， APS group （given 100 mg·L^－1 APS）， DDP group （given 11.46 mg·L^－1 DDP） and APS+DDP group （given 100 mg·L^－1 APS and 11.46 mg·L^－1 DDP）， the cells in various groups were treated with drugs for 24 h. The migration of A549/DDP cells in various groups was detected by Transwell chamber assay； the apoptotic rates and mitochondrial membrane potentials of the A549/DDP cells in various groups were detected by flow cytometry， and the level expression levels of B-cell lymphoma 2 （Bcl-2）， Bcl-2-related X protein （Bax），P-glycoprotein （P-gp），phosphatidylinositol-3 kinase （PI3K）， phosphorylated phosphatidylinositol-3 kinase （p-PI3K）， protein kinase B （AKT） and phosphorylated protein kinase B （p-AKT） proteins in the A549 / DDP cells in various groups were detected by Western blotting method.

The CCK-8 results showed that compared with DDP group， the IC₅₀ of DDP in APS+DDP group was decreased. The Transwell chamber assay results showed that compared with control group， the migration number of A549 / DDP cells in APS group was not significantly changed； compared with DDP group， the migration number of A549 / DDP cells in APS+ DDP group was decreased.The results of flow cytometry showed that compared with control group， the apoptotic rate and mitochondrial membrane potential of A549 / DDP cells in APS group had no significant changes （P>0.05）， and the apoptotic rate and mitochondrial membrane potential of the A549/DDP cells in DDP group were significantly increased （P<0.05）； compared with DDP group， the apoptotic rate and mitochondrial membrane potential of A549 / DDP cells in APS+DDP group were significantly increased （P<0.05）；the Western blotting results showed that compared with control group， the expression levels of Bcl-2 and P-gp proteins in the A549/DDP cells in APS group was significantly decreased （P<0.05）， the ratios of p-PI3K/PI3K and p-AKT/AKT were decreased（P<0.05）， and there was no significant difference in the expression level of Bax protein （P>0.05）；compared with APS group， the expression levels of Bcl-2 and P-gp proteins in the A549 / DDP cells in DDP group were significantly decreased （P<0.05），the ratios of p-PI3K/PI3K and p-AKT/AKT were decreased（P<0.05）， and the expression level of Bax protein was significantly increased （P<0.05）；compared with DDP group， the expression levels of Bcl-2 and P-gp proteins in the A549 / DDP cells in DDP+APS group were significantly decreased （P<0.05）， the ratios of p-PI3K/PI3K and p-AKT/AKT were decreased（P<0.05），and the expression level of Bax protein was significantly increased （P<0.05）.

APS can reverse the drug resistance of A549/DDP cells，and its mechanism may be related to blocking the PI3K/AKT signal pathway and inducing the mitochondrial damage.