To study the effects of Jiangtang Xiaoke Granules containing serum on expressions of protein and genes of phosphoinositide-3 kinase (PI3K)/AKT/FOXO1 signaling pathway in INS-1 cells to explore the molecular mechanism of serum contained Jiangtang Xiaoke Granules on protecting β-cells. Methods:The FOXO1 high expression INS-1 stable cell line was selected and treated with 1%, 5%, 10%, 15% and 20% different concentrations of Jiangtang Xiaoke Granules containing serum. The cell survival rate was calculated by MTT method to observe the toxicity of the drug. The total FOXO1 protein level in each group was detected to determine the optimal drug concentration for subsequent experiments. The cells were transfected with or without the PI3K inhibitor LY294002. Western blotting was used to detect the expression of FOXO1, p-FOXO1, Akt, p-Akt and FOXO1 and p-FOXO1 in the nucleus. The expression of FOXO1 mRNA and Akt mRNA was detected by qRT-PCR. Results:Different concentrations of drug-containing serum were not toxic to cells, and 10% of them were the optimal drug intervention concentration. The expression of phosphorylated FOXO1 and Akt was increased with 10% drug-containing serum. In the cytoplasm and nucleus, the expression of FOXO1 was decreased and the expression of phosphorylation was increased with 10% drug-containing serum, and the expression of FOXO1 and p-FOXO1 were decreased by the inhibitor LY294002. The results of real-time quantitative PCR (qRT-PCR) showed that the expression of Akt mRNA was increased, the expression of FOXO1 mRNA was decreased, and the expression of FOXO1 mRNA was decreased by inhibitor. The results were consistent with the results of Western blotting. Conclusion:The drug-containing serum of Jiangtang Xiaoke Granules can promote the phosphorylation of FOXO1 through the PI3K/AKT/FOXO1 pathway to inhibit the transcription of FOXO nuclear to protect islet B cells.