Abstract: OBJECTIVE: To study the effect of Herba Saginae Japonicae (HSJ) on differentiation of human chronic myeloid leukemia cells (K562). METHODS: K652 cells were organized into experimental groups (with treatment of 250, 125, 62.5 μg/mL HSJ) and a negative control group. Cell proliferation was detected using the MTT assay. Cell morphology was observed after their staining by Wright-Giemsa. Their differentiation ability was determined by the NBT reduction assay. Their expression rates of CD11b, CD14, CD41a and CD42b positive cells were determined using flow cytometry. Western blot method was used to detect their expression of GATA1 and PU.1 proteins. RESULTS: Compared with the negative control group, HSJ exposure caused inhibition of proliferation of the K562 cells. Morphologically, treated cells showed lobulated nuclei and some showed obvious cell differentiation features. The different doses of treated cells showed significantly increased NBT reduction rates (P < 0.05);CD11b, CD14, CD41a and CD42b positive rates (P < 0.05) and GATA1 and PU.1 protein relative contents (P < 0.05) compared with the negative controls (P < 0.05). CONCLUSION: HSJ induced the K562 chronic myeloid leukemia cells to mature in the direction of differentiation.

Key words: Herba Saginae Japonicae, K562 cell, differentiation, leukemia cell