Objective: To investigate the effect of essential oil from Aucklandiae Radix on proliferation and apoptosis inhibition of MV4-11 leukemia cells and discuss its action mechanism. Method: Human leukemia cell line MV4-11 was treated with the essential oil from Aucklandiae Radix (3

6

12

25

50

100 mg·L-1) for different time

and another blank group was set up. Cell viability was estimated by using MTT assay; the apoptosis morphology changes were observed by Hoechst 33258 staining; flow cytometry was used on Annexin V-FITC/propidium iodide staining to detect the cell cycle and the rate of apoptosis; Western blot was used to detect AKT and Caspase-3 protein expression. Result: The essential oil from Aucklandiae Radix had IC50 value of 13.33 mg·L-1; various nuclear changes such as nuclear shrinkage

chromatin condensation and obvious apoptotic bodies were observed after MV4-11 cell line was treated with essential oil from Aucklandiae Radix for 24 h. As compared with the blank group

the cells in G0/G1 phase were significantly reduced and the cells in S phase were significantly increased with the increase from essential oil from Aucklandiae Radix oil dosage (P<0.05

P<0.01). 12

25

50

100

150 mg·L-1 essential oil from Aucklandiae Radix induced apoptosis of MV4-11 (P<0.05); 25

50

100

150 mg·L-1 essential oil from Aucklandiae Radix inhibited AKT phosphorylation and promoted Caspase-3 protein degradation (P<0.05

P<0.01). Conclusion: The essential oil from Aucklandiae Radix can inhibit the proliferation of MV4-11 cells in vitro

and the mechanism may be correlated with inducing cell apoptosis by inhibiting AKT activity.