Abstract: Objective To observe the protective effect of tanshinone ⅡA(TSN) on the apoptosis of human umbilical vein endothelial cells(HUVECs) stimulated by aristolochic acid(AA) and its possible mechanism. Methods Cultivated HUVECs were divided into four groups: control group, AA group(the final concentration of AA was 10 mg/L), TSN treatment group(HUVECs was added with AA after incubation with 0.2, 0.4 and 0.8 mg/L of TSN for one hour) and LY294002 pretreatment group(HUVECs was pretreated with 20 μmol/L of PI3K antagonist LY294002 for 30 min before TSN was added). After 24 hours, cell viabilities were evaluated by the MTT assays. The morphological changes of apoptotic cells were observed by Hoechst 33258 fluorescence staining. The proportions of apoptotic cells were assessed by flow cytometry. Western blot was used to determine the expressions of Bcl-2, Bax and phophorylated Akt. Meanwhile, the caspase-3 activity was detected by colorimetric method. Results Compared with control group, AA increased the proportions of apoptotic cells(P < 0.05), inhibited the expressions of Bcl-2 and phosphorylated Akt(P < 0.05), and promoted the expression of Bax(P < 0.05). After intervention with TSN, the above-mentioned parameter changes were reversed(P < 0.05). The protective effects of TSN were partially inhibited by PI3K antagonist LY294002(P < 0.05). Conclusion TSN can inhibit the apoptosis of HUVECs stimulated by aristolochic acid.

Key words: tanshinone ⅡA, aristolochic acid, endothelial cell, apoptosis, PI3K/Akt signaling pathway