Abstract:

Objective To investigate the inhibitory effect of pseudolaric acid B (PAB) on the growth of glioma C6 cells, and explore the possible molecular mechanism. Methods The effects of different mass concentrations of PAB (0, 0.1, 0.2, 0.4, 0.8, 1.6, 8.0 and 16.0 μg/mL) on the growth of C6 cells were analysed by MTT assay. After treatment with 0 (control), 0.15, 0.3 and 0.6 μg/mL PAB, the apoptosis of C6 cells was detected by flow cytometry with Annexin V-FITC/PI double staining, and the expression of Survivin (apoptosis inhibition protein), LC3 (microtubule-associated protein 1 light chain 3-β) and cleaved poly (ADP-ribose) polymerase (Cleaved-PARP) was determined by RT-PCR and Western blotting. Results MTT assay revealed PAB inhibited the growth of C6 cells in a dose and time dependent manner. The median lethal dosages (IC50) of PAB on C6 cells were 1.23, 1.05, 0.30 and 0.09 μg/mL after treatment with PAB for 12, 24, 36, and 72 h respectively. Flow cytometry indicated that apoptosis of C6 cells occurred 36 h after treatment with 0.15, 0.30 and 0.60 μg/mL PAB, and the apoptosis rates were (24.89±0.92)%, (31.38±0.36)% and (62.84±2.22)% respectively, which were significantly different from that of control group (P＜0.05). RT-PCR and Western blotting demonstrated that the expression of Survivin in C6 cells decreased, and the expression of LC3 and Cleaved-PARP increased after treatment with PAB, which was significantly different from that of control group （P＜0.05 or P＜0.01）.With the concentration increase of PAB, the expression of Survivin, LC3 and Cleaved-PARP in cells changed in a dose dependent manner. Conclusion PAB can inhibit the growth of glioma C6 cells and induce cell apoptosis, which may be associated with the decreased expression of Survivin and increased expression of LC3 and Cleaved-PARP.

Key words: pseudolaric acid B, C6 cells, growth inhibition