Abstract:

Objective To investigate the effect and molecular mechanism of procyanidin on the proliferation, apoptosis and reactive oxygen species （ROS） level of gastric cancer cell line SNU-1 in vitro. Methods SNU-1 cells were divided into control group and 12.5, 50.0, 200.0 μg/ml procyanidin groups. The effect of procyanidin on the proliferation of SNU-1 cells was detected by CCK-8 assay. The apoptosis level and ROS positive rate of cells were detected by flow cytometry, and 2 mmol/L glutathione was added to SNU-1 cells added with 200.0 μg/ml procyanidin to detect the apoptosis level and ROS positive rate of cells. The expression of apoptosis-related protein in cells was detected by Western blotting. Results The results of CCK-8 experiment showed that the proliferation activities of SNU-1 cells in the control group and the 12.5, 50.0, 200.0 μg/ml procyanidin groups were 3.69±0.30, 3.29±0.41, 0.91±0.39, 0.45±0.22 respectively, with a statistically significant difference （F=279.84, P<0.001）. Compared with the control group, the proliferation activities of SNU-1 cells in the three procyanidin groups were significantly inhibited （P=0.006, P<0.001, P<0.001）. The results of flow cytometry showed that the early apoptosis rates of SNU-1 cells in the control group and the 12.5, 50.0, 200.0 μg/ml procyanidin groups were （0.00±0.00）%, （0.00±0.00）%, （0.09±0.07）% and （0.45±0.22）% respectively, with a statistically significant difference （F=7.14, P=0.003）. The 50.0 and 200.0 μg/ml procyanidin groups increased significantly compared with the control group （P=0.003, P=0.007）. The late apoptosis rates of SNU-1 cells in the four groups were （0.00±0.00）%, （0.01±0.00）%, （6.98±0.77）% and （33.32±2.78）% respectively, with a statistically significant difference （F=654.28, P=0.003）. The 50.0 and 200.0 μg/ml procyanidin groups increased significantly compared with the control group （P<0.001, P<0.001）. The positive rates of ROS in SNU-1 cells in the four groups were （0.02±0.01）%, （0.10±0.05）%, （1.15±0.26）% and （1.58±0.22）% respectively, with a statistically significant difference （F=162.24, P<0.001）. The 50.0 and 200.0 μg/ml procyanidin groups increased significantly compared with the control group （P<0.001, P<0.001）. The positive rates of ROS in SNU-1 cells in the 200.0 μg/ml procyanidin group and the glutathione intervention group were （1.25±0.63）% and （0.13±0.02）% respectively, with a statistically significant difference （t=5.39, P=0.001）. The early apoptosis rates of the two groups were （10.56±3.24）% and （2.09±0.24）% respectively, and the late apoptosis rates were （29.65±6.01）% and （23.63±1.52）% respectively, with statistically significant differences （t=2.61, P=0.048; t=3.97, P=0.012）. The expressions of Bcl-2 protein in SNU-1 cells in the control group and the 12.5, 50.0, 200.0 μg/ml procyanidin groups were 1.00±0.00, 0.83±0.05, 0.60±0.14 and 0.41±0.23 respectively, with a statistically significant difference （F=10.63, P=0.004）. The 50.0 and 200.0 μg/ml procyanidin groups decreased significantly compared with the control group （P<0.001, P<0.001）. Conclusion Procyanidin can inhibit proliferation and promote apoptosis of gastric cancer SNU-1 cells in vitro, which may be achieved by increasing intracellular ROS levels and reducing Bcl-2 protein expression.

Key words: Procyanidin, Gastric neoplasms, SNU-1 cells, Reactive oxygen species, Apoptosis