Objective: To explore the synergistically effects and mechanisms of resveratrol (RES) enhanced the oxidative stress and apoptotic cell death induced by As2O3 (arsenic trioxide).
Methods: According to the result of MTT assay, human lung adenocarcinoma A549 cells were divided into four treatment groups as follow: control group, single RES or As2O3 treated group and the group treated with RES and As2O3. Then the differences of cell viability, colony formation, level of ROS, GSH content, mitochondrial membrane potential and apoptosis rate were compared with single or combined treatment. In addition, pre-treatment with L-buthionine sulfoximine (L-BSO), the inhibitory of GSH synthesis, was used to identify the role of GSH in synergistically apoptosis induced by RES and As2O3.
Results: The detected results demonstrated that RES could effectively inhibited the growth of A549 cells when its concentration above 20 μmol/L, and inhibition effects was concentration dependent manner. The rate of colony formation, GSH content, mitochondrial membrane potential and apoptosis rate in combination group were significantly lower than that of single RES or As2O3 treatment group (P < 0.05), whereas, RES markedly increased the level of ROS, the expression of cytochrome c and caspase 3 induced by As2O3. When pre-treatment with BSO before RES and As2O3 combination incubation, beside the apoptosis rate was increased from 30.0% to 77.7%, the GSH content was sharply depleted while ROS massively accumulated in intracellular.
Conclusion: RES could significantly intensified the effects of As2O3 in inhibiting the proliferation, depleting GSH content, ROS accumulation, mitochondrial membrane potential decline and cytochrome c releasing, thus leading to cells apoptosis via Cas-3 activation in a mitochondria-dependent pathway.