Alpha-tocopherol succinate inhibits growth of gastric cancer cells in vitro

BACKGROUND: Vitamin E in the form of alpha-tocopherol succinate (ATS) has been shown to inhibit growth of several cancer cell lines in vitro, including pancreas, breast, and prostate. No data exist on the effect of ATS on gastric cancer cell viability. METHODS: A gastric cancer cell line in suspension form, KATO-III, was plated in 96-well plates at 30,000 cells per well with 100 microl RPMI media. The cells were allowed to incubate for 24 h and were then treated with ATS at doses of 25, 50, or 100 microg/ml. The ATS was dissolved in 1% EtOH solution and control cells received an identical solution of EtOH without ATS. Treated cells were incubated for 24, 48, or 72 h. At the completion of the treatment period, MTT assay was performed to determine cell viability. Statistical analysis was performed using Student's t test. RESULTS: All doses of ATS resulted in inhibition of growth of the KATO-III cells. Both 100 and 50 microg/cc doses inhibited growth at all time points (P<0.005), with 48- and 72-h treatments more effective than 24-h treatment. At 24 and 48 h, 100 microg/cc was more effective at inhibition of growth than 50 microg/ml (P<0.005), but by 72 h the effects of the doses were equivalent; 25 microg/ml inhibited cell growth only at 48 and 72 h. At all time points, 50 and 100 microg/ml doses were more effective at inhibiting cell growth than 25 microg/ml. Conclusions. ATS inhibits gastric carcinoma cell growth in vitro in a dose- and time-dependent fashion. In vivo studies are indicated to further evaluate the potential benefit of this antioxidant against gastric cancer.