Fig. 1.

Cytotoxic effect of acetaldehyde-generating system (AGS) on HepG2.2.15 cells. Cells were treated or not with AGS for 72 h and with interferon-γ (IFNγ) for the last 24 h. A: flow cytometric analysis of annexin V-FITC staining: apoptotic cells collected after UV light treatment was used as positive control, and the other 4 treatment cell groups were incubated with annexin V-FITC and analyzed by flow cytometry. B and C: apoptosis was further tested by immunoblotting with antibody to cleaved caspase-3; β-actin was used for normalization. D: cytotoxicity (necrosis) was measured by lactate dehydrogenase (LDH) release to cell medium; media from cells treated with Triton X-100 were used as positive control (100% LDH leakage). Percent cytotoxicity was calculated as (LDH activity in treatment group divided by LDH activity in positive control). Data from 3 independent experiments are presented as means ± SE. Bars marked with the same lowercase letter are not significantly different from each other; bars with different lowercase letters are significantly different (P ≤ 0 0.05).