Abstract: Douchi is a traditional fermented soybean food with many beneficial health effects. The aim of this study was to determine the in vitro apoptosis-inducing effect of the volatile components of Douchi (VCD) and to examine the relationship between anticancer effects and VCD. After treatment with 0.4, 0.8, and 1.6 mg/mL VCD for 48 h, the proliferation of human nasopharyngeal carcinoma CNE-1 cells was inhibited, and treatment with 1.6 mg/mL VCD had the highest inhibitory effect (84.6%). Treatment with 0.4 and 0.8 mg/mL VCD also showed good inhibitory effects with the apoptosis rates of 29.7% and 55.6%, respectively. The flow cytometry results showed that 36.2% of the 1.6 mg/mL VCD treated CNE-1 cells in the sub-G1 phase. Reversed transcription-polymerase chain reaction (RT-PCR) analysis indicated that VCD could significantly induce apoptosis in CNE-1 cancer cells (P < 0.05) by upregulating cysteine-aspartic acid protease (caspase)-3, caspase-8, caspase-9, Bax, p53, p21, E2F1, p73 and IκB-α expression and by downregulating Bcl-2, Bcl-xL, human inhibitor of apoptosis protein (HIAP)-1, HIAP-2 and NF-κB mRNA expression in a dose-dependent manner. VCD contained 63 chemical compounds that could potentially cause apoptosis in CNE-1 cells. These results showed that VCD had in vitro apoptosisinducing effects in CNE-1 cells, and this effect was ascribed to the complex chemical composition of VCD.

Key words: Douchi, aroma components, apoptosis, CNE-1 cells, reversed transcription-polymerase chain reaction