The in vitro study of apoptosis in NB4 cell induced by citral.

Citral, 3,7-dimethyl-2,6-octadienal, is a key component of the essential oils extracted from several lemon-scented herbal plants. Besides its antifungal activity, the anticancer effect of citral was studied in recent years. In this study, we investigated the effect of citral on the acute promyelocytic leukemia cell line NB4. Citral treatment had an antiproliferative effect in NB4 cells via the induction of apoptosis assessed by morphology, proliferation assay, DNA electrophoresis, Annexin V-FITC/PI staining and caspase-3 activation. And citral induced apoptosis of NB4 cells in a dose- and time-dependent manner. In addition, citral treatment induced decreased mitochondrial membrane potential, indicating that citral induced apoptosis via the mitochondrial pathway. Bax up-regulation and Bcl-2 down-regulation on mRNA level and NF-κB down-regulation on protein level was found in this study, suggesting that Bcl-2, Bax and NF-κB may be involved in the mechanism of the apoptotic effect of citral on NB4 cells. These data suggest that citral has a potential therapeutic effect on leukemia.