Luteolin is known as the flavone subclass of flavonoids in a variety of plants. Luteolin has been shown a potent anticancer effect in several experiments in vitro. However, the bioavailability of luteolin has not yet been fully tested. Therefore, we investigated the effect of luteolin in human fibrosarcoma HT1080 cells. We found that luteolin inhibited the HT1080 cell viability and proliferation in time-and dose- dependent manner as determined by MTT assay. Also, luteolin dramatically increased the p53 and p21 expression as detected by Western blot analysis. Luteolin induced G2/M phase arrest in HT1080 cells. Moreover, we investigated that luteolin significantly induced COX-2 expression in a time-and dose dependent manner. Phosphorylation of ERK was considerably increased by luteolin in HT1080 cells. Inhibition of ERK with PD98059 suppressed luteolin induced p53, p21 and COX-2 expression. Our results suggest that luteolin regulates p53/p21 dependent cell proliferation and COX-2 expression through ERK pathway in HT1080 human fibrosarcoma cells. (Cancer Prev Res 17, 0-225, 2012)

Keywords: Luteolin, Anticancer effect, COX-2, ERK, HT1080