Abstract
Flavonoids have been demonstrated to provide health benefits in humans. Baicalein (5,6,7-trihydroxyflavone) is a phenolic flavonoid compound derived mainly from the root of Scutellaria baicalensis Georgi, a medicinal plant traditionally used in oriental medicine. Baicalein is widely used in Korean and Chinese herbal medicines as anti-inflammatory and anticancer therapy. However, the molecular mechanisms of its activity remain poorly understood and warrant further investigation. This study was performed to investigate the anticancer effect of baicalein on HCT116 human colon cancer cells and the tumor preventing capacity of baicalein on colitis-associated cancer in mice. In in vivo experiments, we induced colon tumors in mice by azoxymethane (AOM) and dextran sulfate sodium (DSS) and evaluated the effects of baicalein on tumor growth. Baicalein treatment on HCT116 cells resulted in a concentration-dependent inhibition of cell growth and induction of apoptotic cell death. The induction of apoptosis was determined by morphological changes and cleavage of poly(ADP-ribose) polymerase. Baicalein also suppressed the activation of NF-kappa B through PPAR gamma activation. These results indicate that the anti-inflammatory effects of baicalein may be mediated through PPAR gamma activation. Finally, administration with baicalein significantly decreased the incidence of tumor formation with inflammation. Our findings suggest that baicalein is one of the candidates for the prevention of inflammation-associated colon carcinogenesis.