Duchesnea phenolic fraction inhibits in vitro and in vivo growth of cervical cancer through induction of apoptosis and cell cycle arrest

Duchesnea indica (Andr.) Focke has been commonly used to treat cancer in Asian countries for centuries, and recently has been shown to possess anticancer properties in vitro and in vivo. But the underlying mechanism of the anticancer action is unclear, especially in in vivo studies. In this study, we investigated the anticancer effect and associated mechanisms of Duchesnea phenolic fraction (DPF) on cervical cancer in vitro and in vivo. Our results showed that DPF significantly inhibited cervical cancer cell proliferation in dose- and time-dependent manners. DPF induced apoptosis as determined by AO/EB staining, DNA fragmentation and flow cytometry. Some apoptosis correlated proteins were altered following DPF treatment. Bax was up-regulated while Bcl-2 was down-regulated, and the expression ratio of Bax/Bcl-2 was increased. These resulted in the translocation of Bax to mitochondria, the release of cytochrome c from the mitochondria to the cytosol and caspase-3 activation. Concurrently, DPF provoked S phase arrest along with significant down-regulation of S phaseassociated proteins, such as cyclin A, cyclin E, cyclin D1 and cdk2. Transplanted U14 cervical cancer mouse model was used to evaluate the antitumor effect of DPF in vivo. Compared with control, DPF treatment markedly prolonged survival of tumor bearing mice and dose-dependently reduced the tumor weight. DPF could induce apoptosis in tumor tissues as evidenced by increased TUNEL-positive cells, activation of caspase-3, upregulation of Bax and down-regulation of Bcl-2. In addition, DPF significantly decreased the expression of cell proliferation markers PCNA and ki67 in tumors. All together, these data sustain our contention that DPF has anticancer properties and merits further investigation as a potential therapeutic agent.