A Study of the Anti-Cancer Effects of the Hexane Fraction of the Methanol Extract of Forsythiae Fructus

BACKGROUND: Forsythiae Fructus (FF) is a well-known medicinal herb derived from the dried fruits of Forsythia suspensa (Thunb.) Vahl. (Oleaceae). Recently, bioactive compounds isolated from hydrophobic solvent fractions of FF have been reported to have anti-oxidant, antibacterial, and anti-cancer effects. OBJECTIVE: Almost all herbal medicines are derived from water extracts, which suggests different extraction methods might enhance the practical efficacies of herbal medicines. In this study, the authors further investigated the most potential anti-cancer fraction, that is, the hexane fraction (FFH) of the methanol extract (FFM) of the dried fruits of Forsythia suspensa. MATERIALS AND METHODS: FFH was investigated by measuring its effects on the viability and apoptotic death of PC-3 cells (a prostate cancer cell line), on the expression levels of Bcl-2, Bax, cytochrome c, procaspase-9, procaspase-3 and PARP, and caspase-3 activity. RESULTS: FFH significantly accelerated apoptotic cell death and decreased the protein levels of Bcl-2, procaspase-9, and procaspase-3. CONCLUSION: FFH can act as a pro-oxidative agent and induce the apoptosis of prostate cancer cells. SUMMARY: Hexane fraction of the methanol extract of Forsythiae Fructus (FFH) at a concentration more than 50 µg/mL significantly reduced PC-3 cell viability. FFH time and dose dependently elevated intracellular ROS levels and increased the proportion of cells arrested in the G(0)/G(1) phase. FFH significantly accelerated apoptotic cell death and diminished the protein expression levels of Bcl-2, procaspase-9, and procaspase-3. The protein expression levels of Bax, cytochrome c, and cleaved PARP were increased by FFH, and so was the caspase-3 activity. [Image: see text] Abbreviations used: FF: Forsythiae Fructus; FFM: Methanol extract of Forsythiae Fructus; FFH: Hexane fraction of the methanol extract; DCFH-DA: 2’,7’-dichlorodihydro-fluorescein diacetate.