Polygonum minus(Polygonaceae) is a medicinal herb distributed throughout eastern Asia. The present study investigated antiproliferative effect ofP. minusand its possible mechanisms. Four extracts (petroleum ether, methanol, ethyl acetate, and water) were prepared by cold maceration. Extracts were subjected to phytochemical screening, antioxidant, and antiproliferative assays; the most bioactive was fractionated using vacuum liquid chromatography into seven fractions (F1–F7). Antioxidant activity was measuredviatotal phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. Antiproliferative activity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Most active fraction was tested for apoptosis induction and cell cycle arrest in HepG2 cells using flow cytometry and confocal microscopy. Apoptotic-related gene expression was studied by RT-PCR. Ethyl acetate extract was bioactive in initial assays. Its fraction, F7, exhibited highest antioxidant capacity (TPC;113.16±6.2 mg GAE/g extract, DPPH;EC50:30.5±3.2 μg/mL, FRAP;1169±20.3 μmol Fe (II)/mg extract) and selective antiproliferative effect (IC50:25.75±1.5 μg/mL). F7 induced apoptosis in concentration- and time-dependent manner and caused cell cycle arrest at S-phase. Upregulation of proapoptotic genes (Bax,p53, andcaspase-3) and downregulation of antiapoptotic gene,Bcl-2, were observed. In conclusion, F7 was antiproliferative to HepG2 cells by inducing apoptosis, cell cycle arrest, andviaantioxidative effects.

The Ferrous Ion Chelating Assay of Pandanus Extracts