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BioMed Research International
Volume 2014 (2014), Article ID 539607, 13 pages
http://dx.doi.org/10.1155/2014/539607
Research Article

Apoptosis Induction by Polygonum minus Is Related to Antioxidant Capacity, Alterations in Expression of Apoptotic-Related Genes, and S-Phase Cell Cycle Arrest in HepG2 Cell Line

1Pharmacology and Toxicology Research Laboratory, Faculty of Pharmacy, University Technology MARA (UiTM), 42300 Bandar Puncak Alam, Selangor Darul Ehsan, Malaysia
2Group on Affinity, Efficacy and Safety Studies (OASES), Brain and Neuroscience Communities of Research, University Technology MARA (UiTM), 40450 Shah Alam, Selangor Darul Ehsan, Malaysia
3School of Pharmaceutical Sciences, University Science of Malaysia (USM), 11800 Minden, Penang, Malaysia
4Department of Food Sciences and Technology, Faculty of Agriculture, University of Sana’a, Sana’a, Yemen

Received 27 February 2014; Accepted 10 April 2014; Published 13 May 2014

Academic Editor: Joohun Ha

Copyright © 2014 Mohd Alfazari Mohd Ghazali et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Polygonum minus (Polygonaceae) is a medicinal herb distributed throughout eastern Asia. The present study investigated antiproliferative effect of P. minus and 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 measured via total 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;  mg GAE/g extract, DPPH; : μg/mL, FRAP; μmol Fe (II)/mg extract) and selective antiproliferative effect (: 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, and caspase-3) and downregulation of antiapoptotic gene, Bcl-2, were observed. In conclusion, F7 was antiproliferative to HepG2 cells by inducing apoptosis, cell cycle arrest, and via antioxidative effects.