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BioMed Research International
Volume 2018 (2018), Article ID 2871710, 11 pages
Research Article

Whole Peptidoglycan Extracts from the Lactobacillus paracasei subsp. paracasei M5 Strain Exert Anticancer Activity In Vitro

1Key Laboratory of Dairy Science of Ministry of Education, Northeast Agricultural University, Harbin 150030, China
2School of Chemical Engineering & Technology, Harbin Institute of Technology, Harbin 150090, China
3School of Food Science and Engineering, Ocean University of China, Qingdao 266100, China

Correspondence should be addressed to Xue Han and Lanwei Zhang

Received 11 July 2017; Accepted 9 November 2017; Published 7 February 2018

Academic Editor: Somboon Tanasupawat

Copyright © 2018 Shumei Wang 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.


The Lactobacillus paracasei subsp. paracasei M5 strain exerted potential anticancer activity through the cell wall. In this study, whole peptidoglycan (WPG) was extracted from the Lactobacillus paracasei subsp. paracasei M5 strain and was evaluated for anticancer effects as well as its properties. SDS-PAGE analysis confirmed the presence of WPG with dominant bands of approximately 14.4 kDa. Further analysis revealed that the amino acids present in the WPG consisted of alanine, glycine, glutamic acid, and lysine in a molar ratio of approximately 8 : 5 : 3 : 3.5. In addition, the cell viability of HT-29 cells with WPG addition was investigated with methyl thiazolyl tetrazolium (MTT) and trypan blue exclusion (TBE) assays, and cell apoptosis was analyzed with a transmission electron microscope, flow cytometry, and semiquantitative RT-PCR. These results showed that WPG exerted cytotoxic effects on colon cancer HT-29 cells in a dose-dependent manner and upregulated proapoptotic genes, while downregulating antiapoptotic genes. The gene expression study definitively revealed that WPG induced a mitochondria-mediated apoptotic pathway.