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Evidence-Based Complementary and Alternative Medicine
Volume 2011, Article ID 731308, 11 pages
http://dx.doi.org/10.1093/ecam/neq032
Original Article

Dioscorea Phytocompounds Enhance Murine Splenocyte Proliferation Ex Vivo and Improve Regeneration of Bone Marrow Cells In Vivo

1Agricultural Biotechnology Research Center, Academia Sinica, no. 128, Section 2, Academia Road, Nangang District, Taipei 115, Taiwan
2Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan
3Department of Cell Biology and Molecular Genetics, University of Maryland, MD, USA
4Department of Forestry, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, Taiwan
5Institute of Chemistry, Academia Sinica, Taipei, Taiwan
6Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
7College of Life Science, National Taiwan University, Taipei, Taiwan
8Institute of Life Science, National Central University, Zhongli, Taiwan

Received 4 September 2009; Accepted 22 March 2010

Copyright © 2011 Pei-Fen Su 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

Specific cytokines have been tested clinically for immunotherapy of cancers; however, cytotoxicity has often impaired their usefulness. Consequently, alternative approaches are increasingly desirable. Dioscorea spp. tuber is a widely used traditional Chinese medicinal herb claimed to confer immunostimulatory activity. In this study, we evaluated Dioscorea as an adjuvant therapy for use alongside chemotherapy for cancer. Phytocompounds from Dioscorea tubers were ethanol fractioned and used for ex vivo splenocyte proliferation assay or in vivo force-feeding of mice pre-treated with the chemotherapy agent 5-fluorouracil. Co-treatment with a 50–75% ethanol-partitioned fraction of the tuber extract of D. batatas (DsCE-II) and interleukin (IL)-2 resulted in a significantly higher rate of murine splenocyte cell proliferation ex vivo than treatment with DsCE-II or IL-2 alone. This DsCE-II fraction, which contains a polysaccharide with a high proportion of β-1,4-linkage mannose (≥64%), also promoted the regeneration of specific progenitor cell populations in damaged bone marrow tissues of 5-fluorouracil-treated mice. Colony-forming unit (CFU) analyses demonstrated that the population of CFU-GM cells, but not CFU-GEMM or BFU-E cells, preferentially recovered to ~67% in the bone marrow of immune-suppressed mice fed with DsCE-II. DsCE-II efficacy level was ~85% of that obtained by subcutaneous administration of recombinant G-CSF proteins (5 μg kg−1) in mice tested in parallel. This study suggests that the DsCE-II fraction of D. batatas extract may be considered for further development as a dietary supplement for use alongside chemotherapy during cancer treatment.