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The anti‐cancer effects of poi (Colocasia esculenta) on colonic adenocarcinoma cells In vitro
Author(s) -
Brown Amy C.,
Reitzenstein Jonathan E.,
Liu Jessie,
Jadus Martin R.
Publication year - 2005
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.1712
Subject(s) - apoptosis , cancer , colorectal cancer , tunel assay , cancer cell , in vitro , biology , cancer research , flow cytometry , immunology , medicine , biochemistry
Hawaiians tend to have lower incidence rates of colorectal cancer and it was hypothesized that this may be due to ethnic differences in diet, specifically, their consumption of poi, a starchy paste made from the taro ( Colocasia esulenta L .) plant corm. Soluble extracts of poi were incubated at 100 mg/mL in vitro for antiproliferative activity against the rat YYT colon cancer cell line. 3 H‐thymidine incorporation studies were conducted to demonstrate that the poi inhibited the proliferation of these cancer cells in a dose‐dependent manner. The greatest suppression of YYT colon cancer growth occurred when 25% concentration was used. When poi was incubated with the YYT cells after 2 days, the YYT cells underwent apoptotic changes as evidenced by a positive terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling (TUNEL) stain. Poi enhanced the proliferation of normal mouse splenocyte control cells, suggesting that poi is not simply toxic to all cells but even has a positive immunostimulatory role. By flow cytometry, T cells (CD4+ and CD8+) were predominantly activated by the poi. Although numerous factors can contribute to the risk of colon cancer, perhaps poi consumption may contribute to the lower colon cancer rates among Hawaiians by two distinct mechanisms. First, by inducing apoptosis within colon cancer cells; second, by non‐specifically activating lymphocytes, which in turn can lyse cancerous cells. Our results suggest for the first time that poi may have novel tumor specific anti‐cancer activities and future research is suggested with animal studies and human clinical trials. Copyright © 2005 John Wiley & Sons, Ltd.