Date of Award

8-2009

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Microbiology

Advisor

Larcom, Lyndon L

Committee Member

Tzeng , Jeremy

Committee Member

Wei , Charlie

Abstract

Despite the great strides made in the treatment of cancer, considerably little progress has been made towards prevention of the disease. In light of this reality, it has become apparent that a greater focus needs to be devoted to research into means of cancer prevention. Due to the significant role that nutrition plays in the development of cancer, the diet presents an attractive and logical target for such research.
Epidemiology has consistently shown an inverse relationship between fruit and vegetable consumption and risk for developing cancer. Additionally, countless in vitro studies on natural products isolated from fruits and vegetables have revealed many properties that could contribute to an anticancer effect. While many epidemiological observations have been made and many in vitro assays have been performed, very little work has been conducted to investigate the actual physiological effect(s) that result from consumption of fruits and vegetables. This study was undertaken in an attempt to begin to address this issue.
The goal of the present study was to evaluate the in vitro anticarcinogenic properties of red raspberry extract and determine the effect of red raspberry consumption on the levels of cytotoxicity exerted by Natural Killer (NK) cells.
Fifteen volunteers participated in the portion of the study evaluating cytotoxic activity of NK cells. Five of the 15 volunteers showed a significant increase in cytotoxic activity levels of NK cells following consumption of red raspberries. Additionally, plasma taken from three individuals following red raspberry consumption showed a significantly higher antiproliferative effect on MCF-7 human breast cancer cells than plasma taken prior to consumption of red raspberries.
When tested in vitro, red raspberry extract demonstrated a significant antiproliferative effect on AGS human stomach cancer and LoVo human colon cancer cell lines. Further testing revealed that pH was not a factor and that the antiproliferative effect could not be attributed solely to antioxidant activity.
Although one of the first studies of its kind, this study provides a glimpse into the downstream physiological effects that result from red raspberry consumption which could contribute to the prevention of cancer. Our results suggest that consumption of red raspberries has the potential to increase the cytotoxic activity of NK cells in some individuals and may also lead to the accumulation of compounds in the plasma which can exert an antiproliferative effect on transformed cells.

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Microbiology Commons

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