Date of Graduation

5-2018

Document Type

Thesis

Degree Name

Master of Science in Food Science (MS)

Degree Level

Graduate

Department

Food Science

Advisor/Mentor

Howard, Luke R.

Committee Member

Bartlett, Andrew

Second Committee Member

Lee, Sun-Ok

Keywords

Antiproliferation; Caco-2; Carrots; Chemoprevention; Nutrition; Terpenoids

Abstract

Epidemiological studies have shown an association between high carrot consumption and low prevalence of cancer. This observation has been thought to be attributed to carrot carotenoids. Despite this, various intervention trials have displayed no changes in incidence or increased incidence of cancer with carotenoid supplementation. It is possible that carrot phenolics are responsible for this association, though this has not been widely accepted. Volatile terpenoids from carrots have not been studied in this regard. Therefore, the primary objective of this study was to compare the antiproliferative effects of carotenoids, phenolics, and volatile terpenoids extracted from carrots on Caco-2 colon cancer cells in vitro. Briefly, carrot carotenoids, phenolics, and volatiles were extracted from carrots using liquid-liquid, solid phase, and distillation extraction techniques respectively. 1000 Caco-2 cells were seeded in a 96-well plate, treated with the carrot carotenoid, phenolic, or volatile extract at a dilution of 50X, 100X, or 200X, then counted at 0, 6, and 12 hours after treatment using the MTS assay. The carrot carotenoids, phenolics, and volatile terpenoids did not exhibit a significantly different treatment effect over time compared to control conditions, (p-value = 0.2757), however a significant antiproliferative effect was seen at the 6 hour time point for all treatments except the volatile extract at a dilution of 200X indicating effectiveness after 6 hours of exposure. A secondary objective of this study was to conduct the same MTS assay on Caco-2 cells using the three most predominant individual compounds present in the carrot volatile extract at their inherent concentrations which were γ-terpinene, Terpinolene, and α-phellandrene. None of these compounds exhibited a significantly different treatment effect over time compared to control conditions, (p-value = 0.4975), however all three provided significantly lower mean cell counts compared to control conditions at the 6 and 12 hour time points, indicating them as effective antiproliferative treatments 6 hours of exposure. Future work is warranted to elucidate mechanisms of action and bioavailability of these experimental treatments.

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