Abstract 1288: The potential of Resveratrol and Nagami kumquat extracts in facilitating DNA repair in Raji cells.
Authors: Helsing Albert V. , El-Naggar Atif , Lynch Philip M. , Xiao Michael , Ramsden Madison , Alegre B Fabrizio , Robison Richard A. , O'Neill Kim L. 
Published: August 2014

Cancer is the second biggest killer in the United States. It has long been recognized that people differ in their susceptibility to many different types of cancer. Some of these differences are the heritable traits that modify the effects of environmental exposures. Genetic instability, which drives tumorigenesis, is itself fuelled by DNA damage and often by errors made by the DNA repair machinery. DNA repair, using natural sources of antioxidants, is a new developing area of cancer prevention. The aim of the current study was to investigate DNA repair capacity and DNA damage of Burkitt's lymphoma (Raji) cells exposed to Resveratrol and different extracts of Nagami kumquat (Fortunella margarita). Nagami kumquat is known as “the little gold gem of the citrus family,” and its pulp has been recently highlighted as one containing the most potent antioxidant and high phenolic contents among citrus fruits. Kumquat skin had the highest vitamin C content (3,069.183 μg/g) when compared to both the seed (506.14 μg/g) and pulp (2,440.448 μg/g). Recent evidence has shown that diets rich in antioxidants, such as those including kumquats, may be effective in lowering an individual's risk for cancer. We measured the DNA repair rate of cells by the Comet Assay, taken at several time points throughout the course of 1 hour. DNA damage was induced by exposing the cells to 4mM H2O2 for 15 minutes. This damage was then measured by the comet assay. We measured the amount of DNA damage at 0, 6, 15, 30 and 60 minutes, in order to determine the DNA repair rate. The results were analyzed with Tri-Tek Comet Score Software Version 1.5. The DNA Repair after one hour, using the kumquat Pulp was highly significant (P&lt;0.05) according to the percentages of the DNA in the tail (3.72%) followed by skin (3.37%) and seed (2.28%). The results indicate that among citrus fruits, Kumquat as an antioxidant has a significant capacity to repair DNA. We were able to observe the effect of the Resveratrol (RV) on the rate of DNA repair which showed a highly significant difference when RV was incubated with the cells for a period of 24 hours compared to the non-treated controls (p&lt;0.001). The DNA repair rate was shorter in RV at 15 minute exposure showing 1.09% compared to the non-treated group at 30 minutes which showed 1.175%. We also compared RV to the kumquat extracts and we found that there was a significant difference between the rates of DNA repair, showing that RV was significantly better compared to kumquat extracts. We can conclude that RV has three times higher DNA repair activity than extracts of Nagami kumquat.

Citation Format: Albert V. Helsing, Atif El-Naggar, Philip M. Lynch, Michael Xiao, Madison Ramsden, B Fabrizio Alegre, Richard A. Robison, Kim L. O'Neill. The potential of Resveratrol and Nagami kumquat extracts in facilitating DNA repair in Raji cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1288. doi:10.1158/1538-7445.AM2013-1288