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Green vegetables reduce cancer risk

At Oregon State University, Roderick Dashwood, (Professor of Environmental and Molecular Toxicology) has been conducting research examining the genetic and epigenetic mechanisms of colorectal cancer development. Several publications from the Dashwood laboratory and their collaborators have detailed the use of the comet assay and other genetic toxicology experiments.


Epidemiological studies indicate that consumption of green-yellow vegetables rich in chlorophyll, vitamin C, vitamin E and carotenoids reduce the risk of cancer. This study sought to examine the anti-genotoxic and antioxidant properties of chlorophyll-rich methanol extracts of Angelica keiskei (a rare plant native to Hachijojima Island, Japan, with several predicted nutritional and health benefits) Oenanthe javanica (an edible east Asian plant also known as Japanese parsley or Chinese celery), and Brassica oleracea (kale).

Ames test

In the Salmonella mutagenicity assay (also known as the Ames test), A. keiskei showed a dose-dependent effect against the action of mutagens, O. javanica was anti-mutagenic at the highest concentration tested and B. oleracea showed no consistent inhibitory activity at non-toxic levels. Colonies were counted using a Sorcerer colony counter supplied by Perceptive Instruments.

Comet assay

The comet assay is used to detect DNA strand breaks as well as alkaline labile lesions. For many laboratories the comet assay has become the tool of choice for detecting DNA damage in eukaryotic cells due to its versatility. Here, using the comet assay with Perceptive Instrument's comet assay analysis system, it was shown that all three plant extracts protected against H2O2-induced genotoxic damage in human HCT116 colon cancer cells.


The scientists concluded that these findings provide support for the anti-genotoxic and antioxidant properties of chlorophyll-rich extracts of A. keiskei, O. javanica, and B. oleracea, through mechanisms that include inhibition of carcinogen activation and scavenging of reactive oxygen species.

Case study based on:
Antioxidant and antigenotoxic activities of Angelica keiskei, Oenanthe javanica and Brassica oleracea in the Salmonella mutagenicity assay and in HCT116 human colon cancer cells
Daejoong Kwon, Sun Yoon, Orianna Carter, George S. Bailey, and Roderick H. Dashwood.
Biofactors. 2006; 26(4): 231–244.