Antioxidant and antigenotoxic activities of Angelica keiskei,
Oenanthe javanica and Brassica oleracea in the Salmonella mutagenicity assay
and in HCT116 human colon cancer cells
Affiliations: Department of Foods and Nutrition, Yonsei University,
Seoul, Korea 120-749 | Linus Pauling Institute, Oregon State University,
Corvallis, OR 97331-6512, USA
Note: [] Address for correspondence: Prof. Sun Yoon, Department of Foods
and Nutrition, Yonsei University, Seoul, Korea 120-749. Tel.: +82 2 21233119;
Fax: +82 2 3653118; E-mail: [email protected]
Abstract: Epidemiological studies indicate that consumption of green-yellow
vegetables rich in chlorophyll, vitamin C, vitamin E, and carotenoids reduce
the risk of cancer. We sought to examine the antigenotoxic and antioxidant
properties of chlorophyll-rich methanol extracts of Angelica keiskei,
Oenanthe javanica, and Brassica oleracea (kale). In the Salmonella
mutagenicity assay, A. keiskei caused dose-dependent inhibition against
three heterocyclic amine mutagens in the presence of S9, O. javanica was
antimutagenic only at the highest concentration in the assay (2 mg/plate), and
B. oleracea showed no consistent inhibitory activity at non-toxic levels.
None of the extracts were effective against three direct-acting mutagens in the
absence of S9. Extracts of A. keiskei and, to a lesser extent O.
javanica, inhibited two of the major enzymes that play a role in the metabolic
activation of heterocyclic amines, based on
ethoxyresorufin-O-deethylase and
methoxyresorufin-O-demethylase assays in vitro. All
three plant extracts were highly effective in assays which measured ferric
reducing/antioxidant power, oxygen radical absorbance capacity, and
Fe^{2+}/H_{2}O_{2}-mediated
DNA nicking. Finally, using the 'comet' assay, all three plant extracts
protected against H_{2}O_{2}-induced
genotoxic damage in human HCT116 colon cancer cells. These findings provide
support for the antigenotoxic 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.
Keywords: Antimutagen, antioxidant, heterocyclic amines, phytochemical, comet assay, DNA breaks
Journal: BioFactors, vol. 26, no. 4, pp. 231-244, 2006
