Affiliations: Department of Food and Nutrition, Hannam University,
Daejeon, Korea
Note: [] Address for correspondence: Hae-Dong Jang, Department of Food
and Nutrition, Hannam University, 133 Ojungdong Daedukgu, Daejeon, Korea. Tel.:
+82 42 629 7393: Fax: +82 42 636 0268; E-mail: haedong@hannam.ac.kr
Abstract: Rooibos tea (Aspalathus linearis) was extracted by refluxing
with water and 75% ethanol as a solvent. Antioxidant activity and protective
effect on DNA strand scission were investigated by using different antioxidant
assay systems and DNA strand nicking assay, respectively. 75% Ethanol extract
has higher content of total soluble phenolics and flavonoid than water extract.
Antioxidant activities such as hydrogen donating capacity and scavenging
activity of hydrogen peroxide were higher in 75% ethanol extract than in water
extract except the rate constant with hydroxyl radical. Peroxyl radical induced
DNA strand scission was prevented by both 75% ethanol and water extract and
hydroxyl radical induced DNA strand scission was not. This result indicates
that total soluble phenolics, specially flavonoid, of Rooibos tea are
responsible for several kinds of antioxidant activities and preventive activity
on peroxyl radical induced DNA strand scission.
Keywords: rooibos tea, total soluble phenolics, antioxidant activity, protective effect on DNA strand scission
Journal: BioFactors, vol. 21, no. 1-4, pp. 285-292, 2004
