Comparison of antioxidant activity and prevention of lymphocyte DNA damage by fruit and vegetable juices marketed in Korea / 한국영양학회지

PURPOSE: Fruit and vegetable juices are known to be rich sources of antioxidants, which have beneficial effects on diseases caused by oxidative stress. The purpose of this study was to directly compare the antioxidant activities of fruit and vegetable juices marketed in Korea. METHODS: We analyzed four fruit juices, two vegetable juices, two yellow-green juices, and six mixed vegetable juices. Antioxidant activities were analyzed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) test, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonate) (ABTS) test, and oxygen radical absorbance capacity (ORAC) assay. Protective effects against DNA damage were determined using an ex vivo comet assay with human lymphocytes. RESULTS: DPPH radical scavenging activities were in the following order: blueberry juice > mixed vegetable C juice > kale juice > mixed vegetable P juice > grape juice. ABTS radical scavenging activities were in the following order: blueberry juice > mixed vegetable C juice > grape juice > mixed vegetable P juice > kale juice. Peroxyl radical scavenging activities as assessed by ORAC assay were in the following order: blueberry juice > kale juice > mixed vegetable C juice > grape juice. Grape or blueberry juice showed strong abilities to prevent DNA damage in lymphocytes, and the difference between them was not significant according to the GSTM1/GSTT1 genotype. CONCLUSION: Antioxidant activities of fruit and vegetable juices and ex vivo DNA protective activity increased in the order of blueberry juice, grape juice, and kale juice, although the rankings were slightly different. Therefore, these juices rich in polyphenols and flavonoids deserve more attention for their high antioxidant capacity.

Effect of Vegetable Juice Supplementation on Serum Lipid Profile and Antioxidant Activity in College Women / 대한지역사회영양학회지

The aim of this study was to assess the effect of 6-week vegetable juice supplementation (360 ml/day) on serum lipid profiles and antioxidant activity in college women. Twenty women (mean age: 21) with normal life style and dietary pattern and who are free of any specific diseases were recruited among the student in S women's university. The subjects consumed vegetable juice to take part in an uncontrolled clinical trial for a 6-week intervention period. While there was no difference in the concentration of total cholesterol and HDL-cholesterol, serum concentrations of TG and HDL/LDL ratio were significantly reduced by 22% (p = 0.013) and 6% (p = 0.007) respectively. Significant decrease in malondialdehyde (p = 0.000) was accompanied by an increase in the activity of serum antioxidant enzymes, such as GSHPx (p = 0.000), SOD (p = 0.007). It was also found that total antioxidant status was improved by 5.4% (p = 0.009). Serum parameters were all changed without affecting body mass index, waist and hip circumferences, or nutrient intakes after six week of supplementation. This study demonstrated that the supplementation regular meals with vegetable juice can favorably affect serum lipid profiles and antioxidant systems, and hence could contribute to reduce the risks of chronic diseases in college women.