Abstract

Aim:
In the current study, commercial ginseng extract would be used for supplementing volunteers. DNA protective activity on human lymphocytes mediated by ginseng would be compared with or without the presence of Chinese turnip.
Methods:
Seven healthy subjects (4 males & 3 females from 37-60 years) after overnight fasting gave 2 mL of blood. Content of 5 ginseng capsules in 200 mL water was then ingested and the subject remained fasting for 2 hours until the second blood sample taken. The subjects were arranged to participate the second part of the experiment with at least 2 weeks apart. The subject ingested the same amount of ginseng extract with a piece of cooked turnip (10 grams). The two occasions could be interchanged. Comet assay was performed on two specimens on the same day for evaluation of DNA damage of lymphocyte with or without oxidative stress.
Results:
For the group with ginseng supplementation, there was a significant decrease in comet score for H2O2 treatment over the 2 hours period while no change in DNA damage for unstressed sample. For the group with ginseng together with turnip supplementation, there was no significant difference in comet score for both H2O2 treatment and PBS treatment. Ginseng extract could reduce DNA damage mediated by H2O2 effectively but this protection effect was antagonized by the ingestion of cooked turnip at the same time.
Conclusion:
Ginseng extract could protect DNA from oxidative stress in vivo while turnip diminished the protection.

Key words: antioxidant, DNA, ginseng, protection, turnip