title: DNA protective effect of ginseng and the antagonistic effect of Chinese turnip: A supplementation study.
abstract: OBJECTIVE
  The aim of this clinical study is to provide scientific evidence for supporting traditional Chinese application and usage to the patients. For this purpose, we tested the ability if Panax ginseng extract to lower oxidative damage to nuclear DNA in human lymphocytes by comparing the effect of cooked Chinese turnip on this effect.
  
  
  METHODS
  Seven healthy subjects (4 males and 3 females from 37 to 60 years) participated two occasions which were at least 2 weeks apart. About 2 mL of fasting blood sample for baseline measurement was taken on arrival. They were requested to ingest the content of 5 ginseng capsules in 200 mL water. The subject remained fasting for 2 h until the second blood sample taken. In the other occasion, the experiment was repeated except a piece of cooked turnip (10 g) was taken with the ginseng extract. The two occasions could be interchanged. Comet assay was performed on two specimens on the same day for the evaluation of lymphocytic DNA damage with or without oxidative stress.
  
  
  RESULTS
  For the group with ginseng supplementation, there was a significant decrease in comet score for hydrogen peroxide (H2O2) treatment over the 2-h 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 H2O2treatment and phosphate-buffered saline treatment. Ginseng extract could reduce DNA damage mediated by H2O2effectively, but this protection effect was antagonized by the ingestion of cooked turnip at the same time.
  
  
  CONCLUSIONS
  In the current study, commercial ginseng extract was used for supplementing volunteers. Ginseng extract could protect DNA from oxidative stressin vivowhile turnip diminished the protection.
authors.affiliation: Department of Applied Science, Hong Kong Institute of Vocational Education (Shatin), Vocational Training Council, Hong Kong.
authors.forename: Yim Tong
authors.initials: YT
authors.lastname: Szeto
authors.affiliation: Department of Pathology, Yan Chai Hospital, Kowloon, Hong Kong.
authors.forename: Kam Shing
authors.initials: KS
authors.lastname: Wong
authors.affiliation: Department of Biochemistry, Chinese University of Hong Kong, Hong Kong.
authors.forename: Andrea
authors.initials: A
authors.lastname: Han
authors.affiliation: School of Biomedical Sciences, Charles Sturt University, NSW, Australia.
authors.forename: Sok Cheon
authors.initials: SC
authors.lastname: Pak
authors.affiliation: School of Biomedical Sciences, Charles Sturt University, NSW, Australia.
authors.forename: Wouter
authors.initials: W
authors.lastname: Kalle
keywords: Antioxidant; DNA; ginseng; protection; turnip