ABSTRACT
Some traditional Chinese medicinal seeds and fruits are well known for their antioxidant properties. This research aims to investigate whether Fructus Lycii, Fructus Schisandrae Chinensis, Fructus Ligustri Lucidi and Semen Cuscutae protect DNA from oxidant challenge by hydrogen peroxide (H(2)O(2)). The standard comet assay was used to assess the genoprotective effect of these medicinal herbs. Blood was taken from three healthy adults, aged from 36 to 42. Lymphocytes were isolated and treated with different concentrations of aqueous herbal extracts, while controls were treated with phosphate buffered saline. The lymphocytes were stressed with 50 µM H(2)O(2). Treated cells were embedded in agarose and layered on slides. These sandwiched lymphocytes were lysed and afterwards subjected to an electric field in an alkaline environment. Damaged DNA was pulled out from the nucleus towards the positive electrode as a comet tail; its density was related to the degree of DNA damage. Finally, the slides were stained with fluorescence dye and tails were visually scored for 100 cells. The experiment was repeated three times and DNA damage in treated cells was compared to the controls. There was no statistical difference in DNA damage among the herb treated cells and untreated cells in the comet assay. Our data demonstrated that the selected medicinal herbs did not show in vitro DNA protection in the comet assay against oxidant challenge.
Subject(s)
Antioxidants/pharmacology , DNA Damage , Drugs, Chinese Herbal/pharmacology , Lymphocytes/drug effects , Oxidative Stress/drug effects , Plants, Medicinal , Comet Assay , Cuscuta , Fruit , Humans , Hydrogen Peroxide , Ligustrum , Lycium , Oxidants , Schisandra , SeedsABSTRACT
The genoprotective effect of American and Asian ginseng on human lymphocytic DNA was studied. Using the comet assay, aqueous extracts of both types of ginseng were shown to diminish hydrogen peroxide-induced DNA damage. In contrast, and in accordance with traditional Chinese medicine beliefs, addition of the juice from Chinese turnip counteracted the beneficial effect of ginseng. Results showed that incubating ginseng along with turnip juice abolished the DNA protective effect of both American and Asian ginseng. Although the exact mechanism has not been elucidated, the counteracting effect of turnip on ginseng seems unlikely to be mediated by enzymatic action as the effect was seen with boiled as well as unboiled turnip extract.
