The Effects of Akaloid Fraction of Korean Ginseng on the Radiation-Induced DNA Strand Breaks / 대한치료방사선과학회지

ABSTRACT

PURPOSE: To investigate the effect of alkaloid fraction from Korean ginseng on radiation-induced DNA double strand breaks(dsb) formation and repair in murine lymphocytes. MATERIALS AND METHODS: We used the neutral filter elution technique to assay 60 Co gamma ray-induced DNA double strand breaks formation and repair in C57BL/6 mouse spleen lymphocytes for evaluation the dose-response relationship in the presence of alkaloid fraction as a radioprotective agent. The lymphocytes were stimulated with phytohemagglutinin (PHA, 2 mug/ml) to label 3 [H]-thymidine. Isotope-labelled lymphocytes in suspension were exposed to 100 Gy at 0degree C in the alkaloid fraction-treated group and elution procedure was performed at pH 9.6. The extents of formation of radiation-induced DNA double strand breaks and repair were compared respectively via strand scission factor (SSF) and relative strand scission factor (RSSF). RESULTS: Alkaloid fraction reduced the formation of double strand breaks with dose modification factor of 2.15, compared to control group. Rejoining of DNA dsb appeared to take place via two components. The first fast component was completed within 20.4 minutes, but the second slow component was not completed until 220.2 minutes after irradiation. About 30% of dsb formed by irradiation was ultimately unrejoined despite the administration of alkaloid fraction. The administration of alakaloid fraction had a great effect on the second slow component of repair ; the half-time of fast component repair was not changed, but that of slow component was 621.8 minutes. CONCLUSION: Neutral filter elution assay proved to be a very effective method to quantitate the extents of DNA dsb formation and its repair. By using this technique, we were able to evaluate the efficiency of alkaloid fraction from Korean ginseng as a valuable radioprotector. Alkaloid fraction can be used prophylactically to prevent or ameliorate the severe radiation damages in workers and neighbors aound the atomic power plants. For more refined study, however, more advanced purification of alkaloid fraction will be neended in the near future.