Pycnogenol(PYC)에 의한 Human Fibrosarcoma Cells의 DNA 손상에 따른 항산화제의 prooxidant 역할

Abstract

Park Yeon-sun Advisor : Prof. Young-Gon Kim, Ph.D Department of Biology, Graduate School of Chosun University

Flavonoids are a group of naturally occurring phenolic compounds which are widely distributed in nature. Although, many dietary flavonoids have been suggested to be beneficial for health as an antioxidants against oxidative stress, however, a number of studies show that these can also exhibit prooxidant role under certain condition. Pycnogenol (PYC), polyphenolyic compounds with antioxidative activity, acted as a prooxidant causing a copper and iron dependent DNA damage in human fibrosarcoma cells (HT1080). Treatment of DNA from plasmid pBR322 and human fibrosarcoma cells with PYC plus copper and iron caused strand scission and the formation of 8-hydroxy-2’-deoxyguanosine (8-OHdG) in DNA. DNA strand breaks and formation of 8-OHdG were closely related to the metal ions and PYC concentrations. On the contrary, PYC further did not induce apoptosis of HT 1080 cells at higher concentrations of PYC in the presence of transition metals in cells, but rather protected cells from prooxidant-induced apotopsis. These results imply that intracellular metal ions induced reactive oxygen species and may have dependent upon the concentrations of antioxidants for protection in the oxidative cleavage of DNA and apoptotic cell death.