This study was undertaken to determine free radical scavenging capacity and oxidative DNA damage protecting activity of methanol extract of red tea stem. The extract was subjected to assess their antioxidant potential using various in vitro systems such as DPPH•, ABTS•+ , super oxide and nitric oxide free radicals and it exhibited IC50 values of 68.88 ± 1.1, 12.08 ± 0.65, 404.38 ± 1.6, 93.6 ± 2.7, µg/mL respectively. Red tea extract also showed ferric reducing ability (FRAP) with 2606.85 mmol Fe (II)/g of extract. Furthermore, Methanol extract of red tea stem showed significant DNA damage protecting activity in concentration dependent manner against H2O2+UV induced photolysis on pUC19 plasmid DNA. Results of this study showed that the methanol extract of Red Tea stem has strong antioxidant potential along oxidative DNA damage protecting capacity that would be the significant sources of natural antioxidants, which might be helpful in preventing the progress of various oxidative stress generated diseases. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidant.

양강추출물(Alpinia officinarum, 70% ethanol extract)과 함유 주성분인 galangin은 프리라디칼소거작용과 지질과산화억제활성을 나타내었으며, H_2O_2 또는 KO_2유도 세포독성에 대해서도 억제적으로 작용하여 세포보호효과를 나타내었다. DNA single strand breakage와 같은 산화적 스트레스에 대해서도 보호작용을 하고 있다. 또한, 마우스 소핵시험에 의하여 adriamycin과 같은 superoxide유발물질에 의한 염색체 수준에서의 손상에 대해서도 억제효과를 나타내었다. 양강추출물은 galangin을 유효성분으로하여 산소프리라디칼들에 의한 산화적 손상에 억제적으로 작용하는 기전으로 산화적 스트레스에 대한 항노화, 암예방제로서의 응용가능성이 높은 추출물로서 향후 기능성 식품으로서의 응용가능성이 높을 것으로 판단되었다.