This study aimed to investigate the various biological activities of Geranium thunbergii such as antimicrobial activity and protective effect against oxidative damage. To evaluate its antioxidant and antimicrobial activities, we first performed methanol extraction; this methanol extract was further partitioned using various solvents. And then, its antioxidant activity was measured using various assays including total phenolic content and protection against oxidative DNA damage, and antimicrobial activities were examined using minimum inhibiting concentration (MIC) test, and paper disc method. In addition, high-performance liquid chromatography was performed to analyze the major chemical components of ethyl acetate fraction. The G. thunbergii fraction with ethyl acetate exhibited higher antioxidant and antimicrobial activities than the other fractions. The results showed that G. thunbergii ethyl acetate fraction at 50 μg/mL had strong DPPH and ABTS radical scavenging activities of 80.88% and 80.12%, respectively. In addition, the ethyl acetate fraction protected DNA from the oxidative damage induced by ferrous ion and hydroxyl radicals and showed high antimicrobial activity with diameter of inhibition zones ranging from 13.33 to 15.67 mm. High-performance liquid chromatography analysis revealed the major phenolic compounds of G. thunbergii to be ellagic acid and gallic acid. These results suggest that G. thunbergii might protect DNA against oxidative stress induced by reactive oxygen species and can be utilized as a natural source of antioxidant and antimicrobial agent in the food industry.

본 연구에서는 타타리메밀싹을 이용한 고부가가치 가공상품을 개발하기 위하여 타타리메밀싹 발효추출물의 영양성분과 생리활성을 검정하였다. 일반 영양성분분석에서는 메밀싹 발효추출물은 단백질, 나트륨, 아연, 마그네슘에서 약간 높은 함량을 보였으나, 메밀전초 발효추출물은 나머지 무기물과 비타민에서 높게 나타났다. 동물실험을 통한 항당뇨 및 혈중지질에 관한 생리활성 검정 결과, 메밀싹 발효추출물이 짧은 기간의 실험임에도 불구하고 혈중 LDL-cholesterol의 수치를 낮추고, HDL-cholesterol의 수치를 올려주어 혈중 total lipid를 낮추는 것을 알 수 있었다. 또한 동맥경화지수인 atherogenic index의 감소를 나타내었다. 이상의 결과를 종합해 볼 때 타타리메밀싹의 발효추출물은 혈중 지질의 개선을 통해 순환기 질환에 효과를 줄 수있다는 가능성을 제시하였다. 하지만 제품화하여 메밀의 새로운 수요창출 및 부가가치를 높이기 위해서는 장기적인 동물실험 및 제품이 갖추어야 할 조건에 대한 관능검사 등 추가적인 연구를 필요로 한다.