소리쟁이 추출물의 항산화 효능

Abstract

본 연구에서는 소리쟁이 에탄올추출물의 항산화 효과를 조사하였다. Pyrogallol의 억제율을 100%로 기준하였을 때, DPPH 라디칼을 50% 억제시키는데 필요한 소리쟁이 추출물의 농도는 2.15 mg/mL으로 <TEX>${\alpha}$</TEX>-tocopherol의 <TEX>$IC_{50}$</TEX>(0.43 mg/mL)에 비해 높게 나타났다. 총항산화능은 ABTS 라디칼에 대한 소거활성으로 측정하였다. 소리쟁이 추출물 0.1 및 1 mg/mL의 총항산화능은 각각 0.47 및 2.33 mM Trolox와 동등한 수준이었으며, <TEX>${\alpha}$</TEX>-tocopherol에 비해 높게 나타났다. 소리쟁이 추출물 0.1 및 1 mg/mL의 superoxide 소거활성은 각각 21.5 및 78.9%이었으며, catechin에 비해 차이가 없었다. 소리쟁이 추출물 20 및 100 <TEX>${\mu}g/mL$</TEX>의 peroxyl 라디칼 소거활성은 각각 62.5 및 156.4 <TEX>${\mu}M$</TEX> Trolox와 동등한 수준이었으며, ascorbic acid에 비해 낮게 나타났다. 소리쟁이 추출물 0.1 및 1 mg/mL의 구리이온 환원력은 각각 0.28 및 1.88 mM Trolox와 동등한 수준이었으며, <TEX>${\alpha}$</TEX>-tocopherol에 비해 유사하거나 높게 나타났다. 소리쟁이 추출물은 hydroxyl 라디칼 및 peroxyl 라디칼로 유발된 supercoiled DNA strand 절단을 억제시켰다. 소리쟁이 추출물 0.5 및 5 mg/mL의 총페놀 함량은 각각 0.58 및 3.85 mM gallic acid와 동등한 수준으로 높게 나타났다. 또한, HepG2 세포주를 이용한 세포배양에서 소리쟁이 추출물 0.1 및 0.5 mg/mL 농도의 첨가는 0.2 mM tert-butyl hydroperoxide로 유도된 세포독성을 각각 38.5 및 63.5% 감소시켰다. 따라서, 본 연구 결과들은 소리쟁이 추출물의 강력한 항산화 효과와 세포독성 억제 효과를 나타내며, 이러한 효능은 적어도 자유라디칼의 산화 억제와 높은 총페놀 함량에 기인하는 것으로 사료된다. The objective of this study was to investigate the antioxidative capacity of ethanol extracts from Rumex crispus L. The concentration of R. crispus L. extract at which DPPH radical scavenging activity was inhibited by 50% was 2.15 mg/mL, which was lower than that of <TEX>${\alpha}$</TEX>-tocopherol (0.43 mg/mL), as compared to 100% by pyrogallol as a reference. Total antioxidant status was examined by total antioxidant capacity against ABTS radical reactions. Total antioxidant capacities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 0.47 and 2.33 mM Trolox equivalents, respectively, which were higher than those of <TEX>${\alpha}$</TEX>-tocopherol. Superoxide scavenging activities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 21.5 and 78.9%, respectively, which were not significantly (p>0.05) different from those of catechin. Oxygen radical absorbance capacities of R. crispus L. extract at concentrations of 20 and 100 <TEX>${\mu}g/mL$</TEX> were 62.5 and 156.4 <TEX>${\mu}M$</TEX> Trolox equivalents, respectively, which were lower than those of ascorbic acid. Cupric reducing antioxidant capacities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 0.28 and 1.88 mM Trolox equivalents, which were similar or significantly (p<0.05) higher than those of <TEX>${\alpha}$</TEX>-tocopherol, respectively. R. crispus L. extract prevented supercoiled DNA strand breakage induced by hydroxyl radical and peroxyl radical. Total phenolic contents of R. crispus L. extract at concentrations of 0.5 and 5 mg/mL were 0.58 and 3.85 mM gallic acid equivalents, respectively. R. crispus L. extract at concentration of 0.1 and 0.5 mg/mL inhibited 0.2 mM tert-butyl hydroperoxide-induced cytotoxicity by 38.5 and 63.5%, respectively, in HepG2 cell culture system. Thus, strong antioxidant and cytotoxicity-inhibiting effects of R. crispus L. extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in total phenolic contents.