Antioxidant and α-Glucosidase Inhibition Activities of Solvent Fractions from Methanolic Extract of Sericea Lespedeza (Lespedeza cuneata G. Don)

비수리(Lespedeza cuneata G. Don) 메탄올 추출물로부터 분획된 용매분획물의 항산화활성과 α-Glucosidase 저해활성

The purpose of this study was to evaluate the antioxidant contents and antioxidant activities of solvent fractions from methanolic extract of sericea lespedeza. To determine the antioxidant compounds in solvent fractions from methanolic extract, total polyphenolic, flavonoid, tannin, and proanthocyanidin contents were measured by spectrophotometric methods. Solvent fractions were evaluated for antioxidative capacity according to DPPH and ABTS radical scavenging activities. Total polyphenolic contents were 12.44, 3.61, 6.39, 27.11, 20.00, and 9.32 mg gallic acid equivalent (GAE)/g extract residue (ER), respectively. Total flavonoid contents were 2.94, 9.92, 7.77, 9.27, 5.11, and 2.66 mg catechin equivalent (CE)/g ER, respectively. Total tannin contents were 8.75, 10.04, 7.42, 17.32, 11.65, and 7.61 mg tannic acid equivalent (TAE)/g ER, respectively. Total proanthocyanidin contents were 346.09, 63.50, 103.76, 288.62, 231.99, and $358.48{\mu}g$ CE/g ER, respectively. DPPH radical scavenging activities of solvent fractions from methanolic extract of sericea lespedeza were 20.62, 5.16, 9.29, 20.80, 20.00 and 20.79 mg Trolox equivalent (TE)/g ER, and ABTS radical scavenging activities were 33.86, 9.24, 17.36, 33.76, 33.49, and 33.86 mg TE/g ER, respectively. SOD-like activities were 4.12, 0.61, 2.01, 9.89, 13.47, and 11.82 units/mL, and ${\alpha}$-glucosidase inhibition activities were 93.85 and 61.64% at concentrations of 50 and $25{\mu}g/mL$ in the water fraction, respectively. The results of this study show that notable antioxidant activities in sericea lespedeza have significant health benefits.

비수리의 식품학적 이용가능성을 확인해 보고자 항산화성분 및 항산화활성, superoxide dismutase 유사활성, ${\alpha}$-glucosidase 저해활성 등에 대해 검토하였다. 비수리 메탄올 추출물과 hexane, chloroform, ethyl acetate, butanol 및 물 분획 등 순차적 용매분획물의 총 폴리페놀 함량은 각각 12.44, 3.61, 6.39, 27.11, 20.00 및 9.32 mg GAE/g extract residue(ER)로 나타났으며, 총 플라보노이드 함량은 각각 2.94, 9.92, 7.77, 9.27, 5.11 및 2.66 mg CE/g ER, 총 탄닌 함량은 각각 8.75, 10.04, 7.42, 17.32, 11.65 및 7.61 mg TAE/g ER, 총 프로안토시아니딘의 함량은 346.09, 63.50, 103.76, 288.62, 231.99 및 $358.48{\mu}g$ CE/g ER로 나타났다. 비수리 메탄올 추출물과 hexane, chloroform, ethyl acetate, butanol 및 물 분획물의 DPPH radical 소거활성은 각각 20.62, 5.16, 9.29, 20.80, 20.00 및 20.79 mg TE/g ER, ABTS radical 소거활성은 각각 33.86, 9.24, 17.36, 33.76, 33.49 및 33.86 mg TE/g ER로 나타났다. SOD 유사활성은 각각 4.12, 0.61, 2.01, 9.89, 13.47 및 11.82 unit/mL의 활성을 보여 butanol 분획과 물 분획에서 유의적으로 높은 활성을 나타내었고 ${\alpha}$-glucosidase 저해활성은 물 분획 50 및 $25{\mu}g/mL$에서 각각 93.85 및 61.64%로 높은 저해활성을 보이는 것으로 나타났다. 이상의 결과에서 비수리 추출물은 항산화성분 및 항산화활성, SOD 유사활성, ${\alpha}$-glucosidase 저해활성을 가지는 물질을 함유한 것으로 보이며, 체내 및 식품에서 활성산소 종 제거에 도움을 줄 수 있을 것으로 보인다.