Antioxidant Capacity and Quinone Reductase Activity of Methanol Extracts and Fractions from Papaya Seed

본 연구에서는 파파야씨의 메탄올 추출몰과 분획물을 이용하여 항산화 활성 및 quinone reductase (QR) 활성을 측정하였다. 파파야씨의 추출물 및 분획물의 총 폴리페놀 함량은 17.74~125.99 μg/mg 이며, 총 플라보노이드 함량은 1.60~32.69 μg/mg 으로 나타났으며, ethyl acetate (EtOAc) 분획층의 총 폴리페놀 및 플라보노이드 함량이 다른 분획층과 비교했을 때 가장 높은 것으로 나타났다. α , α -Diphenyl- β -picrylhydrazyl (DPPH) radicals, 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and hydrogen peroxide를 이용하여 파파야씨 메탄올 추출물 및 분획물의 항산화 활성을 조사한 결과, EtOAc 분획층에서 가장 높은 free radical 억제능을 보였다. 또한 EtOAc 분획층 12.5~50 μg/ml 의 농도에서 QR의 유도활성을 조사한 결과, 50 μg/ml 의 농도에서 3.3배 정도의 QR 유도능을 보였다. 따라서 파파야씨의 EtOAc 분획층에 존재하는 물질들은 QR inducer 로써의 역할이 기대된다. In this study, the antioxidant activity of methanol extracts and fractions from papaya seed were investigated in vitro. Total polyphenol contents of methanol extracts and fractions from papaya seed varied from 17.74 to 125.99 μg/mg and total flavonoid contents varied from 1.60 to 32.69 μg/mg . Contents of polyphenol and flavonoid in ethyl acetate (EtOAc) fraction was found to be extremely high (compared with the other fractions examined). Radical-scavenging activities of methanol extracts and fractions were examined using α , α -diphenyl- β -picrylhydrazyl (DPPH) radicals, 2,2'-azino-bis (3-ethyl-benzthiazoline-6-sulfonic acid) (ABTS) and hydrogen peroxide assay. As a result, ethyl acetate fraction of papaya seed showed the highest radical-scavenging activity in various antioxidant systems. The EtOAc fraction from papaya seed induced QR activity in concentrations of 12.5 to 50 μg/ml with a maximum of a 3.3-fold induction at 50 μg/ml of fraction. Therefore, the most effective QR inducer among these fractions can be said to reside in the EtOAc fraction, indicating that strong constituents responsible for QR induction potency in the papaya seed extract are largely contained in the EtOAc fraction.