Antioxidant Activity of Solvent Extracts from Sargassum thunbergii

In this study, we investigated the antioxidant activity of solvent extracts from Sargassum thunbergii by measuring electron-donating ability (EDA), nitrite- scavenging ability, superoxide dismutase (SOD)-like activity, reducing power and antioxidant activity in $\beta-carotene-linoleate$ model system. Total phenolic compound contents of chloroform and methanol extracts from Sargassum thunbergii were $22.5{\pm}0.8$ mg/100 mL and $20.1{\pm}0.6$ mg/100 mL, respectively. The EDA were proportionally increased with concentration of the extracts except hexane extract. The EDAs were $70.4\%\;and\;63.2\%$ in methanol and water at concentration of $1000{\mu}g/mL$, respectively. The nitrite-scavenging ability of methanol extract (pH 2.5, $1000{\mu}g/mL$) was $89.4{\pm}0.9\%$ that was higher than those of other extracts. SOD-like ability of chloroform extract was stronger than other extracts. Reducing power of chloroform extracts at $1000{\mu}g/mL$ were 0.75 as O.D. value of 700 nm and antioxidant activities measured with $\beta-carotene-linoleate$ model system were in order of methanol $(78.4\%)>BHT\;(72.1\%)>chloroform\;(62.2\%)>water\;(51.4\%)>hexane\;(43.2\%)$. These results indicated that methanol extract from Sargassum thunbergii showed the highest activities on the EDA, nitrate- scavenging ability and antioxidant activities while the chloroform extract had the highest effect on the SOD-like activity and reducing power.

지충이 용매 추출물의 항산화 활성

지충이 (Sargassum rhunbergii)의 기능성 을 밝히고 식품으로서 이용성을 증대시키기 위하여 전자공여 작용, 아질산염 소거작용, SOD 유사활성, 환원력 및 $\beta-carotene-linoleate$ model system을 이용하여 항산화능을 측정하였다. 총 페놀함량은 chloroform 추출물이 $22.5{\pm}0.8$ mg/100 mL, methanol 추출물이 $20.1{\pm}0.6$ mg/100 mL였으며, 전자공여작용은 hexane 추출물을 제외한 모든 시료에서 추출물의 농도가 높을수록 그 효과가 증가하였으며, 특히 추출물의 농도 $1000{\mu}g/mL$일 때 methanol 추출물과 water 추출물에서 각각 $70.4\%$와 $63.2\%$로 radical 소거능이 강했다 아질산염 소거작용은 pH 2.5 반응용액에서 추출물의 농도가 증가 할수록 뛰어난 소거작용을 보였으며 $1000{\mu}g/mL$에서 methanol 추출물이 $89.4{\pm}0.9\%$로 가장 높은 아질산염 소거작용을 보였고 반대로 water 추출물은 $38.6{\pm}0.5\%$로 낮은 소거효과를 보였다. SOD 유사활성은 chloroform 추출물이$1000{\mu}g/mL$ 첨가시 $61.4\%$로 활성이 가장 높았다. $\beta-carotene-linoleate$ model system에서 항산화 활성을 측정하였을 때 시료의 첨가 농도가 증가할수록 항산화 활성이 높아지는 경향을 보였으며 가장 활성이 높은 methanol 추출물의 경우 $1000{\mu}g/mL$ 농도에서 $78.4\%$로 대조구인 BHT$(72.1\%)$ 보다 더 항산화 활성이 높았다.