This study investigated the antioxidant activities of Amaranth (Amaranthus spp. L.) seed extracts. Methanol and hotwater extracts of the seeds were evaluated for their total polyphenol, flavonoid, and tannin content, antioxidant activ-ities, and protective effects against oxidative stress on L-132 cells. The hot water extracts showed higher total phe-nol (4.23mg GAE/g) and tannin (0.511mg TAE/g) content, while the methanol extracts showed higher flavonoidcontent (1.53mg CE/g). The methanol extracts performed better than the water extracts for DPPH radical-scavengingactivity, while the water extracts performed better for ABTS radical-scavenging activity and SOD-like activity. WithL-132 cells, the water extracts showed strong protective effects against oxidative stress in a dose dependent mannerwith an effect three-fold higher than that of the methanol extracts at a concentration of 500µg/mL. A higher inhi-bition activity of nitric oxide in RAW 264.7 cells was observed with the water extracts than with the methanolextracts at a concentration of 250µg/mL. In summary, the water extracts showed the highest total polyphenol andtannin content and a more powerful protective effect against oxidative stress and inhibition effect of NO. Our resultssuggest that amaranth seeds may be useful as natural antioxidant compounds.

본 연구는 아마란스의 붉은 색과 보라색 꽃 열수 추출물과 메탄올 추출물의 폴리페놀과 플라보노이드 함량 측정과 DPPH와 ABTS 라디칼 소거 활성, SOD 유사 활성을 측정하였으며, 세포내에서 생성된 superoxide 라디칼 제거 활성과 산화질소 생성 억제 활성을 분석하여 새로운 식물 유래 라디칼 소거 활성 물질을 개발하기 위하여 시행하였다. 총 폴리페놀의 함량은 아마란스 추출물 중 보라색 꽃 메탄올 추출물이 606.95 ㎎ GAE/100 g으로 가장 높았으며, 플라보노이드 함량도 254.69 ㎎ CE/100 g으로 가장 높았다. 또한 DPPH 라디칼 소거 활성에서도 보라색 꽃 메탄올 추출물의 RC50 값이 155.06 ㎍/㎖로 나타났다. ABTS 라디칼 소거능 측정에서는 250 ㎍/㎖의 농도에서 보라색 꽃 메탄올 추출물의 활성이 53.16%로 가장 좋았으며, 보라색 꽃 열수 추출물(41.55%), 붉은 꽃 열수 추출물(30.52%), 붉은 꽃 메탄올 추출물(30.34%)의 순으로 활성을 나타내었다. 이와 반대로 SOD 유사 활성은 보라색 꽃 열수 추출물에서 메탄올 추출물의 활성보다 3배나 높은 결과를 보여주었다. 세포내 superoxide 라디칼 제거 활성은 200 ㎍/㎖의 농도에서 보라색 꽃 메탄올 추출물 (72.34%)이 붉은 색 꽃 열수 추출물(40.40%)보다 1.79배 높은 활성을 보였다. 세포내 NO 생성 억제 활성을 조사한 결과에서는 보라색 꽃 메탄올 추출물이 250 ㎍/㎖의 농도에서 46.90%의 가장 높은 저해 활성을 보여주었다. 본 연구의 결과, 플라보노이드 함량이 높은 보라색 꽃 메탄올 추출물에서 라디컬소거능이 높았으며 강력한 항산화제 활성을 보여주었다. 이러한 결과로 보아 아마란스 꽃의 새로운 항산화 소재로서 개발 가능성을 보여주었다.

This study examined the anti-inflammatory and whitening effects of Amaranth (Amaranthus spp L.) seed extract. Amaranthus spp L. seeds were extracted using 70% ethanol and then fractionated sequentially with n-hexane, dichloromethan, ethyl acetate and butanol. For the study of anti-inflammatory activity in RAW 264.7 cells, EtOAc fraction of Amaranthus spp L. seeds significantly inhibited nitrogen oxide production as well as the protein level of iNOS. Furthermore, EtOAc fraction of Amaranthus spp L. seeds inhibited expression of TNF-α, PGE2 and the protein level of COX-2 in a dose-dependent manner. Inaddition, the tyrosinase inhibitory activities of the Amaranthus spp L. seed 70% ethanol extract and subfractions were also measured to see if these extracts can be used as an ingredient for whitening cosmetics. Tyrosinase is an oxidase that is a rate-limiting enzyme for controlling the production of melanin. Therefore, tyrosinase inhibitors have become increasingly important in cosmetics and medical products with regards to hyperpigmentation. EtOAc fraction of Amaranthus spp L. seeds showed mushroom tyrosinase inhibitory activity in a dose-dependent manner. This activity was more potent than that of a positive control cynandione A. These results suggest that Amaranthus spp L. seeds may be a valuable natural ingredient for the food and cosmetics industries.