구아바 잎 추출물의 항산화 활성과 항염증 소재로서의 활용 가능성을 확인하고자 하였다. 구아바 잎 추출물의 총 폴리페놀 함량, 총 플라보노이드함량, RAW 264.7 세포에 대한 세포 독성 및 NO 생성 억제를 통한 항염증 효과, 피부에 대한 안전성 평가를 실시하였다. 본 실험 결과, 총 폴리페놀과 플라보노이드의 함량이 각 126.4 mg/g, 223.17 mg/g으로 높은 함량을 확인하였다. 대식세포인 264.7세포에 대한 세포 독성이 나타나지 않았으며 NO 생성을 농도 의존적으로 억제되는 것을 확인하였다. 구아바 잎 추출물을 함유한 크림을 제조하여 1차 첩포 테스트를 실시하여 피부 안전성을 확인한 결과 첩포 24 시간 후와 첩포 제거 24 시간 후에도 피부에 대한 자극은 확인되지 않았다. 이러한 결과를 종합해 볼 때 높은 총 폴리페놀과 플라보노이드의 함량으로 인한 항산화 활성이 우수하고, 세포에 대한 피부 독성이 적고 NO 생성 억제 효과가 확인됨에 따라 항산화 및 항염증 효과를 가진 소재로서의 활용 가능성을 확인하였다.

Pleurotus citrinopileatus was successfully cultivated and commercially available in Korea. The antioxidant, xanthine oxidase, tyrosinase inhibitory activities and polyphenol contents of fruiting bodies of Pleurotus citrinopileatus extracted with acetone, hot water and methanol (hereinafter referred to Fr. Ace, Fr. HW and Fr. MeOH). The antioxidant activities on β-carotene-linoleic acid in the Fr. Ace, Fr. HW and Fr. MeOH were 96.12%, 94.21% and 96.52%, respectively at the concentration of 20 mg/ml. Xanthine oxidase inhibition activity in the Fr. Ace, Fr. HW and Fr. MeOH were 30.12%, 35.42% and 29.02%, respectively at the concentration of 5 mg/ml. Tyrosinase inhibition activity in the Fr. Ace, Fr. HW and Fr. MeOH were 58.78%, 49.25% and 63.29%, respectively at the concentration of 1.0 mg/ml. Total polyphenol contents in the Fr. Ace, Fr. HW and Fr. MeOH were 18.99 mgGAEs/g, 16.73 mgGAEs/g and 18.66 mgGAEs/g. These experimental results suggested that fruiting bodies of P. citrinopileatus contained good physio-chemical substances for promoting human health.

This study attempted to investigate the antioxidant properties of four different species of sand dune plants (Calystegia soldanella, Messerschmidia sibirica, Vitex rotundifolia and Rosa rugosa). In order to validate the antioxidant activity of these plants, we first determined the total amount of flavonoid versus phenolic contents (TFC/TPC) and extracted crude flavonoids for measuring antioxidant activities that were determined by DPPH, ABTS and FRAP assays with radical scavenging effects. We found that highest amounts of TPC were detected in R. rugose with values of 110.20 ㎎/g (leaves) and 65.71 ㎎/g (stems), while the highest amounts of TFC in V. rotundifolia with values of 38.07 ㎎/g (leaves) and 6.55 ㎎/g (stems). We further examined how closely related the amounts of TFC/TPC in antioxidant activities and found that R. rugose has the highest activities of radical scavenging with values of 63.4 ㎍/㎖ and 51.2 ㎍/㎖ determined by DPPH and ABTS assays compared with the value of 21.2 ㎍/㎖ by FRAP assay. It is of note that there is a statistically significant correlation between the resulting antioxidant activities and the total ratio of TFC and TPC, suggesting that the different amounts of TFC/TPC may directly contribute to the various antioxidant activities.

Flavonoids and total polyphenols are important secondary plant metabolites, as they play a role in reducing the oxidative stress caused by ROS In this study, we investigated for flavonoid contents, total polyphenol contents, and antioxidant activities in 27 accessions from 10 Vicia species. Among 27 vicia accessions, NAC17 (V. monantha) and NAC14 (V. hyrcanica) had the highest total flavonoid (1.42 ± 0.09 mg/g) and total polyphenol (124.2 ± 0.5 μg/GAE mg) contents, respectively. In four flavonoids, naringenin showed the highest concentrations in Vicia species. The DPPH and ABTS were the range from 0.2 (NAC24, V. sativa subsp. nigra) to 18.5 (NAC13, V. faba) μg/ASC mg and 19.1 (NAC7, V. cracca) to 253.4 (NAC13, V. faba) μg/Trolox mg, respectively. Among the 10 Vicia species, V. monantha and V. hyrcanica had the highest flavonoid (1.31 ± 0.09 mg/g) and total polyphenol (116.5 ± 2.0 μg/GAE mg) contents, respectively. The highest antioxidant activity was detected in V. faba. These results will expand the flavonoid database and provide information on Vicia species valuable for development of functional foods or feed-additives resources.