Antioxidant and Anti-inflammatory Effects of Solvent Fractions from the Peel of the Native Jeju Citrus ‘Hongkyool’ and ‘Pyunkyool’ Hyun, Ju Mi; Park, Kyung Jin; Kim, Sang Suk; Park, Suk Man; Lee, Young Jae; An, Hyun Joo;
This study investigated the anti-oxidative and anti-inflammatory activity of unripe fruit peel solvent fractions of the native jeju citrus ‘Hongkyool’ (Citrus tachibana Tanaka) and ‘Pyunkyool’ (C. tangerina Hort. ex Tanaka). The total polyphenol content and total flavonoid content were highest in the butanol fraction of both ‘Hongkyool’ (534.4 mg/g, 431.8 mg/g) and ‘Pyunkyool’ (342.9 mg/g, 415.7 mg/g). In both cultivars, the butanol fraction showed the strong antioxidant activity by DPPH radical scavenging and ABTS radical scavenging. The DPPH radical scavenging of the butanol fraction from ‘Hongkyool’ and ‘Pyunkyool’ was 89% and 64% at a concentration of 1 mg/ml, respectively. The ABTS radical scavenging of the butanol fraction from ‘Hongkyool’ and ‘Pyunkyool‘ was 94% and 85% at a concentration of 1 mg/ml, respectively. We investigated the effect of the anti-inflammatory activity of the ethyl acetate fraction from ‘Hongkyool’ and ‘Pyunkyool’ on LPS-induced NO production, IL-6, iNOS, and COX-2 protein expression in Raw 264.7 cells. At concentrations of 50 and 100 μg/ml of the ‘Hongkyool’ ethyl acetate fraction, the anti-inflammatory effect was excellent. These results suggest that ethyl acetate and butanol fractions from ‘Hongkyool’ and ‘Pyunkyool’ could be useful functional materials, with anti-oxidative and anti-inflammatory properties.