Background : Forsythia suspensa Vahl (Oleaceae) is such an antioxidant source which is a slimbing plant widely distributed in China, Japan and Korea. The extracts of the dried fruits have been used for a long time as traditional Asian medicines to treat gonorrhea, erysipedas, inflammation and pharyngitis. It was also reported that F. suspensa was able to suppress vomiting, resist hepatic injure, inhibit of elastase activity, and exhibit diuretic, analgesic, antioxidant, anti-endotoxin and antiviral effects. This study was performed to investigate the antioxidant and whitening effect of F. suspensa extract and fractions.
Methods and Results : Firstly, extract the dried F. suspensa by methanol three times at room temperature and fraction for each solvents (hexane, ethyl acetate, butanol and water). The DPPH radical scavenging activity was measured at 517 ㎚ by using a UV spectrophotometer. The gallic acid and quercetin were used as positive control of total phenol and flavonoid contents assay. Reducing power was conducted four concentration of samples and positive control, measured the absorbance at 700 ㎚. Ethyl acetate fraction showed the highest effect on DPPH radical scavenging activity, total phenol contents, and reducing power. On the other hand, the highest level of total flavonoid contents indicated in butanol fraction. The ethyl acetate fraction indicated the highest percentage of enzyme inhibition at the tested same concentration.
Conclusion : These results suggest that F. suspensa extract and ethyl acetate fraction could be utilized as a antioxidant. Further biological and phytochemical study is needed.