밤꽃 추출물의 생리활성

Abstract

The antioxidant activities of chestnut flower extracts were examined using various antioxidant assays, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, reducing power. We investigated the effect of CF extracts on viability of normal and tumor cells by 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Our results showed that CF extracts was not cytotoxic on mouse embryonic fibroblasts, NIH3T3. The viability of cells was increased significantly with low concentratins of CF extracts and conversely, it reduced cell proliferation and viability of most of the tested cancer cells (human lung cancer cell line, Calu6) in dose-dependent manners. However, CF extracts was not cytotoxic on human hepatocellular carcinoma, SK-Hep-1. Because tyrosinase catalyzes melanin synthesis, tyrosinase inhibitors are important in cosmetic skin-whitening. We examined CF extracts that might be useful for skin-whitening. CF extracts (30, 50 and 100 ㎍/㎖ each) were tested for cytotoxicity on human melanoma (SK-MEL-2). Their effects on tyrosinase and melanin inhibitory activities were further assessed. Results revealed that the prebloomed extracts exhibited the best performance in DPPH assay, reducing power assay. Furthermore, the preM has the highest total flavonoid contents (60.96 ± 1.86 ㎎ of QE/g) and preE has the highest total phenolic contents (467.92 ± 0.45 ㎎ of GAE/g). The results showed that CF extracts showed potent inhibitory effects on L-Dopa (L-3,4-dihydroxyphenylalanine) oxidation catalyzed by tyrosinase. CF extracts exhibited potent inhibitory effects on tyrosinase (preM 72.49%, preE 70.02%, preW 64.14%, postM 72.25%, postE 65.14% and postW 63.38% at 1 ㎎/㎖). Melanin inhibition was dose-dependent manner. In addition, we detected consistent downregulation of tyrosinase mRNA and proteins by CF extracts. These results suggest that CF extracts have inhibitory effect on tyrosinase expression. The overall results of this study indicates that the extracts of chestnut flowers have interesting antioxidant properties and represent a potential source of medicine for the treatment of infectious diseases and cancer, tyrosinase inhibitor for cosmetic skin whitening.