Screening of Biological Activities to Different Ethanol Extracts of Rubus coreanus Miq.

This study was carried out to evaluate biological activities to different ethanol extracts from unripened and ripened fruit (Rubus coreanus Miq.). 25% to 75% ethanol extracts of unripened and ripened fruits were similar to extract yield respectively. Yield of ethanol extract of ripened fruit were approximately 3 times higher than that of unripened fruit. 75% ethanol extract of unripened fruit showed the highest contents of total polyphenol (180.04 ± 0.41 ㎎/g) and total fla- vonoid (50.43 ± 0.81 ㎎/g). Contents of total polyphenol and total flavonoid of unripened fruit were about 2 times higher than those of ripened fruit. IC50 values of DPPH radical scavenging activity and linoleic acid peroxidation inhibition activity of BHA and α-tocopherol showed 13.19 ± 0.21 and 18.16 ± 0.23 ㎍/㎖, 4.25 ± 0.04 ㎍/㎖ and 5.56 ± 0.10 ㎍/㎖ respectively, but 75% ethanol extract of unripened fruit showed the lowest 23.85 ± 0.10 ㎍/㎖ and 7.34 ± 0.07 ㎍/㎖ among other all extracts. IC50 values of LDL (low density lipoprotein) oxidation inhibition activity and α-glucosidase inhibitory activity of 75% ethanol extract of unripened fruit showed the lowest 1.04 ± 0.04 ㎍/㎖ and 7.21 ± 0.13 ㎍/㎖ among other all extracts respectively. Specifically, 75% ethanol extract of unripened fruit has relatively better biological activities than other ethanol extracts, it could be potentially used as bioactive source for health functional foods.