Biofunctional Evaluation of ß-phenylethyl Isothiocyanate in Brassica rapa L.

다국어 초록 (Multilingual Abstract)

Glucosinolates, the precursors of isothiocyanates, are present in Cruciferous vegetables such as Turnip (Brassica rapa L.). Glucosinolates are usually broken down through hydrolysis catalyzed by myrosinase that is released from damaged plant cells. Glucosinolates and their breakdown products, in particular isothiocyanates, have long been known various biological activities including anticarcinogenic, antimicrobial and antioxidant activity. In this study, quantitative analyses of isothiocyanates and total glucosinolates in turnip (Brassica rapa L.) which divided into three parts, were examined by UV-spectrometer, GC and GC/MS. As a result, in quantitative analysis of total glucosinolates, there were no significant differences in different parts of turnip. However, 3-butenyl and 4-pentenyl isothiocyanates in the leaf part were higher than those of other parts. And ß-phenylethyl isothiocyanate which are abundant in peeling part, showed a most high content in turnip. To investigate the various biological effect of ß-phenylethyl isothiocyanate of using MTT assay, disc diffusion method, MIC(minimum inhibitory concentration) and DPPH method. The results indicated that anticarcinogenic activity of ß-phenylethyl isothiocyanate inhibited the growth of human-derived hepatoma cell line (HepG2) in concentration dependent manners. At the highest concentration (100μM), completely suppressed the growth of cells and the approximate IC_(50) values was 24.5μM, respectively. ß-phenylethyl isothiocyanate showed strong antimicrobial activity against food-borne pathogens; Vibrio parahaemolyticus, Staphylococcus aureus subsp, Bacillus cereus, Salmonella choleraesuis subsp. In particular, the efficiency of MIC value of Vibrio parahaemolyticus was the strongest at 100μg/ml. However, free radical scavenging effect of ß-phenylethyl isothiocyanate was not shown in this study. An important finding in this study was that major isothiocyanates in turnip was ß-phenylethyl isothiocyanate. Furthermore, ß-phenylethyl isothiocyanate was observed chemopreventative effects and antimicrobial activities against food-borne pathogens.