Analysis of the isothiocyanates present in three Chinese Brassica vegetable seeds and their potential anticancer bioactivities

Epidemiological studies give evidence that high dietary intake of cruciferous vegetables has been associated with lower risk of cancer, this activity due to their content in glucosinolates (GL), which upon myrosinase hydrolysis release the corresponding isothiocyanates (ITCs). In this study, the isothiocyanates contents and the anticancer activity of ethyl acetate extracts from three kinds of Chinese Brassica vegetable seeds have been examined and analyzed. A correlation was found between the potency of anticancer activity and the amount of isothiocyanates in their extracts. Extracts followed by GC–MS analysis revealed that 3-BITC (3-butenyl isothiocyanate) was mainly found in Chinese kale contained 77.58 ± 7.28 mg/g (dry weight); AITC (allyl isothiocyanate), 3-BITC and iberverin were the predominant isothiocyanates in Oxheart cabbage contained 33.57 ± 3.94, 26.50 ± 1.92 and 22.77 ± 0.00 mg/g, respectively; 3-BITC and sulforaphane were found as the major isothiocyanates in broccoli contained 138.52 ± 3.42 and 49.77 ± 0.18 mg/g, respectively. The amount of total isothiocyanates in broccoli was twice higher than that in other two species. The anticancer activity of broccoli was the highest, and the IC₅₀ value of the extract inhibiting on the growth of A549, LAC, HELA and HepG₂ were 14.38 ± 0.35, 10.38 ± 0.34, 19.45 ± 1.72 and 26.75 ± 0.82 mg/g, respectively. The extracts of Chinese Brassica vegetable seeds have the potential in inducing cancer cells apoptosis by morphology observation. The results of this study got a new kind of Brassica vegetable seeds that could produce high content of isothiocyanates, which is important to preparation of anticancer food additives.