Bioaccessibility of glucosinolates, isothiocyanates and inorganic micronutrients in cruciferous vegetables through INFOGEST static in vitro digestion model.

Green tissues and seeds from cruciferous vegetables growing in conventional and ecological conditions (Brassica carinata; Brassica rapa; Eruca vesicaria and Sinapis alba) were analyzed to determine their contents of glucosinolates, isotihiocyanates (ITCs) and inorganic micronutrients (Ca, Cr, Cu, Fe, Mn, Ni, Se and Zn), and the bioaccessibility of these compounds. Regarding total contents and bioaccessibility values of these compounds, no clear difference was found between the organic and conventional systems. Glucosinolates bioaccessibility present in green tissues were high, with values around 60-78%. In additon, it was quantified in bioaccessible fraction ITCs concentrations such as Allyl - ITC; 3 - Buten - 1 - yl - ITC and 4 - Penten - 1 - yl - ITC. Trace elements bioaccessibility in green tissues was also high for Ca (2.26-7.66 mg/g), Cu (0.60-2.78 µg/g), Se (9.93-74.71 µg/Kg) and Zn (12.98-20.15 µg/g). By contrast, the bioaccessibility of glucosinolates and trace elements in cruciferous seeds was extremely low. With the exception of Cu, these bioaccessibility percentages did not exceed 1% in most cases.

Quantification and in vitro bioaccessibility of glucosinolates and trace elements in Brassicaceae leafy vegetables.

Leaf samples from five Brassicaceae species (Brassica carinata, Brassica oleracea, Brassica rapa, Eruca vesicaria and Sinapis alba) were analyzed to determine their contents of glucosinolates and trace elements, and the bioaccessibility of these compounds. Considerable variability in the total contents and glucosinolate profiles was observed in the Brassicaceae species, with the total amounts ranging from 8.5 µmol/g dw in Brassica oleracea to 32.9 µmol/g dw in Sinapis alba. Bioaccessibilities of the predominant glucosinolates were moderate, ranging from 13.1% for glucoraphanin to 43.2% for gluconapin, which is particularly relevant as they have been implicated in a variety of anti-carcinogenic mechanisms. Trace element concentrations were: Se (28-160 µg/Kg dw); Cr (0.31-4.03 µg/g dw); Ni (0.19-1.53 µg/g dw); Fe (8.6-18.8 µg/g dw); Zn (20.8-41.5 µg/g dw); Ca (6.2-15.2 mg/g dw). Brassicaceae leaves were also moderate dietary sources of Se, Ni, Zn and Ca.

In vivo biological activity of rocket extracts (Eruca vesicaria subsp. sativa (Miller) Thell) and sulforaphane.

Eruca is thought to be an excellent source of antioxidants like phenolic compounds, carotenoids, glucosinolates and their degradation products, such as isothiocyanates. Sulforaphane is one of the most potent indirect antioxidants of Eruca isolated until the date. In this work we investigate: (i) the safety and DNA protective activity of Eruca extracts and sulforaphane (under and without oxidative stress) in Drosophila melanogaster; and (ii) the influence on D. melanogaster life span treated with Eruca extracts and sulforaphane. Our results showed that among the four concentrations of Eruca extracts tested (from 0.625 to 5mg/ml), intermediate concentrations of the Es2 accession (1.25 and 2.5mg/ml) exhibited no genotoxic activity, as well as antigenotoxic activity (inhibition rate of 0.2-0.6) and the lowest concentration of Es2 and Es4 accessions (0.625 mg/ml) also enhanced the health span portion of the live span curves. Sulforaphane presented a high antigenotoxic activity in the SMART test of D. melanogaster and intermediate concentrations of this compound (3.75 µM) enhanced average healthspan. The results of this study indicate the presence of potent antigenotoxic factors in rocket, which are being explored further for their mechanism of action.