Searching for Innovative Functional Foods: Correlation Between Chemopreventive Potential and Bioactive Compounds Accumulation in Brassica Sprouts Grown Under Altered Gravity Conditions

The main aim of this study was to evaluate the effect of space-like environment on the chemopreventive activity of Brassica sprouts against thyroid cancer cells in vitro. For this purpose the sprouts of broccoli, kale, kohlrabi, and Brussels sprouts were cultivated in darkness and in microgravity for 5-7 days. Then, the sprouts' extracts were examined for cytotoxic and antiproliferative activity against thyroid cancer and normal cells. The tested microgravity environment stimulated the cytotoxic activity of kohlrabi sprouts, causing approximately 50% reduction in thyroid cancer cells' viability, while at the same time increasing the viability of normal thyroid cells. Broccoli sprouts showed the strongest antiproliferative activity against normal thyroid cells, with the best effect visible for darkness conditions, which may contribute to the reduction of thyroid hyperplasia. Microgravity and darkness significantly enhanced the antiproliferative activity of kale, especially in 7-day-old sprouts (inhibition approximately 90%). The tested conditions also increased the antiproliferative activity of kohlrabi sprouts, but in the case of Brussels sprouts the effect was unfavorable. The study showed that microgravity and darkness conditions may have significant influence on the chemopreventive role of Brassica sprouts against thyroid cancer cells in vitro, especially in the case of broccoli and kohlrabi sprouts.