Antioxidative And Antiobesity Potential Of Biofortified Broccoli (Brassica oleracea var. italica) Seedlings Enriched With Phenolics And Vitamin C

Due to the high demand for healthy food, various biofortification strategies are developed to improve the quality of food. A promising biofortification technique used to improve the content of healthy phytochemicals in plant food is the interspecific metabolite transfer. It relies on the transfer of specialized metabolites from donor plant extract to acceptor plant. In our study, broccoli (Brassica oleracea var. italica) seedlings were used as an acceptor plant, and as a donor of specialized metabolites, water extract of tea (Camellia sinensis) was used. To test the possibility of enhancing the transfer from donor plant extract through the acceptor plant cell membrane, known membrane permeabilizers, EDTA and Tween, were used in a combination with donor plant extract. Changes in the content of phenolic compounds in broccoli seedlings after the interspecific metabolite transfer were evaluated using spectrophotometric assays and high- performance liquid chromatography (HPLC). A 19% increase in total phenolic content compared to the control was observed in seedlings treated with tea extract in combination with EDTA. In seedlings treated with tea extract in combination with EDTA and Tween a 28% and 27% increase in catechin content was observed, respectively. Furthermore, using HPLC, an increase in vitamin C, flavonoid quercetin and alkaloid caffeine content was observed. Treated seedlings’ extracts also displayed an increase in antioxidant capacity (AC). AC measured by DPPH revealed an increase in seedlings treated with tea and EDTA, AC measured by ABTS revealed an increase in seedlings treated with tea in combination with EDTA or Tween, and AC measured by FRAP revealed an increase in all treated samples, compared to control. It was also revealed that seedlings treated with tea and tea in combination with EDTA possess a higher pancreatic lipase inhibitory activity, suggesting their anti-obesity potential. Results point to interspecific metabolite transfer being a promising and eco-friendly biofortification strategy to improve the phytochemical content and bioactivity of broccoli seedlings.