Abstract

This study focused on radish leaves, which are by-products, with potential health-promoting capacities due to their bioactive compounds in an attempt to replace chemical additives to achieve healthier food products. Because extraction conditions could greatly influence the content and bioactivities of these compounds, response surface methodology was applied to determine optimal extraction conditions taking into consideration the following factors: percentage of organic solvent (ethanol: 0–100%), ultrasound time (0–40 min) and temperature (20–60 °C). Optimal extraction conditions were 63% ethanol, 45 °C and 25 min of ultrasound time. In addition, antioxidant capacity, potent antimicrobial activity as well as the immune response profile by analyzing cytokine induction in dendritic cells were assessed. Radish extract boosted a tolerance response by promoting the strongly transcription of the anti-inflammatory cytokine TGF-β and a trend upregulation of IL-10. In summary, this investigation not only add valued to these radish leaves by the potential use of their extracts as natural ingredients but also satisfy consumer expectations for nutritious products under the “clean label” concept by the prospective design of new functional foods. Graphical abstract: (Figure presented.)