Anti-inflammatory potential of digested Brassica sprout extracts in human macrophage-like HL-60 cells

Cruciferous vegetables have been reported to be a great source of anti-inflammatory compounds. Specifically, sprouts from the Brassicaceae family stand out for their high content of glucosinolates (and their bioactive derivatives, isothiocyanates), phenolic acids, and anthocyanins. Despite the evident anti-inflammatory activity of certain Brassica phytochemicals such as sulforaphane or phenolic acids, the effect of digested Brassica vegetables on inflammation remains understudied. In this work, we aimed to evaluate the anti-inflammatory potential of the bioaccessible forms of cruciferous bioactives (from red cabbage sprouts (RCS) and red radish sprouts (RRS)) obtained upon in vitro gastrointestinal digestion in the HL-60 macrophage-like differentiated human cell line. The study was performed under basal conditions or stimulated with a low dose of LPS for 24 hours as a validated in vitro model of chronic inflammation. The cell viability was determined by MTT assay. The gene expression and production of pro-inflammatory cytokines TNF-α, IL-6 and IL-1β were determined by RT-qPCR and ELISA respectively. Our results revealed no cytotoxicity with any of the treatments in LPS-stimulated macrophage-like HL60 cells. Regarding cytokine production, digestates significantly decreased the production of the three pro-inflammatory cytokines at concentrations of 50 and 100 μg mL^-1 except for IL-1β treated with RCS digestates. Furthermore, the RT-qPCR analysis showed a decrease in the relative expression of pro-inflammatory cytokines in LPS-stimulated cells treated with RRS digestates at 100 μg mL^-1 but not with red cabbage digestates. In conclusion, RRS bioaccessible compounds in the extracts could be used as dietary coadjuvants given their potential anti-inflammatory effect on this in vitro model of chronic inflammation.