Novel multifunctional natural selenium supplement development, in vitro and in vivo analysis, and risk-benefit assessment: Selenium-enriched chicory as a case study

Abstract

Selenium (Se) is essential for the modification of human life functions and has a double-edged sword effect. However, the development of Se supplements for both medicinal and dietary is rare. Critical in vivo and in vitro correlation studies still unexplored. In this study, we developed Se-enriched chicory for the first time using chicory as a model plant. The distribution of Se and its species transformation were elucidated. In vivo and in vitro absorption correlation, safety and risk-benefit management were also focused. Results in this study showed that foliar Se application is more beneficial for cultivating Se-enriched chicory compared to root application. What is striking is SeIV converted to SeVI, SeMet, SeCys2 and SeMeCys in chicory, which is more favorable for human absorption and reduces toxicity. In gastric phase in vitro, Se from Se-enriched chicory exhibited high bioaccessibility (79.4%). The relative bioavailability of liver and kidneys as effect endpoints in vivo at high exposure to Se with 76.5%. In addition, this study first analyzed and established robust in vivo-in vitro correlations of Se in Se-enriched chicory. The prediction model for liver-gastric fluid had the best correlation (R2 = 0.853, p < 0.05). Meanwhile, graded assessment strategy revealed that the risk-benefit of Se-enriched chicory for dietary and TCM needs to be balanced separately. All evidence suggests that Se-enriched chicory could be a new candidate plant for Se supplements in the event of Se deficiency. This research will provide cases and insights into future studies and reduce the uncertainty of Se intake risk and benefit assessment from Se-enriched products.