Multi-model approach combining cell detection, C. elegans assay, non-targeted metabolomics and molecular docking to reveal the sleep-promoting effect and functional components of Hemerocallis leaf beverage.

Sleep disorders are a global health issue, and current treatments often carry side effects and addiction risks. In some regions of China where Hemerocallis are grown, Hemerocallis leaf (HL) were used for sleep-promoting, but they are now often discarded as waste in the Hemerocallis flower industry. This study integrated chemical analysis, in vitro assays, C. elegans behavioral assays, non-targeted metabolomics, and molecular docking to investigate sleep-promoting potential of Hemerocallis leaf beverage (HLB) of two different methods for preparing. Research has found that Hemerocallis Leaf Fermented Beverage (HLFB) exhibited superior total flavonoid content, antioxidant capacity, and anti-neuroinflammatory effects, and significantly prolonged the sleep-like behavior of C. elegans. Non-targeted metabolomics identified flavonoid derivatives (Quercetin 7-Xyloside, Quercetin-3'-Glucuronide, and Cyanidin 3-O-(2-Xylosyl-6'-Glucosyl-Galactoside)) as key components in promoting sleep. Molecular docking predicted that these three representative compounds can bind well to the BZD site (α+/γ - interface) of GABA_A receptors and interacted with key residues His102 and Phe77, similar to the mechanism of the sleep aid drug diazepam. This multi-dimensional strategy provides strong support for the sleep-promoting effect of Hemerocallis leaf and can provide a evidence for the high-value utilization of HL.