Abstract
BackgroundDaylily flowers, the flower and bud parts of Hemerocallis citrina or H. fulva, are well known as Wang-You-Cao in Chinese, meaning forget-one’s sadness plant. However, the major types of active constituents responsible for the neurological effects remain unclear. This study was to examine the protective effects of hydroalcoholic extract and fractions and to identify the active fractions.MethodsThe extract of daylily flowers was separated with AB-8 resin into different fractions containing non-phenolic compounds, phenolic acid derivatives and flavonoids as determined using UPLC-DAD chromatograms. The neuroprotective activity was measured by evaluating the cell viability and lactate dehydrogenase release using PC12 cell damage models induced by corticosterone and glutamate. The neurological mechanisms were explored by determining their effect on the levels of dopamine (DA), 5-hydroxy tryptamine (5-HT), γ-aminobutyric acid (GABA), noradrenaline (NE) and acetylcholine (ACh) in the cell culture medium measured using an LC-MS/MS method.ResultsPretreatment of PC12 cells with the extract and phenolic fractions of daylily flowers at concentrations ranging from 0.63 to 5 mg raw material/mL significantly reversed corticosterone- and glutamate-induced neurotoxicity in a dose-dependent manner. The fractions containing phenolic acid derivatives (0.59% w/w in the flowers) and/or flavonoids (0.60% w/w) exerted similar dose-dependent neuroprotective effect whereas the fractions with non-phenolic compounds exhibited no activity. The presence of phenolic acid derivatives in the corticosterone- and glutamate-treated PC12 cells elevated the DA level in the cell culture medium whereas flavonoids resulted in increased ACH and 5-HT levels.ConclusionPhenolic acid derivatives and flavonoids were likely the active constituents of daylily flowers and they conferred a similar extent of neuroprotection, but affected the release of neurotransmitters in a different manner.
Highlights
Flowers, the flower and bud parts of Hemerocallis citrina or H. fulva, are well known as Wang-YouCao in Chinese, meaning forget-one’s sadness plant
The crude EtOH extracts of H. citrina was further separated using AB-8 macroporous adsorption resin column chromatography and eluted with water, 10%, 30%, 50% and 95% EtOH sequentially to give water, 10%, 30%, 50% and 95% EtOH fractions, respectively
Each fraction was analyzed by Ultra Performance Liquid Chromatography (UPLC)-UV method and the typical chromatograms are shown in Fig. 1b, which shows that the phenolic compounds were present in the 10%, 30% and 50% EtOH fractions and the water and 95% EtOH fractions contained negligible amount of phenolics
Summary
The flower and bud parts of Hemerocallis citrina or H. fulva, are well known as Wang-YouCao in Chinese, meaning forget-one’s sadness plant. Apart from being food materials, the herb has been used as an anodyne, febrifuge, sleeppromoting and sedative agent, and for stimulating the secretion of milk for women in childbirth in China [1] It is well known as Wang-You-Cao in Chinese, meaning forget-one’s sadness plant, and has been recorded to exhibit antidepressant effects in ancient medical books of China, including the famous textbook “Compendium of Materia Medica”. Many previous studies have demonstrated that the hydroalcoholic extracts of daylily flowers conferred antidepressant-like effects in acute stress-induced, chronic unpredictable mild stressinduced and corticosterone-induced depression-like models of rodents and improving learning and memory in animal models [5,6,7,8,9,10]. The underlying mechanisms for the central nervous system (CNS) modulating effects were not entirely clear and were considered to at least partly involve in the anti-inflammatory property and the ability to mediate the brain levels of monoamine neurotransmitters such as serotonin (5-HT), noradrenaline (NE) and dopamine (DA) [7, 9, 10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
