Effects of phenolic constituents of daylily flowers on corticosterone- and glutamate-treated PC12 cells

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.

Ethyl Acetate Fraction of Hemerocallis citrina Baroni Decreases Tert‐butyl Hydroperoxide‐Induced Oxidative Stress Damage in BRL‐3A Cells

“…There was a positive correlation between antioxidant activity and total phenolic and flavonoid content [ 15 , 16 ]. Our results indicated that HCEA had higher flavonoid and total phenolic levels than the other extract fractions did.…”

“…Hemerocallis citrine Baroni (daylily) is a perennial herb of the Liliaceae family [ 14 ], which is indigenous to Asia, and its flowers are used for ornamental purposes and as food and medicine. According to previous studies, Hemerocallis fulva has been used to treat various diseases including depression [ 15 ], inflammation [ 16 ], insomnia [ 17 ], hepatosis [ 18 ], and cancer [ 19 ]. However, no studies have shown the hepatoprotective activity of H. citrine Baroni or any potential mechanism.…”

Aqueous and Ethanol Extracts of Daylily Flower (Hemerocallis fulva L.) Protect HUVE Cells Against High Glucose

“…Flower of daylily ( Hemerocallis fulva L., Figure ) is a vegetable commonly consumed in Asia countries including China and Taiwan. It is reported that daylily flower ethanol extract (EE) displayed free radical scavenging effects in HepG2 cells (Lin, Lu, Huang, & Chen, ); and alleviated neurotoxicity in PC12 cells treated with corticosterone or glutamate (Tian et al., ). The animal studies of Lin et al.…”

Impact of the Dietary Supplement CLOCK® on BDNF and Other Biochemical Measures Related to Cognitive Function and Health in Men and Women

“…Another name is Wang-You Cao, which in Chinese means "forget-one's sadness" plant [8]. Daylily has been used to treat a wide variety of conditions such as depression, jaundice and insomnia.…”

“…Daylily has been used to treat a wide variety of conditions such as depression, jaundice and insomnia. More recently, Daylily has been shown to have neuroprotective properties, which were demonstrated by significantly reversing corticosterone and glutamate-induced neurotoxicity in a dose-dependent manner [8]. Daylily buds have also been shown to have a powerful effect as a Nitric Oxide (NO) scavenger and suppressor in cases where NO is elevated to supraphysiological levels, which was suggested to be useful in reducing inflammation in humans [9].…”