IngredientsHuang hua (黄花, literally "yellow flower") is a Chinese vernacular term applied to the flowers and dried flower buds of plants in the genus Hemerocallis, most prominently Hemerocallis citrina Baroni and Hemerocallis fulva (L.) L. (family Asphodelaceae, formerly placed in Liliaceae or Xanthorrhoeaceae). Hemerocallis citrina Baroni, commonly known as "Huang Hua Cai" in China, is a medicinal and edible vegetable with high nutritional value. It has been widely grown in China, Japan, and Korea, and its flower buds are one of the most commonly consumed vegetables in Asia.
The term "huang hua" is sometimes used loosely and can overlap with related Chinese names. The plant is also known in Chinese as Xuān Cǎo (萱草), Jīn Zhēn (金针, "golden needle"), Jīn Zhēn Huā (金针花), Jīn Zhēn Cài (金针菜), Wàng Yōu Cǎo (忘忧草, "forget-worry herb"), and Huang Hua Cai (黄花菜). The ancient TCM root drug is referred to as Xuān Cǎo Gēn (萱草根) or Hemerocallis Radix.
It is important to note that "huang hua" is a polysemous term in Chinese botanical and culinary usage. Huang Hua, which translates to "yellow flower" in Chinese, refers to several different plants in traditional herbal medicine, most commonly Chrysanthemum morifolium or Hemerocallis fulva (daylily). This article focuses principally on the Hemerocallis species, which constitute the primary botanical basis for the dietary supplement ingredient, the most studied member of the "huang hua" complex from a pharmacological standpoint, and the species most extensively documented in the Chinese medical literature under the overlapping names above.
Hemerocallis citrina Baroni is a species of perennial herb belonging to the family Asphodelaceae. Hemerocallis citrina Borani (huang hua cai in Chinese) is an important horticultural crop whose flower buds are widely consumed as a delicious vegetable in Asia. H. fulva, the orange daylily, is closely related and shares much of the same phytochemical and medicinal profile; Hemerocallis fulva L. is a traditional Chinese medicine, and the flowers of H. fulva are used in ethnic medicine to treat various diseases, including certain central nervous system diseases.
Hemerocallis fulva has been widely planted in eastern Asia including in China, South Korea, and Japan. It is a traditional Chinese plant that has been recorded in ancient books as being an edible and medicinal crop for thousands of years.
Huang hua is encountered in commerce and traditional practice in several distinct forms:
The use of Hemerocallis species in Chinese medicine dates back at least two millennia. The Shen Nong Ben Cao Jing (attributed to the period between the 1st century BC and 2nd century AD) lists medium-grade medicinals able to modify temperament, including Xuan Cao (Radix Hemerocallis Fulvae).
Hemerocallis citrina Baroni, also known as Huang Hua Cai, is an important economic crop native to China, the Korean Peninsula and Japan, with flower buds used as vegetables and functional foods, as documented in the Compendium of Materia Medica. The Ben Cao Gang Mu (Compendium of Materia Medica) is the most complete and comprehensive medical book ever written in the history of traditional Chinese medicine, compiled by Li Shi-zhen (1518–1593), a medical expert of the Ming Dynasty (1368–1644), over a period of 27 years.
The flower buds of H. citrina have been recorded to relieve depression in the medicinal book "Compendium of Materia Medica," a famous Chinese encyclopedia of medicine written in the Ming dynasty.
The famous Chinese medical encyclopedia "Compendium of Materia Medica" composed by Shizhen Li (1518–1593 AD) recorded that H. citrina had effects such as improving sleep, preventing depression, promoting lactation, and aiding digestion.
Within the framework of Traditional Chinese Medicine (TCM), huang hua occupies a specific functional niche. Hemerocallis fulva L. is a common Traditional Chinese Medicine; its flower buds are known to have the ability to clear away heat and dampness, detoxify, and relieve depression.
Its flower buds are known to have ability to clear away heat and dampness, detoxify, and relieve depression; ancient TCM literature shows that its roots have a beneficial effect in calming the spirit and even the temper in order to reduce the feeling of melancholy.
Daylily 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." This name reflects the longstanding association of huang hua with mood support and emotional well-being.
Daylily flower is traditionally used for soothing in Chinese dietary therapy. Beyond emotional uses, Hemerocallis fulva has been used as a conventional food in East Asia, with antivomiting, anti-inflammatory, diuretic, antidepressant, and sedation properties. Some studies have shown that it has the effect of promoting sleep, and is also commonly used as an anti-inflammatory, for the treatment of skin burns.
H. citrina is known to improve sleep, calm the mind, alleviate heat, and promote lactation, attributed to the high content of beneficial secondary metabolites.
Hemerocallis fulva L. belongs to the Liliaceae family, which is widely used in folk emotional health improvement drugs in East Asia (China, Japan) and North America. In Korea, the plant has similarly been used in traditional herbal practice. In Taiwan, dried daylily flowers have been incorporated into both culinary and medicinal traditions, and it is in Taiwan that some early human studies on sleep quality were conducted. Food/medicinal plants described in traditional Chinese dietary therapy include lily buds (Hemerocallis fulva L.), used in diet therapy drawn from close to 200 books published over the past 2,500 years.
The edible flower of Hemerocallis citrina Baroni (H. citrina) is a medicinal and edible vegetable with high nutritional value; the two major kinds of secondary metabolites identified in H. citrina flower are flavonoids and phenolic acids.
Research confirmed that the beneficial secondary metabolites in H. citrina are mainly flavonoids, terpenoids, and phenolic acids, exhibiting various functions, aside from abundant primary metabolites such as proteins, fats, sugars, vitamins, and even various essential amino acids.
Flavonoids are the dominant bioactive class. Key identified compounds include:
Among Hemerocallis fulva varieties, H. fulva (L.) L. var. kwanso Regel had the highest total flavonoid content.
The content of several phenolic acids and flavonoids in aqueous extract (AE) and ethanol extract (EE) of daylily flower was analyzed; results showed that seven phenolic acids and seven flavonoids could be detected in AE or EE, in the range of 29 to 205 and 41 to 273 mg/100 g, respectively. Notable phenolic acids include chlorogenic acid (5-O-caffeoylquinic acid), neochlorogenic acid, and ferulic acid. Antioxidative caffeoylquinic acids and flavonoids have been identified from Hemerocallis fulva flowers.
A total of 144 compounds, including 14 amides, 25 polyphenols, 44 flavonols, 35 anthraquinones, 15 naphthols, and 11 other components, were detected by HPLC-Q-TOF-MS in H. citrina. Anthraquinone derivatives have been noted for potential antiproliferative activity. Novel anthraquinones from daylilies have been investigated for inhibition of human tumor cell proliferation.
Additional compounds identified in the Hemerocallis genus include vanillic acid, kaempferol aglycone, gallic acid, catechin, and various amide compounds. Key network pharmacology targets identified in Hemerocallis radix include MAOA, MAOB, and ESR1, with vanillic acid, anthraquinone, and kaempferol as active components.
Fresh daylily flowers have historically been implicated in food poisoning attributed to colchicine, a potent antimitotic alkaloid. Fresh daylily flower may be toxic if not treated properly owing to the existence of colchicine; cases of food poisoning caused by daylily flower were reported due to the excessive intake of colchicine. However, recent genomic and metabolomic research has substantially revised this understanding. Metabolomics data revealed neither colchicine nor its precursors in H. citrina, challenging the long-standing belief that this alkaloid causes poisoning by the plant. Similarly, colchicine, which had been reported as a toxic compound in the fresh flower buds in previous studies and various news reports, was not found in a comprehensive HPLC-Q-TOF-MS scan of H. citrina. The identity of the actual toxic principle(s) responsible for historical food poisoning cases thus remains under active investigation.
The most extensively studied mechanistic pathway for huang hua relates to its effects on brain monoamine neurotransmitter systems. Ethanol extract of daylily flowers and rutin significantly reduce immobility time and increase swimming time in the forced swimming test; the extract and rutin also increase the serotonin, norepinephrine, and dopamine concentration of brain regions including frontal cortex, hippocampus, striatum, and amygdala.
Rutin and hesperidin, the major flavonoid ingredients of daylily flowers, were proven to exert antidepressant-like properties via the central serotonergic and noradrenergic systems.
The antidepressant-like effects of hydroalcoholic H. citrina extracts are mainly related to flavonoids, especially rutin and hesperidin; the extract prepared using 75% ethanol exhibited the highest active flavonoid content and activity.
Network pharmacology analyses have identified the monoamine oxidase enzymes as key targets. A network pharmacology study aimed to uncover the pharmacological mechanism of the antidepressant effect of Hemerocallis Radix (HR); during the analysis, 11 active components were obtained and screened using ADME method, and 267 HR targets and 740 depressive disorder targets were gathered from various databases.
Aqueous and ethanol extracts of daylily flowers inhibited nitric oxide and interleukin-6 production in lipopolysaccharide-activated macrophages. This inhibition of pro-inflammatory mediators points to suppression of the NF-κB and MAPK pathways, consistent with the polyphenolic content of the extract.
High glucose raised the activity of caspase-3 and caspase-8, suppressed Bcl-2 mRNA expression, and increased Bax mRNA expression, inducing HUVE cell apoptosis; pretreatments with aqueous or ethanol extract at 1% or 2% reduced caspase-3 activity and Bax mRNA expression, and enhanced cell viability.
The antioxidant activity of the plant is attributed primarily to its polyphenolic content. The most abundant compounds—chlorogenic acid and quercetin-3-O-rutinoside—are present in high concentrations; the studied extracts exhibited moderate to high skin-related activities, and these properties were correlated with a high concentration of polyphenols.
The sedative and sleep-promoting effects recorded in traditional use appear to involve anti-inflammatory pathways and possibly GABAergic modulation, though the precise receptor pharmacology has not yet been fully characterized. The reduction of inflammatory mediators (notably IL-6) may contribute to improved sleep architecture, as inflammatory cytokines are known to disrupt sleep.
Daylilies are used medicinally in eastern Asia and extracts of the plant had been shown to inhibit cell proliferation and induce cancer cells to undergo differentiation. Novel anthraquinones from daylilies have been investigated for inhibition of human tumor cell proliferation. These findings derive from in vitro work and do not establish clinical anticancer efficacy.
Traditional basis: Hemerocallis citrina Baroni, a traditional herbal medicine, has been widely used for treating depressive disorders in Eastern-Asia countries.
Animal studies: In one study, the anti-depressive activities of six H. citrina extracts were primarily evaluated; results showed that the water extract of H. citrina flowers (HCW) displays significant anti-depressive activity; a total of 32 metabolites were identified from HCW by HPLC-Q-TOF-MS and NMR; and the anti-depressive activity of the high-level compound rutin in HCW was also estimated. The anti-depressive activity of the high-level compound (rutin) in HCW was also estimated; results indicated that rutin displayed significant anti-depressive activity and was one of the main active ingredients.
The ethanol extract of H. citrina has been reported to elicit antidepressant-like effects depending on monoaminergic systems; some researchers have also suggested that such activity of the ethanol extract is at least partly mediated by neurotrophic and inflammation systems.
Human/clinical evidence: H. citrina has been clinically efficient in relieving depression in patients aged 11 to 80 years, according to one referenced clinical report. However, it should be noted that formal randomized controlled clinical trials meeting contemporary standards of evidence (registered, adequately powered, placebo-controlled) are limited, and the existing human evidence base for huang hua as an antidepressant remains modest.
Evidence strength: Preclinical evidence is substantial (multiple animal behavioral models, mechanistic studies). Limited human clinical data exist. Current evidence is insufficient to support a definitive clinical recommendation.
Human evidence: A published human study is among the strongest pieces of clinical evidence for huang hua. The flowers of daylily (Hemerocallis fulva Linn.) have been used as vegetable and medicinal herb for thousands of years in Taiwan and eastern Asia. Daylily flowers have been demonstrated to exert several biomedical properties; this study provided evidence that daylily flowers exert anti-inflammatory activity in vitro and improved sleep quality in vivo. Adult volunteers who received water extract of daylily flowers showed improved sleep quality, sleep efficiency, and daytime functioning, while sleep latency was reduced, compared to adult volunteers who received water.
Evidence strength: One published human trial (uncontrolled/pilot scale) showing positive results; supported by in vitro anti-inflammatory evidence; further well-controlled randomized trials are needed to confirm.
In vitro evidence: Aqueous and ethanol extracts of daylily flowers inhibited nitric oxide and interleukin-6 production in lipopolysaccharide-activated macrophages. Additional in vitro studies have demonstrated suppression of pro-inflammatory cytokine upregulation and inhibition of indoleamine 2,3-dioxygenase, an enzyme implicated in inflammation-driven depression.
Evidence strength: In vitro evidence only; no adequately powered human clinical trials on anti-inflammatory endpoints have been published.
In vitro and laboratory evidence: Hemerocallis fulva is a medical and edible plant; flavonoid extraction and antioxidant activity from its leaves has been optimized using ultrasound-assisted extraction and response surface methodology. Extracts exhibit free radical scavenging activity consistent with the polyphenol content. Hemerocallis cultivars contain significant amounts of phenolic compounds with good skin-related activities and could be interesting as novel sources of bioactive agents for the pharmaceutical, food and cosmetic industries.
Evidence strength: Robust in vitro antioxidant activity; no dedicated human clinical trials demonstrating systemic antioxidant benefit in vivo.
Research showed that a Hemerocallis citrina extract regulated the abnormal expression of the prolactin signaling pathway, including STAT3, cyclin D1 (CCND1), MAPK1, MAPK8, and JAK2; quercetin, kaempferol, and thymidine were the most important material basis; the mechanism of this promotional effect is mediated by the prolactin signaling pathway in mammary gland.
Evidence strength: Preclinical animal mechanistic evidence. The traditional use for promoting lactation has partial molecular support, but no human clinical trials have been conducted.
The content of several phenolic acids and flavonoids in aqueous and ethanol extracts of daylily flower was analyzed, and the effects of these extracts at 0.5%, 1%, or 2% in HUVE cells against high glucose-induced cell death, oxidative, and inflammatory damage were examined. Pretreatments from AE or EE at 1% or 2% reduced caspase-3 activity and Bax mRNA expression, and enhanced cell viability.
Evidence strength: In vitro cell culture evidence only; no clinical data in human subjects.
Daylilies are used medicinally in eastern Asia and extracts of the plant had been shown to inhibit cell proliferation and induce cancer cells to undergo differentiation. Novel anthraquinones from daylilies have been investigated for inhibition of human tumor cell proliferation.
Evidence strength: Entirely preclinical (in vitro). No human clinical oncology trials have been conducted with daylily extracts.
H. citrina flower has been found to possess beneficial effects including anti-inflammatory, antioxidant, anticancer, antidepressant, antimicrobial, anti-constipation, anti-aging, sleep-improving, and lactation-promoting effects. Based on the convergence of traditional use and laboratory evidence, huang hua is associated with the following body systems:
No standardized dose for huang hua has been established by any major pharmacopeial or regulatory body. The following dosages have been reported specifically in the identified research literature:
Traditional culinary consumption of dried flower buds in East Asia is not typically quantified in the medical literature as a supplement dose; the quantities consumed as a food ingredient (in soups, stir-fries, and other dishes) vary widely.
Fresh daylily flower may be toxic if not treated properly owing to the existence of colchicine; cases of food poisoning caused by daylily flower were reported due to the excessive intake of colchicine; it is therefore significant in food processing to decrease the content of colchicine in daylily flower in consideration of health benefits. Generally, daylily flower is heat-treated in hot water or in steam, and then dried for toxicity reduction and long-term storage; the harvested daylily flower in rural areas was also exposed to sunshine to reduce the potential food safety risk of colchicine.
UV and visible light photolysis can degrade colchicine. Both ultraviolet and visible light irradiation could effectively degrade colchicine into deacetamido-lumicolchicine; the process conformed to first-order kinetics, with a high degradation rate (K = 0.5862 h⁻¹) when colchicine was dissolved in ethanol and irradiated by UV light; cell viability and cell cycle studies proved that photolysis treatment of colchicine could weaken the cytotoxicity effectively.
Recent genomic data, however, challenge the premise that H. citrina is the source of the colchicine responsible for these poisonings. Metabolomics data revealed neither colchicine nor its precursors in H. citrina, challenging the long-standing belief that this alkaloid causes poisoning by the plant. The food safety guidance to cook fresh daylily flowers before consumption nonetheless remains prudent until this question is fully resolved.
A retrospective study examined risks posed to cats by the common daylily (Hemerocallis sp.) following ingestion; records describing ingestion between January 1998 and June 2002 were reviewed; twenty-two cases of confirmed exposure resulting in toxicosis were evaluated; cats that ingest daylilies are at risk for gastrointestinal distress and acute renal failure. Lilies of genera Lilium and Hemerocallis (daylilies) have been shown to cause nephrotoxicity in cats. This nephrotoxic risk applies to cats and does not have a confirmed parallel in human pharmacology; no human case reports of renal failure from dietary or medicinal daylily consumption were identified in the peer-reviewed literature reviewed here.
Toxicity and histopathological analyses were performed to determine whether or not the hydroalcoholic extracts of H. citrina are safe for oral administration in preclinical studies; no major toxic findings were reported at the tested doses in those animal studies, though full dose-escalation toxicity data in humans are not available.
Comprehensive clinical trials on Huang Hua's efficacy and safety in humans remain limited; most evidence to date is based on in vitro or animal studies, and more rigorous, large-scale research is needed to confirm its health benefits. The existing evidence base is predominantly preclinical, and extrapolation of animal or cell-culture data to human clinical applications should be made cautiously.
Rutin and other quercetin-based glycosides present in huang hua are known from the broader pharmacological literature to inhibit certain cytochrome P450 enzymes and modulate P-glycoprotein efflux transporters at high concentrations, which could theoretically affect the metabolism of co-administered drugs. No specific drug interaction studies with huang hua extracts have been published in the peer-reviewed literature reviewed here, and no clinically documented herb-drug interaction reports specific to daylily extracts were identified in the sources available.
Commercial dried daylily products have historically been treated with sulfur dioxide as a preservative. Sulfur-fumigated product is identifiable by a characteristic sour or pungent smell and may pose concerns for individuals with sulfite sensitivity. Low-sulfur processing methods have been developed and are preferentially used in research settings; the dried daylily flowers used in one research study were purchased from the main production site in Taiwan and processed by low-sulfur manufacturing methods.
Huang hua, primarily derived from the flower buds of Hemerocallis citrina and Hemerocallis fulva, has a well-documented history spanning at least two millennia in East Asian traditional medicine, where it has been valued for its mood-calming, sleep-promoting, and heat-clearing properties. The two major kinds of secondary metabolites identified in H. citrina flower are flavonoids and phenolic acids; the flower has been found to possess beneficial effects including anti-inflammatory, antioxidant, anticancer, antidepressant, antimicrobial, anti-constipation, anti-aging, sleep-improving, and lactation-promoting effects. The pharmacological basis for these effects has been partially elucidated in laboratory and animal models, with the flavonoids rutin and hesperidin emerging as primary active constituents for antidepressant-like and anti-inflammatory effects. One small human study supports the sleep-quality application. Modern pharmacology has proved that flower buds of H. citrina extract have significant antidepressant activity, and the polyphenols and flavonoids were regarded as the main active components. The antidepressant actions show more significant effects in H. citrina flower, providing new insights for future clinical medicine development. However, the overall clinical evidence in humans remains limited, and rigorous, large-scale randomized controlled trials across all proposed therapeutic areas are still lacking.
Health conditions that Huang hua may help support.
Body systems that Huang hua may help support.
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