Hydroxy-Safflower Yellow A Mitigates Vascular Remodeling in Rat Pulmonary Arterial Hypertension

Purpose

The underlying causes of pulmonary arterial hypertension (PAH) often remain obscure. Addressing PAH with effective treatments presents a formidable challenge. Studies have shown that Hydroxysafflor yellow A (HSYA) has a potential role in PAH, While the mechanism underlies its protective role is still unclear. The study was conducted to investigate the potential mechanisms of the protective effects of HSYA.

Methods

Using databases such as PharmMapper and GeneCards, we identified active components of HSYA and associated PAH targets, pinpointed intersecting genes, and constructed a protein-protein interaction (PPI) network. Core targets were singled out using Cytoscape for the development of a model illustrating drug-component-target-disease interactions. Intersection targets underwent analysis for Gene Ontology (GO) functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Selected components were then modeled for target interaction using Autodock and Pymol. In vivo validation in a monocrotaline-induced PAH (MCT-PAH) animal model was utilized to substantiate the predictions made by network pharmacology.

Results

We associated HSYA with 113 targets, and PAH with 1737 targets, identifying 34 mutual targets for treatment by HSYA. HSYA predominantly affects 9 core targets. Molecular docking unveiled hydrogen bond interactions between HSYA and several PAH-related proteins such as ANXA5, EGFR, SRC, PPARG, PGR, and ESR1.

Conclusion

Utilizing network pharmacology and molecular docking approaches, we investigated potential targets and relevant human disease pathways implicating HSYA in PAH therapy, such as the chemical carcinogenesis receptor activation pathway and the cancer pathway. Our findings were corroborated by the efficacious use of HSYA in an MCT-induced rat PAH model, confirming its therapeutic potential.

Carthamus tinctorius Suppresses LPS-Induced Anti-Inflammatory Responses by Inhibiting the MAPKs/NF-κB Signaling Pathway in HaCaT Cells

This study aimed to elucidate the anti-inflammatory activity of C. tinctorius leaves by measuring inflammatory parameters such as nitric oxide (NO) production and mRNA expression of iNOS, interleukin-6 (IL-6), and IL-1β in lipopolysaccharide (LPS)-induced HaCaT cells. Further, the effect of C. tinctorius ethanol extract on the MAPKs/NF-κB signaling pathway was examined in HaCaT cells. The phytochemical profile of the ethanol extract of C. tinctorius leaves was determined using UPLC-QTOF-MS/MS. The results indicated that the ethanol extract of C. tinctorius effectively attenuated LPS-induced secretion of NO, IL-6, and IL-1β in HaCaT cells. Further, LPS-stimulated mRNA and protein expressions of iNOS were decreased by pre-treatment with C. tinctorius ethanol extract at the transcriptional level in HaCaT cells. Moreover, the ethanol extract of C. tinctorius suppressed NF-κB signaling in LPS-induced HaCaT cells. This suppression was mediated by MAPKs/NF-κB signaling, inhibiting the phosphorylation of p38 and p65 in HaCaT cells. However, there is no significant effect on the phosphorylation of JNK by the ethanol extract. The QTOF-MS/MS analysis revealed the identification of 27 components in the ethanol extract of C. tinctorius leaves. The data demonstrate that the ethanol extract of C. tinctorius leaves protects the LPS-induced HaCaT cells by inhibiting the expression of iNOS, IL-6, and IL-1β and suppressing the phosphorylation of the p38, p65, p-JNK via inactivation of MAPKs/NF-κB signaling pathway. These results demonstrate that C. tinctorius leaves may serve as a potential candidate to prevent inflammation-related diseases.

Potential effects of hydroxysafflor yellow A on reducing pulmonary inflammation and fibrosis due to SARS-COV2

Cytokine storm is a condition that is characterized by a massive production of proinflammatory cytokines. Failure in balancing the up-regulation and down-regulation causes excessive production of proinflammatory cytokines in the fight against SARS-CoV2 virus infection, leading to lung damage and acute respiratory distress syndrome; in addition, high levels of IL-6 can activate the clotting pathways and vascular endothelial cells, which can inhibit blood circulation and heart muscle function and cause pulmonary, kidney, and liver fibrosis. Hydroxysafflor Yellow A (HSYA) is a compound that has been shown to reduce tissue lung damage through Toll-Like Receptor (TLR) 4, inhibits phosphorylation of the NF-κB pathway, and plays a role in balancing the up-regulation and down-regulation of inflammatory cytokines. This review of literature discusses the ability of HSYA to reduce inflammation that causes pulmonary cell and tissue damage. HSYA can inhibit the activation of the NF-κB signaling pathway and suppress the binding of the TGF-β1 promoter. This molecular mechanism can reduce lung damage by attenuating the inflammatory response by inhibiting the TLR 4-dependent pathways that can improve the condition of mice affected by pulmonary fibrosis, including inflammation that leads to vascular tissue repair. The molecular mechanism of HSYA can inhibit inflammatory mechanisms in lung injury, vascular tissue damage, and liver and kidney fibrosis. Therefore, this literature review can be used as a reference for in vivo research and clinical trials for further research on the ability to heal patients with cytokine storm that causes cardiovascular tissue damage and lung injury in patients infected with SARS-CoV-19.

Hydroxysafflor yellow A improved retinopathy via Nrf2/HO-1 pathway in rats

The aim of the study was to investigate the inhibitory effect of hydroxysaff yellow A (HSYA) on diabetic retinopathy (DR). For this, a total of 27 rats were randomly divided into normal control, model, and HSYA groups. The body weight, blood glucose, and blood–retinal barrier damage of the rats were observed and compared. The pathological change of retinal tissue were measured using H&E staining. The apoptosis of retinal tissue ganglion cells was detected by TUNEL. The interleukin (IL)-1β and tumor necrosis fator (TNF)-α levels were detected using enzyme-linked immunosorbent assay. The level of malondialdehyde (MDA) was detected using thiobarbituric acid method. Superoxide dismutase levels were detected using xanthine oxidase method; Nrf2 and total HO-1 protein expressions were detected using western blot assay; Bcl-2 and P53 protein expression was measured using immunohistochemical staining. The body weight and retinal damage of the HYSA group were significantly improved (p < 0.01, respectively). The apoptosis index of the HYSA group was lower than the model group (p < 0.001). The IL-1β, TNF-α, and MDA levels of the HYSA group were significantly improved in comparison with those of the model group (p < 0.01, respectively). The Nrf-2, HO-1, Bcl-2, and P53 protein expression of HYSA group was significantly improved (p < 0.001, respectively). In conclusion, HYSA can effectively alleviate the apoptosis of retinal ganglion cells in type 2 diabetic rats and improve the progression of DR.

Herbal Active Ingredients: Potential for the Prevention and Treatment of Acute Lung Injury

Acute lung injury (ALI) is a life-threatening clinical syndrome with high morbidity and mortality. The main pathological features of ALI are increased alveolar-capillary membrane permeability, edema, uncontrolled migration of neutrophils to the lungs, and diffuse alveolar damage, resulting in acute hypoxemic respiratory failure. Glucocorticoids, aspirin, and other anti-inflammatory drugs are commonly used to treat ALI. Respiratory supports, such as a ventilator, are used to alleviate hypoxemia. Many treatment methods are available, but they cannot significantly ameliorate the quality of life of patients with ALI and reduce mortality rates. Herbal active ingredients, such as flavonoids, terpenoids, saponins, alkaloids, and quinonoids, exhibit advantages for ALI prevention and treatment, but the underlying mechanism needs further study. This paper summarizes the role of herbal active ingredients in anti-ALI therapy and progresses in the understanding of their mechanisms. The work also provides some references and insights for the discovery and development of novel drugs for ALI prevention and treatment.

Hydroxysafflor Yellow A Inhibits Staphylococcus aureus-Induced Mouse Endometrial Inflammation via TLR2-Mediated NF-kB and MAPK Pathway

The present study is designed to investigate the effect of hydroxysafflor yellow A (HYA) on Staphylococcus aureus (S. aureus)-induced mouse endometrial inflammation and to explore its molecular mechanism. We established a mouse endometritis model by intrauterine injection of S. aureus and intrauterine injection of HYA for treatment. Immunohistochemistry, immunofluorescence, and Western blot were used to detect protein expression in uterine tissue, and qPCR was used to measure mRNA expression. HYA could significantly weak uterine pathological changes caused by S. aureus and reduce MPO activity, CD45, CD3, and ED-1 protein expression in uterine tissues of S. aureus-infected mice. Similarly, HYA also significantly decreased S. aureus induced the increase in TNF-α, IL-1β, and IL-6 in uterine tissue. In vivo, we found that knockdown of TLR2 was very important could significantly reduce S. aureus induced the elevated expression of TNF-α, IL-1β, and IL-6 in mEECs. Importantly, in terine tissues of S. aureus-infected mice, HYA significantly decreased the ratio of p-p65/p65, p-IKBα/IKBα, p-p38/p38, p-Erk/Erk, and p-JNK/JNK expression. HYA displays anti-inflammatory effects on S. aureus mouse endometrial inflammation, and this effect might be related to HYA which could block TLR2-mediated NF-kB and MAPK pathway.

Natural product derived phytochemicals in managing acute lung injury by multiple mechanisms

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS) as common life-threatening lung diseases with high mortality rates are mostly associated with acute and severe inflammation in lungs. With increasing in-depth studies of ALI/ARDS, significant breakthroughs have been made, however, there are still no effective pharmacological therapies for treatment of ALI/ARDS. Especially, the novel coronavirus pneumonia (COVID-19) is ravaging the globe, and causes severe respiratory distress syndrome. Therefore, developing new drugs for therapy of ALI/ARDS is in great demand, which might also be helpful for treatment of COVID-19. Natural compounds have always inspired drug development, and numerous natural products have shown potential therapeutic effects on ALI/ARDS. Therefore, this review focuses on the potential therapeutic effects of natural compounds on ALI and the underlying mechanisms. Overall, the review discusses 159 compounds and summarizes more than 400 references to present the protective effects of natural compounds against ALI and the underlying mechanism.

Hydroxysafflor Yellow A: A Systematical Review on Botanical Resources, Physicochemical Properties, Drug Delivery System, Pharmacokinetics, and Pharmacological Effects

Hydroxysafflower yellow A (HSYA), as a principal natural ingredient extracted from safflower (Carthamus tinctorius L.), has significant pharmacological activities, such as antioxidant, anti-inflammatory, anticoagulant, and anticancer effects. However, chemical instability and low bioavailability have been severely hampering the clinical applications of HSYA during the treatment of cardiovascular and cerebrovascular disease. Therefore, this present review systematically summarized the materials about HSYA, including acquisition methods, extraction and detection methods, pharmacokinetics, pharmacological effects and molecular mechanism, especially focus on the possible causes and resolutions about the chemical instability and low bioavailability of HSYA, in order to provide relatively comprehensive basic data for the related research of HSYA.

Hydroxysafflor Yellow A Together with Blood-Brain Barrier Regulator Lexiscan for Cerebral Ischemia Reperfusion Injury Treatment

Pharmacodynamic and biodistribution effects are two important factors in drug research. As a clinical drug, the neuroprotective effects and mechanisms of hydroxysafflor yellow A (HSYA) have been widely reported but have still not been described in enough detail. In this study, we first aimed to improve the pharmacology of HSYA in nerve injury treatments. The down-regulative expression of cytokines, including NLRP3, ASC, Caspase-1, GSDMD, IL-1β, IL-18, LDH, NF-κB, and p-p56, suggested that HSYA could both suppress pyroptosis and apoptosis pathway activation during the nerve injury. Additionally, HSYA improved the cellular viability in an oxidative stress damage cell model. Second, to further improve the therapeutic effect of the HSYA, we tried to enhance the concentration of HSYA in a lesion. The FDA-approved adenosine receptor agonist Lexiscan (Lex) could inhibit the expression of P-glycoprotein on the endothelial cell surface to transiently increase the permeability of the blood-brain barrier (BBB) without any sustained damage, which was used to assist HSYA in passing through the BBB to increase the accumulation in the brain. Furthermore, living image and distribution detection in vivo showed that the accumulation of HSYA in the brain could be significantly increased with the addition of Lex. Lastly, HSYA together with Lex (Lex-HSYA) could significantly reduce the volume of cerebral infarction, improve the histopathological morphology, and recruit brain-derived neurotrophic factors to alleviate the cerebral ischemia reperfusion injury. In conclusion, the pyroptosis pathway could act as a novel therapeutic target of HSYA in nerve injury treatment, and Lex-HSYA could be a promising candidate for nerve injury treatments.

A Metabolic Perspective and Opportunities in Pharmacologically Important Safflower

Safflower (Carthamus tinctorius L.) has long been grown as a crop due to its commercial utility as oil, animal feed, and pharmacologically significant secondary metabolites. The integration of omics approaches, including genomics, transcriptomics, metabolomics, and proteomics datasets, has provided more comprehensive knowledge of the chemical composition of crop plants for multiple applications. Knowledge of a metabolome of plant is crucial to optimize the evolution of crop traits, improve crop yields and quality, and ensure nutritional and health factors that provide the opportunity to produce functional food or feedstuffs. Safflower contains numerous chemical components that possess many pharmacological activities including central nervous, cardiac, vascular, anticoagulant, reproductive, gastrointestinal, antioxidant, hypolipidemic, and metabolic activities, providing many other human health benefits. In addition to classical metabolite studies, this review focuses on several metabolite-based working techniques and updates to provide a summary of the current medical applications of safflower.

Effects of Hydroxysafflor Yellow A on the PI3K/AKT Pathway and Apoptosis of Pancreatic β-Cells in Type 2 Diabetes Mellitus Rats

BACKGROUND AND AIM

Type 2 diabetes mellitus (T2DM), a complex metabolic disease, has become a major public health issue around the world. Hydroxysafflor yellow A (HSYA) is the major active chemical ingredient of Carthamus tinctorius L. (safflower), which is widely used in patients with cardiovascular and cerebrovascular diseases in China. The aim of this study was to investigate the anti-diabetic effect and potential mechanism of HSYA on the high-fat diet (HFD) and streptozotocin (STZ-)-induced T2DM rats.

MATERIALS AND METHODS

T2DM rats were induced by feeding HFD (60% fat) for four weeks followed by intraperitoneal injection of a low dose of streptozocin (35mg/kg). The T2DM rats were treated with HSYA (120mg/kg) or metformin (90mg/kg) for eight weeks. Biochemical analysis, histological analysis and Western blot analysis were conducted after 8 weeks of intervention.

RESULTS

The treatment with HSYA evidently reduced fasting-blood glucose and insulin resistance in T2DM rats, indicated by results from fasting-blood glucose, oral glucose tolerance test, fasting insulin levels and histology of pancreas islets. The Western blot results revealed that HSYA reversed the down-regulation of PI3K and AKT in liver. The TUNEL assay analysis of pancreatic tissue showed that HSYA could inhibit the apoptosis of pancreatic β-cells to a certain extent. Moreover, HSYA-treatment increased the levels of glycogen synthase and hepatic glycogen and improved lipid metabolism by reducing the triglyceride, total and low-density lipoprotein cholesterol levels, even though it did not change the rats' body weights.

CONCLUSION

The results of this study suggested that HSYA could promote PI3K/Akt activation and inhibit the apoptosis of pancreatic β-cells directly or indirectly, which might be the underlying mechanisms in HSYA to improve insulin resistance and regulate glycolipid metabolism in T2DM rats.

Protective Effect of Hydroxysafflor Yellow A on Nephropathy by Attenuating Oxidative Stress and Inhibiting Apoptosis in Induced Type 2 Diabetes in Rat

Diabetic nephropathy (DN) is a serious complication of diabetes mellitus, and its prevalence has been increasing all over the world, which is also the leading cause of end-stage renal failure. Hydroxysafflor yellow A (HSYA) is the main active chemical component of Carthamus tinctorius L., and it is commonly used in patients with cardiovascular and cerebrovascular diseases in China. The aim of this study was to investigate the renal protective effects and molecular mechanisms of HSYA on high-fat diet (HFD) and streptozotocin- (STZ-) induced DN in rats. The DN rats were treated with HSYA for eight weeks. We assessed creatinine (CR), urea nitrogen (UN), glomerular volume, podocyte number, renal inflammation, oxidative stress, and cells apoptosis markers after HSYA treatment. The number of apoptotic cells was measured by the TUNEL assay, and apoptosis-related proteins BAX, caspase-3, and BCL-2 in the renal tissue were analyzed by western blot. The treatment with HSYA significantly decreased fasting blood glucose, CR, UN, and blood lipid profile, including triglyceride and total and low-density lipoprotein cholesterol, even though it did not change the rats' body weights. The western blot results indicated that HSYA reversed the upregulation of BAX and caspase-3 and significantly increased BCL-2 in renal tissue. Moreover, the levels of TNF-α and the inflammatory products, including free fatty acids (FFA) and lactic dehydrogenase (LDH) in the HSYA group, were significantly decreased. For the oxidative stress marker, the superoxide dismutase (SOD) markedly increased in the HSYA treatment group, while the malondialdehyde (MDA) in the serum and kidney tissue evidently decreased. In conclusion, HSYA treatment preserved kidney function in diabetic nephropathy in the HFD- and STZ-induced rats. The potential mechanism of renal protective effect of HSYA might be through inhibiting oxidative stress, reducing inflammatory reaction, and attenuating renal cell apoptosis. Our studies present a promising use for Hydroxysafflor yellow A in the treatment of type 2 diabetes mellitus.

Hydroxysafflor yellow A (HSYA) targets the platelet-activating factor (PAF) receptor and inhibits human bronchial smooth muscle activation induced by PAF

Hydroxysafflor yellow A (HSYA) is the main active ingredient of edible plant safflower. HSYA has demonstrated anti-inflammatory effects. The inflammatory response is the key mechanism responsible for asthma, and the pro-inflammatory platelet-activating factor (PAF) is known to play a role in the pathology of bronchial asthma. In this study, we stimulated human bronchial smooth muscle cells (HBSMCs) with PAF and examined the effects of HSYA on the resulting asthma-related process. PAF stimulation induced HBSMC activation, induced proliferation, increased expression of the pro-inflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor-α, and activated asthma-related signaling pathways. All these effects were significantly inhibited by treatment with HSYA (9, 27, 81 μmol L^-1). The effects of HSYA were prevented by the addition of a PAF receptor (PAFR) antagonist or by PAFR gene silencing with small interfering RNA. These results suggest that HSYA may inhibit PAF-induced activation of HBSMCs by targeting the PAFR. Overall, these findings provide evidence that HSYA can be applied as a potential therapeutic agent in the treatment of bronchial asthma.

Hydroxysafflor Yellow A: A Promising Therapeutic Agent for a Broad Spectrum of Diseases

Hydroxysafflor yellow A (HSYA) is one of the major bioactive and water-soluble compounds isolated from Carthami Flos, the flower of safflower (Carthamus tinctorius L.). As a natural pigment with favorable medical use, HSYA has gained extensive attention due to broad and effective pharmacological activities since first isolation in 1993. In clinic, the safflor yellow injection which mainly contains about 80% HSYA was approved by the China State Food and Drug Administration and used to treat cardiac diseases such as angina pectoris. In basic pharmacology, HSYA has been proved to exhibit a broad spectrum of biological effects that include, but not limited to, cardiovascular effect, neuroprotection, liver and lung protection, antitumor activity, metabolism regulation, and endothelium cell protection. Although a great number of studies have been carried out to prove the pharmacological effects and corresponding mechanisms of HYSA, a systemic review of HYSA has not yet been seen. Here, we provide a comprehensive summarization of the pharmacological effects of HYSA. Together with special attention to mechanisms of actions, this review can serve as the basis for further researches and developments of this medicinal compound.

The anti-anaphylactoid effects of hydroxysafflor yellow A on the suppression of mast cell Ca2+ influx and degranulation

BACKGROUND

Anaphylaxis is a type of potentially fatal hypersensitivity reaction resulting from the activation of mast cell mediators, especially histamine and lipid mediators. Non-IgE-mediated anaphylaxis can occur because of the direct activation of mast cells. Hydroxysafflor yellow A (HSYA) is the main chemical component of safflower (Carthamus tinctorius) and has been reported to have pharmacological activities. However, the anti-anaphylactoid effect of HSYA has not yet been investigated.

PURPOSE

The aims of this study were to evaluate the anti-anaphylactoid activity of HSYA in vivo and to investigate the underlying mechanism in vitro.

METHODS

The anti-anaphylactoid activity of HSYA was evaluated in a mouse model of hindpaw extravasation. Calcium imaging was used to assess intracellular Ca²⁺ mobilization. The levels of cytokines and chemokines released by stimulated mast cells were measured using enzyme immunoassay kits. Western blotting was used to explore the related molecular signaling pathways.

RESULTS

HSYA markedly inhibited mast cell degranulation by suppressing the activation of intracellular Ca²⁺ mobilization and preventing the release of cytokines and chemokines from mast cells in a dose-dependent manner via the PKC-PLCγ-IP3R signaling pathway.

CONCLUSION

In summary, HSYA has anti-anaphylactoid pharmacological activity, which makes it a potential candidate for the development of a novel agent to suppress drug-induced anaphylactoid reactions.

Hydroxysafflor Yellow A Suppresses Platelet Activating Factor-Induced Activation of Human Small Airway Epithelial Cells

Hydroxysafflor yellow A (HSYA) is a chemical component isolated from the Chinese medicine Carthamus tinctorius L. HSYA has numerous pharmacological effects, including protecting against and mitigating some respiratory diseases such as acute lung injury and chronic obstructive pulmonary disease; however, its effect on asthma remains unclear. We previously found that HSYA attenuated ovalbumin-induced allergic asthma in guinea pigs. Platelet activating factor (PAF) is a phospholipid mediator of inflammation and an important factor in the pathological process of asthma. In this study, we investigated the anti-inflammatory effects of HSYA and its underlying mechanisms in PAF-induced human small airway epithelial cells (HSAECs). PAF-activated cells were pretreated with HSYA and/or the PAF receptor inhibitor, ginkgolide B, and we observed changes in the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha, monolayer permeability of HSAECs, and inflammatory signaling pathways. HSYA attenuated the PAF-induced increase in expression of inflammatory factors and destruction of cell-barrier function, and inhibited the expression of protein kinase C, mitogen-activated protein kinases, activator protein-1, and nuclear factor-κB activation induced by PAF. These findings suggest that HSYA may represent a potential new drug for the treatment of asthma.

Alternative and Natural Therapies for Acute Lung Injury and Acute Respiratory Distress Syndrome

Introduction

Acute respiratory distress syndrome (ARDS) is a complex clinical syndrome characterized by acute inflammation, microvascular damage, and increased pulmonary vascular and epithelial permeability, frequently resulting in acute respiratory failure and death. Current best practice for ARDS involves “lung-protective ventilation,” which entails low tidal volumes and limiting the plateau pressures in mechanically ventilated patients. Although considerable progress has been made in understanding the pathogenesis of ARDS, little progress has been made in the development of specific therapies to combat injury and inflammation.

Areas Covered

In recent years, several natural products have been studied in experimental models and have been shown to inhibit multiple inflammatory pathways associated with acute lung injury and ARDS at a molecular level. Because of the pleiotropic effects of these agents, many of them also activate antioxidant pathways through nuclear factor erythroid-related factor 2, thereby targeting multiple pathways. Several of these agents are prescribed for treatment of inflammatory conditions in the Asian subcontinent and have shown to be relatively safe.

Expert Commentary

Here we review natural remedies shown to attenuate lung injury and inflammation in experimental models. Translational human studies in patients with ARDS may facilitate treatment of this devastating disease.

Hydroxysafflor yellow A inhibits IL-1β-induced release of IL-6, IL-8, and MMP-1 via suppression of ERK, NF-κB and AP-1 signaling in SW982 human synovial cells

Hydroxysafflor yellow A (HSYA), the main active ingredient in medical and edible dual purpose plant safflower, is reported to have multiple bioactivities. In the present study, the anti-inflammatory effects of HSYA and the underlying mechanisms were investigated in interleukin (IL)-1β-induced SW982 human synovial cells. The cells were pretreated with HSYA at various concentrations (2.5, 10 and 40 μM) followed by IL-1β (10 ng mL^-1) stimulation. HSYA significantly inhibited the expression of IL-6, IL-8 and matrix metalloproteinase (MMP)-1 in IL-1β-stimulated SW982 cells. HSYA also inhibited the phosphorylation of extracellular signal-regulated kinase (ERK), p65 and c-Jun. It also suppressed the degradation of IκBα and blocked p65 translocation into the nucleus. These results indicate that the inhibitory effects of HSYA on IL-1β-induced IL-6, IL-8 and MMP-1 release might be mediated via suppression of ERK, nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) signaling pathways. The present data support the potential role of HSYA as an effective therapeutic agent in osteoarthritis.

Hydroxysafflor yellow A (HSYA) targets the NF-κB and MAPK pathways and ameliorates the development of osteoarthritis

The inflammatory environment has been demonstrated to be strongly associated with the progression of osteoarthritis (OA).

Protective cerebrovascular effects of hydroxysafflor yellow A (HSYA) on ischemic stroke

The purpose of the present work was designed to explore protective cerebrovascular effects of hydroxysafflor yellow A (HSYA), and provide preclinical efficacy and mechanism data for its possible application in patients with cerebral ischemia. The protective effect of HSYA on ischemic stroke was evaluated by infarct sizes and neurological scores in Sprague-Dawley (SD) rats with middle cerebral artery occlusion (MCAO). Cerebrovascular permeability was detected by Evans blue dye leakage in MCAO rats. Cerebral blood flow, as well as blood pressure and heart rate were monitored using flow probes in Beagle dogs. Basilar artery tension isolated from Beagle dogs was evaluated with an MPA 2000 data-acquisition system. Coagulation-related function was also judged, including rabbit platelet aggregation by adenosine diphosphate (ADP) and platelet-aggregating factor (PAF), rabbit blood viscosity by a blood viscometer, and thrombus formation by rat arterial-venous shunts. Results showed that HSYA treatment significantly decreased the infarct sizes, neurological scores and cerebrovascular permeability in rats with MCAO. However, cerebral blood flow, blood pressure and heart rate were not affected by HSYA. In vitro, HSYA had a strong effect on cerebrovascular vasodilatation, and significantly decreased platelet aggregation, blood viscosity, and thrombogenesis. Besides well-known anti-coagulation effects, HSYA protects against ischemic stroke by dilating cerebral vessels and improving cerebrovascular permeability.

Anti-fibrosis effect for Hirsutella sinensis mycelium based on inhibition of mTOR p70S6K phosphorylation

Hirsutella sinensis, cultured in vitro, is an attractive substitute for Cordyceps sinensis as health supplement. The aim of this study was to demonstrate whether H. sinensis mycelium (HSM) attenuates murine pulmonary fibrosis induced by bleomycin and to explore the underlying molecular mechanisms. Using lung fibrosis modle induced by intratracheal instillation of bleomycin (BLM; 4 mg/kg), we observed that the administration of HSM reduced HYP, TGF-β1 and the production of several pro-fibrosis cytokines (α-smooth muscle actin, fibronectin and vimentin) in fibrotic mice lung sections. Histopathological examination of lung tissues also demonstrated that HSM improved BLM-induced pathological damage. Concurrently, HSM supplementation markedly reduced the chemotaxis of alveolar macrophages and potently suppressed the expression of inflammatory cytokines. Also, HSM influenced Th1/Th2 and Th17/Treg imbalance and blocked the phosphorylation of mTOR pathway in vivo. Alveolar epithelial A549 cells acquired a mesenchymal phenotype and an increased expression of myofibroblast markers of differentiation (vimentin and fibronectin) after treatment with TGF-β1. HSM suppressed these markers and blocked the phosphorylation of mTOR pathway in vitro. The results provide evidence supporting the use of HSM in the intervention of pulmonary fibrosis and suggest that HSM is a potential therapeutic agent for lung fibrosis.

Hydroxysafflor Yellow A Alleviates Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome in Mice

Hydroxysafflor yellow A (HSYA) is an effective ingredient of the Chinese herb Carthamus tinctorius L. The present study investigated the protective effect of HSYA on lipopolysaccharide (LPS)-induced acute respiratory distress syndrome in mice, and the underlying mechanisms involved. HSYA (14, 28, 56 mg/kg) was intraperitoneally injected to mice once daily from day 1 to 10 after LPS administration. HSYA attenuated the body weight loss, the augmented left index and the increase of pathologic changes in pulmonary inflammation caused by LPS. Treatment with HSYA also alleviated increased expressions of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β1, collagen (Col) I, Col III, α-smooth muscle actin (α-SMA), myeloid differentiation (MD)-2, Toll-like receptor 4 (TLR4) and cluster differentiation (CD)14 at the mRNA (RT-PCR) and protein levels (Western blot and enzyme-linked immuno sorbent assay). Moreover, HSYA inhibited the elevated levels of nuclear factor (NF)-κB and α-SMA in lung tissue (immunohistochemistry), and alleviated the slight collagen deposition in pulmonary tissues (Masson's trichrome staining). HSYA inhibited the specific binding of fluorescein isothiocyanate (FITC)-LPS on human lung epithelial cell line (A549) or human umbilical vein cell line (Eahy926) cells (flow cytometry). These findings suggested that HSYA has a protective effect on acute respiratory distress syndrome (ARDS) induced by LPS through blocking the TLR4/NF-κB pathway, and that the TLR4 receptor might be a target of HSYA on the cell membrane.

Carthorquinosides A and B, Quinochalcone C-Glycosides with Diverse Dimeric Skeletons from Carthamus tinctorius

Two novel quinochalcone C-glycosides, carthorquinosides A (1) and B (2), were isolated from the florets of Carthamus tinctorius. Their structures, including the absolute configurations, were established by analysis of NMR and MS data, together with chemical degradation and electronic circular dichroism spectra. Compound 1 has an unprecedented quinochalcone-flavonol structure linked via a methylene bridge, and compound 2 comprises two glucopyranosylquinochalcone moieties linked via the formyl carbon of an acyclic glucosyl unit. A potential biosynthesis pathway is also proposed. Compounds 1 and 2 exhibited anti-inflammatory activities in LPS-stimulated HUVEC cells by regulating IL-1, IL-6, IL-10, and IFN-γ mRNA expression at concentrations as low as 4 μM, and compound 2 also showed inhibitory activity against topoisomerase I at100 μM.

Hydroxysafflor yellow A alleviates myocardial ischemia/reperfusion in hyperlipidemic animals through the suppression of TLR4 signaling

Hyperlipidemia aggravates myocardial ischemia/reperfusion (MI/R) injury through stimulating excessive inflammatory response. Therefore, blockade of inflammatory signal is a potential therapeutic management for MI/R complicated with hyperlipidemia. Hydroxysafflor yellow A (HSYA, a monomer extracted from Carthamus tinctorius L.), was studied in this article to address that the regulation of inflammatory signal would alleviate MI/R combined with hyperlipidemia injury. High-fat diet induced hyperlipidemia worsened MI/R mediated heart injury (elevation of infarct size, CK-MB and LDH activity), activated TLR4 over-expression in hearts, released inflammatory cytokines (LPS, TNF-α and IL-1β) excessively. HSYA administration suppressed the over-expression of TLR4 and alleviated heart damage caused by MI/R complicated with hyperlipidemia. Furthermore, HSYA had little influence on MI/R injury in TLR4-knockout mice, which indicated that HSYA protected MI/R through TLR4 inhibition. In vitro, hypoxia/reoxygenation (H/R) coexisting with LPS model in neonatal rat ventricular myocytes (NRVMs) induced serious damage compared with H/R injury to NRVMs. HSYA decreased excessive secretion of inflammatory cytokines, down-regulated over-expression of TLR4 and NF-κB in H/R + LPS injured NRVMs. In conclusion, HSYA alleviated myocardial inflammatory injury through suppressing TLR4, offering an alternative medication for MI/R associated with hyperlipidemia.

Hydroxysafflor yellow A inhibits TGF-β1-induced activation of human fetal lung fibroblasts in vitro

Objective

Hydroxysafflor yellow A (HSYA) is one of the chemical component isolated from Chinese medicine Carthamus tinctorius L. Our preliminary study confirmed that HSYA attenuated bleomycin-induced pulmonary fibrosis in mice. In this study, we evaluated the effect of HSYA on TGF-β1-induced activation of human fetal lung fibroblasts (MRC-5) and explored the underlying mechanisms of its activity.

Method

MRC-5 cells activated by TGF-β1 were incubated with HSYA and/or the TGF-β type I receptor inhibitor, SB431542. TGF-β1-induced cell proliferation, α-smooth muscle actin, collagen I alpha 1 and fibronectin expression, Smad, mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3 kinase/Akt signalling pathway activation were observed.

Key findings

Hydroxysafflor yellow A significantly inhibited TGF-β1-induced cell proliferation and the expression, both mRNA and protein, of α-smooth muscle actin, collagen I alpha 1 and fibronectin. HSYA also suppressed TGF-β1 activation of Smad signal transduction via inhibition of Smad2 and Smad3 phosphorylation, their nuclear translocation and the binding activity of Smad3 to type I collagen promoter in MRC-5 cells. In addition, HSYA inhibited TGF-β1-induced phosphorylation of extracellular signal-regulated kinase (ERK). The inhibitory effects of HSYA were similar to SB431542.

Conclusion

These findings suggest that HSYA inhibits TGF-β1-induced activation of MRC-5 cells associated with TGF-β1/Smad and ERK/MAPK signalling pathways.

Hydroxysafflor yellow A improves established monocrotaline-induced pulmonary arterial hypertension in rats

Objective

To evaluate the beneficial effects of hydroxysafflor yellow A (HSYA) on monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) in rats, and to investigate the main pathophysiological mechanism of HSYA in preventing development of MCT-induced PAH.

Methods

Four groups (control, control with HSYA treatment, MCT-exposed, and MCT-exposed with HSYA treatment) were evaluated at day 28 following MCT exposure. Haemodynamic measurements, right ventricular hypertrophy, morphometry, inflammatory cytokines and oxidant expression were assessed.

Results

HSYA significantly reduced haemodynamic changes, right ventricular hypertrophy and morphometric changes induced by exposure to MCT. HYSA also suppressed MCT-induced inflammation and oxidative stress in rat pulmonary tissue.

Conclusions

Experimental MCT-induced PAH may be reduced by HSYA treatment, and the mechanism may involve suppression of inflammation and oxidative stress.

Hydroxysafflor Yellow A Attenuates Neuron Damage by Suppressing the Lipopolysaccharide-Induced TLR4 Pathway in Activated Microglial Cells

Microglia activation initiates a neurological deficit cascade that contributes to substantial neuronal damage and impairment following ischemia stroke. Toll-like receptor 4 (TLR4) has been demonstrated to play a critical role in this cascade. In the current study, we tested the hypothesis that hydroxysafflor yellow A (HSYA), an active ingredient extracted from Flos Carthami tinctorii, alleviated inflammatory damage, and mediated neurotrophic effects in neurons by inducing the TLR4 pathway in microglia. A non-contact Transwell co-culture system comprised microglia and neurons was treated with HSYA followed by a 1 mg/mL lipopolysaccharide (LPS) stimulation. The microglia were activated prior to neuronal apoptosis, which were induced by increasing TLR4 expression in the activated microglia. However, HSYA suppressed TLR4 expression in the activated microglia, resulting in less neuronal damage at the early stage of LPS stimulation. Western blot analysis and immunofluorescence indicated that dose-dependently HSYA down-regulated TLR4-induced downstream effectors myeloid differentiation factor 88 (MyD88), nuclear factor kappa b (NF-κB), and the mitogen-activated protein kinases (MAPK)-regulated proteins c-Jun NH2-terminal protein kinase (JNK), protein kinase (ERK) 1/2 (ERK1/2), p38 MAPK (p38), as well as the LPS-induced inflammatory cytokine release. However, HSYA up-regulated brain-derived neurotrophic factor (BDNF) expression. Our data suggest that HSYA could exert neurotrophic and anti-inflammatory functions in response to LPS stimulation by inhibiting TLR4 pathway-mediated signaling.

Chinese Herbal Preparation Xuebijing Potently Inhibits Inflammasome Activation in Hepatocytes and Ameliorates Mouse Liver Ischemia-Reperfusion Injury

The Chinese herb preparation Xuebijing injection (XBJ) has been widely used in the management of various septic disorders or inflammation-related conditions, however the molecular mechanism of its anti-inflammatory effect remains largely elusive. In the current study, we found that XBJ treatment potently ameliorated mouse hepatic ischemia-reperfusion (IR) injury, manifested as decreased liver function tests (LDH, ALT, AST), improved inflammation and less hepatocyte apoptosis. Notably, XBJ markedly inhibited inflammasome activation and IL-1 production in mouse livers subjected to IRI, even in the absence of Kupffer cells, suggesting Kupffer cells are not necessary for hepatic inflammasome activation upon Redox-induced sterile inflammation. This finding led us to investigate the role of XBJ on hepatocyte apoptosis and inflammasome activation using an in vitro hydrogen peroxide (H₂O₂)-triggered hepatocyte injury model. Our data clearly demonstrated that XBJ potently inhibited apoptosis, as well as caspase-1 cleavage and IL-1β production in a time- and dose-dependent manner in isolated hepatocytes, suggesting that in addition to its known modulatory effect on NF-κB-dependent inflammatory gene expression, it also has a direct impact on hepatocyte inflammasome activation. The current study not only deepens our understanding of how XBJ ameliorates inflammation and apoptosis, but also has immediate practical significance in many clinical situations such as partial hepatectomy, liver transplantation, etc.

Measurement of hydroxysafflor yellow A in human urine by liquid chromatography-tandem mass spectrometry

A rapid and specific high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the quantification of hydroxysafflor yellow A (HSYA) in human urine with isorhamnetin-3-O-neohespeidoside as internal standard (IS). HSYA and IS were extracted from urine samples by simple solid-phase extraction and separated on an Agilent Zorbax SB C18 column (4.6 mm × 150 mm, 5 μm) with the mobile phase of 0.2 mM ammonium acetate: methanol (30/70, v/v) at a flow rate of 0.4 mL/min. Polar endogenous interferences eluted in 0.1-2.5 min were switched into waste channel by the Valve Valco, to reduce the possible matrix effect for MS detection in each run. The MS detection of analytes was performed on a tandem mass spectrometer equipped with an electrospray ionization source in negative mode using multiple-reaction monitoring. The MS/MS ion transitions monitored were m/z 611.3→491.2 for HSYA and m/z 623.2→299.2 for IS. The method was fully validated for selectivity, sensitivity, linearity, precision, accuracy, recovery, matrix effect and stability, and then was applied to the urinary excretion study of injectable powder of pure HSYA in healthy Chinese volunteers for the first time. The results suggested that urine was the main excretion way of HSYA in healthy volunteers, further demonstrating the feasibility and necessity of our current method.

Hydroxysafflor yellow a attenuates small airway remodeling in a rat model of chronic obstructive pulmonary disease

Our previous studies found that hydroxysafflor yellow A (HSYA), an active ingredient in Carthamus tinctorius L., has anti-inflammatory and anti-fibrosis properties. In this study, we investigated the effect of HSYA on small airway remodeling (SAR) in a chronic obstructive pulmonary disease (COPD) rat model induced by cigarette smoke and lipopolysaccharide (LPS). SAR is a common lesion in COPD characterized by thickening of the airway wall, mainly by subepithelial fibrosis. In this study the thickness of the small airway was determined by total wall area/basement membrane perimeter (WAt/Pbm). Collagen deposition of the small airway was assessed by Masson's trichrome staining. HSYA significantly attenuated the thickening and collagen deposition of the small airway and inhibited transforming growth factor β1 (TGF-β1) mRNA and protein expression in COPD rat. In addition, HSYA inhibited the phosphorylation of p38 mitogen-activated protein kinases (MAPK) in the lung tissue of rat. HSYA can attenuate experimentally induced airway remodeling and this attenuation may be attributed to suppression of TGF-β1 expression.

Inhibitory effect of hydroxysafflor yellow a on mouse skin photoaging induced by ultraviolet irradiation

Chronic exposure to ultraviolet (UV) irradiation is believed to be the major cause of skin damage that results in premature aging of the skin, so called photoaging, characterized by increases in skin thickness, formation of wrinkles, and loss of skin elasticity. UV induces damage to skin mainly by oxidative stress and collagen degradation. In this study, we examined the photo-protective effect of hydroxysafflor yellow A (HSYA), a major active chemical component isolated from Carthamus tinctorius L., by topical application on the skin of mice. Exposure of the dorsal depilated skin of mice to UV radiation four times a week for 10 weeks induced epidermal hyperplasia, elastin accumulation, collagen degradation, etc. HSYA at the doses of 50, 100, and 200 μg/mouse was topically applied immediately following each UV exposure. The effects of HSYA were evaluated by a series of tests, including macroscopic and histopathological evaluation of skin, pinch test, and redox homeostasis of skin homogenates. Results showed that the UV-induced skin damage was significantly improved after HSYA treatment, especially at doses of 100 and 200 μg/mouse. This protective effect is possibly related to the anti-oxidative property of HSYA and mediated by promoting endogenous collagen synthesis. This is the first study providing preclinical evidence for the protective effect of HSYA against photoaging.

Macrophage heterogeneity in liver injury and fibrosis

Hepatic macrophages are central in the pathogenesis of chronic liver injury and have been proposed as potential targets in combatting fibrosis. Recent experimental studies in animal models revealed that hepatic macrophages are a remarkably heterogeneous population of immune cells that fulfill diverse functions in homeostasis, disease progression, and regression from injury. These range from clearance of pathogens or cellular debris and maintenance of immunological tolerance in steady state conditions; central roles in initiating and perpetuating inflammation in response to injury; promoting liver fibrosis via activating hepatic stellate cells in chronic liver damage; and, finally, resolution of inflammation and fibrosis by degradation of extracellular matrix and release of anti-inflammatory cytokines. Cellular heterogeneity in the liver is partly explained by the origin of macrophages. Hepatic macrophages can either arise from circulating monocytes, which are recruited to the injured liver via chemokine signals, or from self-renewing embryo-derived local macrophages, termed Kupffer cells. Kupffer cells appear essential for sensing tissue injury and initiating inflammatory responses, while infiltrating Ly-6C(+) monocyte-derived macrophages are linked to chronic inflammation and fibrogenesis. In addition, proliferation of local or recruited macrophages may possibly further contribute to their accumulation in injured liver. During fibrosis regression, monocyte-derived cells differentiate into Ly-6C (Ly6C, Gr1) low expressing 'restorative' macrophages and promote resolution from injury. Understanding the mechanisms that regulate hepatic macrophage heterogeneity, either by monocyte subset recruitment, by promoting restorative macrophage polarization or by impacting distinctive macrophage effector functions, may help to develop novel macrophage subset-targeted therapies for liver injury and fibrosis.

Carthami Flos suppresses neutrophilic lung inflammation in mice, for which nuclear factor-erythroid 2-related factor-1 is required

Carthami Flos (CF) is used in traditional Asian medicine to treat blood stagnation and its associated diseases in patients. While the underlying mechanism for this effect remains unknown, CF has been reported to activate Nrf2, a transcription factor that is critical in protecting from various inflammatory lung diseases including acute lung injury (ALI). Here, we examined whether CF has a therapeutic effect on lung inflammation and assessed the impact of Nrf2 on the effect of CF using an ALI mouse model. Treatment of bone marrow derived macrophages with standardized aqueous extract of CF (AECF) activated Nrf2, resulting in the expression of Nrf2 dependent genes including GCLC, NQO-1 and HO-1. While intranasal LPS treatment of wild type mice resulted in neutrophilic infiltration and a concomitant expression of pro-inflammatory cytokine genes in the lung, the hallmarks of ALI, an intratracheal spraying of AECF to the lung 2h after LPS treatment suppressed the inflammatory response. By contrast, similar treatment in nrf2(-/-) mice with AECF failed to attenuate the inflammatory response. Thus, our results show that AECF attenuated neutrophilic lung inflammation in mice, which required Nrf2. Since AECF administration abrogates lung inflammation after LPS treatment, we propose CF as a potential therapeutics in the management of ALI.

Chemical and biological properties of quinochalcone C-glycosides from the florets of Carthamus tinctorius

Quinochalcone C-glycosides are regarded as characteristic components that have only been isolated from the florets of Carthamus tinctorius. Recently, quinochalcone C-glycosides were found to have multiple pharmacological activities, which has attracted the attention of many researchers to explore these compounds. This review aims to summarize quinochalcone C-glycosides’ physicochemical properties, chromatographic behavior, spectroscopic characteristics, as well as their biological activities, which will be helpful for further study and development of quinochalcone C-glycosides.

Hydroxysafflor yellow A suppresses oleic acid-induced acute lung injury via protein kinase A

Inflammation response and oxidative stress play important roles in acute lung injury (ALI). Activation of the cAMP/protein kinase A (PKA) signaling pathway may attenuate ALI by suppressing immune responses and inhibiting the generation of reactive oxygen species (ROS). Hydroxysafflor yellow A (HSYA) is a natural flavonoid compound that reduces oxidative stress and inflammatory cytokine-mediated damage. In this study, we examined whether HSYA could protect the lungs from oleic acid (OA)-induced injury, which was used to mimic ALI, and determined the role of the cAMP/PKA signaling pathway in this process. Arterial oxygen tension (PaO2), carbon dioxide tension, pH, and the PaO2/fraction of inspired oxygen ratio in the blood were detected using a blood gas analyzer. We measured wet/dry lung weight ratio and evaluated tissue morphology. The protein and inflammatory cytokine levels in the bronchoalveolar lavage fluid and serum were determined using enzyme-linked immunoassay. The activities of superoxide dismutase, glutathione peroxidase, PKA, and nicotinamide adenine dinucleotide phosphate oxidase, and the concentrations of cAMP and malondialdehyde in the lung tissue were detected using assay kits. Bcl-2, Bax, caspase 3, and p22(phox) levels in the lung tissue were analyzed using Western blotting. OA increased the inflammatory cytokine and ROS levels and caused lung dysfunction by decreasing cAMP synthesis, inhibiting PKA activity, stimulating caspase 3, and reducing the Bcl-2/Bax ratio. H-89 increased these effects. HSYA significantly increased the activities of antioxidant enzymes, inhibited the inflammatory response via cAMP/PKA pathway activation, and attenuated OA-induced lung injury. Our results show that the cAMP/PKA signaling pathway is required for the protective effect of HSYA against ALI.

Identification of NF-κB Inhibitors in Xuebijing injection for sepsis treatment based on bioactivity-integrated UPLC-Q/TOF

ETHNOPHARMACOLOGICAL EVIDENCE

Inflammation plays an important role in sepsis, and NF-κB is a key mediator of inflammation. Xuebijing (XBJ) injection is a traditional Chinese medicine injection that was widely used in the treatment of sepsis in China. However, the active constituents and mechanism responsible for its actions have not been investigated experimentally.

AIM OF THE STUDY

To screen the anti-inflammatory components in XBJ injection and investigate the modulation of NF-κB in the treatment of sepsis.

MATERIALS AND METHODS

In this study, the effect of XBJ was assessed in the cecal ligation and puncture (CLP) -induced sepsis model. Subsequently, a bioactivity-integrated ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF) assay system was established for screening potential anti-inflammatory ingredients in XBJ. Ultimately, six active ingredients were confirmed through an in vitro test.

RESULTS

XBJ significantly reduced the mortality rate, anal temperature and expression of TNF-α, IL-1β and IL-6 induced by CLP. Nine potential anti-inflammatory ingredients, including gallic acid, danshensu, protocatechualdehyde, hydroxysafflor yellow A, oxypaeoniflorin, paeoniflorin, safflor yellow A, senkyunolide I and benzoylpaeoniflorin, were found based on the bioactivity-integrated UPLC-Q/TOF assay system. Among these compounds, the NF-κB inhibitor activity of senkyunolide I, safflor yellow A, oxypaeoniflorin, and benzoylpaeoniflorin are first reported here.

CONCLUSIONS

XBJ showed significant efficacy in the treatment of sepsis induced by CLP. Multiple targets of the different components were related to these anti-inflammatory effects, which contributed to the treatment of sepsis by XBJ in a clinical setting.

NMR solution structure study of the representative component hydroxysafflor yellow A and other quinochalcone C-glycosides from Carthamus tinctorius

Hydroxysafflor yellow A (HSYA), a representative component of Carthamus tinctorius, has attracted much attention because of its remarkable cardiovascular activities. Its structure was originally reported in 1993 and has been widely cited to date. In our experiments, its solution structure was studied using NMR techniques in different solvents, including DMSO-d(6), pyridine-d(5), and CD(3)OH. The results indicate that the structure of HSYA is different than the previously described 1b, with 3-enol-1,7-diketo form. The structure has two keto-enol tautomers (2a and 2b), and 2a, with the 1-enol-3,7-diketo form, is the preferred tautomer. On the basis of this finding, other published quinochalcone C-glycoside structures were revised. Furthermore, a trend in the (13)C NMR data of the (E)-olefinic carbons of quinochalcone C-glycosides is summarized, and a hypothesis is proposed for the relationship between the features of the molecular structure and the preferred keto-enol tautomer.