Two new quinochalcone C-glycosides from the florets of Carthamus tinctorius

Genetic diversity, clinical uses, and phytochemical and pharmacological properties of safflower (Carthamus tinctorius L.): an important medicinal plant

Safflower (Carthamus tinctorius L.), a member of the Asteraceae family, is widely used in traditional herbal medicine. This review summarized agronomic conditions, genetic diversity, clinical application, and phytochemicals and pharmacological properties of safflower. The genetic diversity of the plant is rich. Abundant in secondary metabolites like flavonoids, phenols, alkaloids, polysaccharides, fatty acids, polyacetylene, and other bioactive components, the medicinal plant is effective for treating cardiovascular diseases, neurodegenerative diseases, and respiratory diseases. Especially, Hydroxysafflor yellow A (HYSA) has a variety of pharmacological effects. In terms of treatment and prevention of some space sickness in space travel, safflower could be a potential therapeutic agent. Further studies are still required to support the development of safflower in medicine. Our review indicates that safflower is an important medicinal plant and research prospects regarding safflower are very broad and worthy of further investigation.

Highly oxidized rearranged derivatives of quinochalcone C-glycosides from Carthamus tinctorius

Safflopentsides A-C (1-3), three highly oxidized rearranged derivatives of quinochalcone C-glycosides, were isolated from the safflower yellow pigments. Their structures were determined based on a detailed spectroscopic analysis (UV, IR, HR-ESI-MS, 1D and 2D NMR), and the absolute configurations were confirmed by the comparison of experimental ECD spectra with calculated ECD spectra. Compounds 1-3 have an unprecedented cyclopentenone or cyclobutenolide ring A containing C-glucosyl group, respectively. The plausible biosynthetic pathways of compounds have been presented. At 10 μM, 2 showed strong inhibitory activity against rat cerebral cortical neurons damage induced by glutamate and oxygen sugar deprivation.

Chemical composition, pharmacology and pharmacokinetic studies of GuHong injection in the treatment of ischemic stroke

GuHong injection is composed of safflower and N-acetyl-L-glutamine. It is widely used in clinical for cerebrovascular diseases, such as ischemic stroke and related diseases. The objective of this review is to comprehensively summarize the most recent information related to GuHong in the treatment of stroke, including chemical composition, clinical studies, potential pharmacological mechanisms and pharmacokinetics. Additionally, it examines possible scientific gaps in current study and aims to provide a reliable reference for future GuHong studies. The systematic review reveals that the chemical composition of safflower in GuHong is more than 300 chemical components in five categories. GuHong injection is primarily used in clinical applications for acute ischemic stroke and related diseases. Pharmacological investigations have indicated that GuHong acts in the early and recovery stages of ischemic stroke by anti-inflammatory, anti-oxidative stress, anti-coagulation, neuroprotective and anti-apoptotic mechanisms simultaneously. Pharmacokinetic studies found that the main exposed substances in rat plasma after GuHong administration are hydroxysafflor yellow A and N-acetyl-L-glutamine, and N-acetyl-L-glutamine could exert its pharmacological effect across the blood-brain barrier. As a combination of Chinese herb and chemical drug, GuHong injection has great value in drug research and clinical treatment, especially for ischemic stroke disease. This article represents a comprehensive and systematic review of existing studies on GuHong injection, including chemical composition, pharmacological mechanism, and pharmacokinetics, which provides reference significance for the clinical treatment of ischemic stroke with GuHong, as well as provides guidance for further study.

Sesquiterpenoids from the Florets of Carthamus tinctorius (Safflower) and Their Anti-Atherosclerotic Activity

(1) Background: The florets of Carthamus tinctorius L. are traditionally used as a blood-activating drug and can be used for the treatment of atherosclerosis, but no compounds with anti-atherosclerotic activity have been reported. (2) Methods: This study investigated the chemical compounds from the florets of C. tinctorius. Comprehensive spectroscopic techniques revealed their structures, and ECD calculations established their absolute configurations. Nile Red staining, Oil Red O staining, and cholesterol assessment were performed on these compounds and their aglycones for the inhibitory activity against the formation of foam cells induced by oxidized low-density lipoprotein (ox-LDL) in RAW264.7 macrophages. In addition, RAW264.7 macrophages were tested for their anti-inflammatory activity by measuring the inhibition of NO production caused by LPS. (3) Results: Five new sesquiterpenoids (1-5) isolated from the florets of C. tinctorius were identified as (-)-(1R,4S,9S,11R)-caryophyll-8(13)-en-14-ol-5-one (1), (+)-(1R,4R,9S,11R)-caryophyll-8(13)-en-14-ol-5-one (2), (-)-(3Z,1R,5S,8S,9S,11R)-5,8-epoxycaryophyll-3-en-14-O-β-D-glucopyranoside (3), (+)-(1S,7R,10S)-guai-4-en-3-one-11-O-β-D-fucopyranoside (4), and (-)-(2R,5R,10R)-vetispir-6-en-8-one-11-O-β-D-fucopyranoside (5). All compounds except for compound 3 reduced the lipid content in ox-LDL-treated RAW264.7 cells. Compounds 3 and 4 and their aglycones were found to reduce the level of total cholesterol (TC) and free cholesterol (FC) in ox-LDL-treated RAW264.7 cells. However, no compounds showed anti-inflammatory activity. (4) Conclusion: Sesquiterpenoids from C. tinctorius help to decrease the content of lipids, TC and FC in RAW264.7 cells, but they cannot inhibit NO production, which implies that their anti-atherogenic effects do not involve the inhibition of inflammation.

Advances in plant-derived C-glycosides: Phytochemistry, bioactivities, and biotechnological production

C-glycosides represent a large group of natural products with a C-C bond between the aglycone and the sugar moiety. They exhibit great structural diversity, wide natural distribution, and significant biological activities. By the end of 2021, at least 754 C-glycosides and their derivatives have been isolated and characterized from plants. Thus far, 66 functional C-glycosyltransferases (CGTs) have been discovered from plants, and provide green and efficient approaches to synthesize C-glycosides. Herein, advances in plant-derived C-glycosides are comprehensively summarized from aspects of structural diversity and identification, bioactivities, and biotechnological production. New strategies to discover novel C-glycosides and CGTs, as well as the applications of biotechnological methods to produce C-glycosides in the future are also discussed.

Study on changes in pigment composition during the blooming period of safflower based on plant metabolomics and semi-quantitative analysis

Red and yellow pigments are the major ingredients of safflower, often used to color food and cosmetics. Carthamin was the main component of red pigment and hydroxysafflor yellow A and anhydrosafflower yellow B were representative components of yellow pigment. Plant metabolomics and semi-quantitative analysis were used to analyze the changes of pigment composition during the blooming period, especially these characteristic components. Carthamin, hydroxysafflor yellow A, anhydrosafflower yellow B, and other components were screened out as differential metabolites based on plant metabolomics. Then semi-quantitative analysis was used to quantify these three representative components of pigments. Experimental results showed that the content of pigments has dynamic changes along with flowering, in the early blooming period, yellow pigment accumulated much and red pigment was low in content. In the middle period, the accumulation rate of the yellow pigment slowed down and content was stabilized. In the next step, the content of yellow pigments gradually decreased, and the content of red pigments gradually increased. Later, the level of yellow pigment decreased significantly, and the accumulation rate of red pigment increased significantly. Last, the appearance color of safflower was red, with yellow parts barely visible, and accumulation of red pigment was the highest and of the yellow pigment was the lowest in content.

Bioactive Substances in Safflower Flowers and Their Applicability in Medicine and Health-Promoting Foods

Safflower flowers (Carthamus tinctorius) contain many natural substances with a wide range of economic uses. The most famous dye isolated from flower petals is hydroxysafflor A (HSYA), which has antibacterial, anti-inflammatory, and antioxidant properties. This review is aimed at updating the state of knowledge about their applicability in oncology, pulmonology, cardiology, gynecology, dermatology, gastrology, immunology, and suitability in the treatment of obesity and diabetes and its consequences with information published mainly in 2018-2020. They were also effective in treating obesity and diabetes and its consequences. The issues related to the possibilities of using HSYA in the production of health-promoting food were also analyzed.

Hydroxyl safflower yellow B combined with doxorubicin inhibits the proliferation of human breast cancer MCF-7 cells

Doxorubicin (DOX) is currently the preferred chemotherapeutic agent for breast cancer, and hydroxyl safflower yellow B (HSYB) has a tumor growth-inhibiting activity. The present study aimed to investigate the effects of HSYB combined with DOX on the proliferation of human breast cancer MCF-7 cells and explore the underlying mechanism. MTT and cell colony formation assays revealed that the proliferation rate of MCF-7 cells was signifiscantly decreased after HSYB and DOX treatment. Combined HSYB and DOX treatment significantly decreased the expression levels of BCL-2 in MCF-7 cells, while the expression levels of apoptosis-associated proteins, including cleaved caspase-9, BAX and cleaved caspase-3, were markedly increased. Furthermore, flow cytometry and western blot analysis demonstrated that combined HSYB and DOX treatment stimulated an increase in intracellular reactive oxygen species and promoted the release of cytochrome c, leading to apoptosis. The current data suggested that the combination of HSYB and DOX may have marked antitumor activity.

Saffloflavone, a new flavonoid from the flowers of Carthamus tinctorius L. and its cardioprotective activity

A new flavonoid, saffloflavone , along with six known compounds, kaempferol-3-O-rutinoside, kaempferol-3-O-sophoroside, quercetin-3-O-β-d-glucoside, quercetin-7-O-β-d-glucoside, luteolin-7-O-β-d-glucoside and kaempferol 3-O-β-d-glucoside were isolated from the flowers of Carthamus tinctorius L. All the structures were determined by interpretation of their spectroscopic data. The cardioprotective effects of all the isolates against oxidative stress of H9c2 cells induced by H₂O₂ were investigated. The results showed that compounds 4-6 exhibited protective effects against of H9c2 cells injury induced by H₂O_2.

Two new quinochalcone glycosides from the safflower yellow pigments

Two new quinochalcone glycosides, hydroxysafflor yellow A-4'-O-β-D-glucopyranoside (1) and 3'-hydroxyhydroxysafflor yellow A (2), were isolated from the safflower yellow pigments of Carthamus tinctorius. The structures of new compounds were elucidated by a detailed spectroscopic analysis (UV, IR, HR-ESI-MS, 1D and 2D NMR, ECD). The in vitro assay indicated that compound 1 could improve the survived rate of primary mouse cortical neurons on glutamate-induced neurons damage model at a concentration of 10 μM.

Inhibitory Effect of Hydroxysafflor Yellow B on the Proliferation of Human Breast Cancer MCF-7 Cells

BACKGROUND

A recent patent has been issued for hydroxysafflor yellow A (HSYA) as a drug to prevent blood circulation disorders. Hydroxysafflor yellow B (HSYB), an isomer of HSYA with antioxidative effects, has been isolated from the florets of Carthamus tinctorius. The effects of HSYB on the proliferation of cancer cells and its mechanism of action have not been investigated.

OBJECTIVE

The aims of this study were to investigate the anti-cancer effects and the molecular mechanism of HSYB for breast cancer MCF-7 cells.

METHODS

MTT assays and colony formation assays were used to assess the survival and proliferation of MCF-7 cells, respectively. Hoechst 33258 and flow cytometry were used to measure cell apoptosis and flow cytometry to determine effects on the cell cycle. Western blots were used to measure protein levels.

RESULTS

Treatment with HSYB reduced survival and proliferation of human breast cancer MCF-7 cells in a dose-dependent manner. Furthermore, HSYB arrested the MCF-7 cell cycle at the S phase and downregulated cyclin D1, cyclin E, and CDK2. Compared with a control group, HSYB suppressed the protein levels of p-PI3K, PI3K, AKT, and p-AKT in MCF-7 cells. In addition, HSYB decreased the levels of Bcl- 2, increased the levels of Bax, cleaved caspase-3 and caspase-9, and subsequently induced MCF-7 cell apoptosis.

CONCLUSION

These data demonstrate that HSYB arrests the MCF-7 cell cycle at the S phase and induces cell apoptosis. Patent US20170246228 indicates that HSYB can be potentially used for the prevention and treatment of human breast cancer.

The Comprehensive Evaluation of Safflowers in Different Producing Areas by Combined Analysis of Color, Chemical Compounds, and Biological Activity

In the present study, a new strategy including the combination of external appearance, chemical detection, and biological analysis was proposed for the comprehensive evaluation of safflowers in different producing areas. Firstly, 40 batches of safflower samples were classified into class I and II based on color measurements and K-means clustering analysis. Secondly, a rapid and sensitive analytical method was developed for simultaneous quantification of 16 chromaticity-related characteristic components (including characteristic components hydroxysafflor yellow A, anhydrosafflor yellow B, safflomin C, and another 13 flavonoid glycosides) in safflowers by ultra-performance liquid chromatography coupled with triple-quadrupole linear ion-trap tandem mass spectrometry (UPLC-QTRAP^®/MS²). The results of the quantification indicate that hydroxysafflor yellow A, anhydrosafflor yellow B, kaempferol, quercetin, and safflomin C had significant differences between the two types of safflower, and class I of safflower had a higher content of hydroxysafflor yellow A, anhydrosafflor yellow B, and safflomin C as the main anti-thrombotic components in safflower. Thirdly, chemometrics methods were employed to illustrate the relationship in multivariate data of color measurements and chromaticity-related characteristic components. As a result, kaempferol-3-O-rutinoside and 6-hydroxykaempferol-3-O-β-d-glucoside were strongly associated with the color indicators. Finally, anti-thrombotic analysis was used to evaluate activity and verify the suitability of the classification basis of safflower based on the color measurements. It was shown that brighter, redder, yellower, more orange–yellow, and more vivid safflowers divided into class I had a higher content of characteristic components and better anti-thrombotic activity. In summary, the presented strategy has potential for quality evaluation of other flower medicinal materials.

Application of multiple chemical and biological approaches for quality assessment of Carthamus tinctorius L. (safflower) by determining both the primary and secondary metabolites

BACKGROUND

The florets of Carthamus tinctorius L. (safflower) serve as the source of a reputable herbal medicine targeting gynecological diseases. Conventional investigations regarding the quality control of safflower, however, mainly focused on the secondary metabolites with primary metabolites ignored.

PURPOSE

To holistically evaluate the quality difference of safflower samples collected from five different producing regions by multiple chemical and biological approaches with both the primary and secondary metabolites considered.

METHODS

A precursor ions list-triggered data-dependent MS² approach was established by ultra-high performance liquid chromatography/Q-Orbitrap mass spectrometry (UHPLC/Q-Orbitrap MS) to comprehensively identify the secondary metabolites from safflower. Primary metabolites were identified by various 1D and 2D nuclear magnetic resonance (NMR) experiments. Similarity evaluation and quantitative assays of all the characterized primary metabolites and a quinochalcone C-glycoside (QCG) marker, hydroxysafflor yellow A (HSYA), were performed by quantitative ¹H NMR (qNMR) using an external standard method. Multiple in vitro models with respect to the antioxidant, anti-platelet aggregation, and antioxidant stress injury effects, were assayed to determine the efficacy differences.

RESULTS

Totally thirteen primary metabolites (including one nucleoside, two sugars, five organic alkali/acids, and five amino acids) and 135 secondary metabolites (97 QCGs and 38 flavonoids) could be identified or tentatively characterized from safflower. Good chemical consistency was observed between the commercial safflower samples and a standard safflower sample, with similarity varying in the range of 0.95‒0.99. The results from qNMR-oriented quantitative experiments (thirteen primary metabolites and HSYA) and biological assays indicated the quality of safflower samples from Xinjiang (XJ-2 and XJ-4), Hunan (HuN-1 and HuN-2), and Sichuan (SC), was comparable to the standard safflower sample.

CONCLUSION

The integration of multiple chemical (using two analytical platforms, UHPLC/Q-Orbitrap MS and NMR) and biological (four in vitro models) approaches by determining both the primary and secondary metabolites demonstrated a powerful strategy that could facilitate the holistic quality evaluation of traditional Chinese medicine.

DNA Topoisomerase I Inhibitory Activity of Quinochalcone C-glycosides from the Florets of Carthamus tinctorius

The DNA topoisomerase (Topo) I inhibitory activity of six quinochalcone C-glycosides (QCGs) isolated from the florets of Carthamus tinctorius were evaluated in vitro. Among them, anhydrosafflor yellow B (AHSYB, 4) and carthorquinoside B (6) could inhibit DNA Topo I at concentrations as low as 100 μM. Molecular docking study revealed that both of them have the capacity to stabilize Topo I-DNA cleavage complex in silico interacting with the essential binding sites, such as Arg364, Thr718 and TGP11. Besides, both compounds 4 and 6 exhibited no antitumor activity by in vitro cytotoxicity assays.

Isocartormin, a novel quinochalcone C-glycoside from Carthamus tinctorius

A new semi-quinonechalcone C-glycoside isocartormin along with cartormin and safflomin C were isolated from the water extract of Carthamus tinctorius L. The structure of isocartormin was determined by extensive analysis of HR-MS, 1D- and 2D NMR data, and by comparison with those of cartormin reported previously by our group. Isocartormin was identified as a diastereoisomer of cartormin with a reverse configuration at C-18.

Comparative Analysis of the Effects of Hydroxysafflor Yellow A and Anhydrosafflor Yellow B in Safflower Series of Herb Pairs Using Prep-HPLC and a Selective Knock-Out Approach

The flower of Carthamus tinctorius L. (Carthami Flos, safflower), important in traditional Chinese medicine (TCM), is known for treating blood stasis, coronary heart disease, hypertension, and cerebrovascular disease in clinical and experimental studies. It is widely accepted that hydroxysafflor yellow A (HSYA) and anhydrosafflor yellow B (ASYB) are the major bioactive components of many formulae comprised of safflower. In this study, selective knock-out of target components such as HSYA and ASYB by using preparative high performance liquid chromatography (prep-HPLC) followed by antiplatelet and anticoagulation activities evaluation was used to investigate the roles of bioactive ingredients in safflower series of herb pairs. The results showed that both HSYA and ASYB not only played a direct role in activating blood circulation, but also indirectly made a contribution to the total bioactivity of safflower series of herb pairs. The degree of contribution of HSYA in the safflower and its series herb pairs was as follows: Carthami Flos-Ginseng Radix et Rhizoma Rubra (CF-GR) > Carthami Flos-Sappan Lignum (CF-SL) > Carthami Flos-Angelicae Sinensis Radix (CF-AS) > Carthami Flos-Astragali Radix (CF-AR) > Carthami Flos-Angelicae Sinensis Radix (CF-AS) > Carthami Flos-Glycyrrhizae Radix et Rhizoma (CF-GL) > Carthami Flos-Salviae Miltiorrhizae Radix et Rhizoma (CF-SM) > Carthami Flos (CF), and the contribution degree of ASYB in the safflower and its series herb pairs: CF-GL > CF-PS > CF-AS > CF-SL > CF-SM > CF-AR > CF-GR > CF. So, this study provided a significant and effective approach to elucidate the contribution of different herbal components to the bioactivity of the herb pair, and clarification of the variation of herb-pair compatibilities. In addition, this study provides guidance for investigating the relationship between herbal compounds and the bioactivities of herb pairs. It also provides a scientific basis for reasonable clinical applications and new drug development on the basis of the safflower series of herb pairs.

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.

Selective and comprehensive characterization of the quinochalcone C-glycoside homologs in Carthamus tinctorius L. by offline comprehensive two-dimensional liquid chromatography/LTQ-Orbitrap MS coupled with versatile data mining strategies

An offline 2D LC/LTQ-Orbitrap MS approach and versatile data mining techniques were developed to characterize new QCGs from C. tinctorius.