A Metabolic Perspective and Opportunities in Pharmacologically Important Safflower

CSM-CROPGRO model to simulate safflower phenological development and yield

Crop simulation models are valuable tools for decision making regarding evaluation and crop improvement under different field conditions. CSM-CROPGRO model integrates genotype, environment and crop management portfolios to simulate growth, development and yield. Modeling the safflower response to varied climate regimes are needed to strengthen its productivity dynamics. The main objective of the study was to evaluate the performance of DSSAT-CSM-CROPGRO-Safflower (Version 4.8.2) under diverse climatic conditions. The model was calibrated using the field observations for phenology, biomass and safflower grain yield (SGY) of the year 2016-17. Estimation of genetic coefficients was performed using GLUE (Genetic Likelihood Uncertainty Estimation) program. Simulated results for days to flowering, maturity, biomass at flowering and maturity and SGY were predicted reasonably with good statistical indices. Model evaluation results elucidate phenological events with low root mean square error (6.32 and 6.52) and high d-index (0.95 and 0.96) for days to flowering and maturity respectively for all genotypes and climate conditions. Fair prediction of safflower biomass at flowering and maturity showed low RMSE (887.3 and 564.3 kg ha-1) and high d-index (0.67 and 0.93) for the studied genotypes across the environments. RMSE for validated safflower grain yield (101.8 kg ha-1) and d-index (0.95) depicted that model outperformed for all genotypes and growing conditions. Longer appropriate growing conditions at NARC-Islamabad took optimal duration to assimilate photosynthetic products lead to higher grain yield. Safflower resilience to different environments showed that it can be used as an alternate crop for different agroecological regions. Furthermore, CROPGRO-Safflower model can be used as tool to further evaluate inclusion of safflower in the existing cropping systems of studied regions.

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.

Integrated Proteomics and Metabolomics of Safflower Petal Wilting and Seed Development

Safflower (Carthamus tinctorius L.) is an ancient oilseed crop of interest due to its diversity of end-use industrial and food products. Proteomic and metabolomic profiling of its organs during seed development, which can provide further insights on seed quality attributes to assist in variety and product development, has not yet been undertaken. In this study, an integrated proteome and metabolic analysis have shown a high complexity of lipophilic proteins and metabolites differentially expressed across organs and tissues during seed development and petal wilting. We demonstrated that these approaches successfully discriminated safflower reproductive organs and developmental stages with the identification of 2179 unique compounds and 3043 peptides matching 724 unique proteins. A comparison between cotyledon and husk tissues revealed the complementarity of using both technologies, with husks mostly featuring metabolites (99%), while cotyledons predominantly yielded peptides (90%). This provided a more complete picture of mechanisms discriminating the seed envelope from what it protected. Furthermore, we showed distinct molecular signatures of petal wilting and colour transition, seed growth, and maturation. We revealed the molecular makeup shift occurring during petal colour transition and wilting, as well as the importance of benzenoids, phenylpropanoids, flavonoids, and pigments. Finally, our study emphasizes that the biochemical mechanisms implicated in the growing and maturing of safflower seeds are complex and far-reaching, as evidenced by AraCyc, PaintOmics, and MetaboAnalyst mapping capabilities. This study provides a new resource for functional knowledge of safflower seed and potentially further enables the precision development of novel products and safflower varieties with biotechnology and molecular farming applications.

Anticancer, Immunomodulatory, and Phytochemical Screening of Carthamus oxyacantha M.Bieb Growing in the North of Iraq

Carthamus oxyacantha M.Bieb is a promising repository of active phytochemicals. These bioactive compounds work synergistically to promote the plant's antioxidant, anticancer, and immunomodulatory capabilities. The present study aimed to discover the potential immunomodulatory and cytotoxicity of different extracts of Carthamus oxycantha roots. Aqueous ethanol (70%), aqueous methanol (90%), ethyl acetate, and n-hexane extracts were tested against five cell lines (T47D, MDA-MB231, Caco-2, EMT6/P, and Vero). Among these extracts, ethyl acetate and n-hexane extracts showed significant activity in inhibiting the proliferation of cancerous cells because of the presence of several phytochemical compounds, including flavonoids, phenolics, and alkaloids. The n-hexane extract was the most potent extract against T47D and Caco-2 cell lines and had IC50 values of 0.067 mg/mL and 0.067 mg/mL, respectively. In comparison, ethyl acetate extract was active against T47D and MDAMB231, and IC50 values were 0.0179 mg/mL and 0.03 mg/mL, respectively. Both n-hexane and ethyl acetate extracts reduced tumor size (by 49.981% and 51.028%, respectively). Remarkably, Carthamus oxyacantha extracts decreased the average weight of the tumor cells in the in vivo model. The plant induced significant apoptotic activity by the activation of caspase-3, immunomodulation of macrophages, and triggering of pinocytosis. The implications of these intriguing findings demand additional research to broaden the scope of the understanding of this field, opening the doors to the possibilities of using Carthamus oxyacantha M.Bieb as an effective cancer treatment adjuvant in the future.

Unraveling the functional characterization of a jasmonate-induced flavonoid biosynthetic CYP45082G24 gene in Carthamus tinctorius

The cytochrome P450 superfamily of monooxygenases plays a major role in the evolution and diversification of plant natural products. The function of cytochrome P450s in physiological adaptability, secondary metabolism, and xenobiotic detoxification has been studied extensively in numerous plant species. However, their underlying regulatory mechanism in safflower still remained unclear. In this study, we aimed to elucidate the functional role of a putative CtCYP82G24-encoding gene in safflower, which suggests crucial insights into the regulation of methyl jasmonate-induced flavonoid accumulation in transgenic plants. The results showed that methyl jasmonate (MeJA) was associated with a progressive upregulation of CtCYP82G24 expression in safflower among other treatment conditions including light, dark, and polyethylene glycol (PEG). In addition, transgenic plants overexpressing CtCYP82G24 demonstrated increased expression level of other key flavonoid biosynthetic genes, such as AtDFR, AtANS, and AtFLS, and higher content of flavonoid and anthocyanin accumulation when compared with wild-type and mutant plants. Under exogenous MeJA treatment, the CtCYP82G24 transgenic overexpressed lines showed a significant spike in flavonoid and anthocyanin content compared with wild-type and mutant plants. Moreover, the virus-induced gene silencing (VIGS) assay of CtCYP82G24 in safflower leaves exhibited decreased flavonoid and anthocyanin accumulation and reduced expression of key flavonoid biosynthetic genes, suggesting a possible coordination between transcriptional regulation of CtCYP82G24 and flavonoid accumulation. Together, our findings confirmed the likely role of CtCYP82G24 during MeJA-induced flavonoid accumulation in safflower.

Purification, Characterization and Bioactivities of Polysaccharides Extracted from Safflower (Carthamus tinctorius L.)

Polysaccharides are the main bioactive components in safflower. In this study, safflower polysaccharides (SPs) were extracted by ultrasonic assisted extraction, and four purified safflower polysaccharide fractions (named SSP1, SSP2, SSP3, and SSP4, respectively) were obtained. The physicochemical properties and in vitro physiological activities of the four fractions were investigated. The molecular weights (M_W) of the SSPs were 38.03 kDa, 43.17 kDa, 54.49 kDa, and 76.92 kDa, respectively. Glucuronic acid, galactose acid, glucose, galactose, and arabinose were the main monosaccharides. The Fourier transform infrared spectroscopy (FT-IR) indicated that the polysaccharides had α- and β-glycosidic bonds. Nuclear magnetic resonance (NMR) analysis showed that SSP1 had 6 different types of glycosidic bonds, while SSP3 had 8 different types. SSP3 exhibited relatively higher ABTS⁺ scavenging activity, Fe⁺³-reduction activity, and antiproliferative activity. The results will offer a theoretical framework for the use of SPs in the industry of functional foods and medications.

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.

Molecular Characterization of an Isoflavone 2'-Hydroxylase Gene Revealed Positive Insights into Flavonoid Accumulation and Abiotic Stress Tolerance in Safflower

Flavonoids with significant therapeutic properties play an essential role in plant growth, development, and adaptation to various environments. The biosynthetic pathway of flavonoids has long been studied in plants; however, its regulatory mechanism in safflower largely remains unclear. Here, we carried out comprehensive genome-wide identification and functional characterization of a putative cytochrome P45081E8 gene encoding an isoflavone 2'-hydroxylase from safflower. A total of 15 CtCYP81E genes were identified from the safflower genome. Phylogenetic classification and conserved topology of CtCYP81E gene structures, protein motifs, and cis-elements elucidated crucial insights into plant growth, development, and stress responses. The diverse expression pattern of CtCYP81E genes in four different flowering stages suggested important clues into the regulation of secondary metabolites. Similarly, the variable expression of CtCYP81E8 during multiple flowering stages further highlighted a strong relationship with metabolite accumulation. Furthermore, the orchestrated link between transcriptional regulation of CtCYP81E8 and flavonoid accumulation was further validated in the yellow- and red-type safflower. The spatiotemporal expression of CtCYP81E8 under methyl jasmonate, polyethylene glycol, light, and dark conditions further highlighted its likely significance in abiotic stress adaption. Moreover, the over-expressed transgenic Arabidopsis lines showed enhanced transcript abundance in OE-13 line with approximately eight-fold increased expression. The upregulation of AtCHS, AtF3'H, and AtDFR genes and the detection of several types of flavonoids in the OE-13 transgenic line also provides crucial insights into the potential role of CtCYP81E8 during flavonoid accumulation. Together, our findings shed light on the fundamental role of CtCYP81E8 encoding a putative isoflavone 2'-hydroxylase via constitutive expression during flavonoid biosynthesis.

Comparative changes in sugars and lipids show evidence of a critical node for regeneration in safflower seeds during aging

During seed aging, there is a critical node (CN) where the population viability drops sharply. Exploring the specific locations of the CN in different species of plants is crucial for understanding the biological storage properties of seeds and refining seed life span management. Safflower, a bulk oil crop that relies on seeds for propagation, has a short seed life. However, at present, its biological characteristics during storage are not clear, especially the changes in metabolic capability and cell structures. Such knowledge is needed to improve the management of safflower seed life span and effective preservation in gene banks. Here, the seed survival curve of oilseed safflower under the controlled deterioration conditions of 60% relative humidity and 50°C was detected. The seed population showed an inverted S shape for the fall in germination. In the first 12 days of aging, germination remained above 86%. Prior to the CN at approximately day 10 (C10), when viability was in the "plateau" interval, seed vigor reduced at the same imbibition time point. Further analysis of the changes in sugar concentration found that the sucrose content decreased slowly with aging and the content of raffinose and two monosaccharides decreased abruptly at C10. Differentially metabolized lipids, namely lysophospholipids [lyso-phosphatidylcholine (LPC) and lyso-phosphatidylethanolamines (LPE)] and PMeOH, increased at day 3 of aging (C3). Fatty acid content increased by C6, and the content of phospholipids [phosphatidylcholines (PC), phosphatidylethanolamines (PE), and phosphatidylinositols (PI) and glycolipids [digalactosyl diacylglycerol, monogalactosyl diacylglycerol, and sulphoquinovosyl diglycerides (SQDG)] decreased significantly from C10. In addition, the activities of raffinose hydrolase alpha-galactosidase and the glyoxylate key enzyme isocitrate lyase decreased with seed aging. Confocal microscopy and transmission electron microscopy revealed shrinkage of the seed plasma membrane at C10 and the later fragmentation. Seedling phenotypic indicators and 2,3,5-triphenyltetrazolium chloride activity assays also verified that there were significant changes in seeds quality at the CN. In summary, the time point C10 is a CN during seed population aging. Before the CN, sugar and lipid metabolism, especially fatty acid metabolism into sugar, can make up for the energy consumed by aging. After this point, the seeds were irreversibly damaged, and their viability was greatly and rapidly reduced as the cell structure became increasingly destroyed.

The Modulation of Nrf-2/HO-1 Signaling Axis by Carthamus tinctorius L. Alleviates Vascular Inflammation in Human Umbilical Vein Endothelial Cells

Carthamus tinctorius L., known as safflower, has been used in traditional treatment for cardiovascular, cerebrovascular, and diabetic vascular complications. We proposed to investigate how the ethanol extract of Carthamus tinctorius L. (ECT) can be used ethnopharmacologically and alleviate vascular inflammatory processes under cytokine stimulation in human vascular endothelial cells. Using the optimized HPLC method, six markers were simultaneously analyzed for quality control of ECT. Pretreatment with ECT (10–100 μg/mL) significantly reduced the increase of leukocyte adhesion to HUVEC by TNF-α in a dose-dependent manner. Cell adhesion molecules (CAMs) such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial cell selectin (E-selectin) are decreased by ECT. In addition, ECT significantly suppressed TNF-α-induced oxidative stress referring to reactive oxygen species (ROS) production. p65 NF-κB nuclear translocation and its activation were inhibited by ECT. Furthermore, pretreatment of ECT increased the HO-1 expression, and nuclear translocation of Nrf-2. These data suggest the potential role of ECT as a beneficial therapeutic herb in vascular inflammation via ROS/NF-kB pathway and the regulation of Nrf-2/HO-1 signaling axis is involved in its vascular protection. Thus, further study will be needed to clarify which compound is dominant for protection of vascular diseases.

Safflower Extract Inhibits ADP-Induced Human Platelet Aggregation

Safflower extract is commonly used as a traditional Chinese medicine to promote blood circulation and remove blood stasis. The antioxidant and anticancer properties of safflower extracts have been extensively studied, but their antiaggregative effects have been less analyzed. We found that safflower extract inhibited human platelet aggregation induced by ADP. In addition, we further analyzed several safflower extract compounds, such as hydroxysafflor yellow A, safflower yellow A, and luteolin, which have the same antiaggregative effect. In addition to analyzing the active components of the safflower extract, we also analyzed their roles in the ADP signaling pathways. Safflower extract can affect the activation of downstream conductors of ADP receptors (such as the production of calcium ions and cAMP), thereby affecting the expression of activated glycoproteins on the platelet membrane and inhibiting platelet aggregation. According to the results of this study, the effect of safflower extract on promoting blood circulation and removing blood stasis may be related to its direct inhibition of platelet activation.

Assessment of Metabolic Profiles in Florets of Carthamus Species Using Ultra-Performance Liquid Chromatography-Mass Spectrometry

The genus Carthamus is a diverse group of plants belonging to the family Compositae. Florets of Carthamus species exhibit various colors, including white, yellow, orange, and red, which are related to their metabolite compositions. We aimed to investigate the metabolites accumulated in florets of three wild (C. lanatus, C. palaestinus, and C. turkestanicus) and one cultivated (C. tinctorius) species of safflower at three developmental stages. Metabolites were extracted from freeze-dried florets using 70% methanol; qualification and quantification were carried out using liquid chromatography quadrupole time-of-flight mass spectrometry in positive and negative ion modes followed by extraction of the peaks. Fifty-six metabolites, including phenylpropanoids, chalcones, isoflavonoids, flavanones, flavonols, flavones, and other primary metabolites, were identified for the first time in safflower wild species. The orange florets contained high abundances of safflomin A, anhydrosafflor yellow B, and baimaside, whereas white/cream and light-yellow pigmented florets had high abundances of 1,5-dicaffeoylquinic acid, luteolin 7-O-glucuronide, and apigenin 7-O-β-D-glucuronide. The principal component analysis clearly distinguished the samples based on their pigment types, indicating that color is a dominant factor dictating the identity and amount of the metabolites. Pearson correlation data based on levels of metabolites showed that orange and yellow florets were significantly correlated to each other. White and cream pigmented species were also highly correlated. Comparison between three developmental stages of safflower wild species based on their metabolite profile showed inconsistent. The findings of this study broaden the current knowledge of safflower metabolism. The wide diversity of metabolites in safflower materials also helps in efforts to improve crop quality and agronomic traits.

Genome-wide identification and expression analysis of bZIP gene family in Carthamus tinctorius L

The basic leucine zipper (bZIP) is a widely known transcription factors family in eukaryotes. In plants, the role of bZIP proteins are crucial in various biological functions such as plant growth and development, seed maturation, response to light signal and environmental stress. To date, bZIP protein family has been comprehensively identified in Arabidopsis, castor, rice, ramie, soybean and other plant species, however, the complete genome-wide investigation of Carthamus tinctorius-bZIP family still remains unexplained. Here, we identified 52 putative bZIP genes from Carthamus tinctorius using a draft genome assembly and further analyzed their evolutionary classification, physicochemical properties, Conserved domain analysis, functional differentiation and the investigation of expression level in different tissues. Based on the common bZIP domain, CtbZIP family were clustered into 12 subfamilies renamed as (A-J, S, X), of which the X is a unique subfamily to Carthamus tinctorius. A total of 20 conserved protein motifs were found in CtbZIP proteins. The expression profiling of CtbZIP genes deciphered their tissue-specific pattern. Furthermore, the changes in CtbZIP transcript abundance suggested that their transcription regulation could be highly influenced by light intensity and hormones. Collectively, this study highlights all functional and regulatory elements of bZIP transcription factors family in Carthamus tinctorius which may serve as potential candidates for functional characterization in future.