Potential roles of HSYA in attenuating sepsis-induced liver injury through multi-omics analysis

Liver injury is a strong independent predictor of mortality in patients with sepsis, in which gut dysbiosis plays a crucial role. Hydroxyl safflower yellow A (HSYA), an important component of safflower, has been used to treat liver injury in animal models. However, its role in sepsis-induced liver dysfunction and the specific molecular mechanisms remain unclear. In the current study, we first discussed the discrepancy in the gut microbiota between the cecal ligation puncture (CLP) and HSYA groups using 16 S RNA sequencing. Our data demonstrated that HSYA supplementation significantly decreased the relative abundance of Proteobacteria, Firmicutes, and Campylobacterota, and further decreased the abundance of Bacteroidota, suggesting that the protective effects of HSYA against sepsis-induced liver injury may be partially attributed to the alteration of these bacteria. In addition, the metabolomic data identified 823 differentially expressed metabolites associated with sepsis-induced liver injury. After HSYA supplementation, the levels of 56 metabolites were restored to sham-like levels. Transcriptomic analysis revealed 4990 differentially expressed genes (DEGs) between the sham and CLP groups, and after HSYA injection, 1613 genes were modulated. Comprehensive analysis demonstrated that the enrichment pathways of the 903 DEGs mainly focused on inflammatory responses, amino acid metabolism, and Lipid reactions. In conclusion, our study revealed the potential mechanism of action of HSYA in sepsis-induced liver injury through a comprehensive analysis of 16 S RNA sequencing, metabolomics, and transcriptomics, thus providing a theoretical basis for further clinical applications of HSYA.

Hydroxysafflor yellow A inhibits the hyperactivation of rat platelets by regulating the miR-9a-5p/SRC axis

Pathological platelet activation plays a vital role in the prevalence of cardiovascular diseases. Hydroxysafflor yellow A (HSYA) has been shown to have significant anti-platelet aggregation and anti-activation effects, but its mechanism of action is unclear. Our study showed that HSYA inhibited the expression of platelet surface glycoproteins IIβ/III α (GPIIβ/III α) and thromboxane A2 (TXA2) during platelet activation and reduced platelet Ca2+ accumulation. HSYA significantly reduced the number of platelets and inhibited adrenaline-induced platelet hyperaggregation in rats. Transcriptomic analysis of platelets suggested that HSYA significantly suppressed SRC and MAPK3 (ERK1/2) gene expression. YEEI peptide, an SRC activator, could significantly reverse the inhibition of HSYA on the phosphorylation of SRC/PLCγ2/PKCδ/MEK/ERK1/2 pathway proteins and reverse the effect of HSYA on platelet activation-related markers GPIIβ/IIIα protein, TXA2 and cAMP. The SRC genes were further predicted by transcriptome analysis of HSYA-regulated miRNAs combined with bioinformatics techniques. The results suggested that HSYA could significantly upregulate the expression level of the miR-9a-5p gene and further confirmed that miR-9a-5p had a targeted regulatory relationship with SRC by dual-luciferase activity reporter and cell transfection experiments. The inhibitory effect of HSYA on the SRC/PLCγ2/PKCδ/MEK/ERK1/2 pathway was significantly reversed after platelets were transfected with the miR-9a inhibitor, while SRC siRNA attenuated the effect of the miR-9a inhibitor. SRC siRNA was able to attenuate the effect of the miR-9a inhibitor. In conclusion, this study suggests that HSYA can inhibit the activation of the SRC/PLCγ2/PKC δ/MEK/ERK1/2 axis by upregulating platelet miR-9a-5p, thereby reducing the activation of platelets and inhibiting platelet aggregation.

Hydroxysafflor Yellow A Alleviates Acute Myocardial Ischemia/Reperfusion Injury in Mice by Inhibiting Ferroptosis via the Activation of the HIF-1α/SLC7A11/GPX4 Signaling Pathway

Ferroptosis is closely associated with the pathophysiology of myocardial ischemia. Hydroxysafflor yellow A (HSYA), the main active ingredient in the Chinese herbal medicine safflower, exerts significant protective effects against myocardial ischemia/reperfusion injury (MI/RI). The aim of this study was to investigate the protective effects of HSYA against MI/RI and identify the putative underlying mechanisms. An in vivo model of acute MI/RI was established in C57 mice. Subsequently, the effects of HSYA on myocardial tissue injury were evaluated by histology. Lipid peroxidation and myocardial injury marker contents in myocardial tissue and serum and iron contents in myocardial tissue were determined using biochemical assays. Mitochondrial damage was assessed using transmission electron microscopy. H9C2 cardiomyocytes were induced in vitro by oxygen-glucose deprivation/reoxygenation, and ferroptosis inducer erastin was administered to detect ferroptosis-related indicators, oxidative-stress-related indicators, and expressions of ferroptosis-related proteins and HIF-1α. In MI/RI model mice, HSYA reduced myocardial histopathological damage, ameliorated mitochondrial damage in myocardial cells, and decreased total cellular iron and ferrous ion contents in myocardial tissue. HSYA increased the protein levels of SLC7A11, HIF-1α, and GPX4 and mitigated erastin- or HIF-1α siRNA-induced damage in H9C2 cells. In summary, HSYA alleviated MI/RI by activating the HIF-1α/SLC7A11/GPX4 signaling pathway, thereby inhibiting ferroptosis.

Hydroxysafflor Yellow A-Induced Osteoblast Differentiation and Proliferation of BM-MSCs by Up-Regulating Nuclear Vitamin D Receptor

BACKGROUND

Vitamin D receptor (VDR) is critical for mineral and bone homeostasis since it plays an essential role in the osteoblast differentiation of bone marrow mesenchymal stem cells (BM-MSCs). Hydroxysafflor yellow A (HSYA) has the potential to promote bone mineralization and inhibit bone resorption, while its detailed mechanism needs to be elaborated.

OBJECTIVE

This study intends to explore the action of HSYA on the proliferation and differentiation of BM-MSC and the underlying mechanism.

METHODS

Different concentrations of HSYA to BM-MSC and CCK-8, and EdU were used to detect cell viability and proliferation. The alkaline phosphatase (ALP) was used to observe the differentiation ability of BM-MSC osteoblasts. The calcium uptake and mineralization of osteoblast-like cells were observed by alizarin red staining. The level of calcium ion uptake in cells was detected by flow cytometry. AutoDock was performed for molecular docking of HSYA to VDR protein. Immunofluorescence and western blotting were performed to detect the expression of VDR expression levels. Finally, the effect of VDR was verified by a VDR inhibitor.

RESULTS

After treatment with HSYA, the proliferation and calcium uptake of BM-MSC were increased. The level of ALP increased significantly and reached its peak on the 12th day. HSYA promoted calcium uptake and calcium deposition, and mineralization of osteoblasts. The western blotting and immunofluorescence showed that HSYA increased the expression of VDR in the osteoblast-like cell's nucleus and upregulated Osteocalcin, S100 calcium-binding protein G, and CYP24A1. In addition, HYSA treatment increased the expression of osteopontin and the synthesis of osteogenic proteins, such as Type 1 collagen. After the addition of the VDR inhibitor, the effect of HSYA was weakened.

CONCLUSION

HSYA could significantly promote the activity and proliferation of osteoblasts and increase the expression level of VDR in osteoblasts. HSYA may also improve calcium absorption by osteoblasts by regulating the synthesis of calciumbinding protein and vitamin D metabolic pathway-related proteins.

Hydroxysafflor Yellow A Exerts Neuroprotective Effects via HIF-1α/BNIP3 Pathway to Activate Neuronal Autophagy after OGD/R

In the process of ischemic stroke (IS), cellular macroautophagy/autophagy and apoptosis play a vital role in neuroprotection against it. Therefore, regulating their balance is a potential therapeutic strategy. It has been proved that hydroxysafflor yellow A (HSYA) has anti-inflammatory and antioxidant effects, which can both protect neurons. By exploring bioinformatics combined with network pharmacology, we found that HIF1A and CASP3, key factors regulating autophagy and apoptosis, may be important targets of HSYA for neuroprotection in an oxygen glucose deprivation and reperfusion (OGD/R) model. In this study, we explored a possible new mechanism of HSYA neuroprotection in the OGD/R model. The results showed that OGD/R increased the expression of HIF1A and CASP3 in SH-SY5Y cells and induced autophagy and apoptosis, while HSYA intervention further promoted the expression of HIF1A and inhibited the level of CASP3, accompanied by an increase in autophagy and a decrease in apoptosis in SH-SY5Y cells. The inhibition of HIF1A diminished the activation of autophagy induced with HSYA, while the inhibition of autophagy increased cell apoptosis and blocked the neuroprotective effect of HSYA, suggesting that the neuroprotective effect of HSYA should be mediated by activating the HIF1A/BNIP3 signaling pathway to induce autophagy. These results demonstrate that HSYA may be a promising agent for treating IS.

Both Two CtACO3 Transcripts Promoting the Accumulation of the Flavonoid Profiles in Overexpressed Transgenic Safflower

The unique flavonoids, quinochalcones, such as hydroxysafflor yellow A (HSYA) and carthamin, in the floret of safflower showed an excellent pharmacological effect in treating cardiocerebral vascular disease, yet the regulating mechanisms governing the flavonoid biosynthesis are largely unknown. In this study, CtACO3, the key enzyme genes required for the ethylene signaling pathway, were found positively related to the flavonoid biosynthesis at different floret development periods in safflower and has two CtACO3 transcripts, CtACO3-1 and CtACO3-2, and the latter was a splice variant of CtACO3 that lacked 5' coding sequences. The functions and underlying probable mechanisms of the two transcripts have been explored. The quantitative PCR data showed that CtACO3-1 and CtACO3-2 were predominantly expressed in the floret and increased with floret development. Subcellular localization results indicated that CtACO3-1 was localized in the cytoplasm, whereas CtACO3-2 was localized in the cytoplasm and nucleus. Furthermore, the overexpression of CtACO3-1 or CtACO3-2 in transgenic safflower lines significantly increased the accumulation of quinochalcones and flavonols. The expression of the flavonoid pathway genes showed an upward trend, with CtCHS1, CtF3H1, CtFLS1, and CtDFR1 was considerably induced in the overexpression of CtACO3-1 or CtACO3-2 lines. An interesting phenomenon for CtACO3-2 protein suppressing the transcription of CtACO3-1 might be related to the nucleus location of CtACO3-2. Yeast two-hybrid (Y2H), glutathione S-transferase (GST) pull-down, and BiFC experiments revealed that CtACO3-2 interacted with CtCSN5a. In addition, the interactions between CtCSN5a and CtCOI1, CtCOI1 and CtJAZ1, CtJAZ1 and CtbHLH3 were observed by Y2H and GST pull-down methods, respectively. The above results suggested that the CtACO3-2 promoting flavonoid accumulation might be attributed to the transcriptional activation of flavonoid biosynthesis genes by CtbHLH3, whereas the CtbHLH3 might be regulated through CtCSN5-CtCOI1-CtJAZ1 signal molecules. Our study provided a novel insight of CtACO3 affected the flavonoid biosynthesis in safflower.

Hydroxysafflor Yellow A Alters Fuel Selection From Glucose to Fat by Activating the PPARδ Pathway in Myocytes

Modulation of fuel selection is critical in skeletal muscle function. Hydroxysafflor yellow A (HSYA) is the major bioactive component in safflower (Carthamus tinctorius L.) and, in our previous study, has been demonstrated to promote a shift from fast to slow myofiber. However, the effects of HSYA on fuel selection in skeletal muscle and its underlying mechanisms remain unclear. In this study, the in vitro experiments found that water extracts of safflower, rich in HSYA, significantly suppressed the expressions of the genes related to glucose utilization and activated the expressions of the lipolysis genes. Furthermore, HSYA resulted in a shift in substrate utilization toward fat relative to carbohydrates in C2C12 myotubes. Animal tests showed HSYA could significantly reduce the respiratory exchange ratio and prolonge endurance performance in mice and also trigger a switch in intramuscular fuel selection preference from carbohydrates to fat at rest and during exercise. Mechanistic studies revealed that HSYA converted this fuel selection by activating peroxisome proliferator activated receptor δ (PPARδ), and these effects of HSYA could be reversed by specific suppression of PPARδ by PPARδ siRNA. Collectively, our study demonstrated that HSYA can switch substrate utilization from glucose to fat in myocytes by activating PPARδ signaling, resulting in prolonged endurance performance. These findings provided direct evidence for the endurance performance enhancement effect of HSYA and explored new perspectives for the innovation and application of HSYA in the health care industry.

Hydroxy-Safflower Yellow A Alleviates Osteoporosis in Ovariectomized Rat Model by Inhibiting Carbonic Anhydrase 2 Activity

Background: To investigate the therapeutic effect of Hydroxy-safflower yellow A (HSYA) on rat’s osteoporosis and explore its potential mechanism of action.

Methods: Bilateral ovariectomized female rats (OVX) were used to establish a postmenopausal rat model of osteoporosis. HSYA was given as an intervention, and estradiol was used as a positive control. The levels of serum alkaline phosphatase (ALP), calcium ion (Ca²⁺), and inorganic phosphorus (IP) were used to detect bone loss. Three months after modeling, the rats were sacrificed and the rat’s ovaries, kidneys, tibia, and femur were used to calculate the organ index. The bone marrow of the femur of the rats was stained with Giemsa staining. The femur strength of rats was measured by INSTRON. The degree of osteoporosis was detected by pathological staining after decalcification of bone tissue. Predicted the main targets of HSYA in combination with bioinformatics, and the proteins related to osteoclast differentiation were detected in combination with western blotting. The effect of HSYA on the differentiation of RAW264.7 cells into osteoclasts was observed.

Results: The Giemsa staining and serum test results showed that the operation was successful and affected bone metabolism. In the bone strength test, HSYA significantly increased the maximum threshold of femoral load in rats. Pathological examination showed that tibial cartilage, trabecular bone, and cortex significantly increased after treatment with HYSA. The number of osteoblasts increased while the number of osteoclasts decreased—elevated levels of type I and III collagen. Autodock was used for molecular docking of potential targets of HSYA. qPCR and western blot were used to show that the expression levels of CA2 and osteoclast differentiation-related proteins were significantly decreased after HSYA treatment. Cell level results showed that HSYA could inhibit the activity of osteoclasts and the ability of RAW264.7 cells to differentiate into osteoclasts.

Conclusion: HSYA can inhibit the differentiation and formation of osteoclasts by inhibiting the expression of CA2 and relieving osteoporosis symptoms in OVX rats.

Hydroxysafflor yellow A promotes angiogenesis in rat brain microvascular endothelial cells injured by oxygen-glucose deprivation/reoxygenation(OGD/R) through SIRT1-HIF-1α-VEGFA signaling pathway

OBJECTIVE

Angiogenesis led by brain microvascular endothelial cells (BMECs) contributes to the remission of brain injury after brain ischemia reperfusion. In this study, we investigated the effects of hydroxysafflor yellow A(HSYA) on angiogenesis of BMECs injured by OGD/R via SIRT1-HIF-1α-VEGFA signaling pathway.

METHODS

The OGD/R model of BMECs was established in vitro by OGD for 2h and reoxygenation for 24h. At first, the concentrations of vascular endothelial growth factor (VEGF), Angiopoietin (ang) and platelet-derived growth factor (PDGF) in supernatant were detected by ELISA, and the proteins expression of VEGFA, Ang-2 and PDGFB in BMECs were tested by western blot; the proliferation, adhesion, migration (scratch healing and transwell) and tube formation experiment of BMECs; the expression of CD31 and CD34 were tested by immunofluorescence staining. The levels of sirtuin1(SIRT1), hypoxia-inducible factor-1α (HIF-1α), VEGFA mRNA and protein were tested.

RESULTS

HSYA up-regulated the levels of VEGF, Ang and PDGF in the supernatant of BMECs under OGD/R, and the protein expression of VEGFA, Ang-2 and PDGFB were increased; HSYA could significantly alleviate the decrease of cell proliferation, adhesion, migration and tube formation ability of BMECs during OGD/R; HSYA enhanced the fluorescence intensity of CD31 and CD34 of BMECs during OGD/R; HSYA remarkably up-regulated the expression of SIRT1, HIF-1α, VEGFA mRNA and protein after OGD/R, and these increase decreased after SIRT1 was inhibited.

CONCLUSION

SIRT1-HIF-1α-VEGFA signaling pathway is involved in HSYA improves angiogenesis of BMECs injured by OGD/R.

Hydroxysafflor yellow A alleviates cerebral ischemia reperfusion injury by suppressing apoptosis via mitochondrial permeability transition pore

BACKGROUND

Mitochondria are key cellular organelles that are essential for cell fate decisions. Hydroxysafflor yellow A (HSYA) has displayed an impressively essential role in protection of cerebral ischemia/reperfusion (I/R). However, the mitochondrial effect of HSYA on Brain Microvascular Endothelial Cells (BMECs) under I/R remains to be largely unclear.

PURPOSE

To evaluate the protective effects of HSYA-mediated mitochondrial permeability transition pore (mPTP) on cerebral I/R injury and its mechanism.

METHODS

Cerebral I/R injury was established by the model of Middle cerebral artery occlusion (MCAO) in rats. Furthermore, to further clarify the relevant mechanism of HSYA's effects on mPTP, inhibition of extracellular regulated protein kinases (ERK) with U0126 and transfect with Cyclophilin D (CypD) SiRNA to reversely verified whether the protective effects of HSYA were exerted by regulating the Mitogen-activated protein kinase kinase (MEK)/ERK/CypD pathway.

RESULTS

HSYA treatment significantly increased BMECs viability, decreased the generation of ROS, opening of mPTP and translocation of cytochrome c after OGD/R. In addition to inhibited CypD, HSYA potentiated MEK and increased phosphorylation of ERK expression in BMECs, inhibited apoptosis mediated by mitochondrial. Notably, HSYA also significantly ameliorated neurological deficits and decreased the infarct volume in rats.

CONCLUSION

HSYA reduced the CytC export from mitochondrial by inhibited the open of mPTP via MEK/ERK/CypD pathway, contributing to the protection of I/R. Thus, our study not only revealed novel mechanisms of HSYA for its anti-I/R function, but also provided a template for the design of novel mPTP inhibitor for the treatment of various mPTP-related diseases.

Integrated metabolomics and transcriptome analysis on flavonoid biosynthesis in safflower (Carthamus tinctorius L.) under MeJA treatment

BACKGROUND

Safflower (Carthamus tinctorius L.) is an important cash crop, of which the dried tube flower is not only an important raw material for dyes and cosmetics but also an important herb widely used in traditional Chinese medicine. The pigment and bioactive compounds are composed of flavonoids (mainly quinone chalcones), and studies have reported that MeJA can promote the biosynthesis of quinone chalcones, but the mechanism underlying the effect of MeJA in safflower remains unclear. Here, we attempt to use metabolomics and transcriptome technologies to analyse the molecular mechanism of flavonoid biosynthesis under MeJA treatment in safflower.

RESULTS

Based on a UHPLC-ESI-MS/MS detection platform and a self-built database (including hydroxysafflor yellow A, HSYA), a total of 209 flavonoid metabolites were detected, and 35 metabolites were significantly different after treatment with MeJA. Among them, 24 metabolites were upregulated upon MeJA treatment, especially HSYA. Eleven metabolites were downregulated after MeJA treatment. Integrated metabolomics and transcriptome analysis showed that MeJA might upregulate the expression of upstream genes in the flavonoid biosynthesis pathway (such as CHSs, CHIs and HCTs) and downregulate the expression of downstream genes (such as F3Ms, ANRs and ANSs), thus promoting the biosynthesis of quinone chalcones, such as HSYA. The transcription expressions of these genes were validated by real-time PCR. In addition, the promoters of two genes (CtCHI and CtHCT) that were significantly upregulated under MeJA treatment were cloned and analysed. 7 and 3 MeJA response elements were found in the promoters, respectively.

CONCLUSIONS

MeJA might upregulate the expression of the upstream genes in the flavonoid biosynthesis pathway and downregulate the expression of the downstream genes, thus promoting the biosynthesis of quinone chalcones. Our results provide insights and basic data for the molecular mechanism analysis of flavonoid synthesis in safflower under MeJA treatment.

The vascular dilatation induced by Hydroxysafflor yellow A (HSYA) on rat mesenteric artery through TRPV4-dependent calcium influx in endothelial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Hydroxysafflor yellow A (HSYA) is the principal constituent of the flowers of Carthamus tinctorius L., a traditional Chinese herbal medicine, which has been used for the treatment of cerebrovascular and cardiovascular diseases due to its property of promoting blood circulation and removing blood stasis. It is dominated in the water extract of Carthamus tinctorius L., which has been used in the clinical treatment for cardiovascular diseases. HSYA exerts a variety of pharmacological efficacy upon the vascular system. However, the underlying mechanisms remain unclear.

AIM OF THE STUDY

To investigate the vascular dilatation effect of HSYA on rat mesenteric artery (MA) and its potential mechanism.

MATERIALS AND METHODS

Adult male Wistar rats were applied to the study. Tension studies were conducted to determine the dilatation activity of HSYA against pre-contracted mesenteric arterial (MA) rings by U 46619 and Phenylephrine (PE). The vascular activities were measured with or without incubation with some selective inhibitors, including L-N(ω)-nitro-L-arginine methyl ester (L-NAME, a nitro oxide synthase inhibitor), HC-067047 (a selective TRPV4 antagonist), BaCl₂ (a Kir channel blocker), and Indomethacin (Indo, a nonselective cyclooxygenase inhibitor), respectively. Immunocytochemistry, Calcium Imaging, NO Production detection, and Western Blot were also employed to further study the underlying mechanism.

RESULTS

HSYA reversed the constriction of MAs induced by U 46619 in a manner of concentration dependency, and the dilatation capability was reversed by L-NAME. This effect was significantly dependent on the intactness of MA endothelium, accompanying an increment of NO production in mesenteric arterial endothelium cells. The increment of NO production was reversed by inhibiting the PKA. Also, the expression of p-eNOS was activated by HSYA shown in Western Blot assays. The cells imaging revealed a significant increase and drop of the influx of Ca²⁺ before and after treatment with HC-067047.

CONCLUSIONS

These findings suggest that HSYA exerts vessel dilation effect on MAs via a TRPV4-dependent influx of Ca²⁺ in endothelium cells, PKA-dependent eNOS phosphorylation and NO production mechanism. The present study indicates that HSYA has the potential to be a future candidate for the treatment of hypertension.

Pharmacokinetics of Active Components From Guhong Injection in Normal and Pathological Rat Models of Cerebral Ischemia: A Comparative Study

Background and Objectives: Guhong Injection (GHI) is usually administered for the treatment of stroke in clinics. Aceglutamide and hydroxyl safflower yellow A (HSYA) are its key ingredients for brain protective effect. To investigate the pharmacokinetics of aceglutamide and HSYA under pathological and normal conditions, the pharmacokinetic parameters and characteristics of middle cerebral artery occlusion (MCAO) and normal rats given the same dosage of GHI were studied compared. Methods: 12 SD rats were divided into two groups, namely, MCAO and normal groups. Both groups were treated with GHI in the same dosage. Plasma samples were collected from the jaw vein at different time points and subsequently tested by high-performance liquid chromatography (HPLC). Results: After administration of GHI, both aceglutamide and HSYA were immediately detected in the plasma. Ninety percent of aceglutamide and HSYA was eliminated within 3 h. For aceglutamide, statistically significant differences in the parameters including AUC_(0-t), AUC_(0-∞), AUMC_(0-t), AUMC_(0-∞), C_max (P < 0.01), and V_z (P < 0.05). Meanwhile, compared with the MCAO group, in the normal group, the values of AUC_(0-t), AUMC_(0-t), VRT_(0-t), and C_max (P < 0.01) for HSYA were significantly higher, whereas the value of MRT_(0-t) was significantly lower in the normal group. Conclusions: The in vivo trials based on the different models showed that, the pharmacokinetic behaviors and parameters of aceglutamide and HSYA in GHI were completely different. These results suggest that the pathological damage of ischemia-reperfusion has a significant impact on the pharmacokinetic traits of aceglutamide and HSYA.

Overexpression of CtCHS1 Increases Accumulation of Quinochalcone in Safflower

Carthami flos, the dried petal of safflower (Carthamus tinctorius L.) has been widely used in traditional Chinese medicine to treat cardiovascular and cerebrovascular diseases, in which quinochalcone glucosides such as hydrosafflower yellow A (HSYA), carthamin are uniquely present and have been identified as active compounds. In the present study, through sequencing of a safflower floret cDNA library and subsequent microarray analysis, we found 23 unigenes (5 PALs, 1 C4Hs, 5 4CLs, 6 CHSs, 2 CHIs, 2 DFRs, 2 FLSs) involved in flavonoid pathway, of which 4 were up-regulated differentially during quinochalcone glucosides accumulation with the floret developing stage. The up-regulated genes were verified by PCR methods. Considering chalcone synthase are entry enzyme in flavonoid biosynthesis, CHS1 was focused on target gene to verify its function furtherly. Bioinformation analysis showed that CHS1 shared 86.94% conserved residues with CHS from other plants. Subcellular localization showed that CtCHS1 was localized in cytoplasm in onion epidermal cells. The transgenic safflower plant with overexpression CtCHS1 by Agrobacterium-mediated pollen-tube pathway method was firstly generated. The results present that expression of PAL2, PAL3, CHS1, CHS4, CHS6 increased and expression of CHI1 and CHI2 decreased in the transgenic plant floret. Meanwhile, the accumulation of quinochalcone glucosides increased by ∼20-30% and accumulation of quercetin-3-β-D-glucoside and quercetin decreased by 48 and 63% in the transgenic plant floret. These results suggested that CtCHS1 played an important role in quinochalcone glucosides biosynthesis rather than flavonol biosynthesis. These results also demonstrated that the pollen-tube pathway method was an efficient method for gene transformation in safflower. Our study will provide a deep understanding of potential synthetic genes involved in quinochalcone biosynthetic pathway.

Hydroxysafflor yellow A (HSYA) attenuates hypoxic pulmonary arterial remodelling and reverses right ventricular hypertrophy in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Carthamus tinctorius L. is a traditional herbal medicine native to China with properties of promoting blood circulation and removing blood stasis, which is used for the treatment of cerebrovascular and cardiovascular diseases. Hydroxysafflor yellow A (HSYA) is the main constituent isolated from the flower of Carthamus tinctorius L. which is used as a marker substance in the quality control of Carthamus tinctorius L. in Chinese Pharmacopeia.

AIM OF THE STUDY

This study is to investigate the hypertension attenuating effect of HSYA on hypoxia-induced pulmonary artery hypertension model rats, and the possible mechanism.

MATERIALS AND METHODS

The animal models were made by treating adult male Wistar rats (of the same age with the same weight of 200±25g) under hypoxia 24h per day for 9 days with or without administration of HSYA. The pulmonary arterial pressure of rats was measured after anesthetization; The right ventricular hypotrophy was evaluated by the right ventricular hypotrophy index (RVHI=[RV/(LV+S)]) as well as histomorphology assay with Hematoxylin and Eosin (HE) staining; The reducing of pulmonary artery remodelling was evaluated by histomorphology assay with HE staining; The proliferation of pulmonary artery smooth muscle cells (PASMCs) was evaluated by immunohistochemistry assays (PCNA and Ki67) and MTT assay. Cell cycle analysis and Weston-blot analysis were also performed in the study.

RESULTS

HSYA reduced the mean right ventricular systolic pressure (RVSP) of rats with hypoxic pulmonary arterial hypertension (HPH) in a manner of concentration dependency. It significantly inhibited the PASMCs proliferation and attenuated the remodelling of the pulmonary artery and right ventricular hypertrophy.

CONCLUSION

These findings suggested that HSYA protected against hypoxic induced pulmonary hypertension by reversing the remodelling of the pulmonary artery through inhibiting the proliferation and hypertrophy of PASMCs. This is in accordance with our previous finding that HSYA protects against the pulmonary artery vascular constriction. All these results suggest that HSYA may be a promising candidate for HPH treatment.

Hydroxysafflor yellow A suppresses liver fibrosis induced by carbon tetrachloride with high-fat diet by regulating PPAR-γ/p38 MAPK signaling

CONTEXT

One approach to protect against liver fibrosis is the use of herb-derived natural compounds, such as hydroxysafflor yellow A (HSYA). The antifibrosis effect of HYSA against liver fibrosis has been investigated; however, its mechanisms have not yet been entirely revealed.

OBJECTIVES

To study the protective effects of HSYA on liver fibrosis induced by carbon tetrachloride (CCl4) and a high-fat diet (HFD), and to determine the mechanism of action of HSYA.

MATERIALS AND METHODS

CCl4 and HFD were used to mimic liver fibrosis in rats, and serum biochemical indicators were determined. The antifibrosis effects of HSYA were evaluated and its mechanisms were investigated by histopathological analysis, immunohistochemical staining, enzyme-linked immunosorbent assays, real-time-PCR, and western blotting.

RESULTS

HSYA reduced CCl4- and HFD-mediated liver fibrosis and ameliorated serum biochemical indicator, downregulated the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) (0.31 ± 0.03 protein, 0.59 ± 0.02 mRNA) and transformin growth factor-β1 (TGF-β1) (0.81 ± 0.02 protein, 0.58 ± 0.04 mRNA), and upregulated the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) (1.57 ± 0.13 protein, 2.48 ± 0.19 mRNA) and matrix metallopeptidases-2 (MMP-2) (2.31 ± 0.16 protein, 2.79 ± 0.22 mRNA) (p < 0.01, versus model group). These effects were significantly attenuated by PPAR-γ antagonist GW9662 via blocking the phosphorylation of p38 MAPK.

DISCUSSION AND CONCLUSION

These data demonstrate a novel role for HSYA in inhibiting CCl4- and HFD-mediated liver fibrosis, and reveal that PPAR-γ and p38 MAPK signaling play pivotal roles in the prevention of liver fibrosis induced by CCl4 and HFD.

Liquorice, a unique "guide drug" of traditional Chinese medicine: a review of its role in drug interactions

ETHNOPHARMACOLOGICAL RELEVANCE

Liquorice is the root of Glycyrrhiza uralensis Fisch. or Glycyrrhiza glabra L., Leguminosae. It is a widely used herbal medicine native to southern Europe and parts of Asia and has beneficial applications in both the medicinal and the confectionery sectors. Unlike its usage in Europe, liquorice in traditional Chinese medicine is commonly combined with other herbs in a single prescription, as a unique "guide drug" to enhance the effectiveness of other ingredients, to reduce toxicity, and to improve flavor in almost half of Chinese herbal formulas. A review on phytochemical and pharmacological research to explain this unique "guide" effect is suggested for future investigations.

MATERIALS AND METHODS

The information was collected from scientific journals, books, and pharmacopeia. The studies about the traditional uses, randomized controlled trials, chemical, pharmacological and pharmacokinetic data related to liquorice-herb/drug interaction or combination were included in the review.

RESULTS

According to recent reports, the "guide" effect of liquorice is partially through components transformed in liquorice-drug interaction; altering enzyme activity of P450 isoforms, as evidenced by induction of model probe substrates; and modulation of drug transporter proteins such as intestinal P-glycoprotein.

CONCLUSION

The overview and comparison of traditional uses of liquorice with recent pharmacological studies and randomized controlled trials provide new insights into this ancient drug for future investigations and clinical use, especially in drug combination.

Capacity of HSYA to inhibit nitrotyrosine formation induced by focal ischemic brain injury

Peroxynitrite-mediated protein tyrosine nitration represents a crucial pathogenic mechanism of stroke. Hydroxysafflor yellow A (HSYA) is the most important active component of the safflower plant. Here we assess the neuroprotective efficacy of HSYA and investigate the mechanism through anti-nitrative pathway. Rats were subjected to 60-min ischemia followed by reperfusion. HSYA (2.5-10mg/kg) was injected at 1h after ischemia onset. Other groups received HSYA (10mg/kg) treatment at 3-9h after onset. Infarct volume, brain edema, and neurological score were evaluated at 24h after ischemia. Nitrotyrosine and inducible NO synthase (iNOS) expression, as well as NO level (nitrate/nitrite) in ischemic cortex was examined within 24h after ischemia. The ability of HSYA to scavenge peroxynitrite was evaluated in vitro. Infarct volume was significantly decreased by HSYA (P<0.05), with a therapeutic window of 3h after ischemia at dose of 10mg/kg. HSYA treatment also reduced brain edema and improved neurological score (P<0.05). Nitrotyrosine formation was dose- and time-dependently inhibited by HSYA. The time window of HSYA in decreasing protein tyrosine nitration paralleled its action in infarct volume. HSYA also greatly reduced iNOS expression and NO content at 24h after ischemia, suggesting prevention of peroxynitrite generation from iNOS. In vitro, HSYA blocked authentic peroxynitrite-induced tyrosine nitration in bovine serum albumin and primary cortical neurons. Collectively, our results indicated that post-ischemic HSYA treatment attenuates brain ischemic injury which is at least partially due to reducing nitrotyrosine formation, possibly by the combined mechanism of its peroxynitrite scavenging ability and its reduction in iNOS production.