Delineation of Platelet Activation Pathway of Scutellarein Revealed Its Intracellular Target as Protein Kinase C

Review on the pharmacological effects and pharmacokinetics of scutellarein

Scutellarein is a flavonoid from Scutellaria baicalensis Georgi that has been shown to have a variety of pharmacological activities. This review aims to summarize the pharmacological and pharmacokinetic studies on scutellarein and provide useful information for relevant scholars. Pharmacological studies indicate that scutellarein possesses a diverse range of pharmacological properties, including but not limited to anti-inflammatory, antioxidant, antiviral, neuroprotective, hypoglycemic, hypolipidemic, anticancer, and cardiovascular protective effects. Further investigation reveals that the pharmacological effects of scutellarein are driven by multiple mechanisms. These mechanisms encompass the scavenging of free radicals, inhibition of the activation of inflammatory signaling pathways and expression of inflammatory mediators, inhibition of the activity of crucial viral proteins, suppression of gluconeogenesis, amelioration of insulin resistance, improvement of cerebral ischemia-reperfusion injury, induction of apoptosis in cancer cells, and prevention of myocardial hypertrophy, among others. In summary, these pharmacological studies suggest that scutellarein holds promise for the treatment of various diseases. It is imperative to conduct clinical studies to further elucidate the therapeutic effects of scutellarein. However, it is worth noting that studies on the pharmacokinetics reveal an inhibitory effect of scutellarein on uridine 5'-diphosphate glucuronide transferases and cytochrome P450 enzymes, potentially posing safety risks.

Genetic and nongenetic drivers of platelet reactivity in healthy Tanzanian individuals

BACKGROUND

Platelets play a key role in hemostasis, inflammation, and cardiovascular diseases. Platelet reactivity is highly variable between individuals. The drivers of this variability in populations from Sub-Saharan Africa remain largely unknown.

OBJECTIVES

We aimed to investigate the nongenetic and genetic determinants of platelet reactivity in healthy adults living in a rapidly urbanizing area in Northern Tanzania.

METHODS

Platelet activation and reactivity were measured by platelet P-selectin expression and the binding of fibrinogen in unstimulated blood and after ex vivo stimulation with adenosine diphosphate and PAR-1 and PAR-4 ligands. We then analyzed the associations of platelet parameters with host genetic and nongenetic factors, environmental factors, plasma inflammatory markers, and plasma metabolites.

RESULTS

Only a few associations were found between platelet reactivity parameters and plasma inflammatory markers and nongenetic host and environmental factors. In contrast, untargeted plasma metabolomics revealed a large number of associations with food-derived metabolites, including phytochemicals that were previously reported to inhibit platelet reactivity. Genome-wide single-nucleotide polymorphism genotyping identified 2 novel single-nucleotide polymorphisms (rs903650 and rs4789332) that were associated with platelet reactivity at the genome-wide level (P < 5 × 10-8) as well as a number of variants in the PAR4 gene (F2RL3) that were associated with PAR4-induced reactivity.

CONCLUSION

Our study uncovered factors that determine variation in platelet reactivity in a population in East Africa that is rapidly transitioning to an urban lifestyle, including the importance of genetic ancestry and the gradual abandoning of the traditional East African diet.

Identification of phytochemicals in Qingfei Paidu decoction for the treatment of coronavirus disease 2019 by targeting the virus-host interactome

Qingfei Paidu decoction (QFPDD) has been clinically proven to be effective in the treatment of coronavirus disease 2019 (COVID-19). However, the bioactive components and therapeutic mechanisms remain unclear. This study aimed to explore the effective components and underlying mechanisms of QFPDD in the treatment of COVID-19 by targeting the virus-host interactome and verifying the antiviral activities of its active components in vitro. Key active components and targets were identified by analysing the topological features of a compound-target-pathway-disease regulatory network of QFPDD for the treatment of COVID-19. The antiviral activity of the active components was determined by a live virus infection assay, and possible mechanisms were analysed by pseudotyped virus infection and molecular docking assays. The inhibitory effects of the components tested on the virus-induced release of IL-6, IL-1β and CXCL-10 were detected by ELISA. Three components of QFPDD, oroxylin A, hesperetin and scutellarin, exhibited potent antiviral activities against live SARS-CoV-2 virus and HCoV-OC43 virus with IC₅₀ values ranging from 18.68 to 63.27 μM. Oroxylin A inhibited the entry of SARS-CoV-2 pseudovirus into target cells and inhibited SARS-CoV-2 S protein-mediated cell-cell fusion by binding with the ACE2 receptor. The active components of QFPDD obviously inhibited the IL-6, IL-1β and CXCL-10 release induced by the SARS-CoV-2 S protein. This study supports the clinical application of QFPDD and provides an effective analysis method for the in-depth study of the mechanisms of traditional Chinese medicine (TCM) in the prevention and treatment of COVID-19.

Scutellarein stimulates human sperm function by increasing the levels of intracellular calcium and tyrosine phosphorylation

As a kind of flavonoid, scutellarein is widely used to protect against various human diseases. Although the protective effects of scutellarein have been well studied, its influence on human reproduction remains unknown. In this research, we evaluated the effect of scutellarein on human sperm functions in vitro. Three different concentrations of scutellarein (1, 10, 100 μM) were applied to ejaculated human sperm. Fertilisation-essential functions, as well as the intracellular calcium concentration ([Ca²⁺ ]_i ) and protein-tyrosine phosphorylation, two factors which are vital for sperm function regulation, were evaluated. The results demonstrated that all concentrations of scutellarein utilised in this study could significantly increase sperm spontaneous capacitation and acrosome reaction through the enhancement of [Ca²⁺ ]_i . Besides, the level of tyrosine phosphorylation of sperm could also be increased by scutellarein. Meanwhile, the sperm motility could be improved by 10 and 100 μM scutellarein, which also make a significant enhancement in sperm penetration ability and hyperactivation. This is one of the limited studies showing the regulation of scutellarein on human spermatozoa functions and is helpful to enrich its application.

Tetramethylpyrazine Retards the Progression and Fibrogenesis of Endometriosis

The development of more efficacious, non-hormonal therapeutics for endometriosis is still an unmet medical need begging to be fulfilled. Growing evidence indicates that endometriotic lesions are wounds undergoing repeated tissue injury and repair, and, as such, platelets play an important role in lesional progression. Tetramethylpyrazine (TMP), a compound derived from a herb that has been used for thousands of years to combat “blood stasis” in traditional Chinese medicine, is a prescription drug in China for the treatment of cerebrovascular disorders. We tested the hypothesis that TMP can decelerate lesional progression through arresting epithelial-mesenchymal transition (EMT), fibroblast-to-myofibroblast transdifferentiation (FMT), and fibrogenesis. We found in our in vitro experiments that TMP treatment suppresses platelet-induced EMT, FMT, cellular contractility, and collagen production in a concentration-dependent manner. We also showed that in a mouse model of endometriosis, treatment with TMP significantly reduced lesion weight and the extent of lesional fibrosis and improved hyperalgesia, mostly likely through the reduction of lesional aggregation of platelets and the lesional expression of markers of EMT, FMT, and fibrogenesis. In light of our results and in view of its excellent safety profiles, TMP appears to be a promising drug candidate for treating endometriosis.

Updated evidence of Dengzhan Shengmai capsule against ischemic stroke: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke is the most common type of stroke, with high mortality, disability and recurrence rate, which brings a heavy burden to individuals, families and the medical system. Therefore, the intervention and treatment of ischemic stroke are of great significance. Chinese herbal medicine is widely used in treating stroke, for example, Dengzhan shengmai (DZSM) capsule. The current systematic review aims to comprehensively evaluate the efficacy and safety of the DZSM capsule in treating ischemic stroke.

MATERIALS AND METHODS

Eligible randomized controlled trials (RCTs) were included to evaluate the efficacy and safety of Chinese herbal medicine DZSM capsule in treating ischemic stroke. Eight electronic databases were searched up to January 27, 2021. The risk ratio (RR), standardized mean difference (SMD), or weighted mean difference (WMD) with 95% confidence interval (CI) were used to assess DZSM capsule treatment outcomes.

RESULTS

A total of 28 RCTs involving 6683 participants were included in the systematic review and meta-analysis. Compared with conventional therapy group, DZSM capsule plus conventional therapy improved Barthel Index scores (WMD: 8.97, 95%CI: 5.88-12.05) and reduced modified Rankin Scale (WMD: -0.75, 95%CI: -1.02∼ -0.48), reduced neurological functional deficit scores (WMD: -2.81, 95%CI: -4.17∼ -1.44), recurrence rate (RR: 0.57, 95%CI: 0.44-0.73) and mortality (RR: 0.54, 95%CI: 0.31-0.95), improved clinical effect (RR: 1.18, 95%CI: 1.12-1.24) and quality of life (WMD: 21.67, 95%CI: 6.74-36.61), exhibited a beneficial effect on hemorheology such as elevated levels of APTT (SMD: 1.17, 95%CI: 0.87-1.47) and INR (SMD: 1.12, 95%CI: 0.82-1.42), and on lipid metabolism such as levels of TC (SMD: -0.62, 95%CI: -1.04 ∼ -0.20), TG (SMD: -0.72, 95%CI: -1.18∼ -0.26), LDL (SMD: -1.14, 95%CI: -1.57∼ -0.71) and HDL (SMD: 0.93, 95%CI: 0.36-1.50). No trials reported severe adverse events.

CONCLUSION

DZSM capsule appears to be safe and effective in clinical applications for ischemic stroke. Based on conventional therapy, adding the DZSM capsule could reduce the mortality, recurrence rate, and neurological functional deficit scores, improve clinical effect and quality of life. In addition, compared with conventional therapy, the addition of the DZSM capsule played a beneficial role in hemorheology and lipid metabolism, which may attribute to the potential mechanism.

Combined Therapy with Traditional Chinese Medicine and Antiplatelet Drugs for Ischemic Heart Disease: Mechanism, Efficacy, and Safety

Ischemic heart disease is a significant risk factor that threatens human health, and antiplatelet drugs are routinely used to treat cases in clinical settings. Chinese medicine for promoting blood circulation and removing blood stasis (PBCRBSCM) can often be combined with antiplatelet drugs to treat ischemic heart disease. PBCRBSCM can inhibit platelet adhesion, activation, and aggregation; moreover, PBCRBSCM in combination with antiplatelet drugs exerts antiplatelet effects. The mechanism is related to several factors, including the inhibition of platelet activation and aggregation, improvement of the hemodynamic status and coagulation function, and correction of metabolism and inflammation. PBCRBSCM can also regulate the absorption and metabolism of conventional antiplatelet drugs and protect the gastric mucosal epithelial cells against damage induced by conventional antiplatelet drugs. Randomized controlled trials have confirmed that PBCRBSCM preparations and the active ingredients in these preparations can reduce resistance to aspirin and clopidogrel so that the combination of these drugs can exert their antiplatelet effects. In the perioperative treatment of patients with stable angina pectoris, unstable angina pectoris, and acute coronary syndrome undergoing percutaneous coronary intervention therapy, preparations of the active ingredients of PBCRBSCM combined with antiplatelet drugs and other conventional Western medicine treatments have been proven effective. The efficacy and safety of such combinations have also been extensively verified. Considerable progress has been made to understand the antiplatelet mechanism of PBCRBSCM. However, most clinical studies had problems, such as limited sample size and inappropriate research design, which has limited the translational use of PBCRBSCM in antiplatelet therapy. A large-scale, multicenter, randomized controlled study with cardiovascular events as the endpoint is still to be conducted to provide evidence for the combined application of PBCRBSCM and antiplatelet drugs in the prevention and treatment of ischemic heart disease.

Phenolic Bioactives as Antiplatelet Aggregation Factors: The Pivotal Ingredients in Maintaining Cardiovascular Health

Cardiovascular diseases (CVD) are one of the main causes of mortality in the world. The development of these diseases has a specific factor-alteration in blood platelet activation. It has been shown that phenolic compounds have antiplatelet aggregation abilities and a positive impact in the management of CVD, exerting prominent antioxidant, anti-inflammatory, antitumor, cardioprotective, antihyperglycemic, and antimicrobial effects. Thus, this review is intended to address the antiplatelet activity of phenolic compounds with special emphasis in preventing CVD, along with the mechanisms of action through which they are able to prevent and treat CVD. In vitro and in vivo studies have shown beneficial effects of phenolic compound-rich plant extracts and isolated compounds against CVD, despite that the scientific literature available on the antiplatelet aggregation ability of phenolic compounds in vivo is scarce. Thus, despite the current advances, further studies are needed to confirm the cardioprotective potential of phenolic compounds towards their use alone or in combination with conventional drugs for effective therapeutic interventions.

Metabolism and Pharmacological Mechanisms of Active Ingredients in Erigeron breviscapus

BACKGROUND

Erigeron breviscapus (Vant.) Hand-Mazz. is a plant species in the Compositae family. More than ten types of compounds-such as flavonoids, caffeinate esters, and volatile oils-have been identified in Erigeron breviscapus; however, it remains unknown as to which compounds are associated with clinical efficacy. In recent years, flavonoids and phenolic acids have been considered as the main effective components of Erigeron breviscapus. The metabolism and mechanisms of these compounds in vivo have been extensively studied to improve our understanding of the drug.

METHODS

In the present review, we summarize the relationships among these compounds, their metabolites, and their pharmacodynamics. Many methods have been implemented to improve the separation and bioavailability of these compounds from Erigeron breviscapus.

RESULTS

In China, Erigeron breviscapus has been used for many years. In recent years, through the study of its metabolism and the mechanisms of its effective components, the effects of Erigeron breviscapus in the treatment of various diseases have been extensively studied. Findings have indicated that Erigeron breviscapus improves cardiovascular and cerebrovascular function and that one of its ingredients, scutellarin, has potential value in the treatment of Alzheimer's disease, cancer, diabetic vascular complications, and other conditions. In addition, phenolic acid compounds and their metabolites also play an important role in anti-oxidation, anti-inflammation, and improving blood lipids.

CONCLUSION

Erigeron breviscapus plays an important role in the prevention and treatment of cardiovascular/ cerebrovascular diseases, neuroprotection, and cancer through many different mechanisms of action. Further investigation of its efficacious components and metabolites may provide more possibilities for the clinical application of traditional Chinese medicine and the development of novel drugs.

Recent Research on Flavonoids and their Biomedical Applications

Flavonoids, commonly found in various plants, are a class of polyphenolic compounds having a basic structural unit of 2-phenylchromone. Flavonoid compounds have attracted much attention due to their wide biological applications. In order to facilitate further research on the biomedical application of flavonoids, we surveyed the literature published on the use of flavonoids in medicine during the past decade, documented the commonly found structures in natural flavonoids, and summarized their pharmacological activities as well as associated mechanisms of action against a variety of health disorders including chronic inflammation, cancer, cardiovascular complications and hypoglycemia. In this mini-review, we provide suggestions for further research on the biomedical applications of flavonoids.

Scutellarin inhibits caspase-11 activation and pyroptosis in macrophages via regulating PKA signaling

Inflammatory caspase-11 senses and is activated by intracellular lipopolysaccharide (LPS) leading to pyroptosis that has critical role in defensing against bacterial infection, whereas its excess activation under pathogenic circumstances may cause various inflammatory diseases. However, there are few known drugs that can control caspase-11 activation. We report here that scutellarin, a flavonoid from Erigeron breviscapus, acted as an inhibitor for caspase-11 activation in macrophages. Scutellarin dose-dependently inhibited intracellular LPS-induced release of caspase-11p26 (indicative of caspase-11 activation) and generation of N-terminal fragment of gasdermin D (GSDMD-NT), leading to reduced pyroptosis. It also suppressed the activation of non-canonical nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome as evidenced by reduced apoptosis-associated speck-like protein containing a CARD (ASC) speck formation and decreased interleukin-1 beta (IL-1β) and caspase-1p10 secretion, whereas the NLRP3-specific inhibitor MCC950 only inhibited IL-1β and caspase-1p10 release and ASC speck formation but not pyroptosis. Scutellarin also suppressed LPS-induced caspase-11 activation and pyroptosis in RAW 264.7 cells lacking ASC expression. Moreover, scutellarin treatment increased Ser/Thr phosphorylation of caspase-11 at protein kinase A (PKA)-specific sites, and its inhibitory action on caspase-11 activation was largely abrogated by PKA inhibitor H89 or by adenylyl cyclase inhibitor MDL12330A. Collectively, our data indicate that scutellarin inhibited caspase-11 activation and pyroptosis in macrophages at least partly via regulating the PKA signaling pathway.

Compounds from Natural Sources as Protein Kinase Inhibitors

The advantage of natural compounds is their lower number of side-effects when compared to most synthetic substances. Therefore, over the past several decades, the interest in naturally occurring compounds is increasing in the search for new potent drugs. Natural compounds are playing an important role as a starting point when developing new selective compounds against different diseases. Protein kinases play a huge role in several diseases, like cancers, neurodegenerative diseases, microbial infections, or inflammations. In this review, we give a comprehensive view of natural compounds, which are/were the parent compounds in the development of more potent substances using computational analysis and SAR studies.

Prothrombotic effects of high uric acid in mice via activation of MEF2C-dependent NF-κB pathway by upregulating let-7c

Serum uric acid is reportedly associated with thrombosis development. However, still unclear is the mechanism of high uric acid in thrombosis with the involvement of let-7c. In an aim to fill this void, we conducted this study by treating mice and human umbilical vein endothelial cells with high uric acid. Analysis indicated that let-7c was upregulated in hyperuricemia patients as well as in mice and human umbilical vein endothelial cells treated with high uric acid. Furthermore, high uric acid inhibited myocyte enhancer factor-2C, but activated nuclear factor-kappa B pathway in human umbilical vein endothelial cells. Then the targeting relationship between let-7c and myocyte enhancer factor-2C was verified. On the one hand, high uric acid shortened activated partial thromboplastin time and prothrombin time of mice and declined tissue plasminogen activator level. Additionally, the treatment prolonged thrombin time and elevated the levels of thrombosis related molecules or proteins such as Fibrinogen and D-dimer. Nevertheless, these alternations could be reversed by inhibition of let-7c and nuclear factor-kappa B pathway or overexpressing myocyte enhancer factor-2C. To sum up, our results uncovered the pro-thrombotic effect of high uric acid in mice by activating myocyte enhancer factor-2C-dependent nuclear factor-kappa B pathway via let-7c upregulation.

Scutellarein inhibits the development of colon cancer via CDC4‑mediated RAGE ubiquitination

Scutellarein has been identified to serve an anti-tumor function in human colon cancer, but the underlying mechanisms remain largely unclear. The present study further investigated the effect and mechanism of scutellarein, extracted from wild chrysanthemum, in the progression of colon cancer. MTT, clone formation, flow cytometry and tumor-bearing mice assays were used to detect cell viability, clone formation, apoptosis and tumorigenesis, respectively. Western blot and quantitative PCR assays were performed for protein and mRNA expression detection. The results revealed that, compared with the control group, scutellarein treatment significantly inhibited the viability and induced the apoptosis of colon cancer cells (P<0.05), with significant decreases in receptor for advanced glycosylation end products (RAGE) protein expression and stability and an increase in RAGE ubiquitination (P<0.05). However, the effects of scutellarein exerted in cell apoptosis and viability were rescued by RAGE overexpression, and accelerated by RAGE knockdown. Additionally, it was observed that scutellarein treatment induced a significant increase in the expression of cell division control protein 4 (CDC4) compared with the control group (P<0.05), which was then verified to interact with RAGE protein and mediate its ubiquitination. Overexpression of CDC4 inhibited colon cancer cell viability and promoted the apoptosis of SW480 and T84 cells, whereas this function was weakened when RAGE was overexpressed. Furthermore, CDC4 downregulation significantly neutralized scutellarein functions in promoting cell apoptosis and inhibiting cell viability and tumorigenesis in colon cancer cells compared with the scutellarein group (P<0.05). In conclusion, the present study revealed that scutellarein inhibited the development of colon cancer through upregulating CDC4-mediated RAGE ubiquitination.

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

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.

Scutellarin Suppresses Platelet Aggregation and Stalls Lesional Progression in Mouse With Induced Endometriosis

Platelets play an important role in the development of endometriosis. Scutellarin is a flavonoid isolated from a medicinal herb traditionally used as a potent antiplatelet agent. In this study, we sought to evaluate its potential therapeutic effect, if any, in mice with induced endometriosis. Endometriosis was induced in 27 female Balb/c mice by intraperitoneal injection of uterine fragments. Two weeks after the induction, the 27 mice were randomly divided in equal sizes into 3 groups: untreated, which received only vehicle, and low-dose and high-dose groups, which received low- and high dose of scutellarin treatment. Hotplate test was administrated to all mice before endometriosis induction, and before and after the scutellarin treatment. Two weeks after the treatment, a blood sample was drawn before sacrifice and all lesions were harvested. The peripheral platelet activation rate and total lesion weight were assessed, and immunohistochemistry and histochemistry analyses were performed to evaluate the extent of proliferation, angiogenesis, fibroblast-to-myofibroblast transdifferentiation (FMT), and fibrosis in lesions. Compared with untreated mice, mice in both low-dose and high-dose groups had significantly reduced lesion weight and improved hyperalgesia. Scutellarin also reduced the peripheral-activated platelets rate and resulted in significantly reduced platelet aggregation, cellular proliferation, angiogenesis, the extent of FMT, and the extent of fibrosis in lesions. Thus, we conclude that scutellarin is efficacious in treating endometriosis in vivo by suppressing platelet aggregation, inhibiting proliferation, angiogenesis, and fibrogenesis, resulting in reduced lesion size and improved pain behavior. As such, scutellarin may be a potentially promising therapeutics for the treatment of endometriosis.

Scutellarin Suppresses NLRP3 Inflammasome Activation in Macrophages and Protects Mice against Bacterial Sepsis

The NLRP3 inflammasome plays a critical role in mediating the innate immune defense against pathogenic infections, but aberrant activation of NLRP3 inflammasome has been linked to a variety of inflammatory diseases. Thus targeting the NLRP3 inflammasome represents a promising therapeutic for the treatment of such diseases. Scutellarin is a flavonoid isolated from Erigeron breviscapus (Vant.) Hand.-Mazz. and has been reported to exhibit potent anti-inflammatory activities, but the underlying mechanism is only partly understood. In this study, we aimed to investigate whether scutellarin could affect the activation of NLRP3 inflammasome in macrophages. The results showed that scutellarin dose-dependently reduced caspase-1 activation and decreased mature interleukin-1β (IL-1β) release in lipopolysaccharide (LPS)-primed macrophages upon ATP or nigericin stimulation, indicating that scutellarin inhibited NLRP3 inflammasome activation in macrophages. Consistent with this, scutellarin also suppressed pyroptotic cell death in LPS-primed macrophages treated with ATP or nigericin. ATP or nigericin-induced ASC speck formation and its oligomerization were blocked by scutellarin pre-treatment. Intriguingly, scutellarin augmented PKA-specific phosphorylation of NLRP3 in LPS-primed macrophages, which was completely blocked by selective PKA inhibitor H89, suggesting that PKA signaling had been involved in the action of scutellarin to suppress NLRP3 inflammasome activation. Supporting this, the inhibitory effect of scutellarin on NLRP3 inflammasome activation was completely counteracted by H89 or adenyl cyclase inhibitor MDL12330A. As NLRP3-dependent release of IL-1β has a critical role in sepsis, the in vivo activity of scutellarin was assayed in a mouse model of bacterial sepsis, which was established by intraperitoneally injection of a lethal dose of viable Escherichia coli. Oral administration of scutellarin significantly improved the survival of mice with bacterial sepsis. In line with this, scutellarin treatment significantly reduced serum IL-1β levels and attenuated the infiltration of inflammatory cells in the liver of E. coli-infected mice. These data indicated that scutellarin suppressed NLRP3 inflammasome activation in macrophages by augmenting PKA signaling, highlighting its potential therapeutic application for treating NLRP3-related inflammatory diseases.

Scutellarin Prevents Nonalcoholic Fatty Liver Disease (NAFLD) and Hyperlipidemia via PI3K/AKT-Dependent Activation of Nuclear Factor (Erythroid-Derived 2)-Like 2 (Nrf2) in Rats

Background

Nonalcoholic fatty liver disease (NAFLD) is a condition characterized by excessive fat accumulation in the form of triglycerides. The incidence of NAFLD and hyperlipidemia, with their associated risks of end-stage liver and cardiovascular diseases, is increasing rapidly. This study aimed to investigate the effects of scutellarin on the experimental NAFLD in high-fat diet fed and chronic stress rats, and its possible mechanism.

Material/Methods

Sprague-Dawley rats were fed with high-fat diet and subjected to chronic stress for 12 weeks, and administered orally with scutellarin for 4 weeks (n=8), and then blood and livers were harvested for analyzing. Enzyme activity assay, immunofluorescence, Western blot, and quantitative RT-PCR were performed to analyze the factors of the oxidant/antioxidant system and pathway.

Results

After the high-fat diet and chronic stress administration for 12 weeks, serum and liver lipid metabolism of treatment groups with the different doses of SCU effectively improved and the degree of oxidative damage reduced. Using Western blot assay and immunofluorescence (IF) staining assay, Nrf2, HO-1, and PI3K, and AKT proteins significantly increased after SCU treatment for 4 weeks (P<0.01). The hepatic mRNA expression of HO-1, NQO1, and Nrf2 in SCU treatment groups was upregulated significantly through quantitative RT-PCR assay (P<0.05). However, compared to the positive control group, no difference was detected in the SCU (100 or 300 mg/kg) groups (P>0.05). These results indicate that SCU protects against NAFLD in rats via attenuation of oxidative stress.

Conclusions

The antioxidant effects of SCU on NAFLD are possibly dependent on PI3K/AKT activation with subsequent Nrf2 nuclear translocation, which increases expression of HO-1 and NQO1. We therefore suggest that breviscapine may be a potentially useful therapeutic strategy for NAFLD and hyperlipidemia.

Rapid magnetic solid-phase extraction combined with ultra-high performance liquid chromatography and quadrupole-time-of-flight mass spectrometry for analysis of thrombin binders from a crude extract and injection of Erigeron breviscapus

Thrombin, which acts as a serine protease that converts soluble fibrinogen into insoluble strands of fibrin, plays crucial roles in the blood coagulation pathway.