Chrysin 7-O-ß-D-glucuronide, a dual inhibitor of SARS-CoV-2 3CLpro and PLpro, for the prevention and treatment of COVID-19.

The emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) resulted in the coronavirus disease 2019 (COVID-19) pandemic. Given the advent of subvariants, there is an urgent need to develop novel drugs. The aim of this study was to find SARS-CoV-2 inhibitors from Scutellaria baicalensis Georgi targeting the proteases 3CLpro and PLpro. After screening 25 flavonoids, chrysin 7-O-ß-D-glucuronide was found to be a potent inhibitor of SARS-CoV-2 on Vero E6 cells, with half-maximal effective concentration of 8.72 µM. Surface plasmon resonance assay, site-directed mutagenesis and enzymatic activity measurements indicated that chrysin-7-O-ß-D-glucuronide inhibits SARS-CoV-2 by binding to H41 of 3CLpro, and K157 and E167 of PLpro. Hydrogen-deuterium exchange mass spectrometry analysis showed that chrysin-7-O-ß-D-glucuronide changes the conformation of PLpro. Finally, chrysin 7-O-ß-D-glucuronide was shown to have anti-inflammatory activity, mainly due to reduction of the levels of the pro-inflammatory cytokines interleukin (IL)-1ß and IL-6.

A highly selective C-rhamnosyltransferase from Viola tricolor and insights into its mechanisms.

C-Glycosides are important natural products with various bioactivities. In plant biosynthetic pathways, the C-glycosylation step is usually catalyzed by C-glycosyltransferases (CGTs), and most of them prefer to accept uridine 5'-diphosphate glucose (UDP-Glc) as sugar donor. No CGTs favoring UDP-rhamnose (UDP-Rha) as sugar donor has been reported, thus far. Herein, we report the first selective C-rhamnosyltransferase VtCGTc from the medicinal plant Viola tricolor. VtCGTc could efficiently catalyze C-rhamnosylation of 2-hydroxynaringenin 3-C-glucoside, and exhibited high selectivity towards UDP-Rha. Mechanisms for the sugar donor selectivity of VtCGTc were investigated by molecular dynamics (MD) simulations and molecular mechanics with generalized Born and surface area solvation (MM/GBSA) binding free energy calculations. Val144 played a vital role in recognizing UDP-Rha, and the V144T mutant could efficiently utilize UDP-Glc. This work provides a new and efficient approach to prepare flavonoid C-rhamnosides such as violanthin and iso-violanthin.

Assessing risks of algal blooms in water transfer based on algal growth potential.

Water transfer is an effective way to solve the unequal distribution of water resources to meet the needs of urban residents and industry. Annual wet weight data indicated that there may be algal blooms during water transfer. We explored the ecological risk of water transfer from Xiashan to the Jihongtan reservoir through algae growth potential (AGP) tests. The results showed that the Jihongtan reservoir had certain self-regulation abilities. When the total dissolved phosphorus (TDP) concentration was not more than 0.04 mg/L, the risk of algal bloom was low. When the N/P ratio (by mass) was less than 40, the ecological imbalance of algal growth may be caused. When the N/P ratio was 20, it was the best environment for algal growth. Under the current nutrient condition of the Jihongtan reservoir, the volume of ecological safety threshold in water transfer was 60% of the Jihongtan reservoir's capacity. If the nutrient level was further increased, the water transfer threshold would rise to 75%. In addition, water transfer may cause the homogenization of water quality and accelerate the eutrophication process of reservoirs. Regarding risk assessment, we believe that controlling nitrogen and phosphorus are more consistent with the natural evolution of reservoirs than controlling phosphorus alone for solving the problem of eutrophication.

Functional characterization, structural basis, and regio-selectivity control of a promiscuous flavonoid 7,4'-di-O-glycosyltransferase from Ziziphus jujuba var. spinosa.

A highly efficient and promiscuous 7,4'-di-O-glycosyltransferase ZjOGT3 was discovered from the medicinal plant Ziziphus jujuba var. spinosa. ZjOGT3 could sequentially catalyse 4'- and 7-O-glycosylation of flavones to produce 7,4'-di-O-glycosides with obvious regio-selectivity. For 7,4'-dihydroxyl flavanones and 3-O-glycosylated 7,4'-dihydroxyl flavones, ZjOGT3 selectively catalyses 7-O-glycosylation. The crystal structure of ZjOGT3 was solved. Structural analysis, DFT calculations, MD simulations, and site-directed mutagenesis reveal that the regio-selectivity is mainly controlled by the enzyme microenvironment for 7,4'-dihydroxyl flavones and 3-O-glycosylated 7,4'-dihydroxyl flavones. For 7,4'-dihydroxyl flavanones, the selectivity is mainly controlled by intrinsic reactivity. ZjOGT3 is the first plant flavonoid 7,4'-di-O-glycosyltransferase with a crystal structure. This work could help understand the catalytic mechanisms of multi-site glycosyltransferases and provides an efficient approach to synthesise O-glycosides with medicinal potential.

Characterization and protein engineering of glycosyltransferases for the biosynthesis of diverse hepatoprotective cycloartane-type saponins in Astragalus membranaceus.

Although plant secondary metabolites are important source of new drugs, obtaining these compounds is challenging due to their high structural diversity and low abundance. The roots of Astragalus membranaceus are a popular herbal medicine worldwide. It contains a series of cycloartane-type saponins (astragalosides) as hepatoprotective and antivirus components. However, astragalosides exhibit complex sugar substitution patterns which hindered their purification and bioactivity investigation. In this work, glycosyltransferases (GT) from A. membranaceus were studied to synthesize structurally diverse astragalosides. Three new GTs, AmGT1/5 and AmGT9, were characterized as 3-O-glycosyltransferase and 25-O-glycosyltransferase of cycloastragenol respectively. AmGT1G146V/I variants were obtained as specific 3-O-xylosyltransferases by sequence alignment, molecular modelling and site-directed mutagenesis. A combinatorial synthesis system was established using AmGT1/5/9, AmGT1G146V/S and the reported AmGT8 and AmGT8A394F . The system allowed the synthesis of 13 astragalosides in Astragalus root with conversion rates from 22.6% to 98.7%, covering most of the sugar-substitution patterns for astragalosides. In addition, AmGT1 exhibited remarkable sugar donor promiscuity to use 10 different donors, and was used to synthesize three novel astragalosides and ginsenosides. Glycosylation remarkably improved the hepatoprotective and SARS-CoV-2 inhibition activities for triterpenoids. This is one of the first attempts to produce a series of herbal constituents via combinatorial synthesis. The results provided new biocatalytic tools for saponin biosynthesis.

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

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

GuRhaGT, a highly specific saponin 2''-O-rhamnosyltransferase from Glycyrrhiza uralensis.

A highly regio- and donor-specific 2''-O-rhamnosyltransferase GuRhaGT was characterised from the medicinal plant Glycyrrhiza uralensis. GuRhaGT could efficiently catalyse rhamnosylation at 2''-OH of the C-3 glycosyl moiety of triterpenoid saponins.

Repurposing cancer drugs identifies kenpaullone which ameliorates pathologic pain in preclinical models via normalization of inhibitory neurotransmission.

Inhibitory GABA-ergic neurotransmission is fundamental for the adult vertebrate central nervous system and requires low chloride concentration in neurons, maintained by KCC2, a neuroprotective ion transporter that extrudes intracellular neuronal chloride. To identify Kcc2 gene expression­enhancing compounds, we screened 1057 cell growth-regulating compounds in cultured primary cortical neurons. We identified kenpaullone (KP), which enhanced Kcc2/KCC2 expression and function in cultured rodent and human neurons by inhibiting GSK3ß. KP effectively reduced pathologic pain-like behavior in mouse models of nerve injury and bone cancer. In a nerve-injury pain model, KP restored Kcc2 expression and GABA-evoked chloride reversal potential in the spinal cord dorsal horn. Delta-catenin, a phosphorylation-target of GSK3ß in neurons, activated the Kcc2 promoter via KAISO transcription factor. Transient spinal over-expression of delta-catenin mimicked KP analgesia. Our findings of a newly repurposed compound and a novel, genetically-encoded mechanism that each enhance Kcc2 gene expression enable us to re-normalize disrupted inhibitory neurotransmission through genetic re-programming.

Glabrone as a specific UGT1A9 probe substrate and its application in discovering the inhibitor glycycoumarin.

UDP-glucuronosyltransferase 1A9 (UGT1A9) is one of the most important UGT isoforms, and plays an important role in the metabolic elimination of therapeutic drugs via glucuronidation. Herbal medicines affecting the activity of UGT1A9 may influence the metabolism of related drugs, thus causing herb-drug interactions and even adverse effects. However, few methods are available to evaluate the activity of UGT1A9. In this study, a natural product glabrone was discovered as an isoform-specific probe substrate for UGT1A9. The Vmax and Km values of glabrone were 362.6 nmol/min/mg protein and 17.2 µM for human liver microsomes (HLMs), and 382.3 nmol/min/mg protein and 16.6 µM for recombinant human UGT1A9, respectively. Glabrone 7-O-glucuronide, the UGT1A9 metabolite of glabrone, was prepared by using a plant glucuronosyltransferase UGT88D1, and the structure was identified by NMR spectroscopy. Using glabrone as a probe, we established a rapid HPLC method to screen UGT1A9 inhibitors from 54 natural products isolated from the Chinese herbal medicine licorice. Among them, glycycoumarin was found as a potent UGT1A9 inhibitor with an IC50 value of 6.04 µM. In rats, the pretreatment of glycycoumarin (4 mg/kg, i.p.) for 3 days could remarkably increase the plasma concentrations of dapagliflozin while decrease the concentrations of dapagliflozin-O-glucuronide after administration of dapagliflozin (1 mg/kg, i.v.), which is mainly metabolized by UGT1A9. The results indicated the potential risk of herb-drug interactions between licorice and UGT1A9-metabolizing drugs.

Terpenoids from the medicinal mushroom Antrodia camphorata: chemistry and medicinal potential.

Covering: up to February 2020Antrodia camphorata is a medicinal mushroom endemic to Taiwan for the treatment of intoxication, liver injury, cancer, and inflammation. Owing to its rare occurrence and potent pharmacological activities, efforts have been devoted to identify its bioactive constituents, especially terpenoids. Since 1995, a total of 162 terpenoids including triterpenoids, meroterpenoids, sesquiterpenoids, diterpenoids, and steroids have been characterized. The ergostane-type triterpenoids (antcins) and meroterpenoids (antroquinonols) are characteristic constituents of A. camphorata. The terpenoids show anti-cancer, hepatoprotective, anti-inflammatory, anti-diabetic, and neuroprotective activities. This review summarizes the research progress on terpenoids in A. camphorata during 1995-2020, including structural diversity, resources, biosynthesis, pharmacological activities, metabolism, and toxicity. The medicinal potential of the terpenoids is also discussed.

Isolation and characterisation of N-benzyl tadalafil as a novel adulterant in a coffee-based dietary supplement.

A new tadalafil analogue was detected via high-performance liquid chromatography (HPLC)-diode array detection (DAD) during routine screening of health foods suspected of adulteration with erectile dysfunction drugs. The UV absorption spectrum of the unknown was almost identical to that of tadalafil. The analogue was purified by preparative HPLC and structural elucidation carried out by mass spectrometric and NMR spectroscopic experiments. The spectral data revealed that this tadalafil analogue bears a benzyl group instead of the methyl group. The isolated compound was identified as N-benzyl tadalafil. Considering the risk it poses to public health, this new PDE-5 analogues for ED should be included on the inspection list for illegal products.

Dissection of the general two-step di-C-glycosylation pathway for the biosynthesis of (iso)schaftosides in higher plants.

Schaftoside and isoschaftoside are bioactive natural products widely distributed in higher plants including cereal crops and medicinal herbs. Their biosynthesis may be related with plant defense. However, little is known on the glycosylation biosynthetic pathway of these flavonoid di-C-glycosides with different sugar residues. Herein, we report that the biosynthesis of (iso)schaftosides is sequentially catalyzed by two C-glycosyltransferases (CGTs), i.e., CGTa for C-glucosylation of the 2-hydroxyflavanone aglycone and CGTb for C-arabinosylation of the mono-C-glucoside. The two enzymes of the same plant exhibit high homology but remarkably different sugar acceptor and donor selectivities. A total of 14 CGTa and CGTb enzymes were cloned and characterized from seven dicot and monocot plants, including Scutellaria baicalensis, Glycyrrhiza uralensis, Oryza sativa ssp. japonica, and Zea mays, and the in vivo functions for three enzymes were verified by RNA interference and overexpression. Through transcriptome analysis, we found homologous genes in 119 other plants, indicating this pathway is general for the biosynthesis of (iso)schaftosides. Furthermore, we resolved the crystal structures of five CGTs and realized the functional switch of SbCGTb to SbCGTa by structural analysis and mutagenesis of key amino acids. The CGT enzymes discovered in this paper allow efficient synthesis of (iso)schaftosides, and the general glycosylation pathway presents a platform to study the chemical defense mechanisms of higher plants.

Effects of High-Dose Rosuvastatin on Ventricular Remodelling and Cardiac Function in ST-Segment Elevation Myocardial Infarction.

OBJECTIVE: To investigate the effects of high-dose rosuvastatin on ventricular remodelling and cardiac function in ST-segment elevation myocardial infarction (STEMI). MATERIALS AND METHODS: From January 2017 to March 2019, the clinical data of 93 patients with STEMI were collected and analysed, with 46 cases in the conventional-dose group (rosuvastatin, 10 mg/d) and 47 cases in the high-dose group (rosuvastatin, 20 mg/d). Blood lipid (TC, TG, LDL-C and HDL-C), serum inflammatory markers (hs-CRP, IL-6, TNF-α and ICAM-1), ventricular remodelling markers (NT-pro BNP, MMP-9, TIMP-4 and Gal-3) and indicators of cardiac function (LVESD, LVESD, LVESV, LVEDV, IVST and LVEF) were collected from all patients at the time of admission and 8 weeks after rosuvastatin treatment. RESULTS: After treatment with rosuvastatin for 8 weeks, compared with those in conventional-dose group, the levels of TC, TG, LDL-C, hs-CRP, IL-6, TNF-α, ICAM-1, NT-pro BNP, MMP-9 and Gal-3 in the high-dose group decreased significantly (P<0.05), while the increase of HDL-C and TIMP-4 levels was more obvious (P<0.05) than that in the conventional-dose group. Moreover, LVEF was significantly higher (P<0.05) and LVESD, LVESD, LVESV, LVEDV and IVST were significantly lower (P< 0.05) after treatment than before treatment in both groups. The improvement of cardiac ultrasound results in the high-dose group was more significant than that in the conventional-dose group (P< 0.05). CONCLUSION: This study suggests that high-dose rosuvastatin was better than conventional-dose rosuvastatin for improving blood lipid metabolism, reducing the inflammatory response, and preventing and treating ventricular remodelling and myocardial fibrosis, indicating that high-dose rosuvastatin had stronger therapeutic effect on STEMI than conventional-dose rosuvastatin.

Functional Characterization and Structural Basis of an Efficient Di-C-glycosyltransferase from Glycyrrhiza glabra.

A highly efficient di-C-glycosyltransferase GgCGT was discovered from the medicinal plant Glycyrrhiza glabra. GgCGT catalyzes a two-step di-C-glycosylation of flopropione-containing substrates with conversion rates of >98%. To elucidate the catalytic mechanisms of GgCGT, we solved its crystal structures in complex with UDP-Glc, UDP-Gal, UDP/phloretin, and UDP/nothofagin, respectively. Structural analysis revealed that the sugar donor selectivity was controlled by the hydrogen-bond interactions of sugar hydroxyl groups with D390 and other key residues. The di-C-glycosylation capability of GgCGT was attributed to a spacious substrate-binding tunnel, and the G389K mutation could switch di- to mono-C-glycosylation. GgCGT is the first di-C-glycosyltransferase with a crystal structure, and the first C-glycosyltransferase with a complex structure containing a sugar acceptor. This work could benefit the development of efficient biocatalysts to synthesize C-glycosides with medicinal potential.

Nicotinamide riboside alleviates alcohol-induced depression-like behaviours in C57BL/6J mice by altering the intestinal microbiota associated with microglial activation and BDNF expression.

The gut microbiota play an important role in many central nervous system diseases through the gut microbiota-brain axis. Recent studies suggest that nicotinamide riboside (NR) has neuroprotective properties. However, it is unknown whether NR can prevent or protect against alcohol-induced depression. Furthermore, it is unclear whether its therapeutic action involves changes in the composition of the gut microbiome. Here, we investigated the effects of NR in the mouse model of alcohol-induced depression. Treatment with NR improved the alcohol-induced depressive behaviour in mice. In addition, NR decreased the number of activated microglia in the hippocampus, and it reduced the levels of pro-inflammatory (IL-1ß, IL-6, and TNF-α) and anti-inflammatory (IL-10 and TGF-ß) cytokines in the brain of mice with alcohol-induced depression. Furthermore, NR significantly upregulated BDNF and diminished the inhibition of the AKT/GSK3ß/ß-catenin signalling pathway in the hippocampus of these mice. 16S rRNA sequencing revealed that, compared with control and NR-treated mice, the gut microbiome richness and composition were significantly altered in the depressed mice. Spearman's correlation analysis showed that differential gut bacterial genera correlated with the levels of inflammation-related cytokines and BDNF in the brain. After faecal microbiota transplantation, cognitive behaviours, microglial activity, levels of cytokines and BDNF, and activation state of the AKT/GSK3ß/ß-catenin signalling pathway (which is downstream of the BDNF receptor, TrkB) in recipient mice were similar to those in donor mice. Collectively, our findings show that NR dietary supplementation protects against alcohol-induced depression-like behaviours, possibly by altering the composition of the gut microbiota.

Diversity of O-Glycosyltransferases Contributes to the Biosynthesis of Flavonoid and Triterpenoid Glycosides in Glycyrrhiza uralensis.

Licorice (Glycyrrhiza uralensis) is a popular medicinal plant containing more than 70 flavonoid and triterpenoid glycosides. Thus far, only a few reports are available on the glycosylation enzymes involved in their biosynthesis. In this work, we mined the transcriptome data of G. uralensis and discovered 43 candidate genes for O-glycosyltransferase (O-GT). Among them, 17 genes could be expressed in E. coli, and functions of the enzymes were analyzed by catalyzing eight native substrates. As a result, we characterized 11 O-GTs, including isoflavone 7-O-GTs, flavonol 3-O-GTs, and promiscuous O-GTs catalyzing flavones, chalcones, and triterpenoids. They could efficiently synthesize key licorice compounds such as liquiritin, isoliquiritin, ononin, and 3-O-ß-d-glucuronosyl glycyrrhetinic acid. The diversity of O-GTs contributes to the biosynthesis of various glycosides in licorice. These enzymes could also be used as biocatalytic tools to synthesize other bioactive O-glycosides.

Highly specific sophorose ß-glucosidase from Sphingomonas elodea ATCC 31461 for the efficient conversion of stevioside to rubusoside.

Enzyme specificity and particularity is needed not only in enzymatic separation methods, but also in enzymatic determination methods for plant compound extraction. Stevioside, rubusoside, and rebaudioside A are natural sweet compounds from plants. These compounds have the same skeleton and only contain different side-chain glucosyl groups, making them difficult to separate. However, enzymes that target diterpenoid compounds and show specific activity for side-chain glucosyl groups are rare. Herein, we report the identification and characterization of an enzyme that can target both diterpenoid compounds and sophorose, namely, ß-glucosidase SPBGL1 from Sphingomonas elodea ATCC 31461. SPBGL1 displayed high specificity toward sophorose, and activity toward stevioside, but not rebaudioside A. The stevioside conversion rate was 98%. SPBGL1 also operated at high substrate concentrations, such as in 50% crude steviol glycoside extract. Glucose liberated from stevioside was easy to quantify using the glucose oxidase method, allowing the stevioside content to be determined.

Anti-apoptotic effects and mechanisms of salvianolic acid A on cardiomyocytes in ischemia-reperfusion injury.

Prompt myocardial reperfusion during acute myocardial infarction by fibrinolytic therapy, percutaneous coronary intervention, or coronary artery bypass grafting limits the affected area and improves prognosis. However, reperfusion itself can cause cardiomyocyte damage and decrease treatment efficacy. No treatments that effectively prevent myocardial ischemia/reperfusion (I/R) injury are currently available, and are therefore the focus of ongoing research. Salvianolic acid A (SAA), the active ingredient of the traditional Chinese herbal remedy Salvia miltiorrhiza, has anti-thrombotic activity, anti-inflammatory, and anti-cancer activity; regulates blood lipids and provides hepatic and neural protection. Recent studies demonstrated that SAA inhibits cardiomyocyte apoptosis in response to I/R by the PI3K/Akt, GSK-3ß, JNK, and ERK1/2 pathways, and by JNK-ERK1/2 crosstalk. The mechanisms for SAA attenuating cardiomyocytes apoptosis during I/R injury through the P38 MAPK, caspase, JAK/STAT, NF-κB and LOX-1 signaling pathways need further illustration. There may be potential crosstalks between PI3K/Akt and JNK, and Akt/GSK-3ß and ERK1/2 in the process of SAA against I/R-incuced cardiomyocytes apoptosis. This review summarizes the recent evidence of the anti-apoptotic effects and mechanisms of SAA against myocardial I/R injury and discusses the basis of potential clinical applications of SAA.

A comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensis.

CONTEXT: Scutellaria baicalensis Georgi (Lamiaceae) is a popular medicinal plant. Its roots are used as the famous traditional Chinese medicine Huang-Qin, which is recorded in Chinese Pharmacopoeia, European Pharmacopoeia, and British Pharmacopoeia. OBJECTIVE: This review comprehensively summarizes research progress in phytochemistry, pharmacology, and flavonoid biosynthesis of S. baicalensis. METHODS: English and Chinese literature from 1973 to March 2018 was collected from databases including Web of Science, SciFinder, PubMed, Elsevier, Baidu Scholar (Chinese), and CNKI (Chinese). Scutellaria baicalensis, chemical constituents, phytochemistry, biological activities, and biosynthesis were used as the key words. RESULTS: A total of 126 small molecules (1-126) and 6 polysaccharides have been isolated from S. baicalensis. The small molecules can be classified into four structural types, namely, free flavonoids, flavonoid glycosides, phenylethanoid glycosides, and other small molecules. Extracts of S. baicalensis and its major chemical constituents have been reported to possess anti-viral, anti-tumor, anti-bacterial, antioxidant, anti-inflammatory, hepatoprotective, and neuroprotective activities. Key steps in the biosynthetic pathways of Scutellaria flavonoids have also been summarized. CONCLUSIONS: This article could be helpful for researchers who are interested in the chemical constituents, bioactivities, biosynthesis, and clinical applications of S. baicalensis.

[Clinical significance of matrix metalloproteinase-9 and tissue factors secreted by cultured monocyte-derived macrophage of patients with coronary heart disease in vitro and the intervenient effect of puerarin on them].

OBJECTIVE: To investigate the clinical significance of matrix metalloproteinase-9 (MMP-9) and tissue factor (TF) secreted by cultured monocyte-derived macrophages (HMDM) from patients with coronary heart disease (CHD) in vitro, and to evaluate the intervenient effect of puerarin (Pur) on them. METHODS: A total of 40 patients were enrolled, including 12 patients with acute myocardial infarction (AMI), 16 patients with unstable angina pectoris (UAP), 12 patients with stable angina pectoris (SAP). Besides, 8 healthy subjects with normal coronary arteriograph were set as controls. Monocytes acquired from their peripheral blood were incubated for 48 h and induced to differentiate into macrophages by phorbolester 12-myristate 13-acetate (PMA), the contents of MMP-9 and TF in supernatant were assayed, and the relationship of them with patients' age, risk factors of CHD and coronary artery lesion scores were analyzed. HMDMs randomly from selected 12 patients with acute coronary syndrome (ACS) were arranged for observing the intervenient effects of different concentrations of Pur on the levels and activity of MMP-9 and TF. RESULTS: The levels of MMP-9 and TF in UAP and AMI patients were significantly higher than those in SAP patients and healthy subjects (P < 0.01), but no statistical correlation was found between levels of MMP-9 and TF with different CHD risk factors, as well as patients' age and coronary artery lesion scores. The levels and activity of MMP-9 and TF in the 12 ACS patients were significantly decreased in a dose-dependent manner after Pur intervention when compared with the controt group. CONCLUSION: The levels of MMP-9 and TF secreted in vitro by HMDM from CHD patients could be taken as indexes for evaluating patient's condition of ACS. Pur can inhibit the expression and the activity of MMP-9 and TF secreted by HMDM, stabilize the plaque and improve the vulnerability of blood to certain extent.