Preclinical evaluation of the SARS-CoV-2 Mpro inhibitor RAY1216 shows improved pharmacokinetics compared with nirmatrelvir.

Although vaccines are available for SARS-CoV-2, antiviral drugs such as nirmatrelvir are still needed, particularly for individuals in whom vaccines are less effective, such as the immunocompromised, to prevent severe COVID-19. Here we report an α-ketoamide-based peptidomimetic inhibitor of the SARS-CoV-2 main protease (Mpro), designated RAY1216. Enzyme inhibition kinetic analysis shows that RAY1216 has an inhibition constant of 8.4 nM and suggests that it dissociates about 12 times slower from Mpro compared with nirmatrelvir. The crystal structure of the SARS-CoV-2 Mpro:RAY1216 complex shows that RAY1216 covalently binds to the catalytic Cys145 through the α-ketoamide group. In vitro and using human ACE2 transgenic mouse models, RAY1216 shows antiviral activities against SARS-CoV-2 variants comparable to those of nirmatrelvir. It also shows improved pharmacokinetics in mice and rats, suggesting that RAY1216 could be used without ritonavir, which is co-administered with nirmatrelvir. RAY1216 has been approved as a single-component drug named 'leritrelvir' for COVID-19 treatment in China.

Discovery of novel bicyclic[3.3.0]proline peptidyl α-ketoamides as potent 3CL-protease inhibitors for SARS-CoV-2.

The outbreak of SARS-CoV-2 has caused global crisis on health and economics. The multiple drug-drug interaction risk associated with ritonavir warrants specialized assessment before using Paxlovid. Here we report a multiple-round SAR study to provide a novel bicyclic[3.3.0]proline peptidyl α-ketoamide compound 4a, which is endowed with excellent antiviral activities and pharmacokinetic properties. Also, in vivo HCoV-OC43 neonatal mice model demonstrated compound 4a has good in vivo efficacy. Based on these properties, compound 4a worth further SAR optimization with the goal to develop compounds with better pharmacokinetic properties and finally to realize single agent efficacy in human.

Design, synthesis and pharmacological evaluation of 4-(3-chloro-4-(3-cyclopropylthioureido)-2-fluorophenoxy)-7-methoxyquinoline-6-carboxamide (WXFL-152): a novel triple angiokinase inhibitor for cancer therapy.

Angiokinases, such as vascular endothelial-, fibroblast- and platelet-derived growth factor receptors (VEGFRs, FGFRs and PDGFRs) play crucial roles in tumor angiogenesis. Anti-angiogenesis therapy using multi-angiokinase inhibitor has achieved great success in recent years. In this study, we presented the design, synthesis, target identification, molecular mechanism, pharmacodynamics (PD) and pharmacokinetics (PK) research of a novel triple-angiokinase inhibitor WXFL-152. WXFL-152, identified from a series of 4-oxyquinoline derivatives based on a structure-activity relationship study, inhibited the proliferation of vascular endothelial cells (ECs) and pericytes by blocking the angiokinase signals VEGF/VEGFR2, FGF/FGFRs and PDGF/PDGFRß simultaneously in vitro. Significant anticancer effects of WXFL-152 were confirmed in multiple preclinical tumor xenograft models, including a patient-derived tumor xenograft (PDX) model. Pharmacokinetic studies of WXFL-152 demonstrated high favourable bioavailability with single-dose and continuous multi-dose by oral administration in rats and beagles. In conclusion, WXFL-152, which is currently in phase Ib clinical trials, is a novel and effective triple-angiokinase inhibitor with clear PD and PK in tumor therapy.

Flavonoids from the stems of Millettia pachyloba Drake mediate cytotoxic activity through apoptosis and autophagy in cancer cells.

In this study, systematic separation and subsequent pharmacological activity studies were carried out to identify cytotoxic natural products from the dried stems of Millettia pachyloba Drake. Five previously undescribed isoflavones, pachyvones A-E; one previously undescribed xanthone, pachythone A; and twenty-two known compounds were obtained. The structures of these compounds were assigned on the basis of 1D/2D NMR data and high-resolution electrospray ionization mass spectroscopy analysis. Preliminary activity screening with HeLa and MCF-7 cells showed that ten compounds (3-5, 9, 12, 17-19, 24, and 25) had potential cytotoxicity. Further in-depth activity studies with five cancer cell lines (HeLa, HepG2, MCF-7, Hct116, and MDA-MB-231) and one normal cell line (HUVEC) revealed that these ten compounds showed specific cytotoxicity in cancer cells, with IC50 values ranging from 5 to 40 µM, while they had no effect on normal cell lines. To investigate whether the cytotoxicity of these ten compounds was associated with autophagy, their autophagic effects were evaluated in GFP-LC3-HeLa cells. The results demonstrated that compound 9 (durmillone) significantly induced autophagy in a concentration-dependent manner and had the best activity as an autophagy inducer among all of the compounds. Therefore, compound 9 was selected for further study. The PI/Annexin V double staining assay and Western blotting results revealed that compound 9 also induced obvious apoptosis in HeLa and MCF-7 cells, which suggests that it mediates cytotoxic activity through activation of both apoptosis and autophagy. Taken together, this study identified ten natural cytotoxic products from the dried stems of Millettia pachyloba Drake, of which compound 9 induced apoptosis and autophagy and could be an anticancer drug candidate.

Discovery of a Novel Selective Dual Peroxisome Proliferator-Activated Receptor α/δ Agonist for the Treatment of Primary Biliary Cirrhosis.

A novel peroxisome proliferator-activated receptor (PPAR) α/δ dual agonist 5c was developed with an EC50 of 8 nM for PPARα, 5 nM for PPARδ, and >300-fold selectivity against PPARγ (EC50 = 2939 nM), respectively. Further ADME and pharmacokinetic studies indicated 5c possessed distinguished in vitro and in vivo profiles. The excellent in vivo efficacy of compound 5c was demonstrated by the rat primary biliary cirrhosis (PBC) model.

An experimental model for hypertensive crises emergencies: Long-term high-fat diet followed by acute vasoconstriction stress on spontaneously hypertensive rats.

Currently, the prevention and treatment of hypertensive crises especially when it occurs with serious adverse outcomes have led to worldwide controversy. Despite of clinical possibilities of multiple agents, clinical failures still occur frequently. Therefore, early evaluations and observations of different therapies on appropriate animals should be emphasized. In the present study, an animal model for hypertensive crises emergencies was firstly established and experimentally testified. Five-month-male spontaneously hypertensive rat was consecutively fed with 60%-Kcal fat diet for four, six, and eight weeks with body weight and blood pressure monitored every two weeks, and then followed by an acute vasoconstriction stress of 5-min ice-bath treatment in the 4-h time interval of two adrenaline injections (0.8 mg/kg). Forty-four biochemical parameters were detected, covering hepatic and renal function, blood glucose and lipid levels, myocardial enzymes and energy metabolisms, blood coagulative and anti-coagulative system, oxidative stress and anti-inflammatory cytokine, blood viscosity, and RAAS system. Six tissues including heart, brain, liver, kidney, coronary arteries, and mesenteries were removed for pathological observations with hematoxylin-eosin staining. As a result, multi-organ dysfunctions in the heart, brain, liver, kidney, vascular endothelium, and blood system were testified in the modeling rats at weeks 6 and 8. In conclusion, severe consequences of this animal model were highly similar to those in hypertensive crises emergencies, which could be further utilized in the early intervention of hypertensive crises emergencies including the possible risk factors control and efficient therapies assessment. Impact statement In the late 90s, numerous reports predicted that 1-2% of hypertensive individuals would undergo hypertensive crises (HPC) and figures reached as high as 7% when no antihypertensive therapies were administrated. Currently, clinical failures appear frequently due to the improper or excessive medication regimen instead of the illness itself. Therefore, early evaluations and observations of HPC on appropriate animal models ahead of patients should be discussed and emphasized more widely. In the present study, an appropriate animal model for HPC emergencies was firstly established, in which the consequences of long-term high-fat diet feeding followed by an acute vasoconstriction stress on the spontaneously hypertensive rats were experimentally testified. The proposed model would have a wide application prospects in early intervention of HPC emergencies including the controls of possible risk factors and assessments of efficient therapies.

Discovery and optimization of selective FGFR4 inhibitors via scaffold hopping.

Introduction of a Michael acceptor on a flexible scaffold derived from pan-FGFR inhibitors has successfully yielded a novel series of highly potent FGFR4 inhibitors with selectivity over FGFR1. Due to reduced lipophilicity and aromatic ring count, this series demonstrated improved solubility and permeability. However, plasma instability and fast metabolism limited its potential for in vivo studies. Efforts have been made to address these problems, which led to the discovery of compound (-)-11 with improved stability, CYP inhibition, and good activity/selectivity for further optimization.

A simple method to improve the stability of docetaxel micelles.

Self-assembled polymeric micelles have been widely applied in drug delivery systems. In this study, we found that pH value of micellar system solution was the decisive factor of physical stability. Furthermore, the weak basic solution could maintain the solution clarification for a relative long time. To investigate the stability of polymeric micelles in different pH solutions, the micellar particle size and the docetaxel content remaining in solution were detected at predetermined time points. The crystallographic assay of freeze-drying powder was characterized by an X-ray diffractometer. In vitro release results indicated that the PBS had little influence on the sustained-release effect of docetaxel-loaded polymeric micelles (DPM). Besides, the safety of micellar formulation was determined by an MTT assay on HEK293 cells, and the anti-tumor activity was tested on MCF-7 cells. The results demonstrated that DPM adjusted with PBS (DPM (PBS)) was of low toxicity and maintained the effectiveness of docetaxel. In vivo antitumor results indicated that DPM (PBS) had better antitumor efficacy than common docetaxel injection (DTX). Thus it was concluded that regulation of micellar solution PH by PBS is a safe and effective method to improve the physical stability of DPM. It might promote the application of micellar formulation in clinical applications.

PEG-derivatized octacosanol as micellar carrier for paclitaxel delivery.

In this study, PEG-derivatized octacosanol copolymer was successfully developed to improve the anti-tumor activity and eliminate toxicity of the commercial formulation of paclitaxel (PTX). MPEG2K-C28, the conjugation of monomethoxy Poly(ethylene glycol) 2000 and octacosanol, was readily soluble in aqueous solution and self-assembled to form micelles with small sizes (< 20 nm) that are efficient in encapsulating PTX with a drug loading of 9.38 ± 0.18% and an encapsulation efficiency of 93.90 ± 2.12%. Meanwhile, octacosanol is very safe for humans and amazingly exhibits antitumor activity through inhibition activity of matrix metalloproteinases (MMPs) and translocation of the transcription factor (nuclear factor-kappa B, NF-κB) to the nucleus, which may be able to promote synergistic effects with PTX. A sustained and slower in vitro release behavior was observed in the (PTX micelles) than that of Taxol. PTX micelles exhibited more potent cytotoxicity than Taxol in the 4T1 breast cancer cell line. More interestingly, MPEG2K-C28 selectively inhibited the growth of 4T1 cells rather than the normal cells (HEK293 and L929 cell lines), indicating the antitumor activity of octacosanol remained after conjugation with MPEG. Acute toxicity evaluations indicated that MPEG2K-C28 was a safe drug carrier. Pharmacokinetic study revealed that PTX micelles improved the T1/2 and AUC of PTX (compared with Taxol) from 1.910 ± 0.139 h and 13.999 ± 1.109 mg/l × h to 2.876 ± 0.532 h and 76.462 ± 8.619 mg/l × h in vivo, respectively. The maximal tolerated dose (MTD) for PTX micelles (ca. 120 mg PTX/kg) in mice was significantly higher than that for Taxol (ca. 20mg PTX/kg). PTX micelles exhibited slightly better antitumor activity than Taxol but safer in 4T1 breast cancer model in vivo. The cell apoptosis in the immunofluorescent studies and the cell proliferation in the immunohistochemical studies also proved the results. In conclusion, MPEG2K-C28 is a simple, safe and effective drug delivery carrier for PTX, and has some therapeutic effects in 4T1 cells in vitro. PTX micelles showed significant antitumor activity in vivo with low systemic toxicity in 4T1 breast cancer. MPEG2K-C28 micelles entrapping PTX deserve more studies in the future.

Discovery of Selective Histone Deacetylase 6 Inhibitors Using the Quinazoline as the Cap for the Treatment of Cancer.

Novel selective histone deacetylase 6 (HDAC6) inhibitors using the quinazoline as the cap were designed, synthesized, and evaluated for HDAC enzymatic assays. N-Hydroxy-4-(2-methoxy-5-(methyl(2-methylquinazolin-4-yl)amino)phenoxy)butanamide, 23bb, was the most potent selective inhibitor for HDAC6 with an IC50 of 17 nM and showed 25-fold and 200-fold selectivity relative to HDAC1 and HDAC8, respectively. In vitro, 23bb presented low nanomolar antiproliferative effects against panel of cancer cell lines. Western blot analysis further confirmed that 23bb increased acetylation level of α-tubulin in vitro. 23bb has a good pharmacokinetic profile with oral bioavailability of 47.0% in rats. In in vivo efficacy evaluations of colorectal HCT116, acute myelocytic leukemia MV4-11, and B cell lymphoma Romas xenografts, 23bb more effectively inhibited the tumor growth than SAHA even at a 4-fold reduced dose or ACY-1215 at the same dose. Our results indicated that 23bb is a potent oral anticancer candidate for selective HDAC6 inhibitor and deserves further investigation.

Core bioactive components promoting blood circulation in the traditional Chinese medicine compound xueshuantong capsule (CXC) based on the relevance analysis between chemical HPLC fingerprint and in vivo biological effects.

Compound xueshuantong capsule (CXC) is an oral traditional Chinese herbal formula (CHF) comprised of Panax notoginseng (PN), Radix astragali (RA), Salvia miltiorrhizae (SM), and Radix scrophulariaceae (RS). The present investigation was designed to explore the core bioactive components promoting blood circulation in CXC using high-performance liquid chromatography (HPLC) and animal studies. CXC samples were prepared with different proportions of the 4 herbs according to a four-factor, nine-level uniform design. CXC samples were assessed with HPLC, which identified 21 components. For the animal experiments, rats were soaked in ice water during the time interval between two adrenaline hydrochloride injections to reduce blood circulation. We assessed whole-blood viscosity (WBV), erythrocyte aggregation and red corpuscle electrophoresis indices (EAI and RCEI, respectively), plasma viscosity (PV), maximum platelet aggregation rate (MPAR), activated partial thromboplastin time (APTT), and prothrombin time (PT). Based on the hypothesis that CXC sample effects varied with differences in components, we performed grey relational analysis (GRA), principal component analysis (PCA), ridge regression (RR), and radial basis function (RBF) to evaluate the contribution of each identified component. Our results indicate that panaxytriol, ginsenoside Rb1, angoroside C, protocatechualdehyde, ginsenoside Rd, and calycosin-7-O-ß-D-glucoside are the core bioactive components, and that they might play different roles in the alleviation of circulation dysfunction. Panaxytriol and ginsenoside Rb1 had close relevance to red blood cell (RBC) aggregation, angoroside C was related to platelet aggregation, protocatechualdehyde was involved in intrinsic clotting activity, ginsenoside Rd affected RBC deformability and plasma proteins, and calycosin-7-O-ß-D-glucoside influenced extrinsic clotting activity. This study indicates that angoroside C, calycosin-7-O-ß-D-glucoside, panaxytriol, and protocatechualdehyde may have novel therapeutic uses.

Synthesis and lipid-lowering evaluation of 3-methyl-1H-purine-2,6-dione derivatives as potent and orally available anti-obesity agents.

Obesity accompanied with metabolic disorder is often complicated with a strong link of dyslipidemia and insulin resistance, whose indicator is the excess accumulation of triglycerides (TG) in cells. Consideration the idea of lipid-lowering and improving insulin resistance, 34 novel compounds by combination the xanthine scaffold with the chain of Rosiglitazone have been synthesized. Among them, several compounds showed efficiency on reducing TG in 3T3-L1 adipoctyes, and 11c exhibited the most optimal capacity in lipid-lowering and improving obese clinical symptoms in DIO mice. Furthermore, the hydrochloride of 11c (11c·HCl) showed excellent bioavailability, 58.94%, over 2 folds than that (28.03%) of 11c, and the anti-obesity effect of 11c·HCl at 50 mg/kg dose was better than that of Metformin at 150 mg/kg dose in DIO mice, almost reversed HFD to a normal level. Thus, 11c·HCl might be a potent and orally available anti-obesity agent via alleviating the obese clinical symptoms, body fat, improving serum parameters and insulin resistance and TG clearance in liver.

Millettia pachycarpa exhibits anti-inflammatory activity through the suppression of LPS-induced NO/iNOS expression.

The present study was designed to investigate the in vitro and in vivo anti-inflammatory activity of flavonoids isolated from Millettia pachycarpa Benth. The seeds of M. pachycarpa Benth were extracted with ethanol and subjected to chromatographic separation for the isolation of bioactive compounds. Their structures were elucidated by spectroscopic methods. The anti-inflammatory activity of the compounds was investigated by evaluating the inhibition ability of NO production, iNOS activity and iNOS protein expression induced by LPS-stimulated RAW264.7 macrophages in vitro and the carrageenan-induced hind paw edema model in vivo. Molecular docking simulation was also employed to obtain the binding parameters in the binding pocket of iNOS. Thirteen compounds (1-13) were isolated from Chinese herbal medicine M. pachycarpa Benth. Among them, 4-hydroxylonchocarpin (6) and deguelin (7) exhibited remarkable inhibitory rates of 66.5% and 57.7%, respectively, compared with that of 52.5% of indomethacin in LPS-induced macrophages cells. 4-hydroxylonchocarpin (6) with low toxicity (IC50 > 100 µm) exhibited better inhibitory effects to positive control of 1400W on iNOS activity at the concentration of 10 µm. Western blot assay revealed that 4-hydroxylonchocarpin (6) inhibited iNOS protein expression in RAW264.7 cells and molecular docking simulation showed that 4-hydroxylonchocarpin (6) fit well into the binding pocket of iNOS. In the carrageenan-induced paw edema model, our data revealed that the anti-inflammatory potential of 4-hydroxylonchocarpin (6) at 10 mg/kg showed comparable inhibitory ability to indomethacin at 5 h while a higher concentration of 4-hydroxylonchocarpin (6) at 50 mg/kg showed higher inhibitory activity than indomethacin, which was further confirmed by plasma levels of nitrite. The overall results suggest that 4-hydroxylonchocarpin (6) might be used as a potential therapeutic agent for inflammation-associated disorders.

Biphasic modulation of α-ENaC expression by lipopolysaccharide in vitro and in vivo.

Acute lung injury (ALI) is characterized by pulmonary edema, in which the epithelial sodium channel (ENaC) has a critical role in the clearance of edema fluid from the alveolar space. Lipopolysaccharide (LPS), frequently employed to induce ALI in experimental animal models, has been reported to regulate ENaC expression and alveolar fluid clearance. The role of LPS in regulating ENaC expression is currently controversial, with increases and decreases reported in ENaC expression in response to LPS treatment, as well as reports that ENaC expression is not affected by LPS induction. The present study aimed to systematically analyze the regulation of α­ENaC expression in LPS models of ALI at different pathological stages in vitro and in vivo. ENaC expression was observed to increase ≤8 h after LPS treatment, and to decrease thereafter. This finding may explain the contradictory data regarding α­ENaC expression in response to LPS in the lung. The results of the present study, in combination with those of previous studies, indicate that the modulation of α-ENaC expression may not be a direct genetic response to LPS exposure, but a general response of the lung to the pathological changes associated with inflammation, hypoxia and endothelial and epithelial damage involved in the development of ALI. The findings of this study may have potential clinical significance for understanding the pathogenesis of ALI and improving patient outcome.

Network pharmacology analyses of the antithrombotic pharmacological mechanism of Fufang Xueshuantong Capsule with experimental support using disseminated intravascular coagulation rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Fufang Xueshuantong (FXST) Capsule is developed on a traditional Chinese medicine remedy, with a four-herb formula of Panax notoginseng, Radix astragali, Salvia miltiorrhizae and Radix scrophulariaceae. It has been used for treatment of the clinic cardiovascular disease for many years. MATERIALS AND METHODS: Due to its complexity of compositions and polypharmacological effects, it often complicates understanding of the mechanisms of action. In the present work, we have constructed an integrated model of system pharmacology to investigate the polypharmacological mechanisms of FXST formulation for treatment of thrombosis disease. RESULTS: The predicted results showed that 22 ingredients in FXST were closely associated with 41 protein targets related to blood coagulation, fibrinolysis and platelet aggregation. Through analysis of the compound-protein target association, significant cross-targets between each herb indicated the multiple active chemical ingredients might interact with the same target simultaneously and thus explained the synergistic mechanisms of the principle of Traditional Chinese medicines (TCMs) as ''Jun (emperor) - Chen (minister) - Zuo (adjuvant) - Shi (courier)''. To validate the polypharmacological effects predicted by our network pharmacology (NetPharm) analysis, we have carried out experimental investigation the effects of FXST on the disorders of the blood coagulation system in a lipopolysaccharide-induced disseminated intravascular coagulation (DIC) rat model. The results showed that FXST could significantly ameliorate the activation of coagulation system, which is congruent with the cross-target prediction by NetPharm approach. CONCLUSIONS: The combined investigations provide more insight into better understanding of the pharmacological mechanisms of FXST, and may also offer an alternative avenue to further explore the chemical and pharmacological basis of TCMs.

Anti-tumor activity and safety evaluation of fisetin-loaded methoxy poly(ethylene glycol)-poly(epsilon-caprolactone) nanoparticles.

Fisetin (3,3',4',7-tetrahydroxyflavone) is a potential anti-tumor agent but poor water solubility hinders its application and complicates direct parenteral administration. Nanoparticle encapsulation is an efficient way to enhance the solubility of some hydrophobic drugs. In this study, methoxy poly(ethylene glycol)-polycaprolactone (MPEG-PCL) nanoparticles were successfully prepared for fisetin delivery in vitro and in vivo. Narrow distribution fisetin-loaded MPEG-PCL NPs (aproximately100 nm) were obtained via emulsification (O/W) and displayed a sustained release behavior in vitro. Moreover, hemolysis and cell cytotoxicity testing showed that MPEG-PCL is biocompatible and safe for intravenous injection. Most importantly, NPs encapsulation enhanced the anti-cancer activity of fisetin as shown in a subcutaneous LL/2 tumor model, and reduced the hepatotoxicity of fisetin. Therefore, our data demonstrate that fisetin-loaded MPEG-PCL NPs have potential application in cancer chemotherapy.

Bioactivity-guided isolation of anti-inflammation flavonoids from the stems of Millettia dielsiana Harms.

Bioactivity-guided isolation of the EtOAc extract of the stems of Millettia dielsiana Harms yielded two new isoflavones together with nine known ones. Their structures were elucidated by analysis of the spectroscopic data including 2D NMR. All of the isolates were evaluated for their potential to inhibit the LPS-induced production of nitric oxide and TNF-α in murine macrophage RAW 264.7 cells. Among the tested compounds, Millesianin C (1) had the most potent anti-inflammatory effect decreasing NO production similar to that of dexamethasone and decreasing TNF-α secretion better than that of dexamethasone. Their structure-activity relationship was also analyzed.

Protective effects of traditional Chinese medicine formula NaoShuanTong capsule on haemorheology and cerebral energy metabolism disorders in rats with blood stasis.

NaoShuanTong capsule (NSTC), an oral traditional Chinese medicine formula, is composed of Pollen Typhae, Radix Paeoniae Rubra, Rhizoma Gastrodiae, Radix Rhapontici and Radix Curcumae. It has been widely used to treat ischemic stroke in clinic for many years in China. In addition to neuronal apoptosis, haemorheology and cerebral energy metabolism disorders also play an important role in the pathogenesis and development of ischemic stroke. The present study was designed to evaluate the in vivo protective effects of NSTC on haemorheology and cerebral energy metabolism disorders in rats with blood stasis. Sixty specific pathogen-free sprague-dawley rats, male only, were randomly divided into six groups (control group, model group, aspirin (100 mg/kg/d) group, NSTC low-dose (400 mg/kg/d) group, NSTC intermediate-dose (800 mg/kg/d) group, NSTC high-dose (1600 mg/kg/d) group) with 10 animals in each. The rats except those in the control group were placed in ice-cold water (0-4 °C) for 5 min during the time interval (4 h) of two adrenaline hydrochloride injections (0.8 mg/kg) to induce blood stasis. After treatment, whole blood viscosity at three shear rates, plasma viscosity and erythrocyte sedimentation rate significantly decreased in NSTC intermediate- and high-dose groups; erythrocyte aggregation index and red corpuscle electrophoresis index significantly decreased in all the three dose NSTC groups. Moreover, treatment with high-dose NSTC could significantly improve Na+-K+ adenosine triphosphatase (ATPase) and Ca2+ ATPase activity, as well as lower lactic acid level in brain tissues. These results demonstrated the protective effects of NSTC on haemorheology and cerebral energy metabolism disorders, which may provide scientific information for the further understanding of mechanism(s) of NSTC as a clinical treatment for ischemic stroke. Furthermore, the protective effects of activating blood circulation as observed in this study might create valuable insight for the utilisation of NSTC to be a feasible alternative therapeutic agent for patients with blood stasis.

Chinese medicinal formula Fufang Xueshuantong capsule could inhibit the activity of angiotensin converting enzyme.

Fufang Xueshuantong (FXST) capsule, a Chinese medicinal formula composed of four herbals - Panax notoginseng, Radix Astragali, Radix Salvia Miltiorrhizae and Radix Scrophulariaceae, has been used to treat cardiovascular diseases for many years, but the pharmacological mechanisms underlying its effects has not been clarified. This study investigates if a connection between FXST and angiotensin converting enzyme (ACE) might be an explanation for its pharmacological effects. ACE inhibition assay was performed on FXST capsule, 50% ethanol extracts from the four herbals and three selected saponins most abundant in P. notoginseng (Ginsenoside Rg1, Ginsenoside Rb1 and Notoginsenoside R1) using a biochemical test. Reversed-phase high-performance liquid chromatography of liberated hippuric acid from the ACE assay was conducted to determine the inhibitory effect. As a result, FXST and extracts from P. notoginseng showed a significant and dose-dependent inhibition on ACE activity with the IC50 values of 115 µg/ml and 179 µg/ml, respectively. But extracts from the other three herbals and the three selected saponins had no significant effect on ACE inhibition. Compared to other reported plant extracts, FXST could be considered as an effective ACE inhibitor. The inhibition of ACE activity supports the traditional use of FXST on blood circulation and the inhibitory property of FXST is mainly caused by P. notoginseng.

Synthesis, characterization, and application of amino-terminated poly(ethylene glycol)-block-poly(epsilon-caprolactone) copolymer for paclitaxel.

In this paper, we successfully synthesized amino-terminated poly(ethylene glycol)-block-poly (epsilon-caprolactone) (NH2-PEG-PCL) block copolymer from polyethylene glycol 2000, epsilon-caprolactone (epsilon-CL) and hydrazine hydrate. The obtained copolymer was characterized by nuclear magnetic resonance (1H-NMR), the molecular weight and distribution of NH2-PEG-PCL were characterized by Gel permeation chromatography (GPC). The NH2-PEG-PCL copolymer could self-assemble into micelles in water. Paclitaxel (PTX) loaded NH2-PEG-PCL (PNPP) micelles were prepared by solid dispersion technique without organic solvent. The micelles were characterized by XRD, TEM and Malvern laser particle size. The results of this work indicated that PNPP micelles were uniform and spherical shapes in solution. The average size and zeta potential of PNPP (DL = 8%) in water was about 97.1 +/- 1.2 nm, +13.9 +/- 0.6 mV, respectively. The in vitrodrug release profile of PNPP micelles showed a clear slow-release effect. The results suggested that NH2-PEG-PCL copolymer might be an excellent carrier for hydrophobic drugs such as PTX. In particular, the NH2-PEG-PCL polymer has potential value for modifying with ligands to work as active targeting drug delivery carriers, which has great significance for cancer therapeutics.