Latest ArticlesTo screen the antithrombotic effective components group of Trichosanthes extract, and to verify its pharmacodynamics and analyze its mechanism, the HPLC fingerprint of Trichosanthes extract (0.09, 0.45, 0.9 g·kg-1) was established, and the pharmacodynamic indexes of antithrombosis in rats with aspirin (0.01 g·kg-1) as positive control group were determined (the animals used in this experiment were approved by the Medical Ethics Committee of Wannan Medical College). The antithrombotic spectrum-activity relationship of Trichosanthes extract was studied and the effective antithrombotic ingredients group was screened by grey relational analysis. The monomer compound mixed solution (0.006, 0.03, 0.06 g·kg-1) was prepared according to the content of each component in the active component group, and the pharmacodynamics and action mechanism were studied to verify the correctness of the spectrum-effect relationship. The correlation between the 22 components of Trichosanthes extract and antithrombotic efficacy was different and showed dose-effect relationship. Cytosine, uracil, guanine, hypoxanthine, xanthine, adenine, guanosine, and adenosine are the main antithrombotic components of Trichosanthes extract. The ratio of cytosine, uracil, guanine, hypoxanthine, xanthine, adenine, guanosine and adenosine was 3:12:10:5:2:8:13:14. Compared with the model group, the thrombus dry weight of each effective components group could be effectively reduced (P < 0.01 or P < 0.05), but there was no significant difference between each effective components group and the Trichosanthes extract group. Compared with the model group, the TXB2 content in group (0.06 g·kg-1, 0.03 g·kg-1) could be effectively reduced (P < 0.01 or P < 0.05), and the content of 6-keto-PGF1α could be increased in each group (P < 0.01), and the TXB2/6-keto-PGF1α tended to be normal and showed a dose-effect relationship. The effect was better than that in the Trichosanthes extract group (0.45 g·kg-1) (P < 0.01). The effective ingredients group has a good antithrombotic effect, its mechanism is to inhibit platelet aggregation and improve vascular endothelial function.
Hemorrhagic transformation (HT) is a frequent complication of ischemic stroke, especially after thrombolytic therapy. This event is associated with increased morbidity and mortality. Tissue plasminogen activator (t-PA), the only FDA proved drug for breaking blood clots, is underutilized in ischemic stroke, because of its limited therapeutic window and hemorrhagic complications. Due to the lack of clear understanding of the pathological mechanism, there are no effective drugs to decrease the incidence of HT. Pinocembrin is a natural flavonoid compound and has neuroprotective effects in animal ischemic stroke models. In this study, we investigated the role of pinocembrin in t-PA thrombolysis-induced HT in rat thromboembolic stroke model. t-PA was administrated 6 h after ischemia and pinocembrin (5, 10 and 20 mg·kg-1) was given 5 min before t-PA administration. Infarct volume, neurological score and hemoglobin content were evaluated at 24 h after ischemia. Evans blue leakage was used to detect blood-brain barrier (BBB) permeability. All procedures were approved by the Institutional Animal Care and Use Committee of the Peking Union Medical College. The results showed that treatment with t-PA at 6 h after ischemia aggravated brain injury and increased the risk of HT, with infarct volume and brain water content reached 39% and 83.4%, respectively. Pretreatment with pinocembrin decreased the infarct volume and brain water content to 28.5% and 80.3%, and improved neurological function. In addition, the combined application of pinocembrin with t-PA reduced hemoglobin content and Evans blue content in brain tissue by 50% and 40%, indicating that pinocembrin could protect the BBB permeability and reduce the occurrence of HT. Among these doses, 10 mg·kg-1 is most effective. In conclusion, our results demonstrate that the combination of pinocembrin with t-PA protects against cerebral ischemia, reduces the occurrence of HT induced by t-PA thrombolysis. Thus, pinocembrin may be a potential therapeutic drug for t-PA induced HT.
Tropinone reductase Ⅰ (TRI) is a key branch point enzyme in the midstream of tropane alkaloids (TAs) biosynthesis pathway and represents an important target for TAs metabolic engineering, which can lead to metabolic flux of substrate tropinone to TAs. A novel TRI gene was isolated from Datura arborea, a woody resource plant, and designated as DaTRI2 (GenBank accession number is MH705164). The full-length cDNA of DaTRI2 with 1 135 bp exhibits a high sequence homology (96.8%) with DaTRI, and is predicted to encode a protein of 347 amino acids. Deduced DaTRI2 protein contain a conserved TGXXXGXG motif involved in NADPH binding, the catalytic N-S-Y-K tetrad motif and eleven amino acid residues important for binding to its substrate tropinone. The phylogenetic analysis revealed that DaTRI2 and other TRIs from Solanaceous plants belong to the same cluster and DaTRI2 exhibited closest phylogenetic proximity to TRIs from Datura. DaTRI2 was expressed in E. coli and the purified recombinant protein can catalyze both tropinone reduction and tropine oxidation with an optimum pH value of 8.0 and 9.6, respectively. When tropinone was used as the substrate, the Km and Vmax values of DaTRI2 at pH 6.4 were 210.05 μmol·L-1 and 69.6 nkat·mg-1 protein respectively, while the Km and Vmax values for tropine as the substrate were 188.03 μmol·L-1 and 114 nkat·mg-1 protein respectively, at pH 9.6. DaTRI2 transcript was most abundant in the young leaf, followed by the root. Cloning of DaTRI2 gene and biochemical analysis of recombinant DaTRI2 facilitate further research on the molecular mechanism on TAs biosynthesis in woody plants and provide a more potent candidate for TAs metabolic engineering.
Ten novel oleanolic acid (OA) derivatives containing urea or thiourea group were designed and synthesized, the chemical structures were confirmed by 1H NMR, 13C NMR and HR-MS. All of these compounds were evaluated for the inhibitory activity against growth of HepG2 and SGC7901 cells. The results showed that compounds I3 and Ⅱ3 exhibited significant antitumor activities with IC50 of 9.4 and 5.5 μmol·L-1, respectively. Molecular docking studies showed that all these compounds exhibit inhibitory ability against mTOR kinase. Compounds I3 and Ⅱ3 were further evaluated for the inhibitory activity against mTOR kinase. The results showed that I3 and Ⅱ3 exhibited strong inhibitory effect on mTOR kinase with IC50 values of 0.83 and 0.26 μmol·L-1.
Hypophosphatemia is a common metabolism disease in humans. Fibroblast growth factor 23 (FGF23) inhibits phosphate reabsorption by targeting on the renal tubules. FGF23C-tail contains 73 amino acids from C-terminus of FGF23, serves as an inhibitor of FGF23, and can increase phosphate reabsorption. Therefore, FGF23C-tail is an important drug for hypophosphatemia. In this paper, we constructed a fusion protein of FGF23C-tail with HSA, and investigated the expression of the fusion protein in the Pichia pastoris system. The recombinant gene was constructed by fusion PCR. A high-yield strain was selected by G418 resistance and fermentation yield, and the expression yield was 43.7 mg·L-1 in flask. In 5 L fermenters, the highest expression yield could reach 265.6 mg·L-1. FGF23C-tail-HSA could be used as an inhibitor for FGF23, and could significantly increase blood phosphorus levels in rats. The procedures for care and use of animals were approved by the Ethics Committee of YiChun University. This paper provided a basis research for further studying physiological activity of FGF23C-tail-HSA.
A mouse model of cholestatic liver fibrosis was established by bile duct ligation (BDL) method. The effect of ginsenoside Rg1 in the disease progress and the mechanism of cholestatic liver fibrosis are investigated in this mouse model. All animal experiments in this paper have been approved by the Unit Ethics Committee. Analysis of serum biochemical indicators and pathological sections assessed liver function, liver damage and fibrosis in mice. Immunohistochemistry and Western blot assays were used to detect vascular cell adhesion molecule-1 (VCAM-1) in BDL-induced mice. Nuclear factor-κB (NF-κB) and inflammatory factors were detected to investigate related mechanism of Rg1. The results showed that expression of VCAM-1 was up-regulated and peaked at 7 days, followed by decreased expression, but still efficiently expressed compared to the sham-operated group. Compared with the model group, 40 mg·kg-1·d-1 Rg1 treatment reduced serum aspartate transaminase (AST), alanine transaminase (ALT) and total bilirubin (T.Bili) levels (P < 0.05 or P < 0.01) and liver function damage, alleviated BDL-induced liver fibrosis, significantly down-regulated the expression of VCAM-1 (P < 0.05), and inhibited the inflammatory response. In addition, Rg1 significantly reduced NF-κB p65 level in the cellular nucleus (P < 0.05). This study demonstrates that VCAM-1 is dynamically altered during BDL-induced liver fibrosis. Rg1 could dampen inflammation and alleviate cholestatic liver fibrosis via regulation of the NF-κB/VCAM-1 pathway. The results provide an experimental basis for Rg1 application for treating liver fibrosis.
To determine relative molecular weight of astragalus polysaccharides (APs), we used Shodex GS620 gel permeation chromatographic column and differential refraction detector (GPC-RI) with dextran as a reference. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and GPC combined with multi-angle laser light scattering detection (GPC-MALLS) were also used.GPC-RI measure showed four peaks of APs, with the Mw of 1 380 000, 231 000, 18 000, and 480, respectively. Three main peaks were found by GPC-RI-MALLS with the Mw as 1 148 000, 180 000, and 43 000, respectively. Strong signals in 155 000 and 18 000 were detected by MALDI-TOF-MS, which also indicated the sugar moieties of the APs as hexoses. From our study, we found that the GPC-RI method with universal correction is most suitable for Mw determination of the APs. Nevertheless, the three methods should be combined and contrasted with each other to obtain accurate information in research of polysaccharides from Chinese medicine.
In this paper, multifunctional silver-graphene quantum dot nanoparticles coated with phospholipids (ADG-DDPC) were prepared and their properties were evaluated in vitro. Cationic phospholipids 1, 2-diolefinoxy-3-trimethy-laminopropane (DOTAP) was absorbed first onto the surface of the core of silver nanoparticle (AgNPs) through the mutual attraction between the positive and negative charge. Based on the principle of phase transformation and hydrophobic interaction, dstearyl-phosphatidylglycolamine-polyethylene-glycol-cyclic-cRGD peptide (DSPE-PEG2000-cRGD) self-assembled onto the outlayer of DOTAP of AgNPs. A stable multifunctional nano-preparation was formed and its ultraviolet absorption, particle size distribution, morphology, in vitro release behavior, ability to kill cancer cells and cell uptake were studied. The maximum UV absorption of the synthesized nanometer preparation was about 400 nm. Malvern particle size meter and transmission electron microscope showed that the particle size of the nano-preparation was about 30-40 nm and its particle size distribution was uniform. The in vitro release of nano-preparation was positively correlated with the concentration of H2O2. The IC50 value of AgNPs for tumor cells was (347.78±0.06) ng·mL-1, and the IC50 value of ADG-DDPC for tumor cells was (209.68±0.09) ng·mL-1, indicating that ADG-DDPC possessed a stronger cytotoxicity than that of AgNPs. Cell uptake experiment showed that ADG-DDPC could be absorbed by tumor cells and exhibited fluoresce inside those cells. In conclusion, ADG-DDPC was successfully prepared, and in vitro characterization study pointed to that the nano-preparation exhibits a higher antitumor activity than AgNPs.
We were interested in ascertaining differences in developmental neurotoxicity in normal and blood-stasis pregnant mice administered orally Rhizoma Curcumae and the underlying molecular biology mechanisms of any differences. To answer these questions, a blood stasis model was induced by being immersion in ice water. C57BL/6 mice with blood stasis, normal C57BL/6 mice, Nrf2 knock out (KO) mice with blood stasis were randomized into control groups and Rhizoma Curcumae exposure groups. The pregnant mice were administered Rhizoma Curcumae during pregnant day 5 to day 18. The neurodevelopment reflex was examined by the positive occurring time of avoidance precipice reflex tests. Measurement of glutathione (GSH) in brain of the offspring was performed by colorimetric assays. Transcription factor NF-E2-related factor 2 (Nrf2), glutamate cysteine ligase catalytic subunit (GCLc), and glutamate cysteine ligase modifier subunit (GCLm) mRNA and protein expression in brain of the offspring were examined by real-time RT-PCR and Western blot, respectively. All animal care and experiments procedures were reviewed and approved by the Animal Care and Use Committee of Qiqihar Medical College. Our results demonstrated for the first time evidence that C57BL/6 mice treated with Rhizoma Curcumae (10.0 g·kg-1) extended the positive occurring time of avoidance precipice reflex tests of offspring mice compared with the normal control group (P < 0.05). We could not find any significant change in that of blood-stasis pregnant mice offspring compared with the normal control group (P>0.05). Compared with the normal control group, level of glutathione, mRNA and protein expression of Nrf2, GCLc, and GCLm significantly increased in brain of the offspring of blood-stasis pregnant mice (all P < 0.05). However, mice treated with Rhizoma Curcumae (10.0 g·kg-1) did not change those of offspring (all P>0.05). Knock out Nrf2 using CRISPR/Cas9 extended the positive occurring time of avoidance precipice reflex tests of offspring of blood-stasis pregnant mice (P < 0.05). To conclude, developmental neurotoxicity of the blood-stasis pregnant mice to Rhizoma Curcumae was weaker than that of the normal pregnant mice. Cold-induced Nrf2 activation has important roles in "YOU-GU-WU-YUN" phenomenon of Rhizoma Curcumae.
This study offers preliminary insight into the phytoestrogen activity and mechanism of rehmapicrogenin. In this study, we characterized the estrogenic activity of rehmapicrogenin using immature female mice in vivo and MCF-7 cell proliferation assay in vitro. All the procedures for the care of the mice were conducted in accordance with the Regulations of Experimental Animal Administration issued by the State Committee of Science and Technology of the People's Republic of China. Uterine wet weight/body mass ratios, Western blot assay for estrogen receptor, and serum estrogen levels of estradiol (E2), luteinizing hormone (LH) and follicle stimulating hormone (FSH) were investigated. The effects of rehmapicrogenin, and the estrogen receptor antagonist ICI182, 780, the estrogen receptor alpha antagonist MPP, the estrogen receptor beta antagonist THC, the G-protein coupled receptor 30 antagonist G15 combined with rehmapicrogenin on cell proliferation were examined in MCF-7 cells. Rehmapicrogenin (50 mg·kg-1) treatments demonstrated significant estrogenic activity by promoting the development of uterus in immature female mice, as well as increasing the expression of estrogen receptor alpha (ERα) and G-protein coupled receptor 30 (GPR30) at the protein level in uterus, and decreasing FSH and LH compared with the control group. Meanwhile, rehmapicrogenin (6 and 8 μmol·L-1) promoted the proliferation of MCF-7 cells, which were significantly antagonized by ICI182, 780, MPP and G15. This study demonstrates rehmapicrogenin exerts estrogenic effects through ERα and GPR30.