Influence of glycosaminoglycan from Mactra veneriformison antiplatelet aggregation

Author(s):  
Qingman Cui ◽  
Wanying Wang ◽  
Yue Wang ◽  
Chunying Yuan

In this study, influence of glycosaminoglycan from Mactra veneriformis on antiplatelet aggregation in rats was studied. The results showed that glycosaminoglycan (GAG) from Mactra veneriformis could reduce the platele aggregation and the platelet adhesion rates of rats in vivo and in vitro (P<0.05, P<0.01), attenuate calcium ion concentration in rat platelets (P<0.01), increase cAMP concentration in rat platelets (P< 0.05, P<0.01), diminish TXB2 concentrationin in rat plasma (P<0.01), elevate 6-keto-PGF1a concentration in rat plasma (P<0.05, P<0.01) . This study suggests that GAG has obviously inhibitory effects on ADP-induced platelet aggregation in rats, which might account for its anti-thrombitic activity.

1998 ◽  
Vol 88 (2) ◽  
pp. 362-370 ◽  
Author(s):  
Hiroshi Aoki ◽  
Toshiki Mizobe ◽  
Shinji Nozuchi ◽  
Noriko Hiramatsu

Background The inhibitory effects of propofol on platelet aggregation are controversial because the fat emulsion used as the solvent for propofol may affect platelet function. The effects of propofol on platelet intracellular calcium ion concentration and on aggregation were investigated. Methods Platelet aggregation was measured in 10 patients who received an intravenous infusion of propofol. Intralipos, the propofol solvent, was infused in 10 healthy volunteers and platelet aggregation were measured. The in vitro effects of propofol and Intralipos on platelets were also investigated. The inhibitory effects of various concentrations of propofol were studied. The effects of propofol on the changes in intracellular calcium level using a fluorescent dye, fura-2, were also observed. Template bleeding time was measured to determine the effect of propofol in clinical use. Results Platelet aggregation was significantly inhibited by infusion of propofol, although bleeding time was not prolonged. Intralipos did not inhibit platelets either in vivo or in vitro. Propofol significantly inhibited platelet aggregation in vitro and at 5.81 +/- 2.73 microg/ml but not at 2.08 +/- 1.14 microg/ml. The increase of intracellular calcium concentration was inhibited both in influx and discharge of calcium. Conclusions Propofol inhibited platelet aggregation both in vivo and in vitro. Inhibition of platelet aggregation appeared to be caused by propofol itself and not by the fat emulsion. This inhibitory effect was also supported by the suppressed influx and discharge of calcium. No change in the bleeding time suggests that this inhibitory effect does not impair hemostasis clinically.


2021 ◽  
Author(s):  
Mallanayakanakatte D. Milan Gowda ◽  
Jayachandra K ◽  
Vikram Joshi ◽  
Vaddarahally N. Manjuprasanna ◽  
Gotravalli V. Rudresha ◽  
...  

Abstract Eleusine coracana (L.) Gaertn (E. coracana) is one of the highest consuming food crops in Asia and Africa. E. coracana is a plant with several medicinal values including anti-ulcerative, anti-diabetic, anti-viral and anti-cancer properties. However, the anti-inflammatory property of E. coracana remains to be elucidated. Therefore, the objective of present study was to investigate the potential in isolated molecule from E. coracana via a combination of in vitro, in vivo and in silico methods. In this study we have isolated, purified and characterized an anti-inflammatory molecule from E coracana bran extract known as syringol. Purification of syringol was accomplished by combination of GC-MS and RP-HPLC techniques. Syringol significantly inhibited the enzyme activity of sPLA2 (IC50 = 3 µg) and 5-LOX (IC50 = 0.325 µg) in vitro. The inhibition is independent of substrate concentration, calcium ion concentration and was irreversible. Syringol interacts with purified sPLA2 enzymes as evidenced by fluorescence and molecular docking studies. Further, the syringol molecule dose dependently inhibited the development of sPLA2 and carrageenan induced edema. Furthermore, syringol decreases the expression of cPLA2, COX-2, IκBα, p38 and MPO in edematous tissues as demonstrated by western blots. These studies revealed that syringol isolated from E coracana bran may develop as a potent anti-inflammatory molecule.


Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
YC Oh ◽  
YH Jeong ◽  
WK Cho ◽  
SJ Lee ◽  
JY Ma

1996 ◽  
Vol 75 (01) ◽  
pp. 118-126 ◽  
Author(s):  
T Abrahamsson ◽  
V Nerme ◽  
M Strömqvist ◽  
B Åkerblom ◽  
A Legnehed ◽  
...  

SummaryThe aim of this study was to investigate the anti-thrombotic effects of an inhibitor of the plasminogen activator inhibitor-1 (PAI-1) in rats given endotoxin. In studies in vitro, PRAP-1, a Fab-fragment of a polyclonal antibody against human PAI-1, was shown to inhibit PAI-1 activity in rat plasma as well as to stimulate clot-lysis of the euglobulin fraction derived from rat plasma. Endotoxin administered to anaesthetised rats produced a marked increase in plasma PAI-1 activity. To study fibrin formation and lysis in vivo after intravenous (i. v.) injection of the coagulant enzyme batroxobin, 125I-fibrinogen was administered to the animals. The thrombi formed by batroxobin were rapidly lysed in control animals, while the rate of lysis was markedly attenuated in rats given endotoxin. PRAP-1 was administered i.v. (bolus + infusion) to rats given endotoxin and batroxobin and the PAI-1 inhibitor caused a dose-dependent decrease in the 125I-fibrin deposition in the lungs. An immunohistochemical technique was used to confirm this decrease in density of fibrin clots in the tissue. Furthermore, PRAP-1 decreased plasma PAI-1 activity in the rats and this reduction was correlated to the decrease in lung 125I-fibrin deposition at the corresponding time point. It is concluded that in this experimental model the PAI-1 antibody PRAP-1 may indeed inhibit thrombosis in animals exposed to endotoxin.


1972 ◽  
Vol 28 (01) ◽  
pp. 031-048 ◽  
Author(s):  
W. H. E Roschlau ◽  
R Gage

SummaryInhibition of blood platelet aggregation by brinolase (fibrinolytic enzyme from Aspergillus oryzae) has been demonstrated with human platelets in vitro and with dog platelets in vivo and in vitro, using both ADP and collagen as aggregating stimuli. It is suggested that the optimal inhibitory effects of brinolase occur indirectly through the generation of plasma fibrinogen degradation products, without compromising platelet viability, rather than by direct proteolysis of platelet structures.


Toxins ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 157 ◽  
Author(s):  
Adriana Tomoko Nishiya ◽  
Marcia Kazumi Nagamine ◽  
Ivone Izabel Mackowiak da Fonseca ◽  
Andrea Caringi Miraldo ◽  
Nayra Villar Scattone ◽  
...  

Canine oral mucosal melanomas (OMM) are the most common oral malignancy in dogs and few treatments are available. Thus, new treatment modalities are needed for this disease. Bacillus anthracis (anthrax) toxin has been reengineered to target tumor cells that express urokinase plasminogen activator (uPA) and metalloproteinases (MMP-2), and has shown antineoplastic effects both, in vitro and in vivo. This study aimed to evaluate the effects of a reengineered anthrax toxin on canine OMM. Five dogs bearing OMM without lung metastasis were included in the clinical study. Tumor tissue was analyzed by immunohistochemistry for expression of uPA, uPA receptor, MMP-2, MT1-MMP and TIMP-2. Animals received either three or six intratumoral injections of the reengineered anthrax toxin prior to surgical tumor excision. OMM samples from the five dogs were positive for all antibodies. After intratumoral treatment, all dogs showed stable disease according to the canine Response Evaluation Criteria in Solid Tumors (cRECIST), and tumors had decreased bleeding. Histopathology has shown necrosis of tumor cells and blood vessel walls after treatment. No significant systemic side effects were noted. In conclusion, the reengineered anthrax toxin exerted inhibitory effects when administered intratumorally, and systemic administration of this toxin is a promising therapy for canine OMM.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuting Meng ◽  
Xixi Qian ◽  
Li Zhao ◽  
Nan Li ◽  
Shengjie Wu ◽  
...  

Abstract Background The third-generation epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have shown significant therapeutic effects on patients with non-small cell lung carcinoma (NSCLC) who carry active EGFR mutations, as well as those who have developed acquired resistance to the first-generation of EGFR-TKIs due to the T790M mutation. However, most patients develop drug resistance after 8–10 months of treatment. Currently, the mechanism has not been well clarified, and new therapeutic strategies are urgently needed. Methods Osimertinib resistant cell lines were established by culturing sensitive cells in chronically increasing doses of osimertinib. The anticancer effect of reagents was examined both in vitro and in vivo using the sulforhodamine B assay and a xenograft mouse model. The molecular signals were detected by western blotting. The combination effect was analyzed using CompuSyn software. Results We found that bromodomain and extra-terminal proteins (BETs) were upregulated in osimertinib resistant (H1975-OR) cells compared with those in the paired parental cells (H1975-P), and that knockdown of BETs significantly inhibited the growth of H1975-OR cells. The BET inhibitor JQ1 also exhibited stronger growth-inhibitory effects on H1975-OR cells and a greater expression of BETs and the downstream effector c-Myc than were observed in H1975-P cells. The histone deacetylase (HDAC) inhibitor trichostatin A (TSA) showed stronger growth suppression in H1975-OR cells than in H1975-P cells, but vorinostat, another HDAC inhibitor, showed equal inhibitory efficacy in both cell types. Consistently, downregulation of BET and c-Myc expression was greater with TSA than with vorinostat. TSA restrained the growth of H1975-OR and H1975-P xenograft tumors. The combination of TSA and JQ1 showed synergistic growth-inhibitory effects in parallel with decreased BET and c-Myc expression in both H1975-OR and H1975-P cells and in xenograft nude mouse models. BETs were not upregulated in osimertinib resistant HCC827 cells compared with parental cells, while TSA and vorinostat exhibited equal inhibitory effects on both cell types. Conclusion Upregulation of BETs contributed to the osimertinib resistance of H1975 cells. TSA downregulated BET expression and enhanced the growth inhibitory effect of JQ1 both in vitro and in vivo. Our findings provided new strategies for the treatment of osimertinib resistance.


2006 ◽  
Vol 69 (6) ◽  
pp. 2027-2036 ◽  
Author(s):  
Tamás Letoha ◽  
Erzsébet Kusz ◽  
Gábor Pápai ◽  
Annamária Szabolcs ◽  
József Kaszaki ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document