Repeated Oral or Subcutaneous LMWH Has similar Antithrombotic Activity in a Rat Venous Thrombosis Model: Antithrombotic Activity Correlates With Heparin on Endothelium When Orally Administered

Orally administrated fucoidan and its low-molecular-weight derivatives are absorbed differentially to alleviate coagulation and thrombosis

Thrombosis is a serious threat to human health and life. Fucoidan, a sulfated polysaccharide from brown algae, could prevent coagulation and thrombus after intravenous administration. However, more efforts are still needed to develop its oral agent. In the present study, the absorption and excretion of fucoidan (90.8 kDa) and its degradation products, Dfuc1 (19.2 kDa) and Dfuc2 (5.5 kDa), were determined by HPLC-MS/MS after acid degradation and 1-phenyl-3-methyl-5-pyrazolone derivatization, and their anticoagulation and antithrombotic activities were evaluated in vivo after oral administration. Results showed that the maximum concentrations of fucoidan, Dfuc1 and Dfuc2 in rat plasma all achieved at 2 h after oral administration (150 mg/kg), and they were 41.1 ± 10.6 μg/mL, 45.3 ± 18.5 μg/mL and 59.3 ± 13.7 μg/mL, respectively. In addition, fucoidan, Dfuc1 and Dfuc2 could all prolong the activated partial thromboplastin time in vivo from 23.7 ± 2.7 s (blank control) to 25.1 ± 2.6 s, 27.1 ± 1.7 s and 29.4 ± 3.6 s, respectively. Moreover, fucoidan and its degradation products showed similar antithrombotic effect in carrageenan-induced thrombosis mice, and untargeted metabolomics analysis revealed that they all markedly regulated the carrageenan-induced metabolite disorders, especially the arachidonic acid metabolism. Thus, the degradation products of fucoidan with lower molecular weights are more attractive for the development of oral antithrombotic agents.

Effect of Cold Application on Pain and Bruising in Patients With Subcutaneous Injection of Low-Molecular-Weight Heparin: A Meta-Analysis

To evaluate the effect of cold application on pain and bruising after the subcutaneous injection of low-molecular-weight heparin, 8 electronic databases were searched for randomized controlled trials and quasiexperimental studies from the inception of the databases to June 2019. Review Manager 5.3 software was used for the heterogeneity test and meta-analysis. A total of 8 studies including 694 participants were analyzed. The cold application group assessed with the Verbal Descriptor Scale pain assessment tool showed significant reductions in pain intensity immediately after injection. Compared to the control group, the cold application group showed a reduction in the occurrence of bruises at 12 hours, 24 hours, and 48 hours after injection. There was no significant difference in the area of bruising in the cold application group at 48 hours after injection, but the area of bruising at 72 hours after injection was significantly reduced. These results show that cold application can reduce the incidence of pain and bruising after subcutaneous injection of low-molecular-weight heparin and reduce the area of bruising 72 hours after injection. Additional studies with larger sample sizes are needed to confirm these findings.