Effects of humic acid on the viability and coagulant properties of human umbilical vein endothelial cells

✍ Scribed by Yang, Hsin-Ling; Chiu, Hui-Chong; Lu, Fung-Jou

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 561 KB
• Volume: 51
• Category: Article
• ISSN: 0361-8609
• DOI: 10.1002/(sici)1096-8652(199603)51:3<200::aid-ajh4>3.0.co;2-0

✦ Synopsis

We have previously shown that humic acid (well-water humic acid, HA, and synthetic humic acid, SHA) enhances cell surface expression of tissue factor (TF). Here we report that incubation of human umbilical vein endotheiial cells (HUVEC) for 2 hr with HA or SHA cause a rapid rise In TF mRNA levels, as shown by Northern blot analysis.

To understand the cytotoxic and fibrinoiytic effects of HA and SHA on cultured HUVEC, the cells were treated with varying concentrations of HA and SHA for various periods of time. Both HA and SHA (10-200 pglmi) inhibited the viability of subconfluent HUVEC, cultured in the presence or absence of 20% FBS (Fetal Bovine serum) in the culture medium, in a dose-dependent manner. Both HA and SHA induced surface changes In the HUVEC as revealed by scanning electron micrography (SEM). However, protocatechuic acid, the monomer of SHA, did not significantly inhibit cell growth, and showed a cytotoxic effect only at 200 pglml. Furthermore both HA and SHA stimulated HUVEC to produce piasminogen activator inhibitor (PAI-1) and tissue plasminogen activator (1-PA) In a dose and time dependent fashion; the amount of PAI-1 produced was found to exceed that of t-PA. The monomer of SHA did not have this stlmulatory effect. These results distinctly suggest that in addition to the inhibition of viability HA is involved in TF induction and PAI-1 synthesis in HUVEC and these may besome of the plausible mechanisms underlying the thrombotic disorders in Blackfoot disease.