Planta Med 2000; 66(2): 119-123
DOI: 10.1055/s-2000-11126
Original Paper
Georg Thieme Verlag Stuttgart · New York

Screening of Anti-Hypoxia/Reoxygenation Agents by an in vitro Method. Part 2: Inhibition of Tyrosine Kinase Activation Prevented Hypoxia/Reoxygenation-Induced Injury in Endothelial GapJunctional Intercellular Communication

You-Wei Zhang1, 2 , Ikuo Morita1,*, Lei Zhang2 , Gang Shao2 , Xin-Sheng Yao2, , Sei-itsu Murota1
  • 1 Section of Cellular Physiological Chemistry, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
  • 2 Division of Natural Products Chemistry, Shenyang Pharmaceutical University, Shenyang, China
Further Information

Publication History

Publication Date:
31 December 2000 (online)

Abstract

In this study, we demonstrated that hypoxia/reoxygenation (H/R) induced an injury in gap junctional intercellular communication (GJIC) after 2 h of reoxygenation in cultured HUVEC. Free radical scavenger (DMSO) and antioxidant (SOD) did not prevent this GJIC injury at all. Protein kinase C inhibitor (calphostin C) partly blocked this injury. However, the protein tyrosine kinase (PTK) inhibitor genistein completely inhibited this GJIC injury. Compounds 1 [laxogenin-3-O-α-L-arabinosyl-(1¡ú 6)-β-D-glucopyranoside], 2 (macrostemososide A), 3 [laxogenin-3-O-β-D-xylopyranosyl-(1¡ú 4)-α-L-arabinopyranosyl-(1¡ú  6)-β-D-glucopyranoside], 4 (chinenoside II), 5 (β-sitosterol), 6 (daucosterine), 7 (ginsenoside-Rd), 29 (isocumarine), 52 (icariin), 53 (icariside), and 54 (icaritin), which showed obvious influence on H/R-induced PTK activation as stated in Part 1 (except 1), were explored for their effects on GJIC. The results showed that compounds 2 šC 7 and 52 šC 57 partly protected H/R-induced GJIC injury. Compounds 5 and 6 (especially 5), which showed the strongest inhibitory effects on PTK activation, completely blocked H/R-provoked GJIC injury. Compound 1, which did not influence PTK activation, failed to prevent this GJIC injury. In contrast, compound 29, which significantly promoted PTK activation, enhanced this H/R-induced GJIC injury further. Western blotting of connexin 43, an important gap junctional protein for modulating GJIC in HUVEC, revealed that interference with the gap junctional protein might be the most direct mechanism for compounds 2, 5, 29, and 53 to affect H/R-injured GJIC.

References

Prof. Dr. Ikuo Morita

Section of Cellular Physiological Chemistry

Graduate School

Tokyo Medical & Dental University

1-5-45 Yushima

Bunkyo-Ku

Tokyo 113-8549

Japan

Email: morita.cell@dent.tmd.ac.jp

Phone: +81-3-5803-0212

Fax: +81-3-5803-5575