Effects of aspirin and indomethacin on endothelial cell proliferation in vitro

Background and Aim: Non-steroidal anti-inflammatory drugs (NSAID) are associated with delayed peptic ulcer healing. Ulcer healing is dependent on angiogenesis, which requires endothelial cell (EC) proliferation. The present study aimed to determine whether NSAID and prostaglandin E-2 (PGE(2)) inhibited EC proliferation in vitro. Methods: Effects of 50 muL aspirin (10 muM-1 mM), indomethacin (10 muM-1 mM) and PGE(2) (1 muM-0.1 mM) on the proliferation, viability and cell cycle of human dermal microvascular (HuDMEC) and human umbilical vein (HUVEC) EC were assessed using dual staining cell viability, 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide and flow cytometry assays. Results: Proliferation of HuDMEC and HUVEC was significantly inhibited by 0.1 mM/1 mM indomethacin, 1 mM aspirin and 100 muM PGE(2), with a significant (P < 0.05) increase in EC necrosis with 1 mM indomethacin and 100 mM PGE(2). No effects on cell cycle were demonstrated. Conclusions: High concentrations of NSAID inhibit both HuDMEC and HUVEC proliferation in vitro by cytotoxic (indomethacin) or cytostatic ( aspirin and indomethacin) mechanisms. Interestingly, PGE(2) was also antiproliferative. Inhibition of EC proliferation may prevent angiogenesis at the ulcer site, which may in part explain the delayed ulcer healing associated with NSAID. (C) 2003 Blackwell Publishing Asia Pty Ltd.