Biol. Pharm. Bull. 29(5) 1028—1031 (2006)

blood vessels. In the adult, the proliferation rate of endothelial cells is very low compared with that of many other cell types in the body. Angiogenesis occurs under tight regulation in the female reproductive system and during wound healing. Unregulated angiogenesis may result in different pathologies, such as rheumatoid arthritis, diabetic retinopathy, psoriasis, and juvenile hemangiomas. Also, tumor growth and metastasis are angiogenesis-dependent. Chalcones are precursor compounds for flavonoid synthesis in plants. Naturally occurring chalcones exist mostly in hydroxylated forms and many reports have documented their biologically active properties. It has recently been reported that cyclooxygenase-2 (COX2) induces angiogenesis, which is essential for tumor growth. Increased prostaglandin production and enhanced release of angiogenic growth factor by COX-2 may induce neovascularization. COX inhibitors exhibit dramatic anti-angiogenic activity in a number of tumor model systems. In a previous study, we reported that 2 -hydroxy-4 methoxychalcone (HMC), a synthetic chalcone inhibited PGE2 production in 12-O-tetradecanoylphorbol 13-acetate (TPA)-stimulated rat peritoneal macrophages by inhibiting the induction of COX-2 protein. In view of the involvement of COX-2 in angiogenesis, the purpose of the present study was to determine the anti-angiogenic activities of HMC and to use it as an anti-tumor agent. We investigated the possible effects of HMC on angiogenesis using a chorioallantoic membrane (CAM) assay and an in vivo matrigel assay. Also, we found an effect on the proliferation of calf pulmonary arterial endothelial (CPAE) cells and gelatinase/collagenase, and observed substantial anti-tumor activity against sarcoma 180-induced solid tumors and primary tumors in Lewis lung carcinoma (LLC)-bearing C57BL/6 mice. MATERIALS AND METHODS