Synthesis of Naringenin Complexes with Cu and Zn and the Inhibiting Effects on Experimental Choroidal Neovascularization in Rats

OBJECTIVE To compare the inhibiting effects of naringenin complexes with Cu and Zn with free ligand on laser-induced choroidal neovascularization (CNV) in rats. METHODS Naringenin complexes with Cu and Zn have been synthesized and characterized on the basis of elemental analyses， i.r. spectra， u.v. spectra. Male Brown Norway rats were anesthetized to receive krypton laser to induce CNV. 20 model rats were divided randomly into control， naringenin complexes with Cu and Zn groups， 5 rats in each group. Naringenin and its complexes (20mg/kg/d )were given once-daily through intraperitoneal (i.p.) injection after laser treatment for 4 weeks. The sizes of CNV lesions were measured by choroidal flatmounts with fluorescein isothiocyanate dextran for four weeks. RESULTS The animals treated with naringenin complexes with Cu and Zn showed significant decrease in their average CNV sizes (20.90±1.47)×10³μm²， (13.24±1.33)×10³μm²， (13.0±1.28)×10³μm²， compared with the vehicle-treated animals (34.56±1.67)×10³μm²， P<0.05 and <0.01 respectively. Furthermore， naringenin complexes with Cu and Zn reduce the CNV size even more than naringenin (P<0.05 ) . CONCLUSION These results indicate that the biological activity of naringenin can be enhanced by the formation of complexes with Cu and Zn， and complexes of naringenin have stronger inhibition on CNV in the rat model than that of free ligand .