Tissue distribution of 2-methoxyestradiol nanosuspension in rats and its antitumor activity in C57BL/6 mice bearing lewis lung carcinoma

Abstract

The purpose of the present study was to evaluate the tissue distribution and antitumor activity of 2-methoxyestradiol (2-ME) nanosuspension compared with 2-ME solution both in vitro and in vivo. 2-ME nanosuspension was made by nanoprecipitation-high-frequency ultrasonication method with the particle size of 168.4 ± 3.2 nm and the zeta potential of -29.79 ± 1.89 mV. The overall targeting efficiency (TE(Q)) of 2-ME nanosuspension was improved from 28.71 to 51.95% in the lung of rats. MTT assay showed that 2-ME nanosuspension could significantly enhance the in vitro cytotoxicity against lewis lung carcinoma (LLC) cells compared with the 2-ME solution, the IC(50) at 72 h was reduced from 6.35 µM for 2-ME solution to 3.56 µM for 2-ME nanosuspension. The antitumor activity in vivo was investigated in C57BL/6 mice bearing LLC, and the results indicated that 2-ME nanosuspension not only exhibited significant suppression of the tumor growth when compared with that of positive group or cyclophosphamide group at the same dose, but also enhanced the spleen indices. Overall, 2-ME nanosuspension could mainly deliver the drug to lungs and made the drug accumulate in the lungs, so 2-ME nanosuspension has a possible lung cancer therapeutic potential.