Nonsteroidal aromatase inhibitor 1 (Compound 13h) effectively inhibits the enzyme CYP19A1 with an IC50 value of 0.09 nM. This potent inhibitory activity suggests its potential for breast cancer research [1].

Treatment with nonsteroidal aromatase inhibitor 1 at concentrations ranging from 0.001 pM to 100 pM for 1 hour demonstrated significant aromatase inhibition, with an IC50 value of 0.09 nM, indicating excellent efficacy in inhibiting aromatase activity. Furthermore, at a concentration of 1 μM over 48 hours, the same treatment showed no significant effect on the growth of MCF-10A or MDA-MB-231 cells, implying minimal toxicity to normal breast tissue and limited off-target effects. This assessment was supported by both cell viability and cytotoxicity assays conducted on JEG-3, MCF-10A, and MDA-MB-231 cell lines.