PHTPP is a selective ERβ antagonist.

PHTPP acts as a selective antagonist for estrogen receptor beta (ERβ), significantly decreasing follicle-stimulating hormone (FSH)-mediated cyclic AMP (cAMP) production by 80% (p<0.01), without impacting basal cAMP levels. At a concentration of 10^-6 M, PHTPP inhibits estradiol (E2)-stimulated ERβ activity but does not affect E2-induced ERα activity. Furthermore, a high concentration of PHTPP (10^-6 M) marginally enhances class 1 Igf1 mRNA expression and promotes the DPN-induced increase in class 1 Igf1 mRNA expression.

Cells are plated at a density of 3 to 4×10^5 in 1 mL of medium per well in a 24-well plate for cell viability and cAMP analysis. Cells are cultured in Dulbecco's Modified Eagle Medium with PHTPP (1 μM), or ethanol (0.1%) as the vehicle. The incubator is set to an atmosphere of 5% CO2 in air at 37°C, and cultures are allowed to acclimate for at least 24 h. The culture medium is then aspirated and replaced with serum-free DMEM/F12 containing 0.1 μM androstenedione. The cells are collected for intracellular cAMP and to test cell viability. They are for reference only.