Raloxifene hydrochloride (CAS 82640-04-8)

Raloxifene hydrochloride is a selective estrogen receptor modulator (SERM), binding to ERalpha and ERbeta. Tissue-dependently blocks or activates estrogen-induced transcription. Exhibits estrogen agonist behavior in bone but acts as an anti-estrogen in breast and uterine tissue. Raloxifene hydrochloride exhibits inhibitory effects of progesterone receptor induction by estrogen in D12 rat hypothalamic cells. Raloxifene hydrochloride is a substrate of Estrogen Receptor. Raloxifene hydrochloride, a second-generation selective estrogen receptor modulator (SERM), offers a versatile profile in various tissue types. With a high affinity for both ERα (Kd = 90 pM) and ERβ, this compound demonstrates tissue-dependent modulation of ER-induced transcription. In hypothalamic cells, it effectively inhibits estradiol-induced progesterone receptor activity (IC50 = 1 nM). This compound exerts its effects by binding to estrogen receptors in responsive tissues such as liver, bone, breast, and endometrium. In the nucleus, it regulates the transcription of estrogen-regulated genes, displaying agonistic or antagonistic properties depending on the tissue type. Raloxifene hydrochloride acts as an estrogen agonist in lipid metabolism, reducing total and LDL cholesterol levels, while promoting bone health by decreasing bone resorption, bone turnover, and increasing bone mineral density. In uterine and breast tissue, it functions as an estrogen antagonist, and it also exhibits anti-proliferative effects on estrogen-sensitive breast cancer.