Carnosol has been proved to have anti-breast cancer effect in previous research. But its ER subtype's specific regulation and mediation mechanisms remain unclear. The aim of this study is to observe the effect of carnosol on cell proliferation and its estrogen receptor α and β's specific regulation and mediation mechanisms with ER positive breast cancer T47D cell. With estrogen receptor α and β antagonists MPP and PHTPP as tools, the MTT cell proliferation assay was performed to observe the effect of carnosol on T47D cell proliferation. The changes in the T47D cell proliferation cycle were detected by flow cytometry. The effect of carnosol on ERα and ERβ expressions of T47D cells was measured by Western blot. The findings showed that 1 x 10(-5)-1 x 10(-7) mol x L(-1) carnosol could significantly inhibit the T47D cell proliferation, which could be enhanced by MPP or weakened by PHTPP. Meanwhile, 1 x 10(-5) mol x L(-1) or 1 x 10(-6) mol x L(-1) carnosol could significantly increase ERα and ERβ expressions of T47D cells, and remarkably increase ERα/ERβ ratio. The results showed that carnosol showed the inhibitory effect on the proliferation of ER positive breast cancer cells through target cell ER, especially ERβ pathway. In the meantime, carnosol could regulate expressions and proportions of target cell ER subtype ERα and ERβ.
Blotting, Western ; Breast Neoplasms ; metabolism ; pathology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Diterpenes, Abietane ; chemistry ; pharmacology ; Dose-Response Relationship, Drug ; Estrogen Receptor Modulators ; pharmacology ; Estrogen Receptor alpha ; antagonists & inhibitors ; metabolism ; Estrogen Receptor beta ; antagonists & inhibitors ; metabolism ; Female ; Flow Cytometry ; Humans ; Molecular Structure ; Pyrazoles ; pharmacology ; Pyrimidines ; pharmacology

Postmenopausal osteoporosis is one of the commonest systemic bone metabolism diseases among menopausal women, mainly caused by lowering internal estrogen. Although Hormone Replacement Therapy (HRT) is an effective method in clinical practice for years, it shows side-effect in increasing gynecological carcinoma. It has already been proved by clinical tests that multiple traditional Chinese medicine formulas and their monomer ingredients and phytoestrogen-like active constituents contained in traditional Chinese medicines are effective on treating osteoporosis with relatively less side-effects comparing with HRT. They show protective and therapeutic effects by acting on estrogen receptors of targeted tissues and targeted cells and then affecting expressions of bone metabolism-related regulatory proteins and factors in downstream signal conduct paths. Recent studies on estrogen related receptor (ERR) provide new possibilities and pathways for mechanism of traditional Chinese medicine and their active constituents in osteoporosis.
Chemistry, Pharmaceutical ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; therapeutic use ; Humans ; Medicine, Chinese Traditional ; methods ; Osteoporosis, Postmenopausal ; drug therapy ; Receptors, Estrogen ; metabolism