carnosol and Breast-Neoplasms

Cancer remains an important cause of mortality nowadays and, therefore, new therapeutic approaches are still needed. Rosemary (Rosmarinus officinalis L.) has been reported to possess antitumor activities both in vitro and in animal studies. Some of these activities were attributed to its major components, such as carnosic acid, carnosol, ursolic acid, and rosmarinic acid. Initially, the antitumor effects of rosemary were attributed to its antioxidant activity. However, in recent years, a lack of correlation between antioxidant and antitumor effects exerted by rosemary was reported, and different molecular mechanisms were related to its tumor inhibitory properties. Moreover, supported by the U.S. Food and Drug Administration and the European Food and Safety Authority, specific compositions of rosemary extract were demonstrated to be safe for human health and used as antioxidant additive in foods, suggesting the potential easy application of this agent as a complementary approach in cancer therapy. In this review, we aim to summarize the reported anticancer effects of rosemary, the demonstrated molecular mechanisms related to these effects and the interactions between rosemary and currently used anticancer agents. The possibility of using rosemary extract as a complementary agent in cancer therapy in comparison with its isolated components is discussed.

Topics: Abietanes; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Antioxidants; Breast Neoplasms; Cinnamates; Depsides; Drug Interactions; Europe; Humans; Neoplasms; Phytotherapy; Plant Extracts; Rosmarinic Acid; Rosmarinus; Triterpenes; United States; United States Food and Drug Administration; Ursolic Acid

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.

Topics: Abietanes; Blotting, Western; Breast Neoplasms; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Estrogen Receptor alpha; Estrogen Receptor beta; Estrogen Receptor Modulators; Female; Flow Cytometry; Humans; Molecular Structure; Pyrazoles; Pyrimidines

Cytochrome P450-1A1 (CYP1A1) is an extrahepatic phase I metabolizing enzyme whose expression is suppressed under physiologic conditions but can be induced by substrates via the aryl hydrocarbon receptor (AhR). Recent studies have shown that the majority of breast cancer tumors constitutively express CYP1A1. These findings led us to test the hypothesis that CYP1A1 promotes breast cancer progression by evaluating the effects of CYP1A1 knockdown on the proliferation and survival of the MCF7 and MDA-MB-231 lines. Independently of estrogen receptor status, CYP1A1 knockdown decreased colony formation, decreased cell proliferation, blocked the cell cycle at G0-G1 associated with reduction of cyclin D1, and increased apoptosis associated with reduction of survivin. CYP1A1 knockdown markedly increased phosphorylation of AMP-activated protein kinase (AMPK) and decreased phosphorylation of AKT, extracellular signal-regulated kinases 1 and 2 (ERK1/2), and 70-kDa ribosomal protein S6 kinase (P70S6K). AMPK inhibition by compound C partially abrogated the proapoptotic effects of CYP1A1 knockdown, suggesting that effects of CYP1A1 knockdown are mediated in part through AMPK signaling. Consistent with CYP1A1 knockdown, pharmacologic reduction of CYP1A1 levels by the phytopolyphenol carnosol also correlated with impaired proliferation and induced AMPK phosphorylation. These results indicate that reduction of basal CYP1A1 expression is critical for inhibition of proliferation, which is not affected by α-naphthoflavone-mediated inhibition of CYP1A1 activity nor modulated by AhR silencing. This study supports the notion that CYP1A1 promotes breast cancer proliferation and survival, at least in part, through suppression of AMPK signaling and that reduction of CYP1A1 levels is a potential strategy for breast cancer therapeutics.

Topics: Abietanes; AMP-Activated Protein Kinases; Breast Neoplasms; Cell Cycle; Cell Death; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cytochrome P-450 CYP1A1; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Female; Gene Knockdown Techniques; Humans; Models, Biological; Proto-Oncogene Proteins c-akt; Receptors, Aryl Hydrocarbon; RNA, Small Interfering; Signal Transduction