In the previous studies, we reported that carnosic acid (CA) and carnosol (CS) originating from rosemary protected cortical neurons by activating the Keap1/Nrf2 pathway, which activation was initiated by S-alkylation of the critical cysteine thiol of the Keap1 protein by the "electrophilic"quinone-type of CA or CS. Here, we found that CA and CS inhibited the in vitro differentiation of mouse preadipocytes, 3T3-L1 cells, into adipocytes. In contrast, other physiologically-active and rosemary-originated compounds were completely negative. These actions seemed to be mediated by activation of the antioxidant-response element (ARE) and induction of phase2 enzymes. This estimation is justified by our present findings that only CA and CS among rosemary-originated compounds significantly activated the ARE and induced the phase2 enzymes. Next, we performed cDNA microarray analysis in order to identify the gene(s) responsible for these biological actions and found that phase2 enzymes (Gsta2, Gclc, Abcc4, and Abcc1), all of which are involved in the metabolism of glutathione (GSH), constituted 4 of the top 5 CA-induced genes. Furthermore, CA and CS, but not the other compounds tested, significantly increased the intracellular level of total GSH. Thus, we propose that the stimulation of GSH metabolism may be a critical step for the inhibition of adipocyte differentiation in 3T3-L1 cells and suggest that pro-electrophilic compounds such as CA and CS may be potential drugs against obesity-related diseases.
"We have shown that it is possible to take advantage of this intracellular mechanism of electrophilic activation to develop a novel strategy for drug development against neurodegenerative diseases. As an illustration, CA activates the Nrf2 transcriptional pathway and protects various cells and organs against redox stress (Takahashi et al., 2009; Kosaka et al., 2010; Mimura et al., 2010; Tamaki et al., 2010; Maruoka et al., 2011; Satoh et al., 2011; Rezaie et al., 2012; Yanagitai et al., 2012). We have developed a potential strategy for clinical translation of this work based on the following chemical principles (Satoh and Lipton, 2007; Satoh et al., 2013). "
"Carnosic acid (CA), a low-molecular electrophilic compound in rosemary (Rosmarinus officinalis L.), has a variety of neuroprotective functions such as the prevention of neurotoxin-induced neuronal cell death (Park et al., 2008), the promotion of neurite outgrowth in neuronal cells (Kosaka et al., 2010) and the enhancement of nerve growth factor (NGF) expression in astrocytes (Mimura et al., 2011; Yoshida et al., 2011). In these functions of CA, various signaling pathways including the activation of the transcription factor Nrf2 (nuclear factor-erythroid 2 related factor 2), a master regulator of the antioxidant response, is involved (Johnson et al., 2008; Satoh et al., 2008a,b; Takahashi et al., 2009). In contrast, we previously found that, without Nrf2 contribution, CA suppresses A␤ production by the activation of ␣-secretase in cultured SH-SY5Y human neuroblastoma cells (Meng et al., 2013). "
[Show abstract][Hide abstract] ABSTRACT: Amyloid beta (Aβ) peptides are key molecules in the pathogenesis of Alzheimer's disease (AD). The sequential cleavage of amyloid precursor protein (APP) by the β- and γ-secretases generates Aβ peptides; however, the alternate cleavage of APP by the α- and γ-secretases decreases Aβ production. We previously reported that carnosic acid (CA), a phenolic diterpene compound found in the labiate herbs rosemary and sage, suppresses Aβ (1-40 and 1-42) production by activating α-secretase in cultured SH-SY5Y human neuroblastoma cells (Neurosci. Res. 2013; 75: 94-102). Here, we investigated the effect of CA on the production of Aβ peptides (1-40, 1-42 and 1-43) in U373MG human astrocytoma cells. The treatment of cells with CA suppressed Aβ40/42/43 release (55-71% decrease at 50μM). CA treatment enhanced the mRNA expressions of an α-secretase TACE (tumor necrosis factor-α-converting enzyme, also called a disintegrin and metalloproteinase-17, ADAM17); however, the β-secretase BACE1 (β-site APP-cleaving enzyme-1) was not increased by CA. Knockdown of TACE by siRNA reduced soluble-APPα release enhanced by CA and partially recovered the CA-suppressed Aβ40/42/43 release. These results suggest that CA reduces Aβ production, at least partially, by activating TACE in human astroglial cells. The use of CA may have a potential in the prevention of Aβ-mediated diseases.
Neuroscience Research 11/2013; 79(1). DOI:10.1016/j.neures.2013.11.004 · 1.94 Impact Factor
"Using microarray analysis, CA and CS have been shown to activate the ARE and stimulate glutathione metabolism , which inhibited the differentiation of mouse preadiocytes 3 T3-l1 cells to adipocytes . Thus CA may have potential to treat obesity related conditions . Further gene expression studies  indicated that CA and CS protect cortical neurons (HT22 cells) by activating the Keap1/Nrf2 pathway, which induces phase 2 enzymes and subsequently enzymes involved in glutathione metabolism. "
[Show abstract][Hide abstract] ABSTRACT: Studies indicate that extracts and purified components, including carnosic acid, from the herb rosemary display significant growth inhibitory activity on a variety of cancers.
This paper examines the ability of rosemary/carnosic acid to inhibit the growth of human breast cancer cells and to synergize with curcumin.
To do this, we treated human breast cancer cells with rosemary/carnosic acid and assessed effects on cell proliferation, cell cycle distribution, gene expression patterns, activity of the purified Na/K ATPase and combinations with curcumin.
Rosemary/carnosic acid potently inhibits proliferation of ER-negative human breast cancer cells and induces G1 cell cycle arrest. Further, carnosic acid is selective for MCF7 cells transfected for Her2, indicating that Her2 may function in its action. To reveal primary effects, we treated ER-negative breast cancer cells with carnosic acid for 6h. At a low dose, 5 μg/ml (15 μM), carnosic acid activated the expression of 3 genes, induced through the presence of antioxidant response elements, including genes involved in glutathione biosynthesis (CYP4F3, GCLC) and transport (SLC7A11). At a higher dose, 20 μg/ml, carnosic acid activated the expression of antioxidant (AKR1C2, TNXRD1, HMOX1) and apoptosis (GDF15, PHLDA1, DDIT3) genes and suppressed the expression of inhibitor of transcription (ID3) and cell cycle (CDKN2C) genes. Carnosic acid exhibits synergy with turmeric/curcumin. These compounds inhibited the activity of the purified Na-K-ATPase which may contribute to this synergy.
Rosemary/carnosic acid, alone or combined with curcumin, may be useful to prevent and treat ER-negative breast cancer.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.