Zoi Papoutsi

Walnut extract (Juglans regia L.) and its component ellagic acid exhibit anti-inflammatory activity in human aorta endothelial cells and osteoblastic activity in the cell line KS483

Epidemiological studies suggest that the incidence of CVD and postmenopausal osteoporosis is low in the Mediterranean area, where herbs and nuts, among others, play an important role in nutrition. In the present study, we sought a role of walnuts (Juglans regia L.) in endothelial and bone-cell function. As the endothelial cell expression of adhesion molecules has been recognised as an early step in inflammation and atherogenesis, we examined the effect of walnut methanolic extract and ellagic acid, one of its major polyphenolic components (as shown by HPLC analysis), on the expression of vascular cell adhesion molecule (VCAM)-1 and intracellular adhesion molecule (ICAM)-1 in human aortic endothelial cells. After incubating the cells with TNF-alpha (1 ng/ml) in the absence and in the presence of walnut extract (10-200 microg/ml) or ellagic acid (10- 7-10- 5 m), the VCAM-1 and ICAM-1 expression was quantified by cell-ELISA. We further evaluated the effect of walnut extract (10-50 microg/ml), in comparison with ellagic acid (10- 9-10- 6m), on nodule formation in the osteoblastic cell line KS483. Walnut extract and ellagic acid decreased significantly the TNF-alpha-induced endothelial expression of both VCAM-1 and ICAM-1 (P < 0.01; P < 0.001). Both walnut extract (at 10-25 microg/ml) and ellagic acid (at 10- 9-10- 8 m) induced nodule formation in KS483 osteoblasts. The present results suggest that the walnut extract has a high anti-atherogenic potential and a remarkable osteoblastic activity, an effect mediated, at least in part, by its major component ellagic acid. Such findings implicate the beneficial effect of a walnut-enriched diet on cardioprotection and bone loss.

Ursolic Acid Triggers Apoptosis and Bcl-2 Downregulation in MCF-7 Breast Cancer Cells

In this report we determine the ability of ursolic acid (UA) to induce apoptosis and to modulate glucocorticoid receptor (GR) and Activator Protein-1 (AP-1) in MCF-7 cells. The UA-induced apoptosis (53 μM), the PARP cleavage, and the decrease in Bcl-2 protein (53 μM) support the notion that UA induces apoptosis through the intrinsic mitochondrial pathway. UA binds GR (relative binding affinity: 2.57) and translocates GR into nucleus, suggesting its potential as a GR modulator. UA had no effect on GRE- or TRE-driven gene expression. In summary, UA is a GR modulator and may be considered as a potential anticancer agent in breast cancer.

Acteoside and martynoside exhibit estrogenic/antiestrogenic properties.

Acteoside and martynoside are plant phenylpropanoid glycosides exhibiting anticancer, cytotoxic and antimetastatic activities. We investigated their potential to activate estrogen receptor isoforms ERalpha and ERbeta in HeLa cells transfected with an estrogen response element (ERE)-driven luciferase (Luc) reporter gene and an ERalpha or ERbeta expression vector. Their estrogenic/antiestrogenic effects were also assessed in breast cancer cells (MCF7), endometrial cancer cells (Ishikawa) and osteoblasts (KS483), by measuring IGFBP3 levels, cell viability and number of mineralized nodules, respectively, seeking for a natural selective estrogen receptor modulator (SERM). Acteoside and martynoside antagonized both ERalpha and ERbeta (p<0.001), whereas they reversed the effect of E(2) mainly via ERalpha (p<0.001). Martynoside was a potent antiestrogen in MCF-7 cells, increasing, like ICI182780, IGFBP3 levels via the ER-pathway. In osteoblasts, martynoside induced nodule mineralization, which was abolished by ICI182780, implicating an ER-mediated mechanism. Furthermore, its antiproliferative effect on endometrial cells suggests that martynoside may be an important natural SERM. Acteoside was an antiestrogen in breast cancer cells and osteoblasts, without any effect on endometrial cells. Our study suggests that the nature is rich in selective ERalpha and ERbeta ligands, the discovery of which may lead to the development of novel neutraceutical agents.

Selective serotonin re-uptake inhibitors decrease the cytokine-induced endothelial adhesion molecule expression, the endothelial adhesiveness to monocytes and the circulating levels of vascular adhesion molecules

BACKGROUND Selective serotonin reuptake inhibitors (SSRIs) exert cardioprotective effects. We examined whether SSRIs a) modulate endothelial cell expression of vascular cell adhesion molecule (VCAM-1), intracellular adhesion molecule (ICAM-1) and adhesiveness to U937 monocytes, b) reduce the circulating levels of these adhesion molecules in vivo. METHODS We assessed the effect of SSRIs, (citalopram, fluvoxamine and fluoxetine), on TNF-alpha-induced expression of VCAM-1 and ICAM-1 in human aorta endothelial cells and adhesiveness to U937 monocytes. Cells were incubated with TNF-alpha in the absence and in the presence of SSRIs concentrations from 10(-7) M to10(-4) M and the VCAM-1 and ICAM-1 expression was quantified by cell-ELISA. The TNF-alpha-stimulated adhesiveness to U937 monocytes was also assessed. Twenty five patients with chronic heart failure and depression were randomized to receive sertaline 50 mg, p.o., o.d. (n=13) or placebo. At baseline and 3-months after treatment, we measured VCAM-1 and ICAM-1 plasma levels. RESULTS SSRIs decreased the TNF-alpha-induced endothelial expression of VCAM-1 at concentration range 10(-7) M to 10(-4) M (p<0.05). ICAM-1 expression was decreased in the presence of fluvoxamine and fluoxetine at concentrations from 10(-7) M to 10(-4) M (p<0.05) and in the presence of citalopram at concentrations from 10(-7) M to 10(-5) M (p<0.05). All SSRIs inhibited the TNF-alpha-stimulated adhesiveness to U937 cells at 10(-5) M and 10(-4) M (p<0.05). Compared to baseline, there was a greater reduction in ICAM-1 and VCAM-1 levels post-sertaline than post placebo in heart failure patients (p<0.05). CONCLUSION SSRIs may exhibit an anti-inflammatory activity on endothelial cells and reduce circulating VCAM-1 and ICAM-1 in vivo, a mechanism which may partly mediate their cardioprotective effects.

Effect of ellagic acid on the expression of human telomerase reverse transcriptase (hTERT) α+β+ transcript in estrogen receptor-positive MCF-7 breast cancer cells

OBJECTIVES To evaluate the potential of ellagic acid to inhibit the expression of human telomerase reverse transcriptase (hTERT) alpha+beta+ splice variant in MCF-7 breast cancer cells. DESIGN AND METHODS MCF-7 cells were incubated with ellagic acid (10(-)(9) M-10(-5) M) in the absence and in the presence of 17beta-estradiol (10(-8) M), a known inducer of hTERT transcription, and hTERT alpha+beta+ mRNA expression was quantified by real-time RT-PCR. 17beta-estradiol and ICI182780, a known estrogen antagonist, served as positive and negative controls respectively. RESULTS Ellagic acid, when alone, increased hTERT alpha+beta+ mRNA while its coexistence with 17beta-estradiol reduced significantly the 17beta-estradiol-induced increase in hTERT alpha+beta+ mRNA, implicating thus both its estrogenic and anti-estrogenic effects in breast cancer cells. CONCLUSIONS The potential of ellagic acid to down-regulate the 17beta-estradiol-induced hTERT alpha+beta+ mRNA expression may be a mechanism via which ellagic acid exerts, at least in part, its chemopreventive effects in breast cancer.

Deoxybenzoins are novel potent selective estrogen receptor modulators

Deoxybenzoins are plant compounds with similar structure to isoflavones. In this study, we evaluated the ability of two synthesized deoxybenzoins (compound 1 and compound 2) (a) to influence the activity of the estrogen receptor subtypes ERalpha and ERbeta in HeLa cells co-transfected with an estrogen response element-driven luciferase reporter gene and ERalpha- or ERbeta-expression vectors, (b) to modulate the IGFBP-3 and pS2 protein in MCF-7 breast cancer cells, (c) to induce mineralization of KS483 osteoblasts and (d) to affect the cell viability of endometrial (Ishikawa) and breast (MCF-7, MDA-MB-231) cancer cells. Docking and binding energy calculations were performed using the mixed Monte Carlo/Low Mode search method (Macromodel 6.5). Compound 1 displayed significant estrogenic activity via ERbeta but no activity via ERalpha. Compound 2 was an estrogen-agonist via ERalpha and antagonist via ERbeta. Both compounds increased, like the pure antiestrogen ICI182780, the IGFBP-3 levels. Compound 2 induced, like 17beta-estradiol, significant mineralization in osteoblasts. The cell viability of Ishikawa cells was unchanged in the presence of either compound. Compound 1 increased MCF-7 cell viability consistently with an increase in pS2 levels, whereas compound 2 inhibited the cell viability. Molecular modeling confirmed the agonistic or antagonistic behaviour of compound 2 via ER subtypes. Compound 2, being an agonist in osteoblasts, an antagonist in breast cancer cells, with no estrogenic effects in endometrial cancer cells, makes it a potential selective estrogen receptor modulator and a choice for hormone replacement therapy.

Sideritis euboea extract lowers total cholesterol but not LDL cholesterol in humans: a randomized controlled trial

Abstract Aim: Sideritis euboea is used to prepare a widely consumed beverage. We evaluated the biological activity of S. euboea in healthy human subjects, focusing on serum cardiovascular factors, including lipids, inflammation and glucose homeostasis markers. Patients & methods: In a double-blind study, 54 participants were randomly assigned to consume S. euboea aqueous extract food (n = 27, intervention group) or a placebo food (n = 27, control group) for a 1-month period. A total of 47 participants were included in the final ana lysis. Serum lipids (total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, lipoprotein lipase(a)), Homeostasis Model Assessment and inflammatory markers were determined. Results: Total cholesterol was reduced significantly in the intervention group, while no beneficial effects on other lipid parameters and inflammatory markers were observed. In females, S. euboea significantly ameliorated the Homeostasis Model Assessment index. Conclusion: The consumption of S. euboea induces only a significant total cholesterol lowering effect while it exerts insulin-sensitizing actions in females. Larger studies with a longer intervention period should be performed.