scholarly journals Beneficial or harmful influence of phytosterols on human cells?

2008 ◽  
Vol 100 (6) ◽  
pp. 1183-1191 ◽  
Author(s):  
Blazej Rubis ◽  
Anna Paszel ◽  
Mariusz Kaczmarek ◽  
Magdalena Rudzinska ◽  
Henryk Jelen ◽  
...  

So far, a protective influence of phytosterols on the human organism and atherogenesis has been suggested. Most studies have concentrated on the cytotoxic efficacy of phytosterols on cancer cells. However, there are only a few reports showing their influence on normal cells. The aim of the present study was to determine whether dietary plant sterols and their thermal processing products could influence the viability of normal, abdominal endothelial cells that play a crucial role in atherogenesis. Thus, we studied the effect of rapeseed oil-extract components, β-sitosterol, cholesterol and their epoxy-derivatives, 5α,6α-epoxy-β-sitosterol and 5α,6α-epoxycholesterol, on the proliferation and viability of human abdominal aorta endothelial cells HAAE-2 in vitro. We showed strong cytotoxic properties of β-sitosterol in HAAE-2 cells (half maximal inhibitory concentration (IC50) = 1·99 (sem 0·56) μm) and, interestingly, a weaker cytotoxic effect of 5α,6α-epoxy-β-sitosterol (IC50>200 μm). Moreover, we observed a significantly stronger cytotoxic activity of β-sitosterol than cholesterol (IC50 = 8·99 (sem 2·74) μm). We also revealed that β-sitosterol as well as cholesterol caused apoptosis, inducing caspase-3 activity in the cells (60 % increase compared with control cells) that corresponded to the DNA fragmentation analysis in a terminal uridine deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling (TUNEL) study. Although absorption of plant sterols is low compared with cholesterol, they can still influence other physiological functions. Since they effectively reduce serum LDL-cholesterol and atherosclerotic risk but also decrease the viability of cancer cells as well as normal cells in a time- and dose-dependent manner in vitro, their influence on other metabolic processes remains to be elucidated.

Author(s):  
Vahide Askari ◽  
Somayeh Shamlou ◽  
Ali Mostafaie ◽  
Sara Khaleqi

Angiogenesis has essential role in growth and metastasis of tumors. Development of therapies aimed to suppress angiogenesis using medicinal plants is one of the effective approaches for prevention/treatment of cancer. The current study was performed to investigate in vitro anti-angiogenic effect of Teucrium Polium (TP) extract and its fractions. The aerial part of Teucrium Polium was powdered and extracted with 50% ethanol. The extract was fractionated in to aqueous (AQ), n-butanol (BU), ethyl acetate (EA) and n-hexane (HE) fractions. Anti-angiogenic effect of TP was examined on human umbilical vein endothelial cells (HUVECs) in three-dimensional collagen matrix. The endothelial cells form capillary-like branches that can be visualized using phase contrast microscope and the number of tube-like structures can be quantified as a measure of in vitro angiogenesis. Furthermore, anti-proliferative and vascular endothelial growth factor(VEGF )suppressive effect of TP as important factors in the process of angiogenesis were assessed using3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT)and quantitative ELISA, respectively. Based on our findings, among the TP fractions, EA fraction showed the highest inhibitory activity on angiogenesis. This fraction with IC50: 68 µg/mL, inhibited angiogenesis at 60 µg/mL. The crude extract and other fractions of TP inhibited angiogenesis in a dose-dependent manner at doses higher concentrations than EA fraction, significantly.TP extract and EA fraction were able to inhibit proliferation of HUVEC and inhibited VEGF secretion in a dose dependent manner. The ethyl acetate fraction at 60 µg/ml inhibited VEGF secretion perfectly. Our data indicated that ethyl acetate fraction of Teucrium Polium could be a potential candidate for the prevention of angiogenesis in cancer and other related disorders. However, this suggestion needs more quantitative and in vivo investigations for confirmation.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Cailing Jiang ◽  
Shumin Li ◽  
Yanjing Li ◽  
Yuxian Bai

Despite recent advances in chemotherapy and surgical resection, the 5-year survival rate of esophageal cancer still remains at the low level. Therefore, it is very important to discover a new agent to improve the life expectancy of patients with esophageal cancer. Dihydroartemisinin (DHA), a semisynthetic derivative of artemisinin, has recently exhibited promising anticancer activity against various cancer cells. But so far, the specific mechanism remains unclear. We have previously demonstrated that DHA reduced viability of esophageal cancer cells in a dose-dependent manner in vitro and induced cell cycle arrest and apoptosis. Here, we extended our study to further observe the efficacy of DHA on esophageal cancer cells in vivo. In the present study, for the first time, we found that DHA significantly inhibits cell proliferation in xenografted tumor compared with the control. The mechanism was that DHA induced cell apoptosis in both human esophageal cancer cell lines Eca109 and Ec9706 in vivo in a dose-dependent manner. The results suggested that DHA was a promising agent against esophageal cancer in the clinical treatment.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e14635-e14635
Author(s):  
Shiran Shapira ◽  
Ilana Boustanai ◽  
Dina Kazanov ◽  
Ahmad Fokra ◽  
Ezra Bernstein ◽  
...  

e14635 Background: Inactivation of P53 and activation of ras are frequent genetic alterations in cancer. We have shown in vitro and in vivo, that the TA system can selectively and effectively eradicate RAS-mutated cancer cells. Aim: Selective killing of cancer cells while sparing the normal cells based on tumor genetic signature. Methods: A “first generation” ΔE1/ΔE3 human type-5 adenoviral-vectors for gene delivery were designed and constructed to specifically target cancer cells. They are designated as "PY4-mazF-mCherry" (PY4, ras responsive element), "ΔPY4-mazF-mCherry" (control viruses) and "RGC-mazE-IRES-GFP" (RGC, P53 responsive element). Their potency was tested in vitro, by the enzymatic MTT assay, microscopic observation, colony formation assay and FACS analysis, and in a xenograft model of CRC. Next, we generated, small natural vesicles, exosomes, that directly targeted cancer through specific small antibody fragments against CD24 that is expressed in most cancer cells and rarely on normal cells. Results: The TA system ("PY4-mazF-mCherry"+"RGC-mazE-IRES-GFP") induced a massive cell death, in a dose-dependent manner in vitro, 69% as compared to 19% in control co-infected ("ΔPY4-mazF-mCherry"+"RGC-mazE-IRES-GFP") HCT116 CRC cells (mutated RAS and p53). In vivo, growth of HCT116-/- ( KRASmutand P53mut) and HCT116+/+ ( KRASmut and P53wt) tumors were significantly inhibited (70% and 65%, respectively). Conclusions: 1. Abusing the P53 genetic status and the activated Ras pathway holds promising effective and safe strategy to target tumor cells while sparing normal tissues. 2. It is a proof of concept for personalized cancer therapy based on the tumor genetic profile.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 921-921
Author(s):  
Enriqueta Coll-Sangrona ◽  
Ali Amirkhosravi ◽  
Alshad S. Lalani ◽  
Liza Robles ◽  
Hina Desai ◽  
...  

Abstract Calcitriol, the hormonally-active metabolite of Vitamin D3, plays critical roles in calcium homeostasis, cell growth and differentiation, and immunoregulation. The anti-tumor activities of high-dose calcitriol have been demonstrated in a variety of preclinical models of solid tumors, leukemias and lymphomas. Recently, a new dose-intense formulation of calcitriol, termed DN-101 (Asentar™), was developed specifically for cancer therapy which allows for supraphysiological concentrations of calcitriol to be safely delivered in vivo to patients with cancer. In a recent Phase 2 clinical trial, DN-101 significantly increased overall survival and also reduced the incidence of thromboembolic events in men with androgen-independent prostate cancer receiving docetaxel-based chemotherapy. Based on previous observations we hypothesized that calcitriol’s anti-thrombotic effects in vivo may be due to the downregulation of Tissue Factor (TF) antigen and activity and/or upregulation of Thrombomodulin (TM). To test this hypothesis, we incubated A549 lung carcinoma, A375-C15 metastatic melanoma, THP-1 monocytic leukemia, and Eahy926 endothelial cells with increasing concentrations of calcitriol for 24 hrs. For TF induction, tumor cells were stimulated with TNFα for 5 hrs and activity was measured by a clotting assay and a thrombin generation assay (TGA). TM activity was measured by a chromogenic assay. TF and TM surface antigen were assessed by flow cytometry. Calcitriol prevented the induction of TF in TNFα-stimulated THP-1 cells in a dose-dependent manner (from 33% at 1 nM to 94% at 100 nM) as evidenced by a prolongation of plasma clotting time, a decrease in endogenous thrombin potential (ETP), and a reduction of surface TF antigen. In addition, the activity and surface expression of TM on THP-1 cells was increased significantly (40% and 3-fold respectively, P < 0.01) following 100 nM calcitriol treatment. Similarly, in TNFα-stimulated melanoma cells, calcitriol prevented the induction of TF activity (from 26% at 1 nM to 60% at 1 μM) and expression in a dose-dependent manner. High-dose calcitriol treatment also increased melanoma cell TM activity between 8% and 62%. In contrast, constitutively expressed TF activity and antigen were less affected by calcitriol in A549 lung carcinoma cells (12 to 28% reduction at concentrations between 1–100 nM) whilst TM activity and antigen were unaffected. In comparison to the tumor cells, calcitriol had no significant effect on TM or TF activity or antigen in TNFα-stimulated EAhy926 endothelial cells. In conclusion, we have demonstrated that high concentrations of calcitriol inhibit the induction of surface TF expression and upregulates TM in multiple tumor cell lines in vitro. The degree of the inhibition is proportional to the extent of TF induction by TNF-α. These in vitro results provide further support for the anticoagulant properties associated with high concentrations of calcitriol and may provide a rationale for understanding the lower incidence of thromboembolic complications observed in patients with metastatic prostate cancer treated with DN-101.


2006 ◽  
Vol 291 (3) ◽  
pp. G404-G413 ◽  
Author(s):  
Philip T. Nowicki

Studies were carried out to determine the effects of IL-1β on newborn intestinal hemodynamics. IL-1β increased the release of ET-1 by primary endothelial cells in a dose-dependent manner; as well, it reduced expression of the endothelin (ET) type B (ETB) receptor on endothelial cells and increased expression of the ET type A (ETA) receptor on vascular smooth muscle cells. IL-1β increased endothelial cell endothelial nitric oxide (NO) synthase (eNOS) expression but did not enhance eNOS activity as evidenced by release of NOx into conditioned medium in response to acetylcholine or shear stress. The effects of IL-1β on flow-induced dilation were evaluated in terminal mesenteric arteries in vitro. Pretreatment with IL-1β (1 ng; 4 h) significantly attenuated vasodilation in response to flow rates of 100 and 200 μl/min. This effect was mediated, in part, by the endothelin ETA receptor; thus selective blockade of ETA receptors with BQ610 nearly restored flow-induced dilation. In contrast, exogenous ET-1 only shifted the diameter-flow curve downward without altering the percent vasodilation in response to flow. The effects of IL-1β on ileal oxygenation were then studied using in vivo gut loops. Intramesenteric artery infusion of IL-1β upstream of the gut loop caused ileal vasoconstriction and reduced the arterial-venous O2 difference across the gut loop; consequently, it reduced ileal oxygenation by 60%. This effect was significantly attenuated by pretreatment with BQ610. These data support a linkage between the proinflammatory cytokine IL-1β and vascular dysfunction within the intestinal circulation, mediated, at least in part, by the ET system.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Alejandro Cuevas ◽  
Nicolás Saavedra ◽  
Martina Rudnicki ◽  
Dulcineia S. P. Abdalla ◽  
Luis A. Salazar

Propolis has been shown to modulate the angiogenesis in bothin vitroandin vivomodels. Thus, we aimed to evaluate the antiangiogenic properties of an ethanolic extract of Chilean propolis (EEP) and Pinocembrin (Pn). Migration, formation of capillary-like structures of endothelial cells, and sprouting from rat aortic rings were used to assess the antiangiogenic properties of EEP or Pn. In addition, microRNAs and VEGFA mRNA expression were studied by qPCR. ERK1/2 phosphorylation and HIF1αstabilization were assessed by western blot. EEP or Pn attenuated the migration, the capillary-like tube formation, and the sprouting in thein vitroassays. In addition, the activation of HIF1αand ERK1/2 and the VEGFA mRNA expression was significantly inhibited in a dose-dependent manner. In summary, these results suggest that HIF1αand ERK1/2 phosphorylation could be involved in the antiangiogenic effect of Chilean propolis, but more studies are needed to corroborate these findings.


PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Qing He ◽  
Ruiping Pang ◽  
Xin Song ◽  
Jie Chen ◽  
Huixin Chen ◽  
...  

Although thiazolidinediones (TZDs) were found to be ligands for peroxisome proliferators-activated receptorγ (PPARγ), the mechanism by which TZDs exert their anticancer effect remains unclear. Furthermore, the effect of TZDs on metastatic and angiogenesis potential of cancer cells is unknown. Our results in this paper show that rosiglitazone inhibited SGC-7901 gastric cancer cells growth, caused G1 cell cycle arrest and induced apoptosis in a dose-dependent manner. The effects of rosiglitazone on SGC-7901 cancer cells were completely reversed by treatment with PPARγ antagonist GW9662. Rosiglitazone inhibited SGC-7901 cell migration, invasiveness, and the expression of MMP-2 in dose-dependent manner via PPARγ-independent manner. Rosiglitazone reduced the VEGF induced angiogenesis of HUVEC in dose-dependent manner through PPARγ-dependent pathway. Moreover, rosiglitazone did not affect the expression of VEGF by SGC-7901 cells. Our results demonstrated that by PPARγ ligand, rosiglitazone inhibited growth and invasiveness of SGC-7901 gastric cancer cells and angiogenesis in vitro via PPARγ-dependent or -independent pathway.


2016 ◽  
Vol 14 (3) ◽  
pp. 206-211
Author(s):  
Qin Huang ◽  
Ting Du ◽  
Qiu-Xia Qu

Tea polyphenols (TP) are functional substances present in tea, which is one of the most promising preventive agents for cancer. This study was carried out to analyze the effects of TP on the ovarian cancer cells and possible mechanisms involved. TP led to inhibition of cell growth in a time- and dose-dependent manner, and promoted entry into the apoptosis-phase of the cell cycle. TP also decreased the invasion of ovarian cancer cells in vitro. In addition, TP treatment upregulated the mRNA expressions rate of Bax/Bcl-2 and downregulated Cyclin D and MMP2 mRNA expressions. Taken together, our data highlight that TP could be a potential therapeutic strategy for ovarian cancer. These findings also suggested that oncogens are involved in the anti-cancer effects of TP.


1984 ◽  
Vol 107 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Itaru Kojima ◽  
Etsuro Ogata ◽  
Hiroshi Inano ◽  
Bun-ichi Tamaoki

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.


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