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  1. Article ; Online: Limitations of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay when compared to three commonly used cell enumeration assays.

    van Tonder, Alet / Joubert, Annie M / Cromarty, A Duncan

    BMC research notes

    2015  Volume 8, Page(s) 47

    Abstract: Background: The tetrazolium-based MTT assay has long been regarded as the gold standard of cytotoxicity assays as it is highly sensitive and has been miniaturised for use as a high-throughput screening assay. However, various reports refer to ... ...

    Abstract Background: The tetrazolium-based MTT assay has long been regarded as the gold standard of cytotoxicity assays as it is highly sensitive and has been miniaturised for use as a high-throughput screening assay. However, various reports refer to interference by different test compounds, including the glycolysis inhibitor 3-bromopyruvate, with the conversion of the dye to coloured formazan crystals. This study assessed the linear range and reproducibility of three commonly used cell enumeration assays; the neutral red uptake (NRU), resazurin reduction (RES) and sulforhodamine B (SRB) assays, in comparison to the MTT assay. Interference between the MTT assay and three glycolysis inhibitors, 2-deoxyglucose, 3-bromopyruvate and lonidamine, was investigated.
    Results: Data indicate that the NRU, RES and SRB assays showed the smallest variability across the linear range, while the largest variation was observed for the MTT assay. This implies that these assays would more accurately detect small changes in cell number than the MTT assay. The SRB assay provided the most reproducible results as indicated by the coefficient of determination after a limited number of experiments. The SRB assay also produced the lowest variance in the derived 50% inhibitory concentration (IC50), while IC50 concentrations of 3-bromopyruvate could not be detected using either the MTT or RES assays after 24 hours incubation. Interference in the MTT assay was observed for all three tested glycolysis inhibitors in a cell-free environment. No interferences were observed for the NRU, SRB or RES assays.
    Conclusions: This study demonstrated that the MTT assay was not the best assay in a number of parameters that must be considered when a cell enumeration assay is selected: the MTT assay was less accurate in detecting changes in cell number as indicated by the variation observed in the linear range, had the highest variation when the IC50 concentrations of the glycolysis inhibitors were determined, and interference between the MTT assay and all the glycolysis inhibitors tested were observed. The SRB assay performed best overall considering all of the parameters, suggesting that it is the most suitable assay for use in preclinical screening of novel therapeutic compounds with oxido-reductive potential.
    MeSH term(s) Artifacts ; Biological Assay/methods ; Biological Assay/standards ; Cell Count/methods ; Cell Line, Tumor ; Cell Survival/drug effects ; Deoxyglucose/pharmacology ; Glycolysis/drug effects ; Glycolysis/physiology ; Humans ; Indazoles/pharmacology ; Neutral Red/chemistry ; Neutral Red/metabolism ; Observer Variation ; Oxazines/chemistry ; Oxazines/metabolism ; Oxidation-Reduction ; Pyruvates/pharmacology ; Reproducibility of Results ; Rhodamines/chemistry ; Rhodamines/metabolism ; Sensitivity and Specificity ; Staining and Labeling/methods ; Staining and Labeling/standards ; Tetrazolium Salts/chemistry ; Tetrazolium Salts/metabolism ; Thiazoles/chemistry ; Thiazoles/metabolism ; Xanthenes/chemistry ; Xanthenes/metabolism
    Chemical Substances Indazoles ; Oxazines ; Pyruvates ; Rhodamines ; Tetrazolium Salts ; Thiazoles ; Xanthenes ; resazurin (1FN9YD6968) ; lissamine rhodamine B (2609-88-3) ; Neutral Red (261QK3SSBH) ; bromopyruvate (63JMV04GRK) ; Deoxyglucose (9G2MP84A8W) ; thiazolyl blue (EUY85H477I) ; lonidamine (U78804BIDR)
    Language English
    Publishing date 2015-02-20
    Publishing country England
    Document type Comparative Study ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2413336-X
    ISSN 1756-0500 ; 1756-0500
    ISSN (online) 1756-0500
    ISSN 1756-0500
    DOI 10.1186/s13104-015-1000-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Ex vivo Determination of an Estradiol Analogue-Induced Changes on Platelet Morphology and Angiogenic Biomarkers.

    Repsold, Lisa / Pretorius, Etheresia / Joubert, Annie M

    Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada

    2015  Volume 21, Issue 6, Page(s) 1491–1503

    Abstract: Angiogenesis is a closely controlled biological process that takes place during fetal development of blood vessels and wound healing, and includes the development of new blood vessels from preexisting blood vessels. Tumor angiogenesis is a means by which ...

    Abstract Angiogenesis is a closely controlled biological process that takes place during fetal development of blood vessels and wound healing, and includes the development of new blood vessels from preexisting blood vessels. Tumor angiogenesis is a means by which tumors obtain oxygen, nutrition and promote tumor growth. Angiogenesis-regulating proteins are therefore ideal biomarkers in the study of tumor pathophysiology. In our laboratory, a new in silico-designed analogue of 2-methoxyestradiol has been synthesized with angiogenic properties, namely 2-ethyl-3-O-sulfamoyl-estra-1,3,5(10)16-tetraene (ESE-16). The ex vivo influence of ESE-16 on angiogenesis and morphology in platelets of healthy participants was investigated. Scanning electron microscopy revealed no morphological changes in ESE-16-treated platelets. The possible antiangiogenic effect of ESE-16-exposed platelets was determined by means of flow cytometry measurement of angiogenic protein levels, which were significantly increased after platelets were added to tumorigenic breast epithelial cells. This indicates that binding of platelets to cancer cells causes differential release of platelet constituents. Vascular endothelial growth factor levels were decreased in platelets, whereas platelet-derived growth factor and matrix metallopeptidase-9 levels were not significantly affected in platelets. In light of the above-mentioned data, further investigation of ESE-16's influence on morphology and angiogenic markers in platelets of cancer patients is warranted.
    Language English
    Publishing date 2015-12
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1385710-1
    ISSN 1435-8115 ; 1431-9276
    ISSN (online) 1435-8115
    ISSN 1431-9276
    DOI 10.1017/S1431927615015214
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: The in vitro effects of 2-methoxyestradiol-bis-sulphamate on cell numbers, membrane integrity and cell morphology, and the possible induction of apoptosis and autophagy in a non-tumorigenic breast epithelial cell line.

    Visagie, Michelle H / Joubert, Annie M

    Cellular & molecular biology letters

    2010  Volume 15, Issue 4, Page(s) 564–581

    Abstract: 2-methoxyestradiol (2ME2) exerts estrogen receptor-independent anti-proliferative, anti-angiogenic and anti-tumor activity in vitro and in vivo. Due to its low bioavailability and rapid metabolic degradation, several analogues have been developed in ... ...

    Abstract 2-methoxyestradiol (2ME2) exerts estrogen receptor-independent anti-proliferative, anti-angiogenic and anti-tumor activity in vitro and in vivo. Due to its low bioavailability and rapid metabolic degradation, several analogues have been developed in recent years. 2-methoxyestradiol-bis-sulphamate (2-MeOE2bisMATE) is a bis-sulphamoylated derivative of 2ME2 with anti-proliferative activity. The aim of this study was to investigate cell signaling events induced by 2-MeOE2bisMATE in a non-tumorigenic cell line (MCF-12A) by analysing its influence on cell number, morphology and membrane integrity, and the possible induction of apoptosis and autophagy. Dose- and time-dependent studies revealed that 48 h exposure to 2-MeOE2bisMATE (0.4 μM) resulted in a decrease in cell numbers to 79%. A slight increase in the level of lactate dehydrogenase production was observed in the 2-MeOE2bisMATE-treated cells. Morphological studies revealed an increase in the number of cells in metaphase. Hallmarks of apoptosis were also found, namely nuclear fragmentation and apoptotic bodies. In addition, increased lysosomal staining was observed via fluorescent microscopy, suggesting the induction of another type of cell death, namely autophagy. Since 2-MeOE2bisMATE is regarded as a potential anti-cancer agent, it is also imperative to investigate the susceptibility of non-tumorigenic cells to its influence. The data generated from this study contributes to the understanding of the action that 2-MeOE2bisMATE exerts on the non-tumorigenic MCF-12A breast epithelial cell line.
    MeSH term(s) Apoptosis/drug effects ; Autophagy/drug effects ; Breast/cytology ; Cell Count ; Cell Line ; Cell Membrane/drug effects ; Cell Shape/drug effects ; Epithelial Cells/cytology ; Epithelial Cells/drug effects ; Epithelial Cells/physiology ; Estradiol/analogs & derivatives ; Estradiol/metabolism ; Estradiol/pharmacology ; Female ; Humans
    Chemical Substances 2-methoxyestradiol-3,17-bis-O,O-sulfamate ; Estradiol (4TI98Z838E)
    Language English
    Publishing date 2010-08-09
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2108724-6
    ISSN 1689-1392 ; 1425-8153
    ISSN (online) 1689-1392
    ISSN 1425-8153
    DOI 10.2478/s11658-010-0030-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Tumor cell culture survival following glucose and glutamine deprivation at typical physiological concentrations.

    Mathews, Edward Henry / Stander, B André / Joubert, Annie M / Liebenberg, Leon

    Nutrition (Burbank, Los Angeles County, Calif.)

    2014  Volume 30, Issue 2, Page(s) 218–227

    Abstract: Objective: Most glucose (and glutamine)-deprivation studies of cancer cell cultures focus on total depletion, and are conducted over at least 24 h. It is difficult to extrapolate findings from such experiments to practical anti-glycolytic treatments, ... ...

    Abstract Objective: Most glucose (and glutamine)-deprivation studies of cancer cell cultures focus on total depletion, and are conducted over at least 24 h. It is difficult to extrapolate findings from such experiments to practical anti-glycolytic treatments, such as with insulin-inhibiting diets (with 10%-50% carbohydrate dietary restriction) or with isolated limb perfusion therapy (which usually lasts about 90 min). The aim of this study was to obtain experimental data on the effect of partial deprivation of d-glucose and l-glutamine (to typical physiological concentrations) during 0 to 6-h exposures of HeLa cells.
    Methods: HeLa cells were treated for 0 to 6 h with 6 mM d-glucose and 1 mM l-glutamine (normal in vivo conditions), 3 mM d-glucose and 0.5 mM l-glutamine (severe hypoglycemic conditions), and 0 mM d-glucose and 0 mM l-glutamine ("starvation"). Polarization-optical differential interference contrast and phase-contrast light microscopy were employed to investigate morphologic changes.
    Results: Reduction of glucose levels from 6 to 3 mM (and glutamine levels from 1 to 0.5 mM) brings about cancer cell survival of 73% after 2-h exposure and 63% after 4-h exposure. Reducing glucose levels from 6 to 0 mM (and glutamine levels from 1 to 0 mM) for 4 h resulted in 53% cell survival.
    Conclusion: These data reveal that glucose (and glutamine) deprivation to typical physiological concentrations result in significant cancer cell killing after as little as 2 h. This supports the possibility of combining anti-glycolytic treatment, such as a carbohydrate-restricted diet, with chemotherapeutics for enhanced cancer cell killing.
    MeSH term(s) Cell Survival/drug effects ; Culture Media/chemistry ; Glucose/pharmacology ; Glucose/physiology ; Glutamine/pharmacology ; Glutamine/physiology ; Glycolysis ; HeLa Cells ; Humans ; Insulin/blood
    Chemical Substances Culture Media ; Insulin ; Glutamine (0RH81L854J) ; Glucose (IY9XDZ35W2)
    Language English
    Publishing date 2014-02
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 639259-3
    ISSN 1873-1244 ; 0899-9007
    ISSN (online) 1873-1244
    ISSN 0899-9007
    DOI 10.1016/j.nut.2013.07.024
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: The apoptosis inducing effects of Sutherlandia spp. extracts on an oesophageal cancer cell line.

    Skerman, Nicola B / Joubert, Annie M / Cronjé, Marianne J

    Journal of ethnopharmacology

    2011  Volume 137, Issue 3, Page(s) 1250–1260

    Abstract: Aim of study: Oesophageal cancer is the ninth most common cancer in the world and the second most common cancer among South African men. It also has one of the lowest possibilities of cure, with the 5-year survival rate estimated to be only 10% overall. ...

    Abstract Aim of study: Oesophageal cancer is the ninth most common cancer in the world and the second most common cancer among South African men. It also has one of the lowest possibilities of cure, with the 5-year survival rate estimated to be only 10% overall. Sutherlandia frutescens, or the "cancer bush", is a medicinal plant indigenous to southern Africa that is believed to have anti-cancer and anti-proliferative properties. The aim of this study was to investigate the potential apoptosis-inducing effects of two S. frutescens extracts and one Sutherlandia tomentosa extract on the SNO oesophageal cancer cell line.
    Materials and methods: Cell viability and morphology of SNO cells were evaluated following exposure to the extracts. Apoptotic markers including cytochrome c translocation and phosphatidylserine externalisation were quantified by flow cytometry. The activity of caspases 3 and 7 was evaluated with spectrofluorometry. Apoptosis was evaluated in the presence of the pan-caspase inhibitor, Z-VAD-fmk. The effect of the extracts was compared to non-cancerous peripheral blood mononuclear cells (PBMCs).
    Results: Time- and dose-response studies were conducted to establish treatment conditions of 2.5 and 5mg/ml of crude plant extracts. Microscopy studies revealed that S. frutescens- and S. tomentosa-treated SNO cells had morphological features characteristic of apoptosis. Annexin V/propidium iodide flow cytometry confirmed that the extracts do, in fact, induce apoptosis in the SNO cells. Caspase inhibition studies seem to indicate that extracts A (S. frutescens (L.) R. Br. subsp. microphylla from Colesberg), B (S. frutescens (L.) R. Br. subsp. microphylla from Platvlei) and C (S. tomentosa Eckl. & Zeyh from Stil Bay) are able to induce caspase-dependent as well as -independent cell death. The S. frutescens and S. tomentosa extracts were found to be more cytotoxic to cancerous SNO cells when compared to the PBMCs.
    Conclusions: S. frutescens and S. tomentosa extracts show promise as apoptosis-inducing anti-cancer agents.
    MeSH term(s) Adenosine Triphosphate/metabolism ; Amino Acid Chloromethyl Ketones/pharmacology ; Antineoplastic Agents, Phytogenic/isolation & purification ; Antineoplastic Agents, Phytogenic/pharmacology ; Apoptosis/drug effects ; Caspase 3/metabolism ; Caspase 7/metabolism ; Caspase Inhibitors ; Cell Line, Tumor ; Cell Shape/drug effects ; Cell Survival/drug effects ; Cysteine Proteinase Inhibitors/pharmacology ; Cytochromes c/metabolism ; Dose-Response Relationship, Drug ; Esophageal Neoplasms/metabolism ; Esophageal Neoplasms/pathology ; Fabaceae/chemistry ; Flow Cytometry ; Humans ; Leukocytes, Mononuclear/drug effects ; Leukocytes, Mononuclear/pathology ; Phosphatidylserines/metabolism ; Plant Extracts/isolation & purification ; Plant Extracts/pharmacology ; Plants, Medicinal ; Protein Transport ; Spectrometry, Fluorescence ; Time Factors
    Chemical Substances Amino Acid Chloromethyl Ketones ; Antineoplastic Agents, Phytogenic ; Caspase Inhibitors ; Cysteine Proteinase Inhibitors ; Phosphatidylserines ; Plant Extracts ; benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone ; Adenosine Triphosphate (8L70Q75FXE) ; Cytochromes c (9007-43-6) ; CASP3 protein, human (EC 3.4.22.-) ; CASP7 protein, human (EC 3.4.22.-) ; Caspase 3 (EC 3.4.22.-) ; Caspase 7 (EC 3.4.22.-)
    Language English
    Publishing date 2011-10-11
    Publishing country Ireland
    Document type Comparative Study ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 134511-4
    ISSN 1872-7573 ; 0378-8741
    ISSN (online) 1872-7573
    ISSN 0378-8741
    DOI 10.1016/j.jep.2011.07.054
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Molecular crosstalk between apoptosis and autophagy induced by a novel 2-methoxyestradiol analogue in cervical adenocarcinoma cells.

    Theron, Anne E / Nolte, Elsie M / Lafanechère, Laurence / Joubert, Annie M

    Cancer cell international

    2013  Volume 13, Issue 1, Page(s) 87

    Abstract: Background: 2-Methoxyestradiol has been shown to induce both autophagy and apoptosis in various carcinogenic cell lines. Although a promising anti-cancer agent, it has poor bioavailability and rapid in vivo metabolism which decreases its efficiency. In ... ...

    Abstract Background: 2-Methoxyestradiol has been shown to induce both autophagy and apoptosis in various carcinogenic cell lines. Although a promising anti-cancer agent, it has poor bioavailability and rapid in vivo metabolism which decreases its efficiency. In order to improve 2-methoxyestradiol's anti-proliferative properties, a novel 2-methoxyestradiol analogue, 2-ethyl-3-O-sulphamoyl-estra-1,3,5 (10)16-tetraene (ESE-16), was previously in silico-designed in our laboratory. This study investigated ESE-16 for its anti-proliferative potential on a cervical adenocarcinoma cell (HeLa) cell line. Additionally, the possible intracellular crosstalk mechanisms between the two types of cell death were investigated.
    Methods and results: HeLa cells exposed to 0.5 μM ESE-16 for 24 hours showed morphological evidence of both apoptotic and autophagic death pathways as assessed by polarization-optical transmitted light differential interference contrast microscopy, fluorescent microscopy and transmission electron microscopy. Flow cytometric cyclin B1 quantification revealed induction of programmed cell death after halting cell cycle progression in metaphase. Confocal microscopy demonstrated that ESE-16 caused microtubule fragmentation. Flow cytometric analysis of cell cycle progression and phosphatidylserine flip determination confirmed induction of apoptosis. Moreover, an increase in aggresome formation and microtubule-associated protein light chain, LC3, was demonstrated indicative of autophagy. Both caspase 8 and 3 were upregulated in a spectrophotometric analysis, indicating the involvement of the extrinsic pathway of apoptotic induction.
    Conclusions: We conclude that the novel in silico-designed compound, ESE-16, exerts its anti-proliferative effect on the tumorigenic human epithelial cervical (HeLa) cells by sequentially targeting microtubule integrity, resulting in a metaphase block, causing induction of both autophagic and apoptotic cell death via a crosstalk mechanism that involves the extrinsic pathway. Future investigations will expand on signal transduction pathways involved in both apoptosis and autophagy for assessment of ESE-16 effects on microtubule dynamic instability parameters.
    Language English
    Publishing date 2013-08-27
    Publishing country England
    Document type Journal Article
    ISSN 1475-2867
    ISSN 1475-2867
    DOI 10.1186/1475-2867-13-87
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Antimitotic drugs in the treatment of cancer.

    van Vuuren, Rustelle Janse / Visagie, Michelle H / Theron, Anne E / Joubert, Annie M

    Cancer chemotherapy and pharmacology

    2015  Volume 76, Issue 6, Page(s) 1101–1112

    Abstract: Cancer is a complex disease since it is adaptive in such a way that it can promote proliferation and invasion by means of an overactive cell cycle and in turn cellular division which is targeted by antimitotic drugs that are highly validated chemotherapy ...

    Abstract Cancer is a complex disease since it is adaptive in such a way that it can promote proliferation and invasion by means of an overactive cell cycle and in turn cellular division which is targeted by antimitotic drugs that are highly validated chemotherapy agents. However, antimitotic drug cytotoxicity to non-tumorigenic cells and multiple cancer resistance developed in response to drugs such as taxanes and vinca alkaloids are obstacles faced in both the clinical and basic research field to date. In this review, the classes of antimitotic compounds, their mechanisms of action and cancer cell resistance to chemotherapy and other limitations of current antimitotic compounds are highlighted, as well as the potential of novel 17-β estradiol analogs as cancer treatment.
    MeSH term(s) Antimitotic Agents/classification ; Antimitotic Agents/therapeutic use ; Apoptosis/drug effects ; Biomarkers, Tumor/metabolism ; Cell Cycle/drug effects ; Cell Proliferation/drug effects ; Drug Resistance, Neoplasm ; Humans ; Neoplasms/drug therapy ; Neoplasms/metabolism ; Taxoids/therapeutic use ; Vinca Alkaloids/therapeutic use
    Chemical Substances Antimitotic Agents ; Biomarkers, Tumor ; Taxoids ; Vinca Alkaloids
    Language English
    Publishing date 2015-11-12
    Publishing country Germany
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 6820-2
    ISSN 1432-0843 ; 0344-5704 ; 0943-9404
    ISSN (online) 1432-0843
    ISSN 0344-5704 ; 0943-9404
    DOI 10.1007/s00280-015-2903-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Effects of environmental endocrine disruptors, including insecticides used for malaria vector control on reproductive parameters of male rats.

    Patrick, Sean M / Bornman, Maria S / Joubert, Annie M / Pitts, Neville / Naidoo, Vinny / de Jager, Christiaan

    Reproductive toxicology (Elmsford, N.Y.)

    2016  Volume 61, Page(s) 19–27

    Abstract: The male reproductive system is sensitive to endocrine disrupting chemicals (EDCs) during critical developmental windows. Male Sprague-Dawley rats were exposed in utero-, during lactation- and directly to 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane ( ... ...

    Abstract The male reproductive system is sensitive to endocrine disrupting chemicals (EDCs) during critical developmental windows. Male Sprague-Dawley rats were exposed in utero-, during lactation- and directly to 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), 1,1,-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and a mixture of DDT, deltamethrin (DM), p-nonylphenol (p-NP) and phytoestrogens, at concentrations found in a malaria-area. After dosing for 104 days, histological assessments and reproductive-endpoints were assessed. The anogenital distance (AGD) (P=0.005) was shorter in the mixture-exposed group, while the prostate mass (P=0.018) was higher in the DDT-exposed group. A higher testicular mass and abnormal histology was observed in the DDT-(P=0.019), DDE-(P=0.047) and mixture-exposed (P<0.005) groups. This study shows that in utero-, lactational- and direct exposure to EDCs present in a malaria-area negatively affects male reproductive parameters in rats. These findings raise concerns to EDC-exposures to mothers living in malaria-areas and the reproductive health of their male offspring.
    Language English
    Publishing date 2016-06
    Publishing country United States
    Document type Journal Article
    ZDB-ID 639342-1
    ISSN 1873-1708 ; 0890-6238
    ISSN (online) 1873-1708
    ISSN 0890-6238
    DOI 10.1016/j.reprotox.2016.02.015
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  9. Article: Effects of ω3- and ω6-Polyunsaturated Fatty Acids on RANKL-Induced Osteoclast Differentiation of RAW264.7 Cells: A Comparative in Vitro Study

    Boeyens, Jan C. A / Deepak, Vishwa / Chua, Wei-Hang / Kruger, Marlena C / Joubert, Annie M / Coetzee, Magdalena

    Nutrients. 2014 July 09, v. 6, no. 7

    2014  

    Abstract: Polyunsaturated fatty acids (PUFAs) have been reported to have an anabolic effect on bone in vivo, but comparative studies to identify inhibitors of osteoclast formation amongst ω3- and ω6-PUFAs are still lacking. Here we assessed the effects of the ω3- ... ...

    Abstract Polyunsaturated fatty acids (PUFAs) have been reported to have an anabolic effect on bone in vivo, but comparative studies to identify inhibitors of osteoclast formation amongst ω3- and ω6-PUFAs are still lacking. Here we assessed the effects of the ω3-PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the ω6-PUFAs, arachidonic acid (AA) and γ-linolenic acid (GLA) on a RAW264.7 osteoclast differentiation model. The effects of PUFAs on RANKL-induced osteoclast formation were evaluated by counting tartrate resistant acid phosphatase (TRAP)-positive multinucleated cells. PUFAs significantly inhibited RANKL-induced osteoclast formation in a dose-dependent manner with AA- and DHA-mediated inhibition being the strongest. Furthermore, RANKL-induced mRNA- and protein expression of the key osteoclastogenic genes cathepsin K and TRAP were inhibited by AA and more potently by DHA. Owing to the attenuated osteoclastogenesis by DHA and AA, actin ring formation and bone resorptive activity of these cells as evaluated on bone-mimetic plates were severely compromised. Hence, of the tested PUFAs, AA and DHA were found to be the most effective in inhibiting RANKL-induced osteoclast formation with the latter providing the strongest inhibitory effects. Collectively, the data indicates that these PUFAs may play an important role in regulating bone diseases characterized by excessive osteoclast activity.
    Keywords acid phosphatase ; actin ; arachidonic acid ; bone diseases ; cathepsin K ; comparative study ; docosahexaenoic acid ; dose response ; eicosapentaenoic acid ; gamma-linolenic acid ; genes ; in vitro studies ; messenger RNA ; models ; osteoclasts ; protein synthesis
    Language English
    Dates of publication 2014-0709
    Size p. 2584-2601.
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article
    ZDB-ID 2518386-2
    ISSN 2072-6643
    ISSN 2072-6643
    DOI 10.3390/nu6072584
    Database NAL-Catalogue (AGRICOLA)

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  10. Article: The apoptosis inducing effects of Sutherlandia spp. extracts on an oesophageal cancer cell line

    Skerman, Nicola B / Joubert, Annie M / Cronjé, Marianne J

    Journal of ethnopharmacology. 2011 Oct. 11, v. 137, no. 3

    2011  

    Abstract: AIM OF STUDY: Oesophageal cancer is the ninth most common cancer in the world and the second most common cancer among South African men. It also has one of the lowest possibilities of cure, with the 5-year survival rate estimated to be only 10% overall. ... ...

    Abstract AIM OF STUDY: Oesophageal cancer is the ninth most common cancer in the world and the second most common cancer among South African men. It also has one of the lowest possibilities of cure, with the 5-year survival rate estimated to be only 10% overall. Sutherlandia frutescens, or the “cancer bush”, is a medicinal plant indigenous to southern Africa that is believed to have anti-cancer and anti-proliferative properties. The aim of this study was to investigate the potential apoptosis-inducing effects of two S. frutescens extracts and one Sutherlandia tomentosa extract on the SNO oesophageal cancer cell line. MATERIALS AND METHODS: Cell viability and morphology of SNO cells were evaluated following exposure to the extracts. Apoptotic markers including cytochrome c translocation and phosphatidylserine externalisation were quantified by flow cytometry. The activity of caspases 3 and 7 was evaluated with spectrofluorometry. Apoptosis was evaluated in the presence of the pan-caspase inhibitor, Z-VAD-fmk. The effect of the extracts was compared to non-cancerous peripheral blood mononuclear cells (PBMCs). RESULTS: Time– and dose–response studies were conducted to establish treatment conditions of 2.5 and 5mg/ml of crude plant extracts. Microscopy studies revealed that S. frutescens- and S. tomentosa-treated SNO cells had morphological features characteristic of apoptosis. Annexin V/propidium iodide flow cytometry confirmed that the extracts do, in fact, induce apoptosis in the SNO cells. Caspase inhibition studies seem to indicate that extracts A (S. frutescens (L.) R. Br. subsp. microphylla from Colesberg), B (S. frutescens (L.) R. Br. subsp. microphylla from Platvlei) and C (S. tomentosa Eckl. & Zeyh from Stil Bay) are able to induce caspase-dependent as well as -independent cell death. The S. frutescens and S. tomentosa extracts were found to be more cytotoxic to cancerous SNO cells when compared to the PBMCs. CONCLUSIONS: S. frutescens and S. tomentosa extracts show promise as apoptosis-inducing anti-cancer agents.
    Keywords Lessertia frutescens ; Sutherlandia ; apoptosis ; cytochrome c ; flow cytometry ; iodides ; medicinal plants ; men ; microscopy ; mononuclear leukocytes ; plant extracts ; survival rate
    Language English
    Dates of publication 2011-1011
    Size p. 1250-1260.
    Publishing place Elsevier Ireland Ltd
    Document type Article
    ZDB-ID 134511-4
    ISSN 1872-7573 ; 0378-8741
    ISSN (online) 1872-7573
    ISSN 0378-8741
    DOI 10.1016/j.jep.2011.07.054
    Database NAL-Catalogue (AGRICOLA)

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