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In vitro cytotoxic effects of chemical constituents of Euphorbia grandicornis Blanc against breast cancer cells

  • Authors: Kemboi, Douglas , Peter, Xolani , Langat, Moses K , Mhlanga, Richwell , Vukea, Nyeleti , de la Mare, Jo-Anne , Siwe-Noundou, Xavier , Krause, Rui W M , Tembu, Vuyelwa J
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/191747 , vital:45160 , xlink:href="https://doi.org/10.1016/j.sciaf.2021.e01002"
  • Description: Euphorbia grandicornis Blanc is widely utilized in traditional medicine for a variety of ailments including body pains associated with skin irritations, inflammation, and snake or scorpion bites. Compounds from E. grandicornis were characterized using spectroscopic techniques, NMR, IR, MS, and melting points and alongside the extracts were evaluated for in vitro anticancer activity against several cancer cell lines. The root extract afforded known, β-glutinol (1), β-amyrin (2), 24-methylenetirucalla-8-en-3β-ol (3), tirucalla-8,25-diene-3β,24R-diol (4), stigmasterol (5), sitosterol (6), and hexyl (E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (7) based on their NMR spectroscopic data for the first report in E. grandicornis. The extracts and isolated compounds were evaluated for anticancer activities against hormone receptor-positive breast cancer (MCF-7), triple-negative breast cancer (HCC70), and non-tumorigenic mammary epithelial (MCF-12A) cell lines. The CH2Cl2 extract exhibited potent, cytotoxicity against MCF-7, HCC70, and MCF-12A cells. The aerial extract exhibited IC50 values of 1.03, 0.301, and 1.68 µg/mL, and root extract displayed IC50 values of 0.83, 0.83 and 3.98 µg/mL against MCF-7, HCC70, and MCF-12A cells respectively. The root extract thus showed selectivity for the cancer cell lines over the non-cancerous control cell line (SI = 4.80). Hexyl (E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (7) showed significant activity with IC50 values of 23.41, 29.45 and 27.01 µM against MCF-7, HCC70 and MCF-12A cells respectively, suggesting non-specific cytotoxicity.
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  • Date Issued: 2021

Cytotoxicity of triterpenoids from Clerodendrum glabrum against triple negative breast cancer cells in vitro:

  • Authors: Teclegeorgish, Zecarias W , Mokgalaka, Ntebogeng S , Vukea, Nyeleti , de la Mare, Jo-Anne , Tembu, Vuyelwa J
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/161511 , vital:40634 , https://doi.org/10.1016/j.sajb.2020.07.009
  • Description: Clerodendrum glabrum is an indigenous medicinal plant that is used to treat cough, cold, sore throat and chest complaints. The stem bark of Clerodendrum glabrum afforded four tritepenoids namely, 3β-olean-12-en-3-yl palmitate (β-amyrin palmitate), (1), 3β hydroxy 5-glutinene (glutinol), (2), 3β-lup-20(29)-en-3-palmitate (Lupeol-3-palmitate), (3), 3β-lup-20(29)-en-3-ol (lupeol) (4) and one common phytosterol (stigmasterol) (5). The structures were established on the basis of their spectroscopic analysis. The compounds were screened for cytotoxicity against the HCC70 triple negative breast cancer (TNBC), MCF-7 hormone receptor positive breast cancer and MCF-12A non-cancerous mammary epithelial cell lines.
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  • Date Issued: 2020

Repurposing a polymer precursor: Synthesis and in vitro medicinal potential of ferrocenyl 1, 3-benzoxazine derivatives

  • Authors: Mbaba, Mziyanda , Dingle, Laura M K , Cash, Devon , de la Mare, Jo-Anne , Laming, Dustin , Taylor, Dale , Hoppe, Heinrich C , Edkins, Adrienne L , Khanye, Setshaba D
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/165395 , vital:41240 , https://doi.org/10.1016/j.ejmech.2019.111924
  • Description: Cancer and malaria remain relevant pathologies in modern medicinal chemistry endeavours. This is compounded by the threat of development of resistance to existing clinical drugs in use as first-line option for treatment of these diseases. To counter this threat, strategies such as drug repurposing and hybridization are constantly adapted in contemporary drug discovery for the expansion of the drug arsenal and generation of novel chemotypes with potential to avert or delay resistance. In the present study, a polymer precursor scaffold, 1,3-benzoxazine, has been repurposed by incorporation of an organometallic ferrocene unit to produce a novel class of compounds showing in vitro biological activity against breast cancer, malaria and trypanosomiasis.
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  • Date Issued: 2020

Ruthenium complexes with mono-or bis-heterocyclic chelates: DNA/BSA binding, Antioxidant and Anticancer studies

  • Authors: Maikoo, Sanam , Chakraborty, Abir , Vukea, Nyeleti , Dingle, Laura M K , Samson, William J , de la Mare, Jo-Anne , Edkins, Adrienne L , Booysen, Irvin N
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/165463 , vital:41246 , DOI: 10.1080/07391102.2020.1775126
  • Description: Deoxyribonucleic acid (DNA) and bovine serum albumin (BSA) binding interactions for a series of ruthenium heterocyclic complexes were monitored using ultraviolet-visible (UV-Vis) spectrophotometry, fluorescence emission spectroscopy and agarose gel electrophoresis. Investigations of the DNA interactions for the metal complexes revealed that they are groove-binders with intrinsic binding constants in the order of 104 – 107 M−1.
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  • Date Issued: 2020

STIP1/HOP regulates the actin cytoskeleton through interactions with actin and changes in actin-binding proteins cofilin and profilin:

  • Authors: Beckley, Samantha Joy , Hunter, Morgan C , Kituyi, Sarah N , Wingate, Ianthe , Chakraborty, Abantika , Schwarz, Kelly , Makhubu, Matodzi P , Rousseau, Robert P , Ruck, Duncan K , de la Mare, Jo-Anne , Blatch, Gregory L , Edkins, Adrienne L
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/165373 , vital:41238 , https://doi.org/10.3390/ijms21093152
  • Description: Cell migration plays a vital role in both health and disease. It is driven by reorganization of the actin cytoskeleton, which is regulated by actin-binding proteins cofilin and profilin. Stress-inducible phosphoprotein 1 (STIP1) is a well-described co-chaperone of the Hsp90 chaperone system, and our findings identify a potential regulatory role of STIP1 in actin dynamics. We show that STIP1 can be isolated in complex with actin and Hsp90 from HEK293T cells and directly interacts with actin in vitro via the C-terminal TPR2AB-DP2 domain of STIP1, potentially due to a region spanning two putative actin-binding motifs. We found that STIP1 could stimulate the in vitro ATPase activity of actin, suggesting a potential role in the modulation of F-actin formation. Interestingly, while STIP1 depletion in HEK293T cells had no major effect on total actin levels, it led to increased nuclear accumulation of actin, disorganization of F-actin structures, and an increase and decrease in cofilin and profilin levels, respectively. This study suggests that STIP1 regulates the cytoskeleton by interacting with actin, or via regulating the ratio of proteins known to affect actin dynamics.
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  • Date Issued: 2020

The in vitro antiplasmodial and antiproliferative activity of new ferrocene-based α-aminocresols targeting hemozoin inhibition and DNA interaction:

  • Authors: Mbaba, Mziyanda , Dingle, Laura M K , Swart, Tarryn , Cash, Devon , Laming, Dustin , de la Mare, Jo-Anne , Taylor, Dale , Hoppe, Heinrich C , Biot, Christophe , Edkins, Adrienne L , Khanye, Setshaba D
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/149347 , vital:38827 , https://0-doi.org.wam.seals.ac.za/10.1002/cbic.202000132
  • Description: Compounds incorporating ferrocene in a aminocresol scaffold showed antiplasmodial and anticancer activity. SAR studies revealed that an OH group and rotatable C–NH bond are vital for biological activity, with spectrophotometric techniques and docking simulations suggesting a dual mode of action involving hemozoin inhibition and DNA interaction. Targeting multiple pathways could delay the development of clinical resistance.
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  • Date Issued: 2020

Anticancer evaluation of ruthenium (III) complexes with N-donor ligands tethered to coumarin or uracil moieties:

  • Authors: Gramni, Larusha , Vukea, Nyeleti , Chakraborty, Abir , Samson, William J , Dingle, Laura M K , Xulu, Bheki , de la Mare, Jo-Anne , Edkins, Adrienne L , Booysen, Irvin N
  • Date: 2019
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/163477 , vital:41041 , DOI: 10.1016/j.ica.2019.04.01
  • Description: In this study, the synthesis and characterization of new paramagnetic ruthenium(III) complexes: cis-[RuCl2(urdpa)] (1) {Hurdpa = 6-((bis(pyridin-2-ylmethyl)amino)methyl)uracil} and fac-[RuCl3(chrdpa)] (2) {chrdpa = 4-((bis(pyridin-2-ylmethyl)amino)methyl)-7-methoxycoumarin} are reported. These metal complexes have been comprehensively characterized by an array of physicochemical techniques and the X-ray solid-state structures of 1 and Hurdpa have been attained.
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  • Date Issued: 2019

In vitro and in vivo toxicity assessment of biologically synthesized silver nanoparticles from Elaeodendron croceum:

  • Authors: Odeyemi, S W , de la Mare, Jo-Anne , Edkins, Adrienne L , Afolayan, A J
  • Date: 2019
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/163488 , vital:41042 , DOI: 10.1515/jcim-2018-0184
  • Description: The cytotoxic properties of nanoparticles have attracted a great deal of attention in the field of nanoscience and nanotechnology due to their small size and ability to penetrate cellular membranes.
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  • Date Issued: 2019

Plaxenone A and B: Cytotoxic halogenated monoterpenes from the South African red seaweed Plocamium maxillosum

  • Authors: Knott, Michael G , de la Mare, Jo-Anne , Edkins, Adrienne L , Zhang, Angel , Stillman, Martin J , Bolton, John J , Antunes, Edith M , Beukes, Denzil R
  • Date: 2019
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/164446 , vital:41119 , https://doi.org/10.1016/j.phytol.2018.12.009
  • Description: The endemic South African red seaweed Plocamium maxillosum (Poiret) Lamouroux produces two unusual isomeric dichlorinated cyclohexenone monoterpenes, plaxenone A and B (1 and 2). The structures of the isolated compounds were determined from spectroscopic data and their absolute configuration was determined by comparison of the experimental and calculated ECD spectra. Compounds 1 and 2 inhibit the growth of MDA-MB-231 breast cancer cells.
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  • Date Issued: 2019

Heterodimer formation by Oct4 and Smad3 differentially regulates epithelial-to-mesenchymal transition-associated factors in breast cancer progression:

In vitro analysis of putative cancer stem cell populations and chemosensitivity in the SW480 and SW620 colon cancer metastasis model:

  • Authors: Slater, Cindy , de la Mare, Jo-Anne , Edkins, Adrienne L
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/164401 , vital:41115 , DOI: 10.3892/ol.2018.8431
  • Description: The cancer stem cell (CSC) theory implicates a small subpopulation of cells with stem like properties, which is responsible for tumour initiation, development and metastasis. The unique biological and functional characteristics of CSCs, widely associated with treatment resistance, indicate an association between metastasis and stemness. It was hypothesised that metastatic cell lines may be enriched in CSCs and that this would correlate with a more resistant tumour. In the present study, the SW480 and SW620 paired cell lines derived from a colon adenocarcinoma and its lymph node metastasis, respectively were compared as an in vitro model of cancer progression. Their chemosensitivity and CSC properties were investigated. A range of in vitro assays were performed, including the side population assay, ALDEFLUOR assay, tumoursphere assay and assessment of CSC associated surface phenotypes.
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  • Date Issued: 2018

Extracellular Hsp90 and TGFP regulate adhesion, migration and anchorage independent growth in a paired colon cancer cell line model

  • Authors: de la Mare, Jo-Anne , Jurgens, Tamarin , Edkins, Adrienne L
  • Date: 2017
  • Language: English
  • Type: article , text
  • Identifier: http://hdl.handle.net/10962/59920 , vital:27710 , https://doi.org/10.1186/s12885-017-3190-z
  • Description: Tumour metastasis remains the major cause of death in cancer patients and, to date, the mechanism and signalling pathways governing this process are not completely understood. The TGF-ß pathway is the most commonly mutated pathway in cancer, however its role in cancer progression is controversial as it can function as both a promoter and a suppressor of metastasis. Although previous studies have suggested a role for the molecular chaperone Hsp90 in regulating the TGF-ß pathway, the level at which this occurs as well as the consequences in terms of colon cancer metastasis are unknown.
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  • Date Issued: 2017

Isolation, characterization and antiproliferative activity of new metabolites from the South African endemic red algal species Laurencia alfredensis

  • Authors: Dziwornu, Godwin A , Caira, Mino R , de la Mare, Jo-Anne , Edkins, Adrienne L , Bolton, John J , Beukes, Denzil R , Sunassee, Suthananda N
  • Date: 2017
  • Language: English
  • Type: article , text
  • Identifier: http://hdl.handle.net/10962/59963 , vital:27715 , https://doi:10.3390/molecules22040513
  • Description: The marine red algae of the genus Laurencia have been widely studied for their structurally diverse and biologically active secondary metabolites. We report here the natural product investigation of the organic extract of a newly identified South African endemic species, Laurencia alfredensis. A sequence of column chromatography, preparative TLC and normal phase HPLC resulted in the isolation of eleven compounds comprising three labdane-type diterpenes (1-3), four polyether triterpenes (4-7), three cholestane-type ecdysteroids (8-10) and a glycolipid (11). Compounds 1-3, 5-8 and 10 have not previously been reported, while compound 9 is reported here for the first time from a natural source and the known compound 11 isolated for the first time from the genus Laurencia. The structural elucidation and the relative configuration assignments of the compounds were accomplished by extensive use of ID- and 2D-NMR, HR-ESI-MS, UV and IR spectroscopic techniques, while the absolute configuration of compound 1 was determined by single-crystal X-ray diffraction analysis. All compounds were evaluated against the MDA-MB-231 breast and HeLa cervical cancer cell lines. Compound 2 exhibited low micromolar antiproliferative activity (IC50 = 9.3 gM) against the triple negative breast carcinoma and compound 7 was similarly active (IC50 = 8.8 gM) against the cervical cancer cell line.
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  • Date Issued: 2017

Sarqaquinoic acid and related synthetic naphthoquinones inhibit the function of Hsp90

  • Authors: Chiwakata, M , de la Mare, Jo-Anne , Edkins, Adrienne L , Beukes, Denzil R
  • Date: 2016
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/66324 , vital:28933 , https://doi.org/10.1055/s-0036-1596751
  • Description: publisher version , Heat shock protein 90 (Hsp90) is of critical importance in the proper folding of numerous proteins, including those involved in cancer. Consequently, there is significant interest in the discovery and development of Hsp90 inhibitors as anticancer drugs. In this study, we investigated the ability of sargaquinoic acid (SQA) and selected naphthoquinone derivatives to inhibit Hsp90 function. SQA was isolated and purified from Sargassum incisifolium while the naphthoquinones were synthesised via a straightforward sequence incorporating a Diels-Alder reaction between benzoquinone derivatives and myrcene followed by coupling with substituted alkyl or arylamines. Hsp90 inhibition was assessed by a client protein degradation assay. At a concentration of 1µM, SQA showed almost complete inhibition of Hsp90 but only moderate antiproliferative effects (IC50 658µM) against a Hs578T breast cancer carcinoma cell line. Interestingly, the most potent synthetic aminonaphthoquinone inhibited Hsp90 function by 50% at a concentration of 1µM but showed much improved activity against the Hs578T cell line (IC50 0.32µM). Furthermore, unlike geldanamycin, none of the compounds tested upregulates Hsp70 suggesting that these compounds may bind to the C-terminal end of Hsp90.
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  • Date Issued: 2016

Facile synthesis and biological evaluation of assorted indolyl-3-amides and esters from a single, stable carbonyl nitrile intermediate

  • Authors: Veale, Clinton G L , Edkins, Adrienne L , de la Mare, Jo-Anne , de Kock, Carmen , Smith, Peter J , Khanye, Setshaba D
  • Date: 2015
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/66221 , vital:28919 , https://doi.org/10.1016/j.tetlet.2015.02.090
  • Description: publisher version , The synthesis of biologically relevant amides and esters is routinely conducted under complex reaction conditions or requires the use of additional catalysts in order to generate sensitive electrophilic species for attack by a nucleophile. Here we present the synthesis of different indolic esters and amides from indolyl-3-carbonyl nitrile, without the requirement of anhydrous reaction conditions or catalysts. Additionally, we screened these compounds for potential in vitro antimalarial and anticancer activity, revealing 1H-indolyl-3-carboxylic acid 3-(indolyl-3-carboxamide)aminobenzyl ester to have moderate activity against both lines.
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  • Date Issued: 2015

The palladacycle, AJ-5, exhibits anti-tumour and anti-cancer stem cell activity in breast cancer cells:

  • Authors: Aliwaini, Saeb , Peres, Jade , Kröger, Wendy L , Blanckenberg, Angelique , de la Mare, Jo-Anne , Edkins, Adrienne L , Mapolie, Selwyn , Prince, Sharon
  • Date: 2015
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/164874 , vital:41180 , DOI: 10.1016/j.canlet.2014.11.027
  • Description: Breast cancer is the most common malignancy amongst women worldwide but despite enormous efforts to address this problem, there is still limited success with most of the current therapeutic strategies. The current study describes the anti-cancer activity of a binuclear palladacycle complex (AJ-5) in oestrogen receptor positive (MCF7) and oestrogen receptor negative (MDA-MB-231) breast cancer cells as well as human breast cancer stem cells. AJ-5 is shown to induce DNA double strand breaks leading to intrinsic and extrinsic apoptosis and autophagy cell death pathways which are mediated by the p38 MAP kinase. This study provides evidence that AJ-5 is potentially an effective compound in the treatment of breast cancer.
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  • Date Issued: 2015

Breast cancer: current developments in molecular approaches to diagnosis and treatment

  • Authors: de la Mare, Jo-Anne , Contu, Lara , Hunter, Morgan C , Moyo, Buhle , Sterrenberg, Jason N , Dhanani, Karim C H , Mutsvunguma, Lorraine Z , Edkins, Adrienne L
  • Date: 2014
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/164819 , vital:41175 , DOI: 10.2174/15748928113086660046
  • Description: Due to the high heterogeneity of breast cancers, numerous recent patents describe improved methods of detection and classification which promise better patient prognosis and treatment. In particular, there has been a shift towards more effective genetic screening to identify specific mutations associated with breast tumours, which may lead to “personalised medicine” with improved outcomes. Two challenging areas of breast cancer research involve the development of treatments for the highly aggressive triple negative breast cancer subtype as well as the chemotherapy-resistant cancer stem cell subpopulation. In addition, despite numerous recent advances in breast cancer treatment in woman, male breast cancer remains poorly understood and there are limited therapies available which are developed specifically for men. This review serves to report on important developments in the treatment of breast malignancies patented in the past two years as well as to highlight the current gaps in the field of breast cancer therapeutics and areas which require further study.
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  • Date Issued: 2014

Assessment of potential anti-cancer stem cell activity of marine algal compounds using an in vitro mammosphere assay:

  • Authors: de la Mare, Jo-Anne , Sterrenberg, Jason N , Sukhthankar, Mugdha G , Chiwakata, Maynard T , Beukes, Denzil R , Blatch, Gregory L , Edkins, Adrienne L
  • Date: 2013
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/165184 , vital:41216 , DOI: 10.1186/1475-2867-13-39
  • Description: The cancer stem cell (CSC) theory proposes that tumours arise from and are sustained by a subpopulation of cells with both cancer and stem cell properties. One of the key hallmarks of CSCs is the ability to grow anchorage-independently under serum-free culture conditions resulting in the formation of tumourspheres. It has further been reported that these cells are resistant to traditional chemotherapeutic agents.
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  • Date Issued: 2013

Halogenated oxindole and indoles from the South African marine ascidian Distaplia skoogi:

  • Authors: Bromley, Candice L , Parker-Nance, Shirley , de la Mare, Jo-Anne , Edkins, Adrienne L , Beukes, Denzil R , Davies-Coleman, Michael T
  • Date: 2013
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/164918 , vital:41184
  • Description: The known 3,6-dibromoindole (1), 6-bromo-3-chloroindole (2) and 6-bromo-2-oxindole (3) were isolated from the marine ascidian (sea squirt) Distapia skoogi collected from Algoa Bay, South Africa. Standard spectroscopic techniques were used to elucidate the structures of 1-3. All three compounds were found to be moderately cytotoxic to metastatic MDA-MB-231 breast cancer cells.
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  • Date Issued: 2013

Quinones and halogenated monoterpenes of algal origin show anti-proliferative effects against breast cancer cells in vitro:

  • Authors: de la Mare, Jo-Anne , Lawson, Jessica C , Chiwakata, Maynard T , Beukes, Denzil R , Blatch, Gregory L , Edkins, Adrienne L
  • Date: 2012
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/165165 , vital:41214 , DOI: 10.1007/s10637-011-9788-0
  • Description: Red and brown algae have been shown to produce a variety of compounds with chemotherapeutic potential. A recent report described the isolation of a range of novel polyhalogenated monoterpene compounds from the red algae Plocamium corallorhiza and Plocamium cornutum collected off the coast of South Africa, together with the previously described tetraprenylquinone, sargaquinoic acid (SQA), from the brown algae Sargassum heterophyllum. In our study, the algal compounds were screened for anti-proliferative activity against metastatic MDA-MB-231 breast cancer cells revealing that a number of compounds displayed anti-cancer activity with IC50 values in the micromolar range. A subset of the compounds was tested for differential toxicity in the MCF-7/MCF12A system and five of these, including sargaquinoic acid, were found to be at least three times more toxic to the breast cancer than the non-malignant cell line.
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  • Date Issued: 2012
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