Identification and in vitro anti-esophageal cancer activity of a series of halogenated monoterpenes isolated from the South African seaweeds Plocamium suhrii and Plocamium cornutum

Antunes, Edith; Afolayan, Anthonia F.; Chiwakata, Maynard T.; Fakee, Jameel; Knott, Michael G.; Whibley, Catherine; Hendricks, Denver T.; Bolton, John J.; Beukes, Denzil R.

doi:10.1016/j.phytochem.2011.02.003

Cited by 57 publications

(56 citation statements)

References 11 publications

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“…For example, a halogenated phenols metabolite, 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether isolated from the red alga Symphyocladia latiuscula has shown antioxidant and antimicrobial activity [46]. And other halogenated compounds from marine alga exhibited antibacterial, antifungal, antiviral, anti-inflammatory, antiproliferative, cytotoxic, and insecticidal activity [47,48,49,50]. Also, some marine algae to protect themselves from UV rays have UV-absorbing substances that inhibit the penetration of UV ray into their tissue or cells.…”

Section: Resultsmentioning

confidence: 99%

An Ethanol Extract Derived from Bonnemaisonia hamifera Scavenges Ultraviolet B (UVB) Radiation-Induced Reactive Oxygen Species and Attenuates UVB-Induced Cell Damage in Human Keratinocytes

et al. 2012

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The present study investigated the photoprotective properties of an ethanol extract derived from the red alga Bonnemaisonia hamifera against ultraviolet B (UVB)-induced cell damage in human HaCaT keratinocytes. The Bonnemaisonia hamifera ethanol extract (BHE) scavenged the superoxide anion generated by the xanthine/xanthine oxidase system and the hydroxyl radical generated by the Fenton reaction (FeSO4 + H2O2), both of which were detected by using electron spin resonance spectrometry. In addition, BHE exhibited scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical and intracellular reactive oxygen species (ROS) that were induced by either hydrogen peroxide or UVB radiation. BHE reduced UVB-induced apoptosis, as shown by decreased apoptotic body formation and DNA fragmentation. BHE also attenuated DNA damage and the elevated levels of 8-isoprostane and protein carbonyls resulting from UVB-mediated oxidative stress. Furthermore, BHE absorbed electromagnetic radiation in the UVB range (280–320 nm). These results suggest that BHE protects human HaCaT keratinocytes against UVB-induced oxidative damage by scavenging ROS and absorbing UVB photons, thereby reducing injury to cellular components.

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Section: Resultsmentioning

confidence: 99%

An Ethanol Extract Derived from Bonnemaisonia hamifera Scavenges Ultraviolet B (UVB) Radiation-Induced Reactive Oxygen Species and Attenuates UVB-Induced Cell Damage in Human Keratinocytes

et al. 2012

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“…In addition, very few studies of the biological activity of algal metabolites go beyond the standard in vitro cytotoxicity screening tests [14,15]. Recently, a number of polyhalogenated monoterpene compounds were isolated from the red algae Plocamium suhrii, Plocamium cornutum and Plocamium corallorhiza collected from the South African coastline, which were cytotoxic to oesophageal and breast cancer cells in vitro [16,17]. We report that two polyhalogenated monoterpenes isolated from Plocamium cornutum red algae inhibit MCF-7 mammosphere formation in vitro , while having no adverse effects on either the bulk MCF-7 population or non-transformed MCF-12A breast epithelial cells.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2013

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BackgroundThe 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.MethodsIn this study, the tumoursphere assay was validated in MCF-7 cells and used to screen novel marine algal compounds for potential anti-cancer stem cell (CSC) activity in vitro.ResultsMCF-7 breast cancer cells were observed to generate tumourspheres or mammospheres after 3-5 days growth in anchorage-independent conditions and an apparent enrichment in potential CSCs was observed by an increase in the proportion of CD44high/CD24low marker-bearing cells and Oct4 expression compared to those in the bulk population grown in regular adherent conditions. Using this assay, a set of algal metabolites was screened for the ability to inhibit mammosphere development as a measure of potential anti-CSC activity. We report that the polyhalogenated monoterpene stereoisomers RU017 and RU018 isolated from the red alga Plocamium cornutum, both of which displayed no cytotoxicity against either adherent MCF-7 breast cancer or MCF-12A non-transformed breast epithelial cells, were able to prevent MCF-7 mammosphere formation in vitro. On the other hand, neither the brown algal carotenoid fucoxanthin nor the chemotherapeutic paclitaxel, both of which were toxic to adherent MCF-7 and MCF-12A cells, were able to inhibit mammosphere formation. In fact, pre-treatment with paclitaxel appeared to enhance mammosphere formation and development, a finding which is consistent with the reported resistance of CSCs to traditional chemotherapeutic agents.ConclusionDue to the proposed clinical significance of CSC in terms of tumour initiation and metastasis, the identification of agents able to inhibit this subpopulation has clinical significance.

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“…[19] Compounds 14-16 and 18 are known natural products, [2,3,10] but 17 has not yet been reported. Direct oxidative cleavage of the dioxolane produced sensitive aldehydes 12 a/12 b in high yield.…”

Section: Methodsmentioning

confidence: 99%

“…First, the vicinal secondary and tertiary chloride-bearing centers at the C3 and C4 positions, which are present in both the syn and anti diastereomeric forms within this family of natural products, [2,3,10] are both allylic and might cause undesired reactivity. First, the vicinal secondary and tertiary chloride-bearing centers at the C3 and C4 positions, which are present in both the syn and anti diastereomeric forms within this family of natural products, [2,3,10] are both allylic and might cause undesired reactivity.…”

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confidence: 99%

Enantioselective Divergent Syntheses of Several Polyhalogenated Plocamium Monoterpenes and Evaluation of Their Selectivity for Solid Tumors

et al. 2014

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The family of polyhalogenated monoterpenes from Plocamium counts over a hundred known members. Using glyceraldehyde acetonide as a chiral-pool precursor, an enantioselective and divergent strategy was developed that provides a blueprint for the synthesis of many of the small yet complex acyclic members of this family. The broad applicability of this approach is demonstrated with the short, eightstep synthesis of four natural products and three analogues. These syntheses are the first of any members of the acyclic polyhalogenated Plocamium monoterpenes and permitted the evaluation of their selectivity against a range of tumor cell lines.

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Identification and in vitro anti-esophageal cancer activity of a series of halogenated monoterpenes isolated from the South African seaweeds Plocamium suhrii and Plocamium cornutum

Cited by 57 publications

References 11 publications

An Ethanol Extract Derived from Bonnemaisonia hamifera Scavenges Ultraviolet B (UVB) Radiation-Induced Reactive Oxygen Species and Attenuates UVB-Induced Cell Damage in Human Keratinocytes

An Ethanol Extract Derived from Bonnemaisonia hamifera Scavenges Ultraviolet B (UVB) Radiation-Induced Reactive Oxygen Species and Attenuates UVB-Induced Cell Damage in Human Keratinocytes

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

Enantioselective Divergent Syntheses of Several Polyhalogenated Plocamium Monoterpenes and Evaluation of Their Selectivity for Solid Tumors

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