title: β-Bisabolene, a Sesquiterpene from the Essential Oil Extract of Opoponax (Commiphora guidottii), Exhibits Cytotoxicity in Breast Cancer Cell Lines.
abstract: The essential oils from Commiphora species have for centuries been recognized to possess medicinal properties. Here, we performed gas chromatography-mass spectrometry on the essential oil from opoponax (Commiphora guidotti) and identified bisabolene isomers as the main constituents of this essential oil. Opoponax essential oil, a chemical component; β-bisabolene and an alcoholic analogue, α-bisabolol, were tested for their ability to selectively kill breast cancer cells. Only β-bisabolene, a sesquiterpene constituting 5% of the essential oil, exhibited selective cytotoxic activity for mouse cells (IC50 in normal Eph4: >200 µg/ml, MG1361: 65.49 µg/ml, 4T1: 48.99 µg/ml) and human breast cancer cells (IC50 in normal MCF-10A: 114.3 µg/ml, MCF-7: 66.91 µg/ml, MDA-MB-231: 98.39 µg/ml, SKBR3: 70.62 µg/ml and BT474: 74.3 µg/ml). This loss of viability was because of the induction of apoptosis as shown by Annexin V-propidium iodide and caspase-3/7 activity assay. β-bisabolene was also effective in reducing the growth of transplanted 4T1 mammary tumours in vivo (37.5% reduction in volume by endpoint). In summary, we have identified an anti-cancer agent from the essential oil of opoponax that exhibits specific cytotoxicity to both human and murine mammary tumour cells in vitro and in vivo, and this warrants further investigation into the use of β-bisabolene in the treatment of breast cancers.
authors.affiliation: European Cancer Stem Cell Research Institute, School of Biosciences, Cardiff University, Hadyn Ellis Building, Maindy Road, Cathays, Cardiff, CF24 4HQ, UK.
authors.forename: Syn Kok
authors.identifier: http://orcid.org/0000-0002-4333-2510
authors.initials: SK
authors.lastname: Yeo
authors.affiliation: School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK.
authors.forename: Ahmed Y
authors.initials: AY
authors.lastname: Ali
authors.affiliation: European Cancer Stem Cell Research Institute, School of Biosciences, Cardiff University, Hadyn Ellis Building, Maindy Road, Cathays, Cardiff, CF24 4HQ, UK.
authors.forename: Olivia A
authors.initials: OA
authors.lastname: Hayward
authors.affiliation: European Cancer Stem Cell Research Institute, School of Biosciences, Cardiff University, Hadyn Ellis Building, Maindy Road, Cathays, Cardiff, CF24 4HQ, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Turnham
authors.affiliation: School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK.
authors.forename: Troy
authors.initials: T
authors.lastname: Jackson
authors.affiliation: School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK.
authors.forename: Ifor D
authors.initials: ID
authors.lastname: Bowen
authors.affiliation: European Cancer Stem Cell Research Institute, School of Biosciences, Cardiff University, Hadyn Ellis Building, Maindy Road, Cathays, Cardiff, CF24 4HQ, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Clarkson
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D001943:Breast Neoplasms / Q000188:drug therapy*; D020169:Caspases / Q000378:metabolism; D029744:Commiphora / Q000737:chemistry*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D061986:MCF-7 Cells; D051379:Mice; D000081222:Monocyclic Sesquiterpenes; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D012717:Sesquiterpenes / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D000081222:Monocyclic Sesquiterpenes; D009822:Oils, Volatile; D010936:Plant Extracts; D012717:Sesquiterpenes; C004497:bisabolol; D020169:Caspases; C531191:beta-bisabolene
keywords: Commiphora guidottii; apoptosis; bisabolene; breast cancer; opoponax; scented myrrh; sesquiterpene