Please use this identifier to cite or link to this item:
Full metadata record
DC FieldValueLanguage
dc.identifier.citationDarmanin, S. (2003). Investigation of the bioactivity of an extract from Ricinus communis (Master's dissertation).en_GB
dc.description.abstractCancer is a leading cause of death in the western world, ranking second only to cardiovascular disease. A number of drugs used in chemotherapy are derived from natural products, thus highlighting the importance of such compounds. An extract from the leaves of the castor oil plant, Ricinus communis, was obtained by steam distillation. The in vitro cytotoxicity of this extract was studied, on human tumour cell lines and peripheral blood mononuclear cells. The MTT cytotoxicity assay, which measures mitochondrial activity, was used to detect cell viability. A combination of techniques was used to monitor the biochemical and morphological changes characteristic of apoptosis, to investigate the mechanism by which Ricinus communis extract influences SK-MEL-28 melanoma cell growth. Staining with quinacrine dihydrochloride displayed changes in nuclear size and shape, chromatin condensation and fragmentation, and the formation of apoptotic bodies. Sub-diploid nuclei were revealed by flow cytometry. The expression of phosphatidyl sirene on the outer surface of the cell membrane, following double staining with propidium iodide and the annex in V -FITC antibody conjugate, was observed by fluorescence microscopy. Loss of mitochondrial memhrane potential, associated with the early stages of apoptosis, was demonstrated by flow cytometry. GC-MS chromatograms for the extract revealed that the principal constituents of the extract were compounds classified as terpenoids. In conclusion, Ricinus communis extract is composed of a number of terpenoids, which are cytotoxic to a variety of human tumour cell types. They are capable of inducing apoptosis in SK-MEL-28 melanoma cells at low concentrations, while features of necrosis were observed at higher concentrations, as demonstrated by a number of experiments. The lack of a suitable therapeutic window, manifested by the cytotoxicity produced by the extract on PBMC, minimises the use of the whole extract in the clinical setting, nonetheless it might be a useful tool in further anti-cancer studies.en_GB
dc.subjectCastor oil planten_GB
dc.subjectAntibody-dependent cell cytotoxicityen_GB
dc.subjectMitochondrial pathologyen_GB
dc.titleInvestigation of the bioactivity of an extract from Ricinus communisen_GB
dc.rights.holderThe copyright of this work belongs to the author(s)/publisher. The rights of this work are as defined by the appropriate Copyright Legislation or as modified by any successive legislation. Users may access this work and can make use of the information contained in accordance with the Copyright Legislation provided that the author must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the prior permission of the copyright holderen_GB
dc.publisher.institutionUniversity of Maltaen_GB
dc.publisher.departmentFaculty of Medicine & Surgery. Department of Anatomyen_GB
dc.contributor.supervisorCamilleri Podesta', Marie-Therese
dc.contributor.creatorDarmanin, Stephanie
Appears in Collections:Dissertations - FacM&SAna - 2003

Files in This Item:
File Description SizeFormat 
Darmanin_Stephanie_Investigation of the Bioactivity of an Extract from Ricinus Communis.pdf
  Restricted Access
7.49 MBAdobe PDFView/Open Request a copy

Items in OAR@UM are protected by copyright, with all rights reserved, unless otherwise indicated.