Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.583386
Title: Effects of novel apoptotic agents extracted from Commiphora species on cancer cell lines
Author: Bahashwan, Ahmed Abdul-Rahman
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2004
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Abstract:
The apoptotic effects of various concentrations of ethanol-, hexane-, and ethyl acetate-extracted molmol (from Commiphora molmol) and haddi (from Commiphora guidotti) on two cancer cell lines, SI80 and HT1080, and on a normal chick fibroblasts cell line, were studied. In addition, the effects of two commercially obtained molmol ethanol (Flavex) and haddi essential oil extracts (Aldrich) were also studied, and results compared and contrasted with results obtained using freshly extracted molmol and haddi preparations. Furthermore, the effects of two of the chemical constituents of haddi, Trans-Beta-ocimene and Gamma-Bisabolene (obtained commercially) were also studied, using the above-mentioned cell lines. Various techniques were employed to study these effects, including growth assays, MTT viability assay, histological and morphological techniques for the detection of apoptosis (haematoxylin-eosin staining and scanning and transmission electron microscopy), TUNEL technique which is the detection of DNA fragmentation, and Annexin-V assay to detect apoptotic plasma membrane change, using fluorescence microscopy. The results showed that ethanol-extracted molmol and hexane-extracted haddi are apoptosis inducers in the murine SI80 sarcoma cells and HT1080 human fibrosarcoma cells. Morphological analysis showed that both SI80 cells and HT1080 cells exposed to these extracts exhibited characteristics signs of apoptosis, including the formation of pyknotic nuclei, apoptotic cells, apoptotic bodies, blebbing of outer membrane, vacuolation, breaking-up of outer membrane, and loss of microvilli and filopodial attachments, as well as signs of chromatin margination and chromatin condensation alongside the nuclear membrane. Some secondary necrosis was also seen when cells were treated with extracts and tested with Annexin-V, and showed positive signs for changes in membrane phospatidylserine asymmetry. Annexin-V assay also demonstrated that apoptosis and death of SI80 cells was faster than in HT1080 cells. The results showed that both molmol and haddi extracts performed better at higher concentrations than at lower concentrations, and that apoptotic changes in SI80 cells and HT1080 cells were found to be time-dependent. The study also demonstrated that commercial preparations of molmol (Flavex) and haddi essential oil (Aldrich) were effective, but less so than the natural extracts. Molmol extracts at particular concentrations targeted cancer cells, in contrast to haddi extracts, which targeted both cancer and normal cell lines. The results also demonstrated that trans-β-ocimene was more effective than γ-bisabolene in inducing apoptosis in SI80 cells than in HT1080 cells. However, SEM results showed that these two chemicals acted on cancer cells in a similar way to that of haddi extracts. γ-bisabolene was more effective at LC₅₀ concentration (5 mM) in bringing about apoptosis in SI80 cells and HT1080 cells than trans-β-ocimene, at LC₅₀ concentration (100 mM). Both chemicals were very potent inducers of apoptosis.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.583386  DOI: Not available
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