Optimization of extraction of Centella asiatica and Erythroxylum cuneatum and their evaluation as a neuroprotective agent /
Neurodegenerative diseases result from deterioration of neurons which over time will lead to dysfunction and disabilities in the human body. The distribution of brain iron is found to be uneven compared with that of other metals. Iron is present in the substantia nigra, globus pallidus and dentate g...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
Gombak, Selangor :
Kulliyyah of Engineering, International Islamic University Malaysia,
2010
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| Subjects: | |
| Online Access: | Click here to view 1st 24 pages of the thesis. Members can view fulltext at the specified PCs in the library. |
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| Summary: | Neurodegenerative diseases result from deterioration of neurons which over time will lead to dysfunction and disabilities in the human body. The distribution of brain iron is found to be uneven compared with that of other metals. Iron is present in the substantia nigra, globus pallidus and dentate gyrus at a concentration equal to or greater than that found in the liver. These three brain regions are known to be associated with neurodegenerative diseases. Moreover, peculiarly high intensities of iron in the brain have been demonstrated in a number of neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. Neuroprotective is a mechanism within the nervous system which protects neurons from apoptosis or degeneration. Neuroprotective studies carried out so far indicate that iron chelation therapy could be a viable neuroprotective approach for neurodegenerative disorders. The crude extracts of Erythroxylum cuneatum (EC) and Centella asiatica (CA) were subjected to metal chelating activity. The metal chelating potency can be determined by assessing the ability of the targeted neuroprotective agents to compete with ferrozine for ferrous ions. Ferrozine forms complexes with ferrous producing a red color that can be measured quantitatively at 562 nm. The IC50 value was estimated as the drug concentration required for 50% inhibition of the iron-ferrozine complex. The result revealed that methanolic crude extracts of EC and CA exhibited better chelating activity in comparison to aqueous. Response surface methodology was employed by varying the parameters of extraction time, temperature, speed and ratio of raw material to solvent as to improve the chelating activity of CA and EC. The optimized parameters revealed the improvement in chelating activity of CA and EC with IC50 of 0.093 mg/ml and 0.3817 mg/ml respectively. The methanolic crudes were further partitioned to assess the polarity group which is responsible for the neuroprotective activity. It was shown that hexane of CA and ethyl acetate of EC produced the highest activity. SH-SY5Y, a neuroblastoma cell line was used as an in-vitro model for neuroprotective study. The cell growth study excavated the optimum growth of SHSY5Y at 2x105 cells/ml of seeding density, in Minimal Essential Media as a growth media with 48 hours of doubling time and 8 days to reach a stationery phase. The purpose of a neuroprotective agent is to protect the neurons hence it should not exhibit cytotoxicity in the in-vitro model study being employed. Interestingly the cytotoxicty study rendered the non-toxic activity of the extracts towards SH-SY5Y and Vero cell line. The 2D-PAGE analysis illustrated protein spots that was up-regulated in serumfree media treated with Clioquinol, CA and EC with number of spots 155, 202 and 95 respectively. Overall CA exhibited a better potential as a neuroprotective agent compared to EC. Ethyl acetate of CA showed high metal chelating activity and exhibited no cytotoxicity towards neuroblastoma and Vero cell line and therefore maybe developed as a potential candidate for neuroprotective agent. Although this dissertation demonstrated the potential benefits of CA and EC as a neuroprotective agent, the studies generated new challenges to be overcome. The potential candidate must be further studied to the point of identifying the contender chemical compound and protein towards the neuroprotective activity by utilizing the mass spectrometry method. An up-scaling extraction method should be developed if the plant is intended to be commercialized. |
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| Item Description: | Abstracts in English and Arabic. "A thesis submitted in fulfilment of the requirement for the degree of Master of Science (Biotechnology Engineering)"--On t.p. |
| Physical Description: | xxiii, 186 leaves : ill. (some col.) ; 30 cm. |
| Bibliography: | Includes bibliographical references (leaves 155-169). |