| || || Antioxidants -- Therapeutic use -- Fiji|
| || || Screening for acetylcholine esterase inhibitory and anti-oxidant properties in selected Fijian Medicinal Plants |
Author: Chand, Ranish Nitesh
Institution: University of the South Pacific.
Subject: Acetylcholinesterase -- Therapeutic use -- Fiji, Antioxidants -- Therapeutic use -- Fiji, Materia medica, Vegetable -- Fiji
Call No.: Pac QP 609 .A25 C43 2016
Copyright:Under 10% of this thesis may be copied without the authors written permission
Abstract: Alzheimer’s disease (AD) is a progressive, neurodegenerative disorder, a form of dementia that affects mostly elderly people. Symptoms of AD include deterioration of intellectual functions such as memory and learning. An enormous social and economic burden is placed on the society due to its debilitating nature of the disease. It is appalling that there is no cure for the disorder and the available treatments only delay the progression of the disease or provides relief for short period of time. Inhibition of the enzyme, acetylcholinesterase (AChE) is still considered to be the main therapeutic strategy against AD. Many plant derived phytochemicals display AChE inhibitory activity in addition to the currently approved drugs for AD, yet further research is required to discover more effective and cheaper drugs free from side effects. In the present study, Ellman’s assay was used to screen for acetylcholinesterase inhibitors (AChEI) from decoction and ethanol extracts of Fijian medicinal plants. These plants were selected based on the interview about the Fijian medicinal knowledge; that is, the traditional uses that might be associated with acetylcholinesterase inhibition. Thirteen plant species belonging to Melastomataceae, Asteraceae, Apiaceae, Rutaceae, Goodeniaceae, Loganiaceae, Araliaceae, Solanaceae, Polygonaceae, Zingiberaceae and Anacardiaceae families were tested at 0.2 mg/mL, 0.4 mg/mL, 0.6 mg/mL, 0.8 mg/mL, 1.0 mg/mL, 1.5 mg/mL and 2.0 mg/mL concentrations. The most active plants were: Micromelum minutum (IC50 = 4.57 mg/mL), Ageratum conyzoides (IC50 = 5.57 mg/mL), Neuburgia collina (IC50 = 5.74 mg/mL), and Polygonum perfoliata (IC50 = 9.24 mg/mL) for their potent AChE inhibitory activity. Antioxidant activities of these plants were also assessed using the 2,2-diphenyl-1- picryl-hydrazyl (DPPH) scavenging assay. Among the extracts used, antioxidant activity was most significant for Clidemia hirta with an IC50 value of 0.64 mg/mL where even more active compounds than ascorbic acid (IC50 = 1.33 mg/mL) should be present. These plant extracts could prove leads to safer and better candidates for the future selection of drugs against this devastating disease.