Acetylcholinesterase inhibitory activity of plants used as memory- enhancers in traditional South African medicine (original) (raw)
Related papers
South African Journal of Botany, 2018
The review focuses on acetylcholinesterase (AChE) inhibition of extracts and compounds from southern African plants. We provide a detailed inventory of southern African plants used in the treatment of central nervous system (CNS) and memory-related disorders that are potential candidates for novel AChE inhibitors. This was achieved through a detailed literature search using web-based database searches including Google Scholar, Scopus and Web of Science (WoS) as well as ethnobotanical literature on southern African medicinal plants. Bibliometric analysis was performed on the data mined from WoS. In addition, we reviewed the methods used to determine AChE activity and highlighted the success and potential of alkaloids from the Amaryllidaceae. Our findings revealed about 200 southern African medicinal plants that are used for CNS and memory-related disorders. Approximately, 65 southern African plants have been evaluated for AChE inhibitory activity even though the majority of these plants do not have an ethnobotanical basis for such evaluation. Several extracts (e.g. Ammocharis coranica (KerGawl.) Herb., Lannea schweinfurthii Engl, Scadoxus puniceus (L.) Friis & Nordal, Xysmalobium undulatum (L.) W.T.Aiton.) have been found to demonstrate noteworthy (IC 50 ≤ 1 μg/ml) AChE inhibitory activity. Moreover, 30 compounds have been isolated in an attempt to discover AChE inhibitors from southern African plants. The most active (IC 50 ≤ 12 μM) compounds were isolated from Crinum moorei Hook. f., Scadoxus puniceus and Acacia nilotica (L.) Willd. ex Del. subspecies kraussiana (Benth.). Thus far, very few South African studies have looked at the ecological and environmental impact of both naturally occurring and applied AChE inhibitors (e.g. organophosphate and carbamate insecticides) and no studies have considered medical applications other than in Alzheimer's disease (AD) therapy. Furthermore, most of these studies have mainly used an in vitro approach directed at developing treatments of age-related dementia such as AD, despite the decline in pharmaceutical interest of AChE inhibitors in the treatment of AD. It is also apparent that no further steps are taken towards the investigation of in vivo studies and clinical trials. In addition to these existing gaps, the pharmacodynamic and pharmacokinetic studies also need to be adequately addressed in order to generate more coordinated and focused research.
Background: Cholinesterase inhibitory therapy serves as a strategy for the treatment of Alzheimer’s disease (AD), several acetylcholineesterase inhibitors are used for the symptomatic treatment of patients with mild to moderate AD. These compounds have been reported to have adverse effects including gastrointestinal disturbances. Numerous medicinal plants have been used in Traditional Arabic Palestinian Herbal Medicine (TAPHM) for the treatment of several diseases, including improvement of memory, Alzheimer’s disease (AD) and old age related disease. Ethnopharmacological approach and bioassay guided isolation have provided a lead in identifying potential AChE inhibitors from plant sources. This study was therefore aimed at investigating in vitro possible acetylcholinesterase inhibitors (AChEIs) in herbal medicines traditionally used in Palestine for the treatment of memory loss, and to point out the role of these plants as potential sources for development of newly potent and safe n...
Medicinal plants with acetylcholinesterase inhibitory activity
Reviews in the Neurosciences, 2018
Alzheimer’s disease, a progressive neurodegenerative disease, is characterised by hypofunction of acetylcholine (ACh) neurotransmitter in the distinct region of brain. Acetylcholinesterase (AChE) is an enzyme that metabolises the ACh at synaptic cleft resulting in Alzheimer’s disease. Medicinal plants have been used to treat numerous ailments and improve human health from ancient time. A traditional system of medicine is long recognised for its effective management of neurological disorders. The present review confers the scope of some common medicinal plants with a special focus on AChE-mediated central nervous system complications especially Alzheimer’s disease. Literature suggests that medicinal plants reduce neuronal dysfunctions by reducing AChE activity in different brain regions. In some instances, activation of AChE activity by medicinal plants also showed therapeutic potential. In conclusion, medicinal plants have a wide scope and possess therapeutic potential to efficientl...
Tropical Journal of Natural Product Research, 2020
The inhibition of acetylcholinesterase (AChE), an enzyme that catalyzes acetylcholine hydrolysis in the treatment of Alzheimer disease (AD) will increase the levels of acetylcholine in the brain, thus improving cholinergic functions in AD patients. Natural therapies including herbs and medicinal plants are being used in the treatment of memory deficits such as dementia, amnesia, as well as Alzheimer‟s disease in Africa and other parts of the world. Hence, this study evaluated the AChE inhibition and antioxidant potentials of some Nigerian medicinal plants as remedy for AD and other related diseases. Female Wistar Rats (140 – 150 g) were induced with 3.3 mg/kg body weight of 2,2-Dichlorovinyldimethylphosphate (DDVP) with the aim of inducing Alzheimer and other related complications while the induced animals were treated with 3.3 mg/kg body weight of the extracts of the various plants for four weeks in the various groups. The rats were anaesthetized and dissected individually; blood and selected organs were collected. The in vitro and in vivo antioxidants properties and AChE inhibition potentials were evaluated using various standard analytical procedures. The results of the in vitro antioxidants screening, in vivo antioxidant enzymes activities and inhibition of AChE activity of the various extracts demonstrated that the plants extracts may possess powerful antioxidants potentials and AChE inhibitory ability to protect from the effects of AD. The plants‟ leaf extracts could be utilized in drug developments to prevent and cure the consequences of AD and other related diseases.
Background: Cholinesterase inhibitory therapy serves as a strategy for the treatment of Alzheimer’s disease (AD). Several acetylcholinesterase inhibitors (AChEIs) are used for the symptomatic treatment of AD. These compounds have been reported to have adverse effects, including gastrointestinal disturbances. This study was therefore partly aimed at investigating in vitro possible AChEIs in herbal medicines traditionally used in Palestine to treat cognitive disorders, and to point out the role of these plants as potential sources for development of newly potent and safe natural therapeutic agents of AD. Assay of AChE activity plays an important role in vitro characterization of drugs including potential treatments for AD. The most widely used method, is based on Ellman’s method. The reactant used in this method shows chemical reactivity with oxime antidots and thiol leading to false positive reactions. A new alternative assay could be of high interest. Methods: The effect on AChE activity of 92 extracts of 47 medicinal plants were evaluated using a new micro-well plate AChE activity (NA-FB) and Ellman’s assays. In addition, antioxidant activity using DPPH was determined. Results: The main advantages of the new method (NA-FB) is that the colorimetric change is better observable visually allowing spectrophotometric as well as colorimetric assay, and does not show any chemical reactivity with thiol. 67.4% and 37% of extracts inhibited AChE by >50% using the NA-FB and Ellman’s assays, respectively. Using NA-FB assay, 84 extracts interacted reversibly with the enzyme, of which Mentha spicata (94.8%), Foeniculum vulgare (89.81), and Oxalis pes-caprae (89.21) were most potent, and 8 showed irreversible inhibition of which leaves of Lupinus pilosus (92.02%) were most active. Antioxidant activity was demonstrated by 73 extracts Majorana syriaca (IC50 0.21mg/ml), and Rosmarinus officinalis (0.38) were the most active. Conclusions: NA-FB assay has shown to be simple, accurate, sensitive, spectrophotometric and colorimetric, and superior to Ellman’s, and therefore can be used efficiently for qualitative and quantitative studies of AChEI activities of extracts. Palestinian flora have shown to be a rich source for, new and promising agents (AChEIs) for the treatment of AD Further studies are needed to isolate and identify the active compounds responsible for AChEI activities.
2012
Kognitive Storungen sind eine der Ursachen von mentalem Abbau, der von Symptomen wie Erinnerungsverlust und Gedachnisschwund z.b. im Rahmen der Alzheimer-Krankheit begleitet wird. Die Steigerung von cholinergen Funktionen durch Inhibierung von Acetylcholinesterase (AChE) stellt eine therapeutische Moglichkeit zur Behandlung von neurologischen Storungen wie Alzheimer-Krankheit und Demenz dar. In den letzten zwei Jahrzehnten ruckte auch der Einsatz traditioneller Heilpflanzen zur Therapie von Demenz-Krankheiten in den Mittelpunkt des wissenschaftlichen Interesses. Der Iran ist eine der Kulturen mit einer langen und reichen Geschichte der traditionellen Medizin, und speziell der Pflanzenheilkunde. In dieser Studie wurden 40 Heilpflanzen bzw. Pflanzenprodukte wie Harze, die in der Iranischen Traditionellen Medizin zur Behandlung von kognitiven Storungen eingesetzt wurden, untersucht. Zuerst wurden polare methanolische und apolare Dichlormethan-Extrakteaus den selektierten Pflanzen herge...
Molecules, 2016
Inhibition of acetylcholinesterase (AChE) is a common treatment for early stages of the most general form of dementia, Alzheimer's Disease (AD). In this study, methanol, dichloromethane and aqueous crude extracts from 80 Traditional Chinese Medical (TCM) plants were tested for their in vitro anti-acetylcholinesterase activity based on Ellman's colorimetric assay. All three extracts of Berberis bealei (formerly Mahonia bealei), Coptis chinensis and Phellodendron chinense, which contain numerous isoquinoline alkaloids, substantially inhibited AChE. The methanol and aqueous extracts of Coptis chinensis showed IC 50 values of 0.031 µg/mL and 2.5 µg/mL, therefore having an up to 100-fold stronger AChE inhibitory activity than the already known AChE inhibitor galantamine (IC 50 = 4.33 µg/mL). Combinations of individual alkaloids berberine, coptisine and palmatine resulted in a synergistic enhancement of ACh inhibition. Therefore, the mode of AChE inhibition of crude extracts of Coptis chinensis, Berberis bealei and Phellodendron chinense is probably due to of this synergism of isoquinoline alkaloids. All extracts were also tested for their cytotoxicity in COS7 cells and none of the most active extracts was cytotoxic at the concentrations which inhibit AChE. Based on these results it can be stated that some TCM plants inhibit AChE via synergistic interaction of their secondary metabolites. The possibility to isolate pure lead compounds from the crude extracts or to administer these as nutraceuticals or as cheap alternative to drugs in third world countries make TCM plants a versatile source of natural inhibitors of AChE.
Evaluation of Bioactive Compounds as Acetylcholinesterase Inhibitors from Medicinal Plants
Evidence-Based Validation of Herbal Medicine, 2015
As total life expectancy increases, the prevalence of age-related diseases such as Alzheimer's is also increasing. Many hypotheses about Alzheimer's disease have been developed, including cholinergic neuron damage. Acetylcholine is a major neurotransmitter in the brain and cholinergic deficits leads to cognitive dysfunction and decline. Despite decades of research and advances in our understanding of its aetiology and pathogenesis, current pharmacotherapeutic options for AD are still very limited and represent an area of need that is currently unmet. In abnormal activation of AChE, acetylcholine will degrade rapidly, especially in the brain and this is associated with Alzheimer's disease (AD). It has been shown that theraphy with essential oils from medicinal plants can improve cognitive performance in Alzheimer's disease patients. Eugenol from these essential oils is reported to inhibit acetylcholinesterase, both in vitro and in vivo. This paper is set to Determine inhibitory/stimulatory effect of tested extracts on acetylcholine esterase (AChE) activity. The sampled out plant extracts include Thymus vulgaris, Berberis vulgaris and Calluna vulgaris with which inhibition or activation by different chemical catalysts is performed to establish their effects in the tested natural extracts. Experimental design is used where the reagents are determined and chemical reactions performed in the procedures as outlined in the methodology section. The results of the cholinergic/ anticholinergic effect of tested natural extracts are then recorded. This study reflects that most of the extracts inhibited AChE activity with berberis vulgaris showing highest inhibitory effect.
2020
Alzheimer's disease (AD) is a progressive neurodegenerative disorder which neurons degenerate or lose their structure and function leading to memory impairment and cognitive deficiency due to decreased levels of acetylcholine via acetylcholinesterase (AChE). Substances that inhibit and reduce the activity of this enzyme were found to ameliorate the symptoms of AD. Acorus calamus (Lubigan), is an herb that has been used for memory loss and reported to have neuroprotective activity. This study focuses on the potential in vitro acetylcholinesterase inhibitory activity of the plant’s rhizomes. Maceration of the powdered rhizomes of Acorus calamus was done with ethanol. The extract was then subjected to solvent-solvent extraction using hexane, carbon tetrachloride, chloroform, and water. Phytochemical screening revealed phenols, tannins, flavonoids, and alkaloids in the chloroform fraction (LRChF) while the other fractions and the ethanolic extract had the same constituents with addi...