Acetylcholinesterase and butyrylcholinesterase inhibitory activity of some selected Nigerian medicinal plants

Abstract

RESUMO: "Atividade inibitória da acetilcolinesterase e butirilcolinesterase de algumas plantas medicinais da Nigéria". As plantas podem ser úteis para estimular a memória, bem como serem usadas para combater o envelhecimento. Vinte e duas plantas, de dezesseis famílias, foram investigadas in vitro oara verificar sua atividade inibidora das enzimas acetilcolinesterase (AChE) e butirilcolinesterase (BuChE) pelo método espectrofotométrico de Ellman in situ e métodos de bioautografia utilizando fisostigmina como padrão. Pelo menos três partes morfológicas de cada planta foram analisadas e a concentração de ensaio foi de 42,5 µg/mL. Algumas plantas foram ativas em ambas as enzimas, embora com algumas partes mais ativas que outras. A casca da raiz de Spondias mombin apresentou a maior atividade as duas enzimas, 64,77% para AChE e 83,94% para BuChE. Outras partes das plantas selecionadas apresentaram boa seletividade em suas ações. As plantas seletivamente ativos contra AChE foram as casca do caule e casca da raiz de Alchornia laxiflora (41,12%), e casca da raiz de Callophyllum inophyllurn (56,52%). As folhas de C. jagus (74,25%), folhas de Morinda lucida (40,15%), folhas e casca do caule de Peltophorum pterocarpum (49,5% e 68,85%, respectivamente), physiostigmine inibiu 90,31%. Em geral, atividades melhoras foram apresentadas contra BuChE. Folhas, casca da raiz e casca do caule Bombax bromoposenze foram particularmente ativos. A inibição foi acima de 80%. Outras partes de algumas espécies também foram seletivas, como as partes aéreas de Antiaris africana, Cissampelos owarensis (78,96%), folhas e casca do caule de Combretum molle (90,42% e 88,13%, respectivamente), casca da raiz e de tubérculos de Dioscorea dumentorum (mais de 87%), folhas de G cola, cascas de raiz de Markhamia tomentosa, casca do caule de Pycnanthus angolensis e folhas de Tetrapleura tetraptera. A maioria destas plantas são utilizadas como alimentos ou ingredientes alimentares na Nigéria e podem ser responsáveis pela baixa incidência da doença de Alzheimer no país e desempenhar determinadas funções na mediação da doença.Unitermos: Plantas medicinais, acetilcolinesterase, butrilcolinesterase, perda da memória. ABSTRACT:Plants have been found to be useful as memory enhansers as well as antiaging. Twenty two of such plants from sixteen families were investigated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities using the in vitro Ellman's spectrophotometric and in situ bioautographic methods with physostigmine as standard. At least three morphological parts were examined for each of the plants investigated and the test concentration was 42.5 μg/ mL. Some plants were active on both enzymes though with some morphological parts being more active than others. The root bark of Spondias mombin showed the highest activity to the two enzymes; 64.77% and 83.94% on AChE and BuChE respectively. Other plant parts of the selected plants exhibited some remarkable selectivity in their actions. Those selectively active against...

Cognitive-Enhancing Properties of Morinda Lucida (Rubiaceae) and Peltophorum Pterocarpum (Fabaceae) in Scopolamine-Induced Amnesic Mice

“…The extracts showed dose-dependent cognitive enhancing activity with Peltophorum pterocarpum having shorter escape latency time of 14.60 + 1.55 at 8 mg/kg and thus appears to have better cognitive enhancing ability when compared with Morinda lucida with escape latency of 23.33 + 4.33 at the same dose. The cognitive enhancing activity observed in this study can be due to previously reported cholinesterase inhibitory property of these plants (Elufioye et al, 2010) since acetyl cholinesterase inhibitors are known to counteract scopolamine induced amnesia (Lee et al, 2009). This is probably because the effects of scopolamine in learning and memory are also mediated by cholinergic neurons in the ventral forebrain, particularly in those arising from the medial septal nuclei or the diagonal band of Broca and projecting to the hippocampus (Bejar et al, 1999).…”

“…K Heyne and Morinda lucida (L) Rubiaceae are commonly found in recipes used as memory enhancer or anti-aging in Nigeria ethno-medicine. The leaves of these plants have been previously reported to inhibit cholinesterase (Elufioye et al, 2010., Sridharamurthy et al, 2012) an enzyme that causes a decline of ACh in the brain by breaking it down. Acetylcholine is critical for an adequately functioning memory and it is the subject of the major researches for treatment of memory defects like those found in Alzheimer's disease.…”

Neuroprotective Effect of Decalepis hamiltonii in Paraquat-Induced Neurotoxicity in Drosophila melanogaster: Biochemical and Behavioral Evidences

“…Enhancement of AchE activity causes more acetylcholine degradation and consequent reduction in acetylcholine receptor stimulation which leads to a decrease in cholinergic neurotransmission and related functions such as cell proliferation and enhanced apoptosis [43][44][45]. Deficiency in acetylcholine and consequent cholinergic neurotransmissions is one of the cognitive symptoms of Alzheimer's disease (AD) [46]. It has been also shown that, acetylcholine is involved in reduction of LPO by scavenging superoxide anions [47].…”

Modulation of Key Biochemical Markers Relevant to Stroke by Antiaris Africana Leaf Extract Following Cerebral Ischemia/Reperfusion Injury

“…The hydrolytic enzyme, cholinesterase, regulates ACh levels by breaking down this neurotransmitter in many tissues. AChE activity is altered in response to redox imbalance and affected by various degree of injury to the organism which can stimulate rapid ACh degradation and consequently, decreased stimulation of ACh receptors leading to negative effects on cholinergic neurotransmission as well promotion of cognitive impairment (Elufioye et al, 2010;Abdalla et al, 2013 The neurotransmitter, dopamine, is produced from the amino acid, tyrosine, through the catalytic action of tyrosine hydroxlase (TH) which is the rate-limiting enzyme in the pathway. (Daubner and Wang, 2011).…”