Cognitive-enhancing properties of Morinda lucida (Rubiaceae) and Peltophorum pterocarpum (Fabaceae) in scopolamine-induced amnesic mice

Background: Cognitive disorders associated with aging have been successfully managed by African traditional medical practitioners using various plants. This study evaluated the cognitive enhancing potentials of Morinda lucida (L) Rubiaceae and Peltophorum pterocarpum (DC) ex. K Heyne in scopolamine induced amnesic animals.Materials and Methods: The anti-amnesic activity of the ethyl acetate extracts of Morinda lucida and Peltophorum pterocarpum at doses of 4 mg/kg, 6 mg/kg and 8 mg/kg were assessed in scopolamine induced amnesic mice using Morris water maze test model. Effect of the extracts on the histology of the hippocampus was also evaluated.Results: The ethyl acetate extract of Morinda lucida and Peltophorum pterocarpum ameliorated scopolamine induced memory deficit in the animals under study. There was no effect of the extract on the histology of the hippocampus. However, there was an increase in the density of cells in the hippocampus of treated group as compared to the untreated.Conclusion: Morinda lucida and Peltophorum pterocarpum showed considerable enhancement of cognition in scopolamine induced amnesic mice.Keywords: Morinda lucida, Peltophorum pterocarpum, Morris water maze, Scopolamine, Hippocampu

COGNITIVE-ENHANCING PROPERTIES OF MORINDA LUCIDA (RUBIACEAE) AND PELTOPHORUM PTEROCARPUM (FABACEAE) IN SCOPOLAMINE-INDUCED AMNESIC MICE

Background: Cognitive disorders associated with aging have been successfully managed by African traditional medical practitioners using various plants. This study evaluated the cognitive enhancing potentials of Morinda lucida (L) Rubiaceae and Peltophorum pterocarpum (DC) ex. K Heyne in scopolamine induced amnesic animals. Materials and Methods: The anti-amnesic activity of the ethyl acetate extracts of Morinda lucida and Peltophorum pterocarpum at doses of 4 mg/kg, 6 mg/kg and 8 mg/kg were assessed in scopolamine induced amnesic mice using Morris water maze test model. Effect of the extracts on the histology of the hippocampus was also evaluated. Results: The ethyl acetate extract of Morinda lucida and Peltophorum pterocarpum ameliorated scopolamine induced memory deficit in the animals under study. There was no effect of the extract on the histology of the hippocampus. However, there was an increase in the density of cells in the hippocampus of treated group as compared to the untreated. Conclusion: Morinda lucida and Peltophorum pterocarpum showed considerable enhancement of cognition in scopolamine induced amnesic mice

Cholinesterase inhibitory activity and structure elucidation of a new phytol derivative and a new cinnamic acid ester from Pycnanthus angolensis

AbstractThe leaves of Pycnanthus angolensis (Welw.) Warb., Myristicaceae, are used as memory enhancer and anti-ageing in Nigerian ethnomedicine. This study aimed at evaluating the cholinesterase inhibitory property as well as isolates the bioactive compounds from the plant. The acetylcholinesterase and butyrylcholinesterase inhibitory potentials of extracts, fractions, and isolated compounds were evaluated by colorimetric and TLC bioautographic assay techniques. The extract inhibited both enzymes with activity increasing with purification, ethyl acetate fraction being most active fraction at 65.66±1.06% and 49.38±1.66% against acetylcholinesterase and butyrylcholinesterase, respectively while the supernatant had 77.44±1.18 inhibition against acetylcholinesterase. Two new bioactive compounds, (2E, 18E)-3,7,11,15,18-pentamethylhenicosa-2,18-dien-1-ol (named eluptol) and [12-(4-hydroxy-3-methyl-oxo-cyclopenta-1,3-dien-1yl)-11-methyl-dodecyl](E)-3-(3,4-dimethylphenyl)prop-2-enoate (named omifoate A) were isolated from the plant with IC50 of 22.26μg/ml (AChE), 34.61μg/ml (BuChE) and 6.51μg/ml (AChE), 9.07μg/ml (BuChE) respectively. The results showed that the plant has cholinesterase inhibitory activity which might be responsible for its memory enhancing action, thus justifying its inclusion in traditional memory enhancing preparation

Novel cholinesterase inhibitory effect of α-spinasterol isolated from the leaves of Acacia auriculiformis A. CUNN Ex. Benth (Fabaceae)

Purpose: To investigate the in vitro anticholinesterase, α-glucosidase and antioxidant activities of α-spinasterol isolated from Acacia auriculiformis leaves.Methods: The powdered leaves of Acacia auriculiformis were extracted with 70 % ethanol and the dried hydroalcoholic extract was suspended in water and partitioned with ethyl acetate and n-butanol to give their soluble fractions. The in vitro inhibitory activities of α-spinasterol were determined against cholinesterase and, α-glucosidase enzymes, and free radical scavenging potentials using (1,1-diphenyl-2-picrylhydarzyl (DPPH) and 2,2-azino-bis (3-Ethylbenzothiazoline-6-sulphonic acid (ABTS) antioxidantassays.Results: The compound, α-spinasterol, exhibited moderate anticholinesterase activity (IC50 value of 44.19±2.59 μg/mL which was significantly  different at (p < 0.05) when compared to the standard galanthamine (IC50 value of 1.73 ± 1.10 μg/mL). It also displayed a good α-glucosidase  inhibitory activity with IC``` value of 8.65 ± 1.71μg/mL which was not significantly different when compared to the standard, acarbose with IC50 value of 2.79±0.81 μg/mL. This compound, however, exhibited weak free radical scavenging activities at 26.93 ± 0.00 and 35.16 ±.0.26 % inhibition of DPPH+ and ABTS+ radicals as compared to ascorbic acid and Trolox (73.88 ± 0.04 and 99.82 ± 0.00%) respectively.Conclusion: The results show that α-spinasterol isolated from Acacia auriculiformis exerts potent inhibitory effect against cholinesterase enzyme which might serve as a lead in the search for drugs against Alzheimer disease and diabetes mellitus. Keywords: Acacia auriculiformis, α-Spinasterol, Galanthamine, Acarbose, Trolox, Ascorbic aci

Anticholinesterase and Antioxidant Activities of Spilanthes filicaulis Whole Plant Extracts for the Management of Alzheimer’s Disease

Background: Spilanthes filicaulis is a tropical herb implicated as a memory enhancer in ethnomedicine. Objective: The study investigated acetyl/butyryl cholinesterase inhibitory and antioxidant activities of different extracts of S. filicaulis whole plant and correlated them to its phytochemical constituents. Methods: The powdered whole plant was successively extracted with n-hexane, ethyl acetate and methanol. Acetyl cholinesterase (AChE) and Butyryl cholinesterase (BuChE) inhibitory activity were evaluated by Ellman colorimetry assay. Antioxidant activity was tested using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ferric reducing power and nitric oxide scavenging assays. Total phenolic, flavonoid and tannin were estimated using standard methods. Correlation was determined using Quest Graph™ Regression Calculator. Results: Various extracts exhibited concentration-dependent AChE and BuChE inhibitory activity with ethyl acetate extract being the highest with IC50 of 0.77 μg/mL and 0.92 μg/mL for AChE and BuChE respectively. The ethyl acetate extract also showed the highest reducing power when compared with the other extracts. The methanol extract had slightly higher phenolic and flavonoid content and showed the highest DPPH radical scavenging effect. DPPH scavenging, AChE and BuChE inhibition had high correlation with the total flavonoid content with R2 values of 1.00, 0.800 and 0.992 respectively while nitric oxide scavenging had high correlation with phenolics and tannins with R2 = 0.942 and 0.806 respectively. Conclusion: These results show that the extracts of the whole plant of S. filicaulis possess significant AChE/BuChE inhibitory and antioxidant properties, mostly due to its flavonoid content, suggesting the possible use of the plant in neurodegenerative diseases such as AD

Molecular docking study on columbin isolated from Tinospora cordifolia as a cholinesterase inhibitor

Purpose: To investigate the acetylcholinesterase (AChE) inhibitory potential of columbin and also to assess its binding affinity against AChE protein. Methods: Crystals of columbin were isolated from the ethyl acetate fraction of Tinospora cordifolia using column chromatography and its structure was determined using x-ray crystallography. Ellman colorimetric assay was used to determine the AChE inhibitory effect in vitro while molecular docking was performed using the MOE 2015.010 software. The selected protein data bank (PDB) was modeled using PDB ID: 10CE (pacific electric ray). Results: The crystal and structure refinement data of columbin were: C20H22O6, Orthorhombic, P212121, a = 7.4951(2) Å (α = 90°), b = 11.6451(3) Å (β = 90°), c = 19.5882(5) Å (γ = 90°), V=1709.68(8) Å3, Z = 4, Density (calculated) = 1.392 Mg/m3, absorption coefficient = 0.851 mm-1, goodness-of-fit on F2 =1.091, T = 100(2) K. Columbin demonstrated good AChE inhibitory effect with half-maximal inhibitory concentration (IC50) of 1.2993 ± 0.17 mg/mL. Molecular docking data revealed that it exhibited hydrophobic and hydrogen bonding interactions with the surrounding residues, and this accelerated complexation between the ligands and the active site of the enzyme. Conclusion: Columbin may be useful in the management of neurodegenerative conditions such as Alzheimer’s disease