In vitro Antioxidant and Anticholinesterase Activities of Ouratea fieldingiana (Gardner) Eng. Leaf Extract and Correlation with Its Phenolics Profile with an in silico Study in Relation to Alzheimer’s Disease

Abstract

Ouratea fieldingiana is a native medicinal plant from Northeastern Brazil and many biological properties are due to the phenolic constituents. The objective of this work was performing the characterization of O. fieldingiana leaf constituents to correlate with antioxidant and anticholinesterase activities by in vitro and in silico studies and thus contribute to find new agents against Alzheimer’s disease. The high-performance liquid chromatography revealed the presence of the flavonoids rutin, isoquercitrin, kaempferol-3-O-rutinoside, quercetin, apigenin and amentoflavone. The antioxidant activities by the (2,2-diphenyl-1-picrylhydrazyl) (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methodologies, showed good results with half maximal inhibitory concentration (IC50) values ranging from 5.63 to 11.47 μg mL-1 and 2.72 to 23.71 μg mL-1, respectively. Acetylcholinesterase inhibition assay pointed out the flavone apigenin with best activity. Computational studies evaluated the interaction of flavonoids with the enzyme acetylcholinesterase co-crystallized with the galantamine, used as standard. All flavonoids exhibited binding energy greater than that of galantamine, but only apigenin showed strong interaction with the active site of the enzyme and other bind probably to different allosteric centers. Then, O. fieldingiana extract and flavonoids with good anti-radical activity and presenting a broad-spectrum action against acetylcholinesterase (AChE) enzyme ought to be tested in clinical studies to discover new neuro-therapeutic candidates.

Chemical Characterization, Phenolic Compounds Quantification, and Assessment of Antioxidant and Anti‐Acetylcholinesterase Activities of Byrsonima sericea DC fruits

“…It is widely used in Chinese medicine and has several biological activities, such as antioxidant, antiinflammatory, antitumor, antimicrobial and healing. These properties make it a potential target for in vivo tests to combat SARS-Cov-2 and memory deficit [5] Our data reinforce the results of previous studies that have identified the presence of flavonoids the rutin, isoquercitrin, kaempferol-3-O-rutinoside and quercetin. [1] Table 1.…”

“…[31] Although alkaloids are the main targets of research to develop drugs against AD, other compounds are interesting for new studies, such as the flavonoids rutin, isoquercitrin, kaempferol-3-O-rutinoside, quercetin, apigenin and amentoflavone, all of which have high potential for AChE inhibition. [5]…”

“…[4] AD is the main human neuro-degenerative pathology, often associated with aging, causing cognitive and neuropsychiatric manifestations, particularly progressive impairment of short-term memory. [5] Individuals with AD do not synthesize acetylcholine (ACh), an essential substance for memory and learning. Inhibition of acetylcholinesterase (AChE) causes an increase in ACh levels, reversing the memory deficit and improving disease-related symptoms, which makes AChE inhibitors the most viable therapeutic targets in research for the treatment of this pathology.…”

“…The intake of antioxidant substances helps to reduce the incidence of Alzheimer's disease (AD) [4] . AD is the main human neurodegenerative pathology, often associated with aging, causing cognitive and neuropsychiatric manifestations, particularly progressive impairment of short‐term memory [5] …”

In vitro inhibition of acetylcholinesterase activity by yellow field pea (Pisum sativum) protein-derived peptides as revealed by kinetics and molecular docking

“…Frontiers in Nutrition 08 frontiersin.org (30) characterized in vitro cholinesterase inhibition by phenolic compounds from a native medicinal plant in Northeastern Brazil (Ouratea fieldingiana) and two standards (physostigmine and galantamine) were used as the positive controls. The study reported that the IC 50 of the phenolic compounds ranged between 3.12 µg/ml (apigenin) and 12.00 µg/ml (rutin).…”