Phytochemical Analysis and Evaluation of Biological Activity of Lawsonia inermis Seeds Related to Alzheimer's Disease.

Majid Balaei-Kahnamoei,Mahnaz Khanavi,Tahmineh Akbarzadeh,Mina Saeedi,Arezoo Rastegari,Mohammad Reza Shams Ardekani,Wen Yi Kang

doi:10.1155/2021/5965061

Abstract

Using Lawsonia inermis L. (henna) seeds has been frequently recommended for the improvement of memory in Iranian Traditional Medicine (ITM). In this respect, different fractions of the plant were prepared and evaluated for their in vitro biological assays related to Alzheimer's disease (AD), including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity as well as metal chelating ability and DPPH antioxidant activity. The dichloromethane and ethyl acetate fractions were able to inhibit the BChE selectively with IC50 values of 113.47 and 124.90 μg/mL, respectively, compared with donepezil as the reference drug (IC50 = 1.52 μg/mL). However, all fractions were inactive toward AChE. Phytochemical analysis of the dichloromethane fraction indicated the presence of β-sitosterol (1), 3-O-β-acetyloleanolic acid (2), 3-O-(Z)-coumaroyl oleanolic acid (3), betulinic acid (4), and oleanolic acid (5). The inhibitory activity of isolated compounds was also evaluated toward AChE and BChE. Among them, compounds 2 and 5 showed potent inhibitory activity toward BChE with IC50 values of 77.13 and 72.20 μM, respectively. However, all compounds were inactive toward AChE. Moreover, molecular docking study confirmed desired interactions between those compounds and the BChE active site. The ability of fractions and compounds to chelate biometals (Cu2+, Fe2+, and Zn2+) was also investigated. Finally, DPPH antioxidant assay revealed that the ethyl acetate (IC50 = 3.08 μg/mL) and methanol (IC50 = 3.64 μg/mL) fractions possessed excellent antioxidant activity in comparison to BHA as the positive control (IC50 = 3.79 μg/mL).

Highlights

Alzheimer’s disease (AD) is characterized as the most common neurodegenerative disease leading to a gradual decrease in memory, cognitive disorders, psychological and behavioral disturbances, and serious problems in daily activities
AD is the consequence of multiple etiological factors including genetics, environment, and lifestyle [4]. e exact origin of AD is not clear and different factors including reduced levels of acetylcholine (ACh) in the brain [5], intracellular hyperphosphorylation of tau protein and formation of neurofibrillary tangles (NFTs) [6], accelerated aggregation of β-amyloid peptides [7], dyshomeostasis and miscompartmentalization of the biometal ions (Fe2+, Cu2+, and Zn2+) [8], calcium overload
Cholinesterases (ChEs) including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are two cholinergic enzymes involved in the hydrolysis of ACh into choline and acetic acid to terminate synaptic transmission in the brain

Summary

Introduction

Alzheimer’s disease (AD) is characterized as the most common neurodegenerative disease leading to a gradual decrease in memory, cognitive disorders, psychological and behavioral disturbances, and serious problems in daily activities. BChE activity was found to be very high in the hippocampus of patients with AD, the tissue which is strongly associated with cognitive functions [17]. All these indicate that the inhibition of AChE alone does not afford a proper planning process for the treatment of AD and the inhibition of BChE should be considered

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Conclusion