The Anticholinesterase Properties of Plants from the Northeast of Brazil Selected by an Ethnopharmacological Study for Disorders Relating to the Nervous System.
BACKGROUND
Various factors may trigger Alzheimer's disease and the cholinergic hypothesis, which is one of the most widely accepted, argues damage to the brain nuclei, may reduce the production of the choline acetyltransferase enzyme, and cause a decline in the synthesis of acetylcholine (ACh). Studies have thus focused on discovering molecules that are capable of inhibiting the action of cholinesterase enzymes that degrade ACh, thereby preventing the evolution of the disease.


OBJECTIVE
The aim of the present study is to assess the anticholinesterase properties of extracts of medicinal plants in a semi-arid region of Northeast of Brazil.


METHODS
The species were selected by way of an ethnobotanical study and were collected if there were some indications that they are related to the nervous system. The plant samples were extracted using hexane, ethyl acetate, and methanol. Anticholinesterase activity in vitro was assessed by way of bioautography in thin layer chromatography and microassays in 96-well plates.


RESULTS
Twenty-three species of plant were collected, and 75 extracts were analyzed. The bioautography revealed that 26.7% of the samples showed inhibitory activity against the acetylcholinesterase (AChE) enzyme. After the test for false positives, 8% of the samples were found to inhibit AChE. Thirty samples were analyzed by microassay (500 μg/mL), on which 86.7% showed moderate to powerful anticholinesterase activity.


CONCLUSIONS
Of the extracts tested, Citrus limonum, Ricinus communis, and Senna occidentalis stand out as was the most promising in terms of anticholinesterase activity and may serve as a guide for the discovery and development of new substances for the treatment of AD.


CONCLUSIONS
The bioautography revealed that 26.7% of the samples showed inhibitory activity against the acetylcholinesterase enzymeSamples were analyzed by microassay (500 μg/mL), upon which 86.7% showed moderate to powerful anticholinesterase activityCitrus limonum, Ricinus communis, and Senna occidentalis stand out as being the most promising in terms of anticholinesterase activityC. limonum, R. communis, and S. occidentalis may serve as a guide for the discovery and development of new substances for the treatment of Alzheimer's disease. Abbreviations used: AChE: Acetilcolinesterase.
Department of Pharmaceutical Sciences, Health Sciences Center, Federal University of Pernambuco, Recife, Brazil.
Valerium Thijan Nobre
VT
de Almeida E Castro
University Center Valley Ipojuca, Caruaru, Brazil.
Tadeu Jose da Silva Peixoto
TJ
Sobrinho
Department of Pharmaceutical Sciences, Health Sciences Center, Federal University of Pernambuco, Recife, Brazil.
Allan Jonathan Chernichiarro
AJ
Corrêa
Health Sciences Center, Federal University of Tocantins, Palmas, Brazil.
Thiago Antonio
TA
de Sousa Araújo
Department of Antibiotics, Health Sciences Center, Federal University of Pernambuco, Recife, Brazil.
Terezinha Gonçalves
TG
Da Silva
Department of Pharmaceutical Sciences, Health Sciences Center, Federal University of Pernambuco, Recife, Brazil.
Elba Lucia Cavalcanti
EL
de Amorim
Acetylcholinesterase; Alzheimer′s disease; Caatinga; dementia; semi-arid