Acetylcholinesterase Inhibitory Activity de Habranthus tubispathus

CAVALLARO, V.; ALZA, N.P.; MURRAY, A.P.

Córdoba

Congreso; 1º Reunión Internacional de Ciencias Farmaceúticas; 2010

Habranthus tubispathus, (L`Hér.)Traub (Amaryllidaceae) is native to Argentina, Chile, Uruguay and Paraguay (1). So far no phytochemical studies have been reported on this specie. Plants of the Amaryllidaceae family are known to contain isoquinoline alkaloids, commonly called Amaryllidaceae alkaloids. Some of these alkaloids are acetylcholinesterase (AChE) inhibitors (2). The main role of AChE is the termination of nerve impulse transmission at the cholinergic synapses by rapid hydrolysis of acetylcholine. Inhibition of this enzyme is currently used for the treatment of Alzheimer´s disease, senile dementia, ataxia and myasthenia gravis (3). We proposed the isolation and characterization of the bioactive alkaloids from the bulbs of H. tubispathus. Results The IC50 value of the ethanolic extract of H. tubispathus was 998,9 microg/mL+/- 12,0 microg/mL. This value was obtained by probit analysis from four determinations, each one performed in triplicate. The Rf values of the white spots observed in the TLC bioautographic method for the detection of AChE inhibitors was coincident with those of the orange spots observed when we reveled with Dragendorff`s reagent. So, we proceeded to the isolation of the alkaloids, responsible of the AChE inhibition. Conclusions H. tubispathus shows an important inhibition of AChE in comparison with the IC50 value of other species of the Amaryllidaceae family previously reported (4). This activity can be explained by the presence of active alkaloids.