Acetylcholinesterase inhibitory activity of Haplophyton cimicidum

Abstract

In Oaxaca, México, Haplophyton cimicidum is used in combination with other plants as part of a folk strategy against arthropod pests of crops and cattle. Methanolic and crude alkaloid (acid–base extraction) extracts of H. cimicidum leaves were analysed by thin-layer chromatography (TLC) and assayed in vitro for acetylcholinesterase (AChE) inhibitory activity using Spodoptera frugiperda homogenates as source of enzyme. Derivatised chromatographic plates indicated the presence of indoles and alkaloids in the extracts. The crude alkaloid extract exhibited a higher number of compounds than the methanolic extract as judged by the number of spots on TLC plates. The crude alkaloid extract had a weak inhibition potential of AChE with a lower IC₅₀ (93 μg mL^− 1) than the methanolic extract (159 μg mL^− 1). Indole alkaloids may be responsible for the activity, though a subsequent analysis of the extract components is necessary to determine the active alkaloid(s).

Keywords::

• Apocynaceae
• Haplophyton cimicidum
• alkaloids
• cholinesterase inhibition
• thin layer chromatography

Acknowledgements

The authors thank Laura Lina-García for technical assistance in rearing the insects and J. Luis Contreras for plant collection.