Neuroactive venom compounds obtained from Phlogiellus bundokalbo as potential leads for neurodegenerative diseases: insights on their acetylcholinesterase and beta-secretase inhibitory activities in vitro.

Simon Miguel M Lopez,Angelic Gayle J Lao,Librado A Santiago,Jeremey S Aguilar,Aaron Joseph L Villaraza,Cydee Marie V Ramones,Leonardo A Guevarra Jr,Jerene Bashia B Fernandez,Myla R Santiago-Bautista,Mark Kevin P Devanadera,Mitzi Rain R Estrella

doi:10.1590/1678-9199-jvatitd-2021-0009

Abstract

Background Spider venom is a rich cocktail of neuroactive compounds designed to prey capture and defense against predators that act on neuronal membrane proteins, in particular, acetylcholinesterases (AChE) that regulate synaptic transmission through acetylcholine (ACh) hydrolysis - an excitatory neurotransmitter - and beta-secretases (BACE) that primarily cleave amyloid precursor proteins (APP), which are, in turn, relevant in the structural integrity of neurons. The present study provides preliminary evidence on the therapeutic potential of Phlogiellus bundokalbo venom against neurodegenerative diseases.Methods Spider venom was extracted by electrostimulation and fractionated by reverse-phase high-performance liquid chromatography (RP-HPLC) and characterized by matrix-assisted laser desorption ionization-time flight mass spectrometry (MALDI-TOF-MS). Neuroactivity of the whole venom was observed by a neurobehavioral response from Terebrio molitor larvae in vivo and fractions were screened for their inhibitory activities against AChE and BACE in vitro.Results The whole venom from P. bundokalbo demonstrated neuroactivity by inducing excitatory movements from T. molitor for 15 min. Sixteen fractions collected produced diverse mass fragments from MALDI-TOF-MS ranging from 900-4500 Da. Eleven of sixteen fractions demonstrated AChE inhibitory activities with 14.34% (± 2.60e-4) to 62.05% (± 6.40e-5) compared with donepezil which has 86.34% (± 3.90e-5) inhibition (p > 0.05), while none of the fractions were observed to exhibit BACE inhibition. Furthermore, three potent fractions against AChE, F1, F3, and F16 displayed competitive and uncompetitive inhibitions compared to donepezil as the positive control. Conclusion The venom of P. bundokalbo contains compounds that demonstrate neuroactivity and anti-AChE activities in vitro, which could comprise possible therapeutic leads for the development of cholinergic compounds against neurological diseases.

Highlights

Spider venom is a rich cocktail of neuroactive compounds designed to Spider venoms Phlogiellus bundokalbo Neurological diseases prey capture and defense against predators that act on neuronal membrane proteins, in particular, acetylcholinesterases (AChE) that regulate synaptic transmission through acetylcholine (ACh) hydrolysis – an excitatory neurotransmitter – and betasecretases (BACE) that primarily cleave amyloid precursor proteins (APP), which are, in turn, relevant in the structural integrity of neurons
The elution behavior of each peak constituent is influenced by the composition of the solvent system, ACN and trifluoroacetic acid (TFA) in H2O, which were semi-polar in nature and affected the elution profile of the whole venom
The peak intensities indicate differences in levels of compounds present in the venom that are principally detected in the semi-polar region

Summary

Introduction

Spider venom is a rich cocktail of neuroactive compounds designed to Spider venoms Phlogiellus bundokalbo Neurological diseases prey capture and defense against predators that act on neuronal membrane proteins, in particular, acetylcholinesterases (AChE) that regulate synaptic transmission through acetylcholine (ACh) hydrolysis – an excitatory neurotransmitter – and betasecretases (BACE) that primarily cleave amyloid precursor proteins (APP), which are, in turn, relevant in the structural integrity of neurons. Intrinsic and extrinsic etiologies such as aberrations in brain metabolism, inflammation, genetic mutations, oxidative damage, and neurotransmitter dysfunction involving several cytosolic and membrane proteins act in a concerted and cooperative manner that contribute to the formation and aggregation of insoluble amyloid-beta (Aβ) and hyperphosphorylated microtubule binding-tau proteins into senile plaques and neurofibrillary tangles, respectively. These events primarily drive increasing cellular stress, resulting in neuronal cell death at initial brain regions, the cerebral cortex, basal ganglia, thalamus, and hippocampus [12]. This results in loss of neurons that phenotypically leads to disrupted cognitive and motor responses from afflicted patients [13]

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