Inhibitory effect on acetylcholinesterase and toxicity analysis of some medicinal plants

Abstract

This study aimed to analyse the inhibition of different extracts of Rosmarinus officinalis, Pistacia terebinthus and Sideritis dichotoma on acetylcholinesterase enzyme of Drosophila melanogaster. Additionally, the biological features including antioxidant activity, phenolic contents, antibacterial effects and in vivo toxicities were identified using radical scavenging, Folin Ciocalteu, disc diffusion methods, and larval (eclosion) assay using Drosophila, respectively. Also, GC-MS was used to determine of the terpene-derivative compositions of the plants. IC50 values on acetylcholinesterase were determined between 0.57±0.02-2.54±0.11µg µL-1 for ethanol, 0.86±0.05-2.19±0.15µg µL-1 for methanol and 1.98±0.13-4.76±0.24µg µL-1 for water extracts. Inhibition types of Rosmarinus, Pistacia and Sideritis were uncompetitive, competitive and competitive, respectively. The antioxidant activities of the extracts were between 77.87±1.72-96.94±1.84% against DPPH and 90.57±2.18-98.18±2.36% against ABTS+ radicals. GC/MS results showed that carvacrol and thymol were the major monoterpenes of Pistacia and Sideritis, while limonene and borneol were the main monoterpenes of Rosmarinus. The strongest antibacterial activities were observed with Rosmarinus and Sideritis against Staphylococcus aureus and Escherichia coli, respectively with an inhibition zone larger than 15 mm. According to the in vivo toxicity study, all extracts were found non-toxic to Drosophila, and they ameliorated H2O2 induced decrease of puparation, survival rate and eclosion values.