Saeed Pirmoradi,
Volume 11, Issue 1 (7-2023)
Abstract
Background: Alzheimer’s disease (AD) is a neurodegenerative disease characterized by decreased cognitive function in patients due to forming Aβ peptides and neurofibrillary tangles (NFT) in the brain. Therefore, the need to develop new treatments can reduce this risk. Acetylcholinesterase is one of the targets used in the design of new drugs for the treatment of AD. The researchers obtain new inhibitory ligands based on natural compounds from various medicinal plants, such as the family of Asteroideace, Malvacea, Zingbracea, Hypericacea, and Ebenacea, for treating Alzheimer’s disease.
Methods: After selecting the reference compound of the enzyme acetylcholinesterase inhibitor with the help of bioinformatics tools such as pharmit and ZINCPHARMER for virtual search through the structural and pharmacologic properties of the reference inhibitor compound, several thousand natural structures of several serious ligands were obtained. Then, the ligands were compared by examining the docking process with the acetylcholinesterase enzyme, and their interactions were visualized with the help of Discovery Studio. Then, the top selected ligands in terms of toxicity, allergy, toxicity, and ADME prediction were evaluated with tools such as molsoft, PKCSM, ADMEtlab2.0, Swiss ADME.
Results: The results revealed that these obtained ligands, like donepezil, have the ability of favorable interactions with different amino acids, the crucial of which are HIS381, TRP385, and GLN527 of AChE, and they all fall in the active site or binding pocket of the active site. The present docking supports this hypothesis that these compounds are possible and valuable small molecule ligands for targeting/inhibiting acetylcholinesterases. Indicatively, according to the binding free energy calculation results, it can be concluded that these ligands can compete with donepezil and affect the formation of acetylcholinesterase complexes. Cholinesterase/donepezil can have an excellent competitive inhibitory effect on it.
Conclusion: On the other hand, the study on the designed ligands showed that with favorable interactions and lower binding energy, they form more stable complexes with acetylcholinesterase and can be proposed as inhibitors competing with donepezil in a bind to this enzyme.
Mojtaba Raeisi , Paria Tavakkoli , Masood Aman Mohammadi ,
Volume 13, Issue 1 (9-2025)
Abstract
Background: Essential oils derived from medicinal plants have attracted increasing attention as natural alternatives to synthetic antimicrobial agents, especially in food safety and preservation. Urtica dioica (nettle) and Malva spp. (mallow) are traditionally known for their medicinal properties, yet their combined antibacterial effects remain underexplored. This study investigated the in vitro antibacterial activity of nettle and mallow essential oils, both individually and in combination (1:1 ratio), against ten common foodborne pathogens responsible for spoilage and contamination.
Methods: Essential oils were extracted from U. dioica and Malva spp., then tested alone and in a 1:1 (v/v) combination for their antibacterial efficacy using agar disk diffusion and broth microdilution assays. The tested bacterial strains included Pseudomonas aeruginosa, Streptococcus pyogenes, Alcaligenes faecalis, Serratia marcescens, Salmonella enteritidis, Staphylococcus aureus, Shigella dysenteriae, Listeria monocytogenes, Klebsiella pneumoniae, and Escherichia coli. Gentamicin (10 µg/disk) was used as a positive control. Data were analyzed to calculate the inhibition zone diameter (DIZ), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). All experiments were performed in triplicate (n = 3), and results were expressed as mean ± standard deviation (SD). Statistical analysis was carried out using one-way ANOVA followed by Tukey’s post hoc test to compare differences among treatment groups.
Results: All essential oil formulations showed antibacterial activity, with MIC values for nettle essential oil (NEO) ranging from 1,250 to 5,000 µg/mL and for mallow essential oil (MEO) from 2,500 to 10,000 µg/mL. The 1:1 combination of NEO and MEO retained NEO’s favorable MIC and delivered a lower MBC for K. pneumoniae compared to MEO alone. Across strains, MIC differences were not uniformly significant. For L. monocytogenes, NEO showed equal MIC and MBC (1,250 µg/mL), indicating its bactericidal activity.
Conclusion: Nettle and mallow essential oils possess significant antibacterial activity against key foodborne pathogens. Their simultaneous application yielded additive effects against some pathogens. These findings support the potential of these essential oils as natural antimicrobial agents to be used in food preservation systems, including for antimicrobial packaging and as edible coatings or surface sanitizers.
