Antimicrobial and memory enhancing activities of Byrsocarpus coccineus Schum. and Thonn. and Ficus exasperata Vahl using broth micro-dilution method

Abstract

Alzheimer's disease (AD) is a type of dementia with cholinergic neuronal loss, and memory improvement is aided by acetylcholinesterase inhibition. Existing drugs are not curative, leading to interest in alternative treatments. Therefore, this research work assessed the microbial and acetylcholinesterase-inhibiting effects of Byrsocarpus coccineus Schum and Thonn as well as Ficus exasperata Vahl. Phytochemical screening, brine shrimp lethality assay, modified Ellman's anticholinesterase assay and broth micro-dilution assay of the crude extracts were used to identify the memory-enhancing and antimicrobial properties of the crude extracts, and data were analyzed using GraphPad Prism and One-way ANOVA. B. coccineus and F. exasperata inhibited AChE at concentration-dependent rates, with B. coccineus root showing the highest inhibition at 5.00 mg/mL (97.4 ± 0.8%). F. exasperata showed the highest minimum inhibitory concentrations (MIC) against Staphylococcus aureus, Klebsiella pneumonia. Bacillus subtilis, S. aureus, Escherichia coli, and Klebsiella pneumoniae all had minimum inhibitory concentrations (MICs) of 12.5 μg/mL, 25 μg/mL, 50 μg/mL, and 50 μg/mL, respectively, while Candida albicans and Trichophyton rubrum had MICs of 25 μg/mL and 50 μg/mL, respectively. Stem and root of Byrsocarpus coccineus and Ficus exasperata exhibited acetylcholinesterase inhibiting potentials in a concentration-dependent manner. The leaves, stems, and roots of both plants revealed variations in inhibiting the growth of the tested microorganisms. Byrsocarpus coccineus and Ficus exasperata may be promising sources and templates for AChE-inhibiting and antimicrobial drug discovery and development.