Chemical, antibacterial and antioxidant assessment of Persea americana seeds, leaves, and stem bark extract and in-silico pharmacokinetic properties of the prominent compounds

Abstract

This work aims to identify the bioactive compound in the seeds, leaves, and stem bark of P. americana (avocado pear) responsible for some of its medicinal properties, as well as to examine the pharmacological properties. The phytochemical analyses confirmed the presence of alkaloids, flavonoids, tannins, saponins, and steroids in the seeds, leaves, and stem bark of Persea americana (avocado pear) at variable compositions. From the GC-MS analysis, fifteen, twenty-three, and twenty-four compounds were identified in the seeds, leaves, and stem bark of which dodecanoic acid (33.326%), phytol (27.583%), and cis-verbenol (8.927%) as the most prominent compounds respectively. The extracts showed potent growth inhibition against five pathogenic bacteria organisms (Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Streptococcus pneumoniae, and Staphylococcus epidermidis) in comparison with gentamicin used as a standard antibacterial agent. The free radical scavenging activity of the extracts was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method with ascorbic acid as a reference standard. The extracts showed significant antioxidant activity at minimum and maximum concentrations of 25 and 400 μg/ml. The stem bark extract (24.445 – 94.025 %) showed the highest antioxidant activity followed by the seeds extract (23.445 – 91.575 %) before the leaves extract (22.530 – 89.775 %). Comparatively, the highest antibacterial and antioxidant activity exhibited by the stem bark extract could be attributed to the amount of bioactive compounds present in it as shown by the GC/MS analysis. The docking result of the prominent compounds showed that all of the test compounds had negative binding affinities, indicating that the compounds had been successfully docked to the receptors. The compounds showed good pharmacokinetic properties, such as high blood-brain barrier absorption, oral bioavailability, and water solubility, in the in-silico ADME and drug-likeness predictions. The findings in this research give credence to the compounds as promising potential drug candidates for the treatment and management of diseases and infections in herbal medicine.