Unveiling the Potent Antiviral and Antioxidant Activities of an Aqueous Extract from Caesalpinia mimosoides Lamk Cheminformatics and Molecular Docking Approaches

Abstract

Our group previously demonstrated that Caesalpinia mimosoides Lamk exhibits many profound biological properties including anticancer antibacterial and antioxidant activities. However its antiviral activity has not yet been investigated. Here the aqueous extract of C. mimosoides was prepared from the aerial parts (leaves stalks and trunks) to see whether it exerts anti-influenza (H1N1) effects and to reduce the organic solvents consumed during extraction making it a desirable approach for the large-scale production for medical uses. Our plant extract was quantified to contain 7 g of gallic acid (GA) per 100 g of a dry sample as determined using HPLC analysis. It also exerts potent antioxidant activities comparable to those of authentic GA. According to untargeted metabolomics (UPLC-ESI(-)-QTOF-MS/MS) with the aid of cheminformatics tools (MetFrag (version 2.1) SIRIUS (version 5.8.3) CSI:FingerID (version 4.8) and CANOPUS) the major metabolite was best annotated as 揼allic acid� phenolics (e.g. quinic acid shikimic acid and protocatechuic acid) sugar derivatives and dicarboxylic acids were deduced from this plant species for the first time. The aqueous plant extract efficiently inhibited an influenza A (H1N1) virus infection of MDCK cells with an IC50 of 5.14 ?g/mL. Of equal importance hemolytic activity was absent for this plant extract signifying its applicability as a safe antiviral agent. Molecular docking suggested that GA interacts with conserved residues (e.g. Arg152 and Asp151) located in the catalytic inner shell of the viral neuraminidase (NA) sharing the same pocket as those of anti-neuraminidase drugs such as laninamivir and oseltamivir. Additionally other metabolites were also found to potentially interact with the active site and the hydrophobic 430-cavity of the viral surface protein suggesting a possibly synergistic effect of various phytochemicals. Therefore the C. mimosoides aqueous extract may be a good candidate for coping with increasing influenza virus resistance to existing antivirals. ? 2023 by the authors.