Attenuation of dermal wounds through topical application of ointment containing phenol enriched fraction of Caesalpinia mimosoides Lam

Integrative computational analysis of anti-influenza potential in Caesalpinia mimosoides Lamk hydroethanolic extract

In a recent study, we used chemical analysis to show that the Caesalpinia mimosoides aqueous extract, which contains a high concentration of simple phenolics, has strong anti-influenza activity. We determined through molecular docking methods that its potential target inhibitor is the neuraminidase. Therefore, our study objectives were to evaluate whether the aqueous-ethanol extract (30% v/v) of this plant species exhibits greater antiviral activity than the aqueous plant extract. The C. mimosoides hydroethanolic extract exhibited potent antioxidant activity in the DPPH assay, with an IC50 value of 15.01 µg/mL, comparable to authentic quercetin (IC50 = 12.72 µg/mL) and approximately 4.91 times greater than standard gallic acid (IC50 = 3.06 µg/mL). Through untargeted metabolomic analyses (UPLC-ESI(±)-QTOF-MS/MS) and subsequent stepwise computational metabolomics analyses, we identified the extract as primarily containing simple phenolics (e.g., gallic acid, ellagic acid, shikimic acid, and chlorogenic acid), flavonoid derivatives (e.g., quercetin, taxifolin, myricitrin, and afzelin), and other bioactive components, including dicarboxylic acids and germacrone. The polyphenol-rich extract showed strong anti-influenza activity, with an IC50 of 2.33 µg/mL against the influenza A/PR/8/34 virus and no cytotoxic effects, as indicated by a CC50 greater than 50 µg/mL. This represents an approximately 3.35-fold increase in effectiveness compared to its corresponding aqueous extract (IC50 = 7.81 µg/mL). Furthermore, the extract demonstrated no hemolytic activity, even at a maximum concentration of 2,000 µg/mL, suggesting its potential as a safe antiviral agent. Molecular docking analyses revealed that the identified phytochemicals can simultaneously interact with the "drug-target binding sites" of neuraminidase (NA) and PB2 subunit of influenza RNA polymerase, indicating their potential polypharmacological effects. The antiviral activity of the ethanolic-aqueous extract against other strains is being explored due to the versatile biological effects of phenolic substances.

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

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 "gallic 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 µg/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.

Ethyl gallate isolated from phenol-enriched fraction of Caesalpinia mimosoides Lam. Promotes cutaneous wound healing: a scientific validation through bioassay-guided fractionation

The tender shoots of Caesalpinia mimosoides Lam. are used ethnomedically by the traditional healers of Uttara Kannada district, Karnataka (India) for the treatment of wounds. The current study was aimed at exploring phenol-enriched fraction (PEF) of crude ethanol extract of tender shoots to isolate and characterize the most active bio-constituent through bioassay-guided fractionation procedure. The successive fractionation and sub-fractionation of PEF, followed by in vitro scratch wound, antimicrobial, and antioxidant activities, yielded a highly active natural antioxidant compound ethyl gallate (EG). In vitro wound healing potentiality of EG was evidenced by a significantly higher percentage of cell migration in L929 fibroblast cells (97.98 ± 0.46% at 3.81 μg/ml concentration) compared to a positive control group (98.44 ± 0.36%) at the 48th hour of incubation. A significantly higher rate of wound contraction (98.72 ± 0.41%), an elevated tensile strength of the incised wound (1,154.60 ± 1.42 g/mm²), and increased quantity of connective tissue elements were observed in the granulation tissues of the 1% EG ointment treated animal group on the 15th post-wounding day. The accelerated wound healing activity of 1% EG was also exhibited by histopathological examinations through Hematoxylin and Eosin, Masson's trichome, and Toluidine blue-stained sections. Significant up-regulation of enzymatic and non-enzymatic antioxidant contents (reduced glutathione, superoxide dismutase, and catalase) and down-regulation of oxidative stress marker (lipid peroxidation) clearly indicates the effective granular antioxidant activity of 1% EG in preventing oxidative damage to the skin tissues. Further, in vitro antimicrobial and antioxidant activities of EG supports the positive correlation with its enhanced wound-healing activity. Moreover, molecular docking and dynamics for 100 ns revealed the stable binding of EG with cyclooxygenase-2 (-6.2 kcal/mol) and matrix metalloproteinase-9 (-4.6 kcal/mol) and unstable binding with tumor necrosis factor-α (-7.2 kcal/mol), suggesting the potential applicability of EG in inflammation and wound treatment.