Antibacterial and antibiofilm potentials of Rumex dentatus root extract characterized by HPLC-ESI-Q-TOF-MS

The control of infections is one of the key strategies to treat cuts, wounds, lung, and skin infections. In this study the folkloric use of Rumex dentatus (R. dentatus) roots in the mentioned conditions was scientifically investigated. The methanolic (MeOH) crude extract of R. dentatus root was fractionated (n-hexane, ethyl acetate and water) via bioassay-guided method, and its antibacterial activity was evaluated using the agar well diffusion and Minimum inhibitory concentration (MIC) assays against clinical isolate of Pseudomonas aeruginosa (P. aeruginosa). The antibiofilm activity was measured using the crystal violet staining method. The crude extract, fractions and sub-fractions tested showed the MICs values ranging from 200 to 1000 μg/mL respectively. Among the fractions, notably, the water fraction exhibited the highest activity against P. aeruginosa. The water fraction was then subjected to thin layer chromatography (TLC). Following spectrometric analysis using HPLC-ESI-Q-TOF-MS, gallic acid and emodin were identified as the primary components within the same fraction, responsible for eliciting antibacterial and antibiofilm effects. The in-silico studies conducted with AutoDock Vina on the LasR protein, using both isolated gallic acid and emodin, confirm the binding affinity of these molecules to the active sites of the LasR protein that has regulatory role in building of biofilm formation and its pathogenicity. By scientifically validating the infection-controlling properties of R. dentatus, this research provides compelling evidence that supports its traditional use as reported in folklore. Moreover, this study contributes to our understanding of the plant's potential in managing infections, thereby substantiating its traditional therapeutic application in a scientific context.