GC-MS profiling, in vitro antioxidant and toxicity evaluation, and in silico pharmacokinetic and molecular docking prediction of the phytocompounds of Rungia repens (L.) Nees targeting SarA of Staphylococcus aureus

Abstract

The medicinal plant Rungia repens (L.) Nees (Acanthaceae) is commonly known as kodagasalai in Tamil. It is recognized for its antipyretic, diuretic, anti-inflammatory, and vermifunge properties. The present study is primarily focused on identifying the phytocompounds and evaluating the antioxidant activity and cytotoxicity of R. repens leaf extract. In silico molecular docking studies were performed for SarA, an anti-virulence target of Staphylococcus aureus, and pharmacokinetic prediction was carried out to identify a suitable compound for drug delivery. The total flavonoid (TFC), phenolic content (TPC), and antioxidant activity of the ethanol extract were found to be 65.31 ± 7.2 mg QUE/g, 202.40 ± 2.97 mg GAE/g, and 76.166% ± 0.15% radical-scavenging activity, respectively, with an IC50 value of 311.9 ± 1.27 μg/mL. The extract exhibited no toxic effects up to 250 μg/mL against L929 cell line. GC-MS analysis identified 19 phytoconstituents in the R. repens ethanol leaf extract. Antibacterial activity against S. aureus exhibited an inhibition zone of 14 ± 1.73 mm. Phthalic acid, butyl undecyl ester showed a binding energy of −10.0 kcal/mol against SarA of S. aureus. ADME prediction revealed suitable phytocompounds of R. repens for drug development. Overall, the results indicate that R. repens has abundant compounds with biological activity and offers a source for drug development and delivery strategies.