Phytochemical Profiling and Pharmacological Evaluation of Leaf Extracts of Ruellia tuberosa L.: An In Vitro and In Silico Approach

The present study was designed to appraise the photoprotective, antioxidant, and antibacterial bioactivities of Ruellia tuberosa leaves extracts (RtPE, RtChl, RtEA, RtAc, RtMe, and RtHMe). The results showed that, RtHMe extracts of R. tuberosa was rich in total phenolic content, i. e., 1.60 mgGAE/g dry extract, while highest total flavonoid content was found in RtAc extract, i. e., 0.40 mgQE/g. RtMe showed effective antioxidant activity (%RSA: 58.16) at the concentration of 120 mu L. RtMe, RtEA and RtHMe exhibited effective in vitro antibacterial activity against Gram-negative bacteria (E. coli). In silico docking studies revealed that paucifloside ( 11.743 kcal/mol), indole-3-carboxaldehyde ( 7.519 kcal/mol), nuomioside ( 7.275 kcal/mol), isocassifolioside ( 6.992 kcal/mol) showed best docking score against PDB ID 2EX8 [penicillin binding protein 4 (dacB) from Escherichia coli, complexed with penicillin-G], PDB ID 6CQA (E. coli dihydrofolate reductase protein complexed with inhibitor AMPQD), PDB ID 2Y2I [Penicillin-binding protein 1B in complex with an alkyl boronate (ZA3)] and PDB ID 2OLV (from S. aureus), respectively. Docked phytochemicals also showed good drug likeness properties.

Automated summary

This study evaluated the photoprotective, antioxidant, and antibacterial properties of Ruellia tuberosa leaf extracts. The results showed that the methanol extract of R. tuberosa had high total phenolic content, while the acetic acid extract had the highest total flavonoid content. The methanol extract exhibited effective antioxidant activity and the methanol, ethyl acetate, and methanol-chloroform extracts showed effective antibacterial activity against E. coli. In silico docking studies identified phytochemicals that showed good docking scores and drug likeness properties against various proteins.