Experimental investigations on Camellia kissi Wall. for antioxidant, anti-quorum sensing and anti-biofilm activities

Abstract

Plants are known for their widespread biological activities with special reference to the use in folkloric medicines for the treatment of several metabolic disorders and infectious diseases from ancient times. The presence of bioactive phytochemicals especially phenolic compounds, tocopherol, phytol etc. is responsible for the potential bioactivities of plants. In this work, the ability of ethanolic extract of Camellia kissi wall. to scavenge free radicals was investigated. Also, the anti-quorum sensing and anti-biofilm activity of C. kissi against Pseudomonas aeruginosa PAO1 was examined. The crude extract of C. kissi wall showed a significant antioxidant potential against DPPH and hydroxyl radicals with a scavenging percentage of 73.77 ± 3.58 and 75.3 ± 4.45 % respectively. The plant extract also significantly inhibited the QS mediated pyocyanin synthesis, bacterial motility and recalcitrant biofilm establishment in P. aeruginosa PAO1. Confocal laser scanning microscopic (CLSM) analysis confirmed the anti-biofilm efficacy. The in vitro anti QS potential of C. kissi wall. was further confirmed by molecular docking studies specifically targeting the QS transcriptional regulatory protein, LasR. The present result will provide ample avenues to exploit medicinal plants in attenuating the QS regulated microbial infections and oxidative stress in the post-antibiotic era.