Study of andrographolide bioactivity against Pseudomonas aeruginosa based on computational methodology and biochemical analysis

Andrographolide is one of the main biologically active molecules isolated from Andrographis paniculata (A. paniculata), which is a traditional Chinese herb used extensively throughout Eastern Asia, India, and China. Pseudomonas aeruginosa, often known as P. aeruginosa, is a common clinical opportunistic pathogen with remarkable adaptability to harsh settings and resistance to antibiotics. P. aeruginosa possesses a wide array of virulence traits, one of which is biofilm formation, which contributes to its pathogenicity. One of the main modulators of the P. aeruginosa-controlled intramembrane proteolysis pathway is AlgW, a membrane-bound periplasmic serine protease. In this work, we have used a set of density functional theory (DFT) calculations to understand the variety of chemical parameters in detail between andrographolide and levofloxacin, which show strong bactericidal activity against P. aeruginosa. Additionally, the stability and interaction of andrographolide and levofloxacin with the protein AlgW have been investigated by molecular docking and molecular dynamics (MD) simulations. Moreover, the growth and inhibition of biofilm production by P. aeruginosa experiments were also investigated, providing insight that andrographolide could be a potential natural product to inhibit P. aeruginosa.