Phytochemical compositions of Xylopia aethiopica (Ata), antibacterial activity and molecular docking of bioactive andrographolide with target proteins

Xylopia aethiopica is a known medicinal plant in West Africa, with ethno-medicinal values.  The present study evaluates antibacterial potential of X. aethiopica against uropathogens in order to validate its traditional use. Gas chromatography-mass spectrometry (GC-MS) analysis displayed important phytoconstituents of ethanolic extracts and molecular docking study was used to identify potential drug candidates for urinary tract infection by predicting the binding affinity of andrographolide with target bacterial proteins using AutoDock Vina wizard. Preliminary phytochemical screening revealed the presence of flavonoids, tannins, saponins, terpenoids alkaloids and cardiac glycosides. The leaf extracts of X. aethiopica showed remarkable antibacterial activities. The minimum inhibitory concentration (MIC) by broth microdilution method was 25 mg/mL with MIC-index value of 1.0. The GC–MS analysis revealed the presence of 37 bioactive compounds, some of which have various pharmacological activities relevant to urinary tract infection. The major phytoconstituent identified was andrographolide. Molecular docking simulation showed better binding between andrographolide and structural protein and cell adhesion protein of Bacillus thuringiensis and Proteus mirabilis respectively. However, ciprofloxacin bound better with structural protein than andrographolide. The drug-likeness and pharmacokinetic ADMET filter of the compound met all the prescribed features and as such could be a good novel drug designed formulated for the treatment of infections caused by Bacillus and P. mirabilis. The results obtained in the present study are a pointer to the possible use of X. aethiopica plants the management of several ailments, which may lead to the development of novel drugs. Key words: X. aethiopica; andrographolide; molecular docking; gas chromatography-mass spectroscopy (GC-MS); phytoconstituents.