Affiliation:
1. Department of Biosciences, University of Wah, Wah Cantt, Pakistan
2. Atta ur Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, Pakistan
3. Department of Biotechnology, University of Mianwali, Punjab, Pakistan
Abstract
Objectives The current study was conducted to evaluate the antibacterial potential of leaf and fruit extracts of Zanthoxylum armatum against two pathogenic bacterial isolates, Staphylococcus aureus and Staphylococcus epidermidis. Methods Twelve commercially available antibiotics were tested S. aureus and S. epidermidis by antimicrobial susceptibility test (AST). Qualitative analysis of phytochemicals was performed to evaluate the presence of certain secondary metabolites. The activity of Z. armatum extracts against S. aureus and S. epidermidis was measured as a maximum zone of inhibition exhibited by each leaf and fruit extract. An in-silico study was conducted on flavonoids and alkaloids to show their binding affinity with the PBP2a receptor protein of S. aureus and TcaR of S. epidermidis. Results The AST revealed that S. aureus was resistant to Penicillin, Ampicillin, Clindamycin, Vancomycin, Rifampicin, Novobiocin, and Oxacillin, whereas S. epidermidis was resistant to Streptomycin, Oxacillin, Tetracycline, and Novobiocin. Qualitative analysis of phytochemicals resulted in the presence of Saponins, fixed oils, flavonoids, alkaloids, starch, and fatty acids in both leaf and fruit extracts. The maximum zone of inhibition against S. aureus was produced by methanolic leaf extracts of Z. armatum and chloroform fruit extracts. For S. epidermidis, the best activity was exhibited by benzene leaf extracts and methanolic fruit extracts. An in-silico study showed that flavonoids Nitidine and Nevadensin exhibited binding affinity with the PBP2a receptor protein higher than selected antibiotics, ie, Penicillin, Chloramphenicol, and Oxacillin. TcaR of S. epidermidis interacted with Tambuletin, followed by Nitidine and Kaempferol. Conclusion After in vitro testing, in silico analysis advised extracting and purifying the bioactive components from Z. armatum extracts that showed significant interaction with bacterial virulence proteins for use as natural antibiotics against antibiotic-resistant bacteria.