In vitro and in silico Studies: Penicillin-Binding Protein 2a (PBP2a) Inhibition by Stigmasterol in Banyan Hanging Roots (Ficus benjamina L.) as Novel Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA)

The most common cause of nosocomial infection worldwide is caused by Gram-positive coccus bacteria or what we commonly call Methicillin-resistant Staphylococcus aureus (MRSA). This study aimed to find novel antimicrobial agents from the banyan tree (Ficus benjamina L.) hanging roots to treat MRSA. Docking experiment and well diffusion were used as in silico and in vitro experiments respectively to identify the potential of stigmasterol against MRSA. The data were analyzed statistically with one-way variance analysis (ANOVA), post-doc Tukey assay, correlation, and regression by SPSS Amos 24. In the in silico experiment, stigmasterol was strongly associated with penicillin-binding protein 2a (PBP2a) on the active side of LYS289. Thus, it had the potential to inhibit PBP2a. Disruption of cell walls, the release of cytoplasmic contents, and a decrease in the cellular volume of MRSA were caused by the inhibition of PBP2a. The well diffusion test results showed the inhibition zone in 50 - 100 μg/ml of stigmasterol against MRSA. The inhibition zone was in the range of 7.38 – 10.17 mm. The inhibition diameter indicated a significant difference with a p-value < 0.05. The results of statistical analyses indicate that stigmasterol is effective as an antimicrobial against MRSA. Stigmasterol has potential as a potential microbial agent for the therapy of MRSA.