Antibacterial, antifungal, antibiofilm and antioxidant properties of Orthosiphon stamineus Benth.: An in vitro analysis

Indwelling medical devices have been playing a major role in healthcare settings in providing health support for patients.Among the several medical devices, catheter insertion gained much attention due to their infectious nature by allowing microbial entry and colonization on their surfaces resulting in biofilm formation which makes the treatment more critical.Therefore, alternative antimicrobial agents are urgently needed to avoid such a situation, and plant-based natural biomolecules have always been attractive owing to plenty of health benefits.Hence, our study investigated the antimicrobial potential of the methanolic crude extract of Orthosiphon stamineus Benth.Some of the microbes causing catheter-associated urinary tract infections, like Candida albicans, Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis.The antimicrobial potential was analyzed by well diffusion method and the minimal inhibitory concentrations (MICs) were found to be 0.312 mg/ml against each one of the selected pathogens.The antibiofilm activity was studied using the crystal violet method and it was found that the extract could effectively inhibit the formation of biofilms when applied with different concentrations of O. stamineus.The antibiofilm activity was quantified against mature biofilms after treatment with various concentrations and the extract reduced the biofilms by 87%, 86%, 88%, and 88% in the cases of S. aureus, C. albicans, E. faecalis, and E. coli, respectively.The in vitro bladder model revealed the antimicrobial potential of O. stamineus coated catheters against the test pathogens.In addition, O. stamineus crude extract showed potent antioxidant properties using DPPH assay and also had no cytotoxicity on L929 cells.Thus, the phytocompounds in the plant O. stamineus need to be further purified and studied in detail for their use as an alternative agent for CAUTI management.