Anti-biofilm activity of Barringtonia asiatica (Lin.) Kurz seed extract against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin resistant Staphylococcus aureus (MRSA)

Abstract

Biofilm-associated infections caused by <i>Staphylococcus aureus,</i> particularly methicillin-resistant strains (MRSA), are challenging to treat due to their resistance to conventional antibiotics. Natural plant extracts, such as crude saponin from <i>Barringtonia asiatica </i> seeds, offer a promising alternative for antimicrobial and antibiofilm applications. In this study, a 1.86% yield of crude saponin (30.94 g) was extracted, with foam test confirming saponin presence. The extract inhibited bacterial growth with an MIC₅₀ of 75mg/mL for both MSSA and MRSA, while MIC₉₀ values exceeded 300 mg/mL, and minimum bactericidal concentration results indicated primarily bacteriostatic effects. The extract also effectively prevented biofilm formation, with MBIC₅₀ values at 9.4 mg/mL and MBIC₉₀ values of 75 mg/mL for MSSA and 150 mg/mL for MRSA, showing comparable activity to vancomycin at concentrations of 75 mg/mL or higher. However, the extracts’ ability to eradicate established biofilms was limited, as MBEC₅₀ and MBEC₉₀ values for both strains were above 300 mg/mL. Overall, these findings suggest that <i>B. asiatica</i> seed extract possesses strong biofilm-inhibitory properties but limited biofilm-eradicating capacity, supporting its potential role as a preventive or adjunctive treatment for early biofilm management.