Bactericidal and antibiofilm activities of Piper betle extract against Burkholderia pseudomallei: in vitro and in silico approaches.

Burkholderia pseudomallei biofilm is a significant virulence factor in infection. This study aimed to investigate antibacterial and antibiofilm activities of Piper betle extract against B. pseudomallei. The MIC and MBC values of the extract against the isolates were 0.5-1.0 mg/mL. At 2 × MIC, the cells showed cell shrinkage and abnormalities. At 1/2 × MIC, the extract displayed 40-71% inhibition of biofilm formation. At 8 × MIC, the extract reduced the viability of mature biofilms by 60-86%. Hydroxychavicol and eugenol, the main compounds in the extract, showed binding activity to CdpA, an enzyme implicated in biofilms as observed by in silico studies. Hydroxychavicol exhibited the highest affinity for CdpA, with a distance of 2.27 Å. Molecular dynamics simulations revealed that hydroxychavicol forms a stable complex with cyclic di-GMP phosphodiesterase, maintaining protein structural integrity with minimal conformational changes. The results suggested that Piper betle may have medicinal benefits by inhibiting biofilm-related infections.