Antibacterial and Anti-biofilm Effect of Lactuca serriola Extract Against Clinically Isolated Porphyromonas gingivalis and Prevotella intermedia: An in vitro study

Abstract

Objective: To investigate the antibacterial and anti-biofilm effect of Lactuca serriola (LS) extract against clinically isolated Porphyromonas gingivalis (P. gingivalis) and Prevotella intermedia (P. intermedia). 
 Methods: LS extract was prepared by solvent extraction method. Gas chromatography mass spectrometry (GC-MS) was used to analyze phytochemical components. Plaque samples were obtained from periodontitis patients with probing pocket depth ≥6mm to isolate P. intermedia. Microbiological tests and conventional polymerase chain reaction (PCR) were used to confirm P. intermedia. Antibacterial activities of LS against the confirmed clinical strains (P. intermedia and revised P. gingivalis) were determined by agar well diffusion method. Broth macro dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The anti-biofilm assay of the LS was performed by using tube adhesion method. 
 Results: Antibacterial activity of LS against clinical isolates revealed that the inhibition zones ranged from 11.75 ±0.95mm to 24.25 ±1.7mm for P. gingivalis and 12.75 ±0.95mm to 25.5 ±1.29mm for P. intermedia. The MICs of LS extract were 212.5mg/mL and 106.2 mg/mL, while the MBCs were 425mg/mL and 212.5mg/mL against P. gingivalis and P. intermedia, respectively. The anti-biofilm of LS extract exhibited strong anti-biofilm activity. 
 Conclusions: LS extract exhibited bactericidal and anti-biofilm activity against clinically isolated P. gingivalis and P. intermedia in an in vitro study.