Antibacterial Activities of Effective Section of Magnolia Officinalis

Objectives:To extract the effective section from magnolia officinalis and evaluate its antimicrobial activities against oral pathogens in vitro. Methods:Magnolia officinalis was extracted using chemical method. Assay of antibacterial activity of these fractions was investigated by disc diffusion testing and broth microdilution method; Assay of bactericidal activity was performed by the determination of minimal bactericidal concentrations (MBCs) and time-kill studies. Results:Three fractions were obtained by extract procedures. The results showed that fraction 1 and 2 produced inhibitory zones against all bacteria (p<0.05) while the values of fraction 3 for inhibitory zones were not statistically different from control (p>0.05). The bacteriostatic effects of fraction 2 required concentrations of 0.39 to 0.78 mg/ml, and the bactericidal effects required sterilizing concentrations of 2.76 to 6.67 mg/ml. The values of MIC for fraction 1 were 5.27~12.12mg/ml but it did not display any bactericidal effect at the concentrations tested in this study. After 8 h of incubation the growth of cariogenic strains tested was blocked by fraction 2 of 10mg/ml completely. Fraction 2 displayed bactericidal effects on periodontopathic bacteria after 10 h of incubation. Conclusions:Fraction 2 was the effective section of magnolia officinalis that possessed potential inhibiting growth of the oral pathogens.