Antimicrobial activity of water-soluble mangostin derivatives of ethanol extracts of Garcinia mangostana L. peel, and ethanol extracts of Psoralea corylifolia L. fruit and Glycyrrhiza uralensis root on oral bacteria associated with endodontic infections / 대한치과재료학회지

ABSTRACT

This study was performed to evaluate the antibacterial activity of water-soluble mangostin derivatives (WsMD) of the ethanol extract of the peel of Garcinia mangostana L. (mangosteen) and the ethanol extracts of the fruit of Psoralea corylifolia L. and the root of Glycyrrhiza uralensis (licorice) against oral bacteria associated with endodontic infections. Cytotoxicity of the three natural products was tested on human embryonic kidney 293 cells (HEK 293) using the methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay or the cell counting method. Antimicrobial activity was evaluated based on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The highest concentrations of the WsMD of the ethanol extract of the peel of mangosteen and ethanol extracts of P. corylifolia L. fruit and licorice root without cytotoxic effects on HEK 293 cells were 20, 400, and 320 µg/ml, respectively. The MIC and MBC values of the WsMD of the ethanol extract of the peel of mangosteen and ethanol extracts of P. corylifolia L. fruit against 35 isolates (23 species) of pulpitis- and periapical disease-causative bacteria were 1.25–20 µg/ml and 25–200 µg/ml, respectively, except for Dialister invisus KCOM 1973. The ethanol extract of licorice root had MBC values of 40–320 µg/ml against 27 of 35 bacterial strains. These results showed that the WsMD of the ethanol extract of mangosteen peel had the highest antibacterial activity among the three natural extracts and suggested it as a potential root canal irrigation agent.