Antibacterial activity and mechanism of sanguinarine againstProvidencia rettgeriin vitro

Abstract

BackgroundSanguinarine (SAG), a benzophenanthridine alkaloid, occurs inPapaveraceas,BerberidaceaeandRanunculaceaefamilies. Studies have found that SAG has antioxidant, anti-inflammatory, and antiproliferative activities in several malignancies and that it exhibits robust antibacterial activities. However, information reported on the action of SAG againstProvidencia rettgeriis limited in the literature. Therefore, the present study aimed to evaluate the antimicrobial and antibiofilm activities of SAG againstP. rettgeriin vitro.MethodsThe agar dilution method was used to determine the minimum inhibitory concentration (MIC) of SAG againstP. rettgeri. The intracellular ATP concentration, intracellular pH (pHin), and cell membrane integrity and potential were measured. Confocal laser scanning microscopy (CLSM), field emission scanning electron microscopy (FESEM), and crystal violet staining were used to measure the antibiofilm formation of SAG.ResultsThe MIC of SAG againstP. rettgeriwas 7.8 μg/mL. SAG inhibited the growth ofP. rettgeriand destroyed the integrity ofP. rettgericell membrane, as reflected mainly through the decreases in the intracellular ATP concentration, pHinand cell membrane potential and significant changes in cellular morphology. The findings of CLSM, FESEM and crystal violet staining indicated that SAG exhibited strong inhibitory effects on the biofilm formation ofP. rettgeriand led to the inactivity of biofilm-relatedP. rettgericells.