Exploration of Antimicrobial Ingredients in Psoralea corylifolia L. Seed and Related Mechanism against Methicillin-Resistant Staphylococcus aureus

Abstract

With the abuse of antibiotics, bacterial antibiotic resistance is becoming a major public healthcare issue. Natural plants, especially traditional Chinese herbal medicines, which have antibacterial activity, are important sources for discovering potential bacteriostatic agents. This study aimed to develop a fast and reliable method for screening out antimicrobial compounds targeting the MRSA membrane from Psoralea corylifolia Linn. seed. A UPLC-MS/MS method was applied to identify the prenylated flavonoids in major fractions from the extracts of Psoralea corylifolia Linn. seed. The broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) of different fractions and compounds. The morphological and ultrastructural changes of MRSA were determined by scanning electron microscopy (SEM). The membrane-targeting mechanism of the active ingredients was explored by membrane integrity assays, membrane fluidity assays, membrane potential assays, ATP, and ROS determination. We identified eight prenylated flavonoids in Psoralea corylifolia Linn. seed. The antibacterial activity and mechanism studies showed that this type of compound has a unique destructive effect on MRSA cell membranes and does not result in drug resistance. The results revealed that prenylated flavonoids in Psoralea corylifolia Linn. seeds are promising candidates for the development of novel antibiotic agents to combat MRSA-associated infections.

Bavachin Rejuvenates Sensitivity of Colistin against Colistin-Resistant Gram-Negative Bacteria

“…Membrane permeability is one of the important factors for antibiotic activity and membrane-targeted antibiotics usually have fast bactericidal activity [3,19,46]. Bavachin has been reported to destroy the CM of Gram-positive bacteria in a dose-dependent manner [24]. In this study, we found that bavachin alone had no effect on CM of Gram-negative bacteria, it is possible that the low permeability of the outer membrane prevents agents from entering the cell [47].…”

“…As an important Chinese herbal medicine, Psoraleae Fructus is often used to treat osteoporosis and vitiligo [21]. At present, bavachin has been reported to be involved in multiple processes, including obesity suppression [20], anti-inflammation [22], anticancer [23], antibacterial [24], and immunoadjuvant activity [25]. In addition, it has been reported that bavachin exerted good antibacterial activity against Gram-positive bacteria by disrupting the cytoplasmic membrane (CM), whereas it has no antibacterial effect on GNB [24].…”

“…At present, bavachin has been reported to be involved in multiple processes, including obesity suppression [20], anti-inflammation [22], anticancer [23], antibacterial [24], and immunoadjuvant activity [25]. In addition, it has been reported that bavachin exerted good antibacterial activity against Gram-positive bacteria by disrupting the cytoplasmic membrane (CM), whereas it has no antibacterial effect on GNB [24]. However, there has been no study on the synergistic activity between bavachin and colistin against GNB.…”

A practical method for rapid discrimination of constituents in Psoraleae Fructus by UPLC‐Q‐Orbitrap MS

“…First, the C ring lost substituents on the side chain progressively to produce fragment ions at m/z 323.1272 and m/z 267.0648, and then, the fragment at m/z 239.0699 formed when B ring lost a molecule of CO, while the RDA reaction occurred to give fragment ion at m/z 137.0232. From these characteristic fragments, compound 19 was identified as Corylifol A 32–34 . The ESI‐MS2 and the possible cleavage pathway were shown in Figure 3.…”