Chlorinated emodin as a natural antibacterial agent against drug-resistant bacteria through dual influence on bacterial cell membranes and DNA

Feixia Duan,Wen Huang,Guang Xin,Hai Niu

doi:10.1038/s41598-017-12905-3

Feixia Duan, Wen Huang + Show 2 more

Open Access

https://doi.org/10.1038/s41598-017-12905-3

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Abstract

The rise in infections caused by drug-resistant pathogens and a lack of effective medicines requires the discovery of new antibacterial agents. Naturally chlorinated emodin 1,3,8-trihydroxy-4-chloro-6-methyl-anthraquinone (CE) from fungi and lichens was found to markedly inhibit the growth of Gram-positive bacteria, especially common drug-resistant bacterial strains, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE). CE was confirmed to cause significant potassium leakage, cell membrane depolarization and damage to the selective permeability of cell membranes in bacterial cells, resulting in bacterial cell death. In addition, CE was shown to have a strong electrostatic interaction with bacterial DNA and induce DNA condensation. Thus, CE is a promising natural antibacterial pharmacophore against Gram-positive bacteria, especially common drug-resistant MRSA and VRE isolates, with a dual antibacterial mechanism that damages bacterial cell membranes and DNA.

Highlights

The emergence of drug-resistant bacteria and a lack of effective antibacterial agents in clinical practice has increasingly put public health at serious risk[1,2,3,4,5,6]
We evaluated the antibacterial activity of CE against 181 strains of laboratory and clinically isolated bacterial strains, including the common drug-resistant bacteria methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE) and vancomycin-resistant Enterococcus faecalis (VRE)
We evaluated the antibacterial activity of CE against 141 clinically isolated Gram-positive bacterial strains, including S. aureus, S. epidermidis, S. pneumonia, Enterococcus and Peptostreptococcus, especially 45 drug-resistant clinical isolates of MRSA, MRSE and VRE

Summary

Introduction

The emergence of drug-resistant bacteria and a lack of effective antibacterial agents in clinical practice has increasingly put public health at serious risk[1,2,3,4,5,6]. New antibacterial agents are urgently needed to combat this crisis, and natural bioactive compounds are important sources for new antibacterial pharmacophores. The bacterial cell membrane is essential for the survival and multiplication of bacteria. The selection for resistance to membrane-active antibacterial agents would require a modification of the charge of membrane lipids or to the membrane constituents, which is poorly compatible with the survival of bacteria[15]. The cell membrane is a promising target for novel antibacterial agents against drug-resistant bacteria. We evaluated the antibacterial activity of CE against 181 strains of laboratory and clinically isolated bacterial strains, including the common drug-resistant bacteria methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE) and vancomycin-resistant Enterococcus faecalis (VRE). 5–2j 0.03− > 256j revealed that CE, which affects the functions of the bacterial membrane and DNA, could be a promising natural antibacterial agent to combat drug-resistant bacteria Positive control 2f 2g 0.5–2g 1–2g 128g 128g 2f 0.5–2f 0.5f >256f 2f 2f 0.25–1h 8–1000h 0.062–256j 4i — 4i 2–256i 0. 5–2j 0.03− > 256j revealed that CE, which affects the functions of the bacterial membrane and DNA, could be a promising natural antibacterial agent to combat drug-resistant bacteria

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