Eleutheroside K isolated from Acanthopanax henryi (Oliv.) Harms suppresses methicillin resistance of Staphylococcus aureus

Abstract

Acanthopanax (A.) henryi (Oliv.) Harms contain many bioactive compounds commonly used in traditional Chinese medicine. The objective of the present study was to investigate the antibacterial activity of the single constituent, Eleutheroside K (ETSK) isolated from the leaves of A. henryi (Oliv.) Harms, against methicillin‐resistant Staphylococcus (S.) aureus (MRSA). Broth microdilution assay was used to measure the minimal inhibitory concentration (MIC) and the MIC values of ETSK against eight clinical S. aureus strains were all 50 µg ml−1. At sub‐inhibitory concentrations, a synergistic effect between oxacillin (OXA) and ETSK was confirmed using checkerboard dilution assay and time‐kill curve analysis. The bacteriostatic effect became more pronounced when ETSK was used in combination with detergent (Triton X‐100) or ATPase inhibitor (N, N′‐dicyclohexylcarbodiimide). According to western blot analysis, the down‐regulated expression of Penicillin‐binding protein 2a (PBP2a) further validated that the bacterial activity was inhibited when treated with ETSK in a dose‐dependent manner. Results based on our study verified that ETSK significantly suppressed MRSA infections and emphasized the potential application of ETSK as a novel anti‐MRSA natural drug.

Eleutheroside K Isolated from Acanthopanax henryi (Oliv.) Harms Inhibits the Expression of Virulence-Related Exoproteins in Methicillin-Resistant Staphylococcus aureus

“…There are few studies on the pharmacological activity of ETSK. By determining the antibacterial susceptibility, our previous studies confirmed the pharmacological mechanism of ETSK reversing the methicillin resistance caused by MRSA and displayed a minimal inhibitory concentration of 50 µg/mL [ 24 ]. In this context, the antibacterial ability of ETSK will be further investigated by analyzing the effect of ETSK on the secretion of staphylococcal virulence factors in vitro.…”

“…Real-time RT-PCR was performed as previously described [ 26 ]. In our previous experiment, it has been determined that the minimum inhibitory concentration of ETSK against ATCC 33,591 is 50 µg/mL [ 24 ]. The ATCC 33,591 strain was grown to an absorbance value of 0.9 at an optical density 600 nm (OD 600nm ) and treated with sub-inhibitory concentrations (6.25–25 µg/mL) of ETSK for 4 h [ 26 ].…”

Shugan Jieyu Capsule in Post-Stroke Depression Treatment: From Molecules to Systems

“…The main glycosides are Acanthopanax glycosides A, B, C, D, E, F, and G. Polysaccharides mainly include glucose, sucrose, alkali-soluble polysaccharide and water-soluble polysaccharide. Fatty acids and quinones mainly include methyl oleate, ethyl oleate, 10, -octadecadienoic acid, 10, -octadecadienoic acid, ethyl ester, mymyritic acid, palmitic acid, 9, 11-octadecadienoic acid, hexadecadienoic acid ( Li et al, 2021 ).…”

Acanthopanax henryi: Review of Botany, Phytochemistry and Pharmacology

“…Rosin (34) and eugenol glucoside (43) were isolated from fruits and flowers of AH, respectively [12,21]. Ferulic acid (35), syringin (37), and trans-coniferin (38) have been obtained from the roots of AH [19]. Meanwhile, trans-p-hydroxycinnamic acid (39), (E)-caffeic acid methyl ester (40), trans-coniferyl aldehyde (41), and trans-sinapaldehyde (42) were retrieved from the stem part of this plant [20].…”

“…Moreover, one latest study reported that another pentacyclic triterpenoid saponin, Eleutheroside K (20), isolated from the leaves of AH, can effectively inhibit the growth of MRSA through down-regulating the expression of PBP2a [35].…”