Antibacterial Activity of Anthraquinones Isolated from Reynoutria Japonica Against Staphylococcus aureus: An in Silico and In Vitro Approach

Abstract

Staphylococcus aureus (S. aureus) is an opportunistic pathogen, which is listed among bacteria of immediate concern by World Health Organization (WHO). Alternative treatment options are needed to control the infections caused by S. aureus because the level of antibiotic resistance has reached to the alarming level with the currently available treatment methods. Therefore, the current study was designed to check the antibacterial activity of anthraquinones i.e. citreorosein, emodin, physcion, emodin-1-O-beta-D-glucoside, emodin-8-O-beta-D-glucoside and physcion-8-O-beta-D-glucoside extracted from Reynoutria japonica (R. japonica) against the clinical isolates of S. aureus. Antibacterial activity of the isolated compounds was determined using minimum inhibitory concentration (MIC) method. Among all anthraquinones, citreorosein, emodin and physcion displayed the promising growth inhibitory activity against Methicillin Sensitive S. aureus (MSSA) and Methicillin Resistant S. aureus (MRSA). In addition, a molecular docking study revealed high binding ability of citreorosein and emodin to the active site of DNA gyrase protein of the bacteria. Furthermore, we checked the major and minor constituents in roots R. japonica and revealed that the most potent compounds were the major constituents. These findings advance our knowledge of R. japonica potential as a functional food and popular herbal remedy.