Effectiveness and mechanism of Zingiber officinale var. rubrum (red ginger) ethanol extract as an inhibitor of Escherichia coli and Staphylococcus aureus

Abstract

Escherichia coli and Staphylococcus aureus are bacteria responsible for infectious diseases worldwide. With increasing cases of antibiotic resistance due to current medical developments, there is a growing need to explore alternative substances with bactericidal or bacteriostatic properties, including those derived from natural sources. Zingiber officinale var. rubrum (red ginger) is known for its medicinal properties, particularly its antibacterial effects. This study aimed to evaluate the ability of red ginger to inhibit the growth of E. coli and S. aureus. Phytochemical tests were done to identify the active compounds in the extract, while antibacterial activity was assessed using the minimum inhibitory concentration (MIC). The mechanism of antibacterial action was investigated with a spectrophotometer and scanning electron microscope (SEM). The results revealed that the red ginger extract contains active compounds such as alkaloids, flavonoids, saponins, tannins, and terpenoids. The minimum inhibitory concentrations were 125 μg/ mL for E. coli and 500 μg/mL for S. aureus, respectively. The addition of red ginger ethanol extract at MIC 1 and MIC 2, measured at an absorbance of 260 nm and 280 nm, significantly affected cell leakage compared to the control (p<0.01). SEM analysis showed that bacterial cells treated with red ginger extract appeared damaged and vacuolated. Therefore, it can be concluded that red ginger extract has an inhibitory effect on the growth of E. coli and S. aureus, and may be recommended as an alternative to natural antibiotics for treating infectious diseases.