Antioxidant Properties and Antimicrobial Effect of Zingiber officinale Extract towards Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa

Abstract

Bacterial infection and emergence of multi-drug resistant bacteria have been a great obstacle in today's medicine development. Emergence of multi-drug resistant bacteria strains reduces the efficiency of currently available antimicrobial agents. Besides, oxidative stress, which is commonly correlated to numerous amounts of diseases also need to be tackled. Previous studies found that consumption of food containing natural antioxidant may help in reducing the risk of death-threatening diseases. Therefore, this study aimed to discover potential antioxidant and antimicrobial activity of Zingiber officinale against pathogenic bacteria strains such as E. coli, S. aureus and P. aeruginosa. Z. officinale rhizome ethanol extract was tested for antimicrobial activity through well diffusion method. Antioxidant property of the extract was tested using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) method. According to the findings on antimicrobial assay, Z. officinale able to inhibit S. aureus and P. aeruginosa while E. coli remain resistant against ginger extract. At the concentration of 80 to 100mg/ml of ginger extract, the mean zone of inhibition against S. aureus ranged from 11mm to 15mm. Meanwhile, at concentration of 5 to 100mg/ml of extract, the inhibition zone of P. aeruginosa, ranged from 40mm to 64mm (±9mm). Additionally, IC50 value for Z. officinale extract is 0.4623μg/ml compared to ascorbic acid with IC50 value of 4.1602μg/ml. It is evident that Z. officinale has higher antioxidant property than ascorbic acid. Present findings and data gained through this study can be used to boost the application of natural or plant-based products in medicine to combat the emergence of drug-resistant bacteria.