Evaluation of antioxidant and antibacterial activity of Hordeum vulgare methanolic extract / Nur Faizah Mohamad

Nowadays, not much attention has been given to whole grains as a natural medicines eventhough they possess the antioxidant and antimicrobial properties. The aim of this study is to determine the antioxidant level of the H. vulgare extract as well as to evaluate their antimicrobial activity. The quantification of total phenolic content and total flavonoid content of the methanolic extract of H. vulgare was determined using the Folin-Ciocalteu and aluminium chloride methods while the antimicrobial activity was determined by agar well diffusion assay. The concentration of methanolic extract used were 50 mg/ml, l 00 mg/ml, 250 mg/ml and 500 mg/ml. From the result, the phenolic content ranges from 0.010 ± 0.001 mg GAE/g (lowest concentration is 50 mg/ml) to 0.182 ± 0.062 mg GAE/g (highest concentration is 500 mg/ml) while the flavonoid content ranges from 0.479 ± 0.005 mg QE/g at the concentration 50 mg/ml to 1.585± 0.194 mg QE/g at the concentration of 500 mg/ml. For antimicrobial activity, the inhibition zones of E. coli ranges from 9.67 mm to 15.67 mm, while S. aureus ranges from 5.33 mm to 18.33 mm and Klebsiella sp. ranges from 13.00 mm to 16.33 mm at different concentration starting from 50 mg/ml up to 500 mg/ml. However, the positive control which is the Tetracycline showed inhibition zones ranging from 17.00 mm to 19.67 mm. Meanwhile, the negative control DMSO showed no inhibition zones at all. In conclusion, H. vulgare methanolic extract was able to show antioxidant and antimicrobial activity against pathogenic bacteria tested.