Antioxidant & antibacterial activities of hylocereus polyrhizus peels / Adriana Azmina Nisa Ibrahim

Hylocereus polyrhizus peels have been suggested to contain medicinal value in terms of antioxidant and antibacterial effects. Since, there are few and outdated research about antioxidant and antibacterial activity of red dragon fruit peels extract can be found in Malaysia thus, a newly study was carried out to complement the previous research. In this experiment, the Hylocereus polyrhizus peels extract were prepared using maceration technique. 80% methanol was used as the extracting solvent. The extraction yield about 2.5% of Hylocereus polyrhizus peels crude extract which was obtained using a hot plate. The crude extract were then run through 2,2-diphenyl-1picrylhydrazyl (DPPH) assay. Through the antioxidant test, results revealed the highest % of radical scavenging activity of red dragon fruit peels at the concentration of 100 μg/ml (71.047%). However, a better antioxidant activity was shown by a standard ascorbic acid. In Disc-diffusion test, ampicillin antibiotic was used as positive control while the 5% DMSO was used as negative control. Antibacterial activity of Hylocereus polyrhizus peels extract was examined at 20, 60 and 100 μg/ml concentrations against Bacillus licheniformis, and Escherichia coli. E.coli exhibit inhibition zone with measurement range of 11 mm (20 μg/ml), 13 mm (60 μg/ml) and 12 mm (100 μg/ml), suggesting a strong antibacterial activity. Overall, it can be concluded that Hylocereus polyrhizus peels can be further utilised for its natural antioxidant and antibacterial content.