Background : In this study, we have examined antioxidative effects and antimicrobial activity of methanol extracts of several plant resources (three varieties of Asimina triloba L., Momordica charantia L., Psidium guajava L. and Alium ampeloprasum L.)
Methods and Results : The antioxidant activities were assayed by five methods based on total polyphenol and flavonoid contents, scavenging of DPPH, ABTS and reducing power analysis. Total polyphenol contents was the highest in Psidium guajava and Mango, the varieties of Asimina triloba as the contents of 95.85, 95.81 ㎎/g, respectively. Total flavonoid content was the highest in Psidium guajava (54.3 ㎎/g). DPPH free radical scavening activity of all extracts was ranged from 10.5 - 85.8%, and significantry great activities was found at Psidium guajava leaf. Methanol extracts of Psidium guajava and Asimina triloba showed showed greater ABTS scavening activities compared to others. Reducing power of all extracts was linearly proportional to the concentration. Especially, the extracts of Psidium guajava and three varieties of Asimina triloba showed greater reducing power than that of other resources. The antimicrobial activities of extracts were tested by paper disc assay and minimum inhibitory concentration test. Antimicrobial activity of Psidium guajava leaf extract was shown relatively high activity against all investigated strains.
Conclusion : The results suggest that Psidium guajava leaf extract be a new functional cosmetic ingredient with antioxidant effect and antimicrobial activity.