There are three main goals in our study. The first is screening the source of the Tyrosinase inhibitor. The materials included Auricularia polytricha、 Antrodia sp.、Monascus sp.、leaves of Citrus grandis、Pomegranate、leaves of Avocado、Black sesame、leaves of Calamondin、peel of Pitaya、and Lycium seed oil. The result of the first part of experiment indicated that pomegranate extracts showed the highest tyrosinase inhibitory activity. The second is exploring the extraction conditions of Pomegranate including temperature, extract solvents, extract time and inhibition of tyrosinase by extract concentrations. The results indicated that the extracts of Pomegranate peel could reach the best inhibition effect at 90℃(86%) from the temperature ranges via ambient temperature to 90℃; however, the extracts of Pomegranate seeds showed the best inhibition at 80℃(56%) from the same temperature range. Different combinations between extraction solvents (i.e., water, ethanol, methanol, hexane, and ethyl acetate) and testing materials exhibited different extraction efficiency in terms of inhibitory effect on tyrosinase activity. For instance, the extract of pomegranate peel showed better inhibition effect in the solvents of water, ethanol and methanol. The extract of pomegranate seeds exert better inhibition in the 3 solvent of water. In terms of durance of extraction from 15 minutes to 5 hours, two hours was the best for pomegranate peels to show best inhibitory effect; while in the case of pomegranate seeds, it was 1 hour (55%). In order to determine threshold amount of material, which could have best performance in the tyrosinase inhibition, the amount of testing materials was set at 10 to 100mg per milliliter. In the case of pomegranate peels and seeds, 50mg/ml was the best quantity for extraction. The third is to evaluate the potential inhibition effect of pomegranate on the acne pathogens. The results indicated that water and ethanol extracts exhibited certain antibiotic activativities on Staphylococcus aureus; while water、ethanol and methanol extracts had better antibiotic response to Propionibacterium acnes.a
