Preliminary screening of 44 plant extracts for anti-tyrosinase and antioxidant activities.

In order to find new tyrosinase inhibitors and antioxidant materials, we investigated 44 plants, which were evaluated for the anti-tyrosinase and antioxidant activities. The mushroom tyrosinase inhibition assay and 2, 2-Diphenyl-1- picrylhydrazyl (DPPH) radical scavenging assay were conducted to evaluate these activities. Among all tested plant extracts, Morus alba L. (positive control), Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba, Momordica charantia L., Cuminum cyminum L. et al. exhibit higher tyrosinase inhibition. Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba, Rosa rugosa Thunb. and Eugenia caryophyllata Thunb. perform the highest antioxidant activity, similar to vitamin C (the positive control). A low positive correlation is found in the DPPH radical scavenging and tyrosinase inhibition assay. Considering these factors, the extracts of Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba, Alpinia officinarum Hance and Zanthoxylum bungeanum Maxim. exhibit high anti-tyrosinase and antioxidant activities and could be used in the cosmetic industry. Further studies are warranted to characterize the compounds responsible for the anti-tyrosinase and antioxidant properties of these plant extracts.