; YAMASHITA, T.
; FADEL, G.
; DEL BEN, A.
; MACHADO, L.O.
; SEITO, L.N.
; PEREDA, C.V.
; DI STASI, L.C.
Univ Estadual Paulista - UNESP, Department of Pharmacology, Botucatu, SP, Brazil.
Research, Chemyunion Química Ltda. email@example.com
anti-tyrosinase; antioxidant; melanin; skin; medicinal plants
many disorders and aesthetic problems, such as hiperpigmentation and melasma. After ultraviolet exposition,
oxygen and nitrogen reactive species (RONs) are produced and contribute to melanin biosynthesis. RONs
promote DNA lesion and melanocytes proliferation or apoptosis. Therefore, the search for chemical agents
and medicinal plants able to modulate the metabolism of skin pigmentation has been used as an innovative
strategy to develop new products that prevent overproduction of melanin or act as skin-lightening agents.
2.Objective. To perform a pharmacological screening of medicinal plants with anti-tyrosinase and antioxidant
activities in order to select more promissory skin-lightening products.
3.Material and Methods. Plant extracts (40 plants extracts from 28 medicinal plants) were produced by
reflux using methanol/water 1:10. Antioxidant activity was evaluated by the assay of lipid peroxidation in rat
brain membrane and quercertin used as reference drug. Inhibitory effects on tyrosinase activity were assessed
through an enzymatic assay with mushroom tyrosinase and kojic acid used as drug reference. For each
pharmacological activity IC
values were determined and potency relative to reference drug was calculated.
values of 40 extracts were calculated and evaluated, as the power relationship (RP) with
antioxidant and anti-tyrosinase. The best anti-tyrosinase results were RP = 33,3% to Rheum rhapotincum and
RP = 22,2% to Coccoloba uvifera. And the best antioxidant results were RP = 41,1% to Stryphnodendron
barbatiman and RP = 18,9% to Anacardium occidentalis.
5.Conclusions. The most promising plants with anti-tyrosinase activity were Rheum rhapotincum and
Coccoloba uvifera, while Stryphnodendron barbatiman and Anacardium occidentalis were potent antioxidant
products. Other plant species as potential source of skin-lightening products were Schinus terebenthifolius,
Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq
Fundação de Amparo à Pesquisa do Estado de São Paulo - FAPESP