No abstract

These results suggest that HEGG inhibition relates to its tyrosinase activity. Therefore, the hydroalcoholic extract of Garcinia gardneriana shows great potential for use as a depigmenting agent in hyperpigmentation disorders.

Garcinia gardneriana is popularly used in skin disorders; therefore, this article investigated the effect of G. gardneriana extracts from leaves, bark and seeds and two isolated compounds in ear oedema and leucocytes migration caused by croton oil. The topical application of the extract of G. gardneriana leaves was able to reduce (70 € 3%, and ID 50 0.33 mg ⁄ ear) ear oedema, while the seeds (51 € 5%) and the wood (60 € 12%) extracts were less effective. In a time-course evaluation, the leaf extract (1 mg ⁄ ear) was effective when applied 2 hr before and until 3 hr after the stimulation, presenting a higher effectiveness when applied right after croton oil (83 € 7% inhibition). In addition, the leaf extract was able to diminish the myeloperoxidase (MPO) activity in 64 € 13%, which suggests the inhibition of leucocyte infiltration that was confirmed by histological analysis. Also, both biflavonoids isolated from the leaves of G. gardneriana, fukugetin (or morelloflavone) and 13-naringenin-II 8-eriodictyol (GB-2a), were able to reduce ear oedema, with ID 50 values of 0.18 (0.10-0.28) and 0.22 (0.15-0.31) mg ⁄ ear, respectively, besides the inhibition of MPO activity of 52 € 6% and 64 € 5%, respectively. Using the fluorescent probe 2¢,7¢-dichlorodihydrofluorescein diacetate, the leaf extract, fukugetin and GB-2a topically applied to the ear treated with croton oil reduced 52 € 15%, 63 € 17% and 83 € 4%, respectively, the production of reactive oxygen species of the skin. Thus, these results reveal the anti-inflammatory effect of G. gardneriana leaves for topical usage, and both biflavonoids are responsible for this effect.

The leaves and flowers extracts of P. venusta stimulates B16F10 melanogenesis at very low concentrations. These findings support the folk medicinal use of P. venusta on the treatment of hypopigmentation diseases, such as vitiligo.

Taken together, these results suggest that the extract from flowers of Combretum leprosum could be considered as a new potential tool for the treatment of several skin inflammatory diseases since it reversed the skin inflammatory and hyperproliferative process in a very significant manner. Further investigations are needed in order to verify the cellular mechanism and safety of Combretum leprosum extract.