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Rhus tripartitum(Ucria) Grande leaves and fruits were investigated for their contents in phenolic compounds, essential oils, and fatty acids. Chemical composition and antioxidant potential of these secondary metabolites were investigated using chromatographic tools and different antioxidant tests. Results displayed high amounts of phenolic compounds in leaves, concomitant with important antioxidant potentialities, probably due to their richness in phenolic acids and flavonoids as identified by reverse phase high performance liquid chromatography (RP-HPLC). Amounts of essential oils were higher in leaves. Oxygenated sesquiterpenes are exclusively synthesized by the fruits, expressing better antioxidant activities.

Hypopigmentation diseases are usually managed using UVB light which increases the patients' risk for skin cancer. Here, we evaluated the melanogenesis stimulatory effects of leaf extracts of Erica multiflora, a medicinal plant from the Mediterranean region, and its active component, lup-20 (29)-en-3-one, as possible therapeutic agents to address hypopigmentation disorders. B16 murine melanoma cells were treated with E. multiflora extracts or its active component lupenone to evaluate their effects on melanin biosynthesis. The mechanism underlying the observed effects was also determined. Bioactivity-guided fractionation of fifteen ethyl acetate fractions identified fraction 2 to have melanogenesis stimulatory effects due to its ability to decrease mitogen-activated protein kinase phosphorylated extracellular signal- regulated kinases 1 and 2 activation. Preparative TLC of ethyl acetate fraction 2 revealed the presence of lup-20(29)-en-3-one as the major bioactive component. B16 cells treated with lup-20(29)-en-3-one increased melanin content without cytotoxicity. To determine the mechanism for the observed effects of lup-20(29)-en-3-one, the tyrosinase enzyme activity, the tyrosinase protein expression, and the activation of phosphorylated extracellular signal-regulated kinases 1 and 2 were determined. In addition, the expression of the tyrosinase mRNA was quantified using real-time PCR. Results showed that lup-20(29)-en-3-one has no effect on the tyrosinase enzyme activity but can increase tyrosinase expression at both the transcriptional and translational levels. The increase in the tyrosinase mRNA expression was most likely due to the inhibited mitogen-activated protein kinase phosphorylated extracellular signal-regulated kinases 1 and 2 activation. We report for the first time that E. multiflora ethyl acetate extract and its active compound lup-20(29)-en-3-one stimulate melanogenesis by increasing the tyrosinase enzyme expression via mitogen-activated protein kinase phosphorylated extracellular signal-regulated kinases 1 and 2 phosphorylation inhibition, making it a possible treatment for hypopigmentation diseases. [ABSTRACT FROM AUTHOR]