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.