Callicarpa longissima extract, carnosol-rich, potently inhibits melanogenesis in B16F10 melanoma cells

Abstract

Cosmetic industries focus on developing materials and resources that regulate skin pigmentation. Melanin, the major pigment in human skin, protects the skin against damage from ultraviolet light. An ethanolic extract of the leaves of Callicarpa longissima inhibits melanin production in B16F10 mouse melanoma cells by suppressing microphthalmia-associated transcription factor (MITF) gene expression. Following purification and analysis using liquid chromatography-mass spectrometry (LC-MS), NMR, and biochemical assays, carnosol was determined to be responsible for the major inhibitory effect of the C. longissima extract on melanin production. Carnosol is an oxidative product of carnosic acid, whose presence in the extract was also confirmed by an authentic reference. The carnosol and carnosic acid content in the extract was approximately 16% (w/w). These results suggest that C. longissima is a novel, useful, and attractive source of skin-whitening agents.

The Importance of 11α-OH, 15-oxo, and 16-en Moieties of 11α-Hydroxy-15-oxo-kaur-16-en-19-oic Acid in Its Inhibitory Activity on Melanogenesis

“…Melanin measurement was performed as described previously [14]. Briefly, the cells were washed twice with phosphate-buffered saline and were recovered in 2-mL collection tubes, followed by centrifugation at 8,000 rpm for 1.5 min.…”

“…Quantitative real-time PCR analysis, including primer sets, has been described previously [14]. Briefly, total RNA was extracted using an EZ1 RNA Universal Tissue Kit (Qiagen, The Netherlands), and cDNA was synthesized using a ReverTra Ace qPCR RT Master Mix (Toyobo, Osaka, Japan).…”

“…The pGL3-mouse tyrosinase promoter and mouse MITF overexpression vectors have been described previously [14]. To prepare the 3× M-box-luciferase vector, 2 complementary nucleotides (5′-CGC GAA AAG TCA GTC ATG TGC TTT TCA AAA GTC AGT CAT GTG C TT TTC AAA AGT CAG TCA TGT GCT TTT C and 5′-GAT CGA AAA GCA CAT GAC TGA CTT TTG AAA AGC ACA TGA CTG ACT TTT GAA AAG CAC ATG ACT GAC TTT T) were annealed at room temperature.…”

“…In turn, MITF binds to the tyrosinase promoter and upregulates the expression of this gene. We have recently identified carnosol and canosic acid from Callicarpa longissima as candidates for skin whitening reagents that act by targeting MITF expression [14]. …”

Diterpenes and Their Derivatives as Potential Anticancer Agents

“…This diterpene also inhibited multiple myeloma cells via the TLR4/NF‐κB signalling pathway (Gao and Wang, ) and is evident to suppress the melanin content and TYR activity by decreasing GSK3β‐dependent Akt; microphthalmia‐associated transcription factor (MITF) and TYR family and promoting the degradation of β‐catenin in B16F10 cells, HEM cells and UVB‐induced brown guinea pig skin (Zhu et al , ). In a study, the diterpene carnosol isolated from C. longissima was found to suppress the MITF gene expression in B16F10 mouse melanoma cells (Yamahara et al , ).…”