Manassantin A inhibits cAMP-induced melanin production by down-regulating the gene expressions of MITF and tyrosinase in melanocytes

College of Pharmacy, Yeungnam University, Kyungsan, Korea College of Pharmacy, Chungbuk National University, Cheongju, Korea College of Pharmacy, Chungnam National University, Daejeon, Korea.
Experimental Dermatology (Impact Factor: 3.76). 05/2011; 20(9):761-3. DOI: 10.1111/j.1600-0625.2011.01296.x
Source: PubMed


Microphthalmia-associated transcription factor (MITF) is inducible in response to cAMP through the cAMP-responsive element-binding protein (CREB) and plays a pivotal role in the melanocyte-specific expression of tyrosinase or tyrosinase-related proteins (TRPs) for melanin biosynthesis. Manassantin A from Saururus chinensis inhibits cAMP-induced melanin production in B16 melanoma cells. Here, we focused on molecular basis of the antimelanogenic activity. Manassantin A consistently inhibited the cAMP elevator 3-isobutyl-1-methylxanthine (IBMX)- or dibutyryl cAMP-induced melanin production in B16 cells or in melan-a melanocytes by down-regulating the expression of tyrosinase or TRP1 gene. Moreover, manassantin A suppressed MITF induction through IBMX-activated CREB pathway, directly inhibiting the Ser-133 phosphorylation of CREB. However, manassantin A did not affect IBMX-increased cAMP levels in these cells but also other cAMP-dependent melanogenic pathways through post-translational modifications of MITF. This putative molecular mechanism of manassantin A in the inhibition of melanin production suggests its pharmacological potential in skin hyperpigmentation.

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Available from: Jong Keun Son, Oct 20, 2014
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    • "Although the detailed mechanism underlying this effect remains elusive, it was hypothesized that manassantin A affects expression of genes regulatory for HIF-1α accumulation. Indeed, manassantin A has been reported to affect expression of a variety of genes (e.g., ICAM-1, MITF), and is also known to suppress the NF-κB transcriptional activity [23], [24]. Interestingly, manassantin A was also reported to inhibit activation of multiple signaling pathways such as pathways mediated by ERK, p38, JNK and STAT3 [25], [26]. "
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    ABSTRACT: The dineolignan manassantin A from Saururaceae was recently identified as a hypoxia-inducible factor 1 (HIF-1) inhibitor, but its in-vivo anti-tumor effect has not been explored. We synthesized a series of manassantin A derivatives, and found that replacing the central tetrahydrofuran moiety with a cyclopentane ring yielded a compound (LXY6006) with increased HIF-1-inhibitory activity yet decreased stereochemically complexity amenable to a simplified synthesis scheme. LXY6006 inhibited HIF-1α nuclear accumulation induced by hypoxia, and inhibited cancer cell growth as a consequence of G2/M arrest. Oral administration of LXY6006 significantly inhibited growth of breast, lung, and pancreatic tumors implanted in nude mice. These results indicate that LXY6006 represents a novel class of agents targeting a broad range of human cancers.
    PLoS ONE 06/2014; 9(6):e99584. DOI:10.1371/journal.pone.0099584 · 3.23 Impact Factor
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    ABSTRACT: Uneven skin pigmentation is a significant cosmetic concern, and the identification of topically applicable molecules to address this issue is of general interest. We report that the tetrapeptide PKEK (Pro-Lys-Glu-Lys) can exert skin whitening effects based on one in vitro and four double-blinded vehicle-controlled in vivo studies. (i) Treatment of human keratinocytes with PKEK significantly reduced UVB-stimulated mRNA expression of interleukin (IL)-6, IL-8 and TNF-α and, most importantly, proopiomelanocorticotropin (POMC), i.e. a gene encoding the pigmentation-inducing soluble mediator α- (α-MSH). (ii) PKEK treatment significantly inhibited UVB-induced upregulation of genes encoding for IL-1α, IL-6, IL-8, TNF-α as well as POMC and tyrosinase in 10 healthy volunteers pretreated with PKEK for 4 weeks once daily. (iii) In a study enrolling 39 Caucasian women, facial pigment spots significantly faded after 6 weeks when PKEK was combined with the skin whitener sodium ascorbyl phosphate (SAP), whereas PKEK or SAP alone led to less pronounced fading of the pigment spots. (iv) Addition of PKEK enhanced the skin whitening potency of a SAP-containing preparation if applied for 8 weeks to the back of hands of 19 Caucasians. (v) 27 Japanese women were treated on their faces twice daily with an SAP only or a PKEK+SAP-containing formulation for 8 weeks. Application of PKEK+SAP significantly reduced skin pigmentation by 26% and by 18% according to SCINEXA score. We demonstrate that PKEK has the capacity to reduce UVB-induced skin pigmentation and may be suited to serve as a skin tone-modulating agent in cosmetic products.
    Experimental Dermatology 11/2011; 21(2):140-6. DOI:10.1111/j.1600-0625.2011.01415.x · 3.76 Impact Factor
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    ABSTRACT: Objectives : The purpose of this study was to investigate the melanogenesis inhibition effect of Saururus chinensis BAILL (SC) on in B16F10 melanoma cells. Methods : SC was fractionated ethanol extract by the hexane, ethyl acetate, butanol and water. We confirmed the inhibitory effect of tyrosinase activity and melanogenesis of all fraction samples. Results : Hexane fraction of Saururus chinensis BAILL (HSC), ethyl acetate of SC (ESC), and butanol of SC (BSC) were discovered to inhibit tysoinase activity and melanogenesis in the absence or presence of -MSH. However, water fraction of SC (WSC) did not affect tyrosinase activity and melanogenesis. In addition, all fractions did not inhibit the catalytic activity of cell-free tyrosinase from B16F10 melanoma cell lines. Conclusions : These results suggest that HSC, ESC and BSC reduce pigmentation by indirectly regulating tyrosinase.
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