arbutin and glycolic-acid

Resveratrol is known to inhibit cellular melanin synthesis by multiple mechanisms. Glycolic acid (GA) is used in skin care products for its excellent skin penetration. The purpose of this study was to examine the anti-melanogenic effects of resveratryl triglycolate (RTG), a novel hybrid compound of resveratrol and GA, in comparison with resveratrol, GA, resveratryl triacetate (RTA) and arbutin. Resveratrol, RTG, and RTA inhibited the catalytic activity human tyrosinase (TYR) more potently than arbutin or GA did. Their cytotoxic and anti-melanogenic effects were examined using murine melanoma B16/F10 cells and human epidermal melanocytes (HEMs). The cytotoxicity of RTG was similar to that of resveratrol and RTA. RTG at 3-10 μM decreased melanin levels and cellular TYR activities in α-melanocyte-stimulating hormone-stimulated B16/F10 cells, and L-tyrosine-stimulated HEMs. RTG also suppressed mRNA and protein expression of TYR, tyrosinase-related protein 1, L-3,4-dihydroxyphenylalanine chrome tautomerase, and microphthalmia-associated transcription factor (MITF) in HEMs stimulated with L-tyrosine. This study suggests that, like resveratrol and RTA, RTG can attenuate cellular melanin synthesis effectively through the suppression of MITF-dependent expression of melanogenic enzymes and the inhibition of catalytic activity of TYR enzyme. RTG therefore has potential for use as a cosmeceutical ingredient for skin whitening.

Topics: alpha-MSH; Animals; Arbutin; Cell Culture Techniques; Cell Line, Tumor; Enzyme Inhibitors; Epidermal Cells; Esterification; Glycolates; Humans; Intramolecular Oxidoreductases; Keratolytic Agents; Melanins; Melanocytes; Membrane Glycoproteins; Mice; Microphthalmia-Associated Transcription Factor; Monophenol Monooxygenase; Oxidoreductases; Resveratrol; Stilbenes

Exposure of skin cells, particularly keratinocytes to various nuclear factor-kappaB (NF-kappaB) activators (e.g. tumor necrosis factor-alpha, interleukin-1, lipopolysaccharides, and ultraviolet light) leads to phosphorylation and degradation of the inhibitory protein, IkappaB. Liberated NF-kappaB is translocated into the nucleus where it can change or alter expression of target genes, resulting in the secretion of extracellular signaling molecules including melanotrophic factors affecting melanocyte.. In order to demonstrate the possible role of NF-kappaB activation on the synthesis of melanotrophic factors from the keratinocytes, the activities of NF-kappaB induced by melanogenic inhibitors (MIs) were determined in human HaCaT keratinocytes transfected with pNF-kappaB-SEAP-NPT plasmid. Transfectant cells released the secretory alkaline phosphatase (SEAP) as a transcription reporter in response to the NF-kappaB activity and contain the neomycin phosphotransferase (NPT) gene for the dominant selection marker for geneticin resistance.. MIs such as niacinamide, kojic acid, hydroquinone, resorcinol, arbutin, and glycolic acid were preincubated with transfectant HaCaT cells for 3 h and then ultraviolet B (UVB) was irradiated. NF-kappaB activation was measured with the SEAP reporter gene assay using a fluorescence detection method.. Of the MIs tested, kojic acid (IC(50)=60 microM) was found to be the most potent inhibitor of UVB-upregulating NF-kappaB activation in transfectant HaCaT cells, which is followed by niacinamide (IC(50)=540 microM). Pretreatment of the transfectant HaCaT cells with the MIs, especially kojic acid and niacinamide, effectively lowered NF-kappaB binding measured by electrophoretic mobility shift assay. Furthermore, these two inhibitors remarkably reduced the secretion level of IL-6, one of melanotrophic factors, triggered by UV-radiation of the HaCaT cells.. These observations suggest that MIs working at the in vivo level might act partially through the modulation of the synthesis of melanotrophic factors in keratinocyte.

Topics: Arbutin; Cell Line; Glycolates; Humans; Hydroquinones; Keratinocytes; NF-kappa B; Niacinamide; Pyrones; Recombinant Proteins; Resorcinols; Transfection; Ultraviolet Rays

A novel series of hybrid L-ascorbic acid (vitamin C) phosphodiesters linked at the C-2 hydroxyl group with other biologically active substances, namely myo-inositol, arbutin, 4-hydroxy-L-proline, and glycolic acid were synthesized, and their thermal stability and reducing activity against free radicals were estimated in vitro. All of the phosphodiesters exhibited high thermal stabilities; however, their antioxidant activities in vitro were generally lower than that of vitamin C.

Topics: Antioxidants; Arbutin; Ascorbic Acid; Bepridil; Biphenyl Compounds; Esters; Free Radicals; Glycolates; Hydroxyproline; Inositol; Magnetic Resonance Spectroscopy; Molecular Structure; Oxidation-Reduction; Phosphorylation; Picrates; Temperature