OBJECTIVETo investigate the interference effect of nicotinamide on UVA-induced melanin genesis and melanin transport in human skin melanocyte.

METHODSThe optimum UVA dose expected to cause cell proliferation: 0.2 J/cm(2), nicotinamide was added immediately after the 0.2 J/cm(2) UVA exposure and the melanin content, cell cycles, cell apoptosis and mRNA express level were measured respectively.

RESULTSMelanin content in melanocytes was increased significantly after exposed to 0.2 J/cm(2) UVA. Melanin content in melanocytes was decreased after treatment with 10.0 mmol/ml nicotinamide following UVA exposure, but the cell cycles and the cell apoptosis rate were not significantly altered. mRNA express levels of TYR, TRP-1 were modulated by nicotinamide.

CONCLUSIONNicotinamide has more effect on decreasing melanin genesis after UVA exposure, nicotinamide also plays a role in modulating the mRNA express of TYR, TRP-1 gene. It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.

Cells, Cultured ; Humans ; Melanins ; biosynthesis ; Melanocytes ; drug effects ; metabolism ; radiation effects ; Niacinamide ; pharmacology ; Ultraviolet Rays ; adverse effects

OBJECTIVETo study the effects of aloesin and arbutin on normal cultured human melanocytes in synergetic method.

METHODSBuilding up the system of cultured human melanocytes. The cultured melanocytes in vitro were treated with the mixture of aloesin and arbutin. The cell viability and tyrosinase activity was measured by MTT assay, utilization of L-Dopa as the substrate respectively; melanin content was measured by image analysis system. Furthermore, the effects of the mixture on melanocytes were compared with that of aloesin and arbutin.

RESULTSThe mixture of aloesin and arbutin showed an inhibition on tyrosinase activity of human melanocytes and reduced significantly melanin content. Between the mixture and the single use of aloesin or arbutin, there is significant difference (P < 0.05). On the other hand, the mixture has little influence on melanocytes viability and there is negative significance.

CONCLUSIONThe mixture of aloesin and arbutin can significantly inhibit the tyrosinase activity and melanogenesis of cultured human melanocytes. It showed the effects of aloesin and arbutin in a synergistic manner. It is worth to give farther study later.

Arbutin ; pharmacology ; Cells, Cultured ; Chromones ; pharmacology ; Dose-Response Relationship, Drug ; Drug Synergism ; Glucosides ; pharmacology ; Humans ; Melanocytes ; cytology ; drug effects ; metabolism ; Monophenol Monooxygenase ; drug effects ; metabolism

OBJECTIVETo investigate the effects of 8-methoxypsoralen on human melanocytes [Ca(2+)]i and cytoskeleton actin organization in vitro.

METHODSHuman melanocytes were obtained from normal foreskins. Laser confocal microscope was employed to measure [Ca(2+)]i and rhodamine-conjugated phalloidin was used to visualize the cytoskeleton actin.

RESULTS8-methoxypsoralen increased [Ca(2+)]i and induced organization of actin stress fiber cytoskeleton.

CONCLUSION8-methoxypsoralen might influence the migration of melanocytes by increasing the intracellular free Ca(2+) concentration and cytoskeleton actin reorganization.

Actins ; biosynthesis ; genetics ; Calcium ; metabolism ; Cell Movement ; drug effects ; Cells, Cultured ; Cytoskeletal Proteins ; biosynthesis ; genetics ; Humans ; Melanocytes ; cytology ; drug effects ; metabolism ; Methoxsalen ; pharmacology ; Skin ; cytology

OBJECTIVETo investigate the effects of Liuweidihuang Decoction on the proliferation and melanin synthesis of cultured human melanocytes in vitro.

METHODSMTT assay was used to assess the proliferation of cultured human melanocytes after treatment with Liuweidihuang Decoction, and NaOH assay was employed to determine melanin synthesis.

RESULTSLiuweidihuang Decoction at the concentration of 5%-15% did not affect the proliferation of the melanocytes (P>0.05), and the decoction at 20%-30% significantly inhibited the cell proliferation, especially at the optimal concentration of 30% (P<0.01). The decoction promoted melanin synthesis in the melanocytes at the concentration of 10%-15% with the optimal concentration of 15% (P<0.01) but failed to produce such an effect at 20%-30%.

CONCLUSIONLiuweidihuang Decoction exert a two-way regulation on the proliferation and melanin synthesis of cultured human melanocytes in vitro.

Cell Proliferation ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Melanins ; biosynthesis ; Melanocytes ; cytology ; drug effects ; metabolism

OBJECTIVETo investigate the effects of Liuwei Dihuang (LWDH) decoction on serotonine (5-HTs), melatonin and the activity of the rate-limiting enzymes ANNAT and HIOMT in cultured human melanocytes and in melanocytes co-cultured with keratinocytes.

METHODSCCK-8 assay was used to assess the proliferation of melanocytes and melanocytes co-cultured with keratinocytes after treatment with the serum from rabbits fed with LWDH decoction. High-performance liquid chromatography was used to determine 5-HT and melatonin contents, and real-time fluorescent PCR was employed to evaluate the ANNAT and HIOMT activities in the cell cultures.

RESULTSThe serum from rabbits fed with LWDH Decoction at low doses did not affect the proliferation of melanocytes co-cultured with keratinocytes, but at the concentrations of 20%-40%, the serum significantly inhibited the proliferation of melanocytes, and the effect was optimal with a concentration of 40% (P<0.05). 5-HT and melatonin contents in the cell culture decreased as the serum concentration increased (P<0.05), which was the most obvious with a serum concentration of 40% (P<0.01). Exposure of the cells to low and moderate doses of the serum caused a dose-dependent decrease in AANAT activity (P<0.05), but the serum produced no significant changes in the level of HIOMT mRNA expression in the cells.

COUCLUSIONSThe serotoninergic/melatoninergic system mediate the regulation of melanin metabolism by LWDH Decoction, the mechanism of which may involve 5-HTs, melatonin and ANNAT.

Animals ; Cells, Cultured ; Coculture Techniques ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Keratinocytes ; Melanins ; metabolism ; Melanocytes ; drug effects ; metabolism ; Melatonin ; metabolism ; Rabbits ; Serotonin ; metabolism ; Serum ; chemistry

OBJECTIVETo observe the effect of Tribulus terrestris extract on melanocyte stimulating hormone (MSH) expression in C57BL/6J mouse hair follicles, and investigate the role of Tribulus terrestris extract in activation, proliferation, epidermal migration of dormant hair follicle melanocytes.

METHODSThe aqueous extract of Tribulus terrestris was administered orally in specific pathogen-free C57BL/6J mouse at the daily dose equivalent to 1 g/1 kg in adult human, and the expression and distribution of MSH in the mouse hair follicles was observed with immunohistochemistry.

RESULTSThe positivity rate of MSH expression in the hair follicle melanocytes was 75% in mice treated with the extract, significantly higher than the rate of only 18.75% in the control group (P<0.01).

CONCLUSIONThe aqueous extract of Tribulus terrestris can significantly increase MSH expression in the hair follicle melanocytes by activating tyrosinase activity and promoting melanocyte proliferation, melanine synthesis, and epidermal migration of dormant melanocytes.

Administration, Oral ; Animals ; Cell Proliferation ; drug effects ; Female ; Hair Follicle ; cytology ; drug effects ; metabolism ; Immunohistochemistry ; Melanocyte-Stimulating Hormones ; biosynthesis ; Melanocytes ; cytology ; drug effects ; metabolism ; Mice ; Mice, Inbred C57BL ; Plant Extracts ; administration & dosage ; pharmacology ; Random Allocation ; Tribulus ; chemistry

BACKGROUNDTopical tacrolimus has been used for vitiligo as a common treatment option for more than ten years while the underlying mechanism is still uncertain. The aim of this study was to investigate the direct effects of tacrolimus on the melanogenesis and migration on human A375 melanoma cells. The expression of c-KIT mRNA and protein of human A375 cells were also investigated.

METHODSThe cultured A375 human melanoma cells were randomly assigned to control and tacrolimus treatment groups (10, 10(2), 10(3) and 10(4) nmol/L). The cell proliferation was measured with Cell Counting Kit-8 assays. Melanin content was measured with NaOH method. Transwell migration assay was used to measure cell migration. The expression of c-KIT mRNA and protein were measured with real-time fluorescence quantitative polymerase chain reaction and immunohistochemistry respectively.

RESULTSThe cell proliferation of the 10(3) and 10(4) nmol/L tacrolimus groups were significantly lower (0.666 ± 0.062 and 0.496 ± 0.038) as compared with the control (0.841 ± 0.110, P < 0.05). The mean melanin content in all groups treated with different concentration of tacrolimus (10, 10(2), 10(3), 10(4) nmol/L) increased compared with the control group (P < 0.05). Dose-dependent increase in cell migration were seen in all tacrolimus-treated groups (P < 0.01). The expression of c-KIT mRNA level in A375 cells exposed to tacrolimus (10(3) and 10(4) nmol/L) had significantly increased by 3.03-fold and 3.19-fold respectively compared with the control (P < 0.05).

CONCLUSIONSAlthough tacrolimus had no effects on cell proliferation on A375 human melanoma cells, it could increase the melanin content and cell migration. The expression of c-KIT mRNA and protein increased dose-dependently in tacrolimus-treated groups as compared with the control. Our study demonstrated that tacrolimus could enhance the melanogenesis and cell migration on A375 cells.

Cell Line, Tumor ; Cell Movement ; drug effects ; genetics ; Cell Proliferation ; drug effects ; Humans ; Immunohistochemistry ; Melanins ; metabolism ; Melanocytes ; cytology ; drug effects ; Proto-Oncogene Proteins c-kit ; genetics ; metabolism ; RNA, Messenger ; genetics ; Tacrolimus ; pharmacology

OBJECTIVEDespite the causes for melanin increase, the increased gene expression of TYR is a common pathological process. Based on this viewpoint, antisense-S-Oligo of TYR was designed and synthesized to regulate synthesis of melanin in order to explore the treatment for skin pigmentation.

METHODSThe cultured melanocytes were divided into 3 groups. The group 1 was treated with endothelin, group 2 treated with ultraviolet ray and group 3 was used as the control. In each group, the 5' antisense-S-Oligo, the 3' antisense-S-Oligo, the mixed antisense-S-Oligo of TYR or Dotap only was added. The melanin content and TYR gene expressions were examined.

RESULTSThe 5' antisense-S-Oligo, the 3' antisense-S-Oligo and the mixed antisense-S-Oligo significantly inhibited the increase of melanin content and TYR gene expression, which were caused by endothelin or ultraviolet ray treatment. Of the three treatments, the 3' antisense-S-Oligo showed the strongest effect.

CONCLUSIONAntisense-S-Oligo has significant regulating effects on TYR gene expression and melanin content. The 3' antisense-S-Oligo is more effective than the 5' antisense-S-Oligo.

3' Flanking Region ; genetics ; 5' Flanking Region ; genetics ; Endothelins ; pharmacology ; Gene Expression ; Melanins ; biosynthesis ; Melanocytes ; drug effects ; metabolism ; radiation effects ; Oligodeoxyribonucleotides, Antisense ; genetics ; pharmacology ; Tyrosine ; genetics ; metabolism ; Ultraviolet Rays

In this study, the essential oil from lotus flower extract, including petals and stamens, was assessed with regard to its effects on melanogenesis in human melanocytes. The lotus flower essential oil was shown to stimulate melanin synthesis and tyrosinase activity in a dose-dependent manner. The lotus flower essential oil induced the expression of tyrosinase, microphthalmia-associated transcription factor M (MITF-M), and tyrosinase-related proten-2 (TRP-2) proteins, but not tyrosinase mRNA. Moreover, it increased the phosphorylation of ERK and cAMP response element binding protein (CREB). In order to verify the effective components of the lotus flower oil, its lipid composition was assessed. It was found to be comprised of palmitic acid methyl ester (22.66%), linoleic acid methyl ester (11.16%), palmitoleic acid methyl ester (7.55%) and linolenic acid methyl ester (5.16%). Among these components, palmitic acid methyl ester clearly induced melanogenesis as the result of increased tyrosinase expression, thereby indicating that it may play a role in the regulation of melanin content. Thus, our results indicate that lotus flower oil may prove useful in the development of gray hair prevention agents or tanning reagents.
Blotting, Western ; Cell Proliferation ; Cyclic AMP/metabolism ; Cyclic AMP Response Element-Binding Protein/genetics/metabolism ; Flowers/*chemistry ; Gas Chromatography-Mass Spectrometry ; Humans ; Intramolecular Oxidoreductases/genetics/metabolism ; Lotus/*chemistry ; Melanins/*biosynthesis ; Melanocytes/*drug effects/metabolism ; Microphthalmia-Associated Transcription Factor/genetics/metabolism ; Monophenol Monooxygenase/genetics/metabolism ; Phosphorylation ; Plant Oils/*pharmacology ; RNA, Messenger/genetics/metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Skin/cytology/drug effects/metabolism

Pigmentation may result from melanocyte proliferation, melanogenesis, migration or increases in dendricity. Recently, it has been reported that secreted phospholipase A2(sPLA2) known as a component of bee venom (BV), stimulates melanocyte dendricity and pigmentation. BV has been used clinically to control rheumatoid arthritis and to ameliorate pain via its anti-inflammatory and antinociceptive properties. Moreover, after treatment with BV, pigmentation around the injection sites was occasionally observed and the pigmentation lasted a few months. However, no study has been done about the effect of BV on melanocytes. Thus, in the present study, we examined the effect of BV on the proliferation, melanogenesis, dendricity and migration in normal human melanocytes and its signal transduction. BV increased the number of melanocytes dose and time dependently through PKA, ERK, and PI3K/Akt activation. The level of cAMP was also increased by BV treatment. Moreover, BV induced melanogenesis through increased tyrosinase expression. Furthermore, BV induced melanocyte dendricity and migration through PLA2activation. Overall, in this study, we demonstrated that BV may have an effect on the melanocyte proliferation, melanogenesis, dendricity and migration through complex signaling pathways in vitro, responsible for the pigmentation. Thus, our study suggests a possibility that BV may be developed as a therapeutic drug for inducing repigmentation in vitiligo skin.
Animals ; Base Sequence ; Bee Venoms/*pharmacology ; Cell Movement/drug effects ; Cell Proliferation/drug effects ; Cells, Cultured ; Cyclic AMP/metabolism ; DNA Primers/genetics ; Forskolin/pharmacology ; Gene Expression/drug effects ; Humans ; Melanins/biosynthesis ; Melanocytes/cytology/*drug effects/physiology ; Microphthalmia-Associated Transcription Factor/biosynthesis/genetics ; Monophenol Monooxygenase/biosynthesis/genetics ; Signal Transduction/drug effects