This study aims to compare six commercial adult toothpaste (labeled as A, B, C, D, E, and F) for cytotoxicity and melanocyte function alterations in vitro using primary human epidermal melanocytes from a Caucasian donor (HEMn-LP cells) as a model of oral melanocytes. Cells were incubated with toothpaste extracts (50% w/v) in culture media at dilutions (1:25, 1:50, 1:100, 1:200, 1:500, 1:800, and 1:1000) for 24 h. MTS and LDH assays were used to assess cytotoxicity. The effects of noncytotoxic toothpaste concentrations on melanocyte functional endpoints were then examined using spectrophotometric methods. All toothpaste showed concentration-dependent cytotoxicity that was heterogeneous across toothpaste containing SLS detergent. IC50 values of cytotoxicity followed the order: A = E > C > B > D > F. To compare toothpaste, they were tested at 1:800 and 1:1000 dilutions that were noncytotoxic after 24 h. None of the toothpaste affected cellular melanin production. However, toothpaste A, C, and D suppressed tyrosinase activity at both dilutions, while toothpaste B suppressed tyrosinase activity only at 1:800 dilution. Toothpaste A, C, E, and F elevated ROS production at 1:800 dilution, with no change at 1:1000 dilution. Toothpaste has a heterogeneous effect on melanocytes. Toothpaste B, E, and F at 1:1000 dilution were the safest as they did not alter melanocyte functions at this dilution, although toothpaste F is the least cytotoxic of these. Future studies are necessary to expand these results in a physiological environment of oral tissue. The findings of this study provide novel insight into the biocompatibility studies of toothpaste on oral melanocytes. They can aid dental practitioners and consumers in selecting noncytotoxic toothpaste that do not contribute to ROS generation by melanocytes in the oral cavity or lead to cytotoxicity and impaired cellular function.

Skin hyperpigmentation is a worldwide condition associated with augmented melanogenesis. However, conventional therapies often entail various adverse effects. Here, we explore the safety range and depigmentary effects of polysaccharides extract of Tricholoma matsutake (PETM) in an in vitro model and further evaluated its efficacy at the clinical level. An induced-melanogenesis model was established by treating B16-F10 melanoma cells with 8-methoxypsoralen (8-MOP). Effects of PETM on cell viability and melanin content were examined and compared to a commonly used depigmentary agent, α-arbutin. Expressions of key melanogenic factors and upstream signaling pathway were analysed by quantitative PCR and western blot. Moreover, a placebo-controlled clinical study involving Chinese females with skin hyperpigmentation was conducted to measure the efficacy of PETM on improving facial pigmented spots, melanin index, and individual typology angle (ITA°). Results demonstrated that PETM (up to 0.5 mg/mL) had little effect on the viability and motility of B16-F10 cells. Notably, it significantly suppressed the melanin content and expressions of key melanogenic factors induced by 8-MOP in B16-F10 melanoma cells. Western blotting results revealed that PETM inhibited melanogenesis by inactivating c-Jun N-terminal kinase (JNK), and this inhibitory role could be rescued by JNK agonist treatment. Clinical findings showed that PETM treatment resulted in a significant reduction of facial hyperpigmented spot, decreased melanin index, and improved ITA° value compared to the placebo-control group. In conclusion, these in vitro and clinical evidence demonstrated the safety and depigmentary efficacy of PETM, a novel polysaccharide agent. The distinct mechanism of action of PETM on melanogenic signaling pathway positions it as a promising agent for developing alternative therapies.

BACKGROUND: According to the Compendium of Materia Medica (Shizhen Li, Ming dynasty) and Welfare Pharmacy (Song dynasty), Psoraleae Fructus (PF), a traditional Chinese medicine (TCM) has a bitter taste and warm nature, which has the effect of treating spleen and kidney deficiency and skin disease. Although PF has been widely used since ancient times and has shown satisfactory efficacy in treating vitiligo, the active substances and the mechanism of PF in promoting melanogenesis remain unclear.
OBJECTIVE: To explore the active substances and action mechanisms of PF in promoting melanogenesis.
METHODS: Firstly, UPLC-UV-Q-TOF/MS was used to characterize the components in PF extract and identify the absorption components and metabolites of PF after oral administration at usual doses in rats. Secondly, the active substances and related targets and pathways were predicted by network pharmacology and molecular docking. Finally, pharmacodynamic and molecular biology experiments were used to verify the prediction results.
RESULTS: The experimental results showed that 15 compounds were identified in PF extract, and 44 compounds, consisting of 8 prototype components and 36 metabolites (including isomers) were identified in rats\' plasma. Promising action targets (MAPK1, MAPK8, MAPK14) and signaling pathways (MAPK signaling pathway) were screened and refined to elucidate the mechanism of PF against vitiligo based on network pharmacology. Bergaptol and xanthotol (the main metabolites of PF), psoralen (prototype drug), and PF extract significantly increased melanin production in zebrafish embryos. Furthermore, bergaptol could promote the pigmentation of zebrafish embryos more than psoralen and PF extract. Bergaptol significantly increased the protein expression levels of p-P38 and decreased ERK phosphorylation in B16F10 cells, which was also supported by the corresponding inhibitor/activator combination study. Moreover, bergaptol increased the mRNA expression levels of the downstream microphthalmia-associated transcription factor (MITF) and tyrosinase in B16F10 cells. Our data elucidate that bergaptol may promote melanogenesis by regulating the p-P38 and p-ERK signaling pathway.
CONCLUSIONS: This study will lay a foundation for discovering potential new drugs for treating vitiligo and provide feasible ideas for exploring the mechanism of traditional Chinese medicine.

Effects of butyric acid, a bacterial metabolite implicated in periodontitis progression, have never been examined on oral melanocytes. Herein, primary human epidermal melanocytes were used as a model for oral melanocytes. Results show the adverse effects of butyric acid (sodium butyrate; NaB) on them, which comprise marked cytotoxicity at higher concentrations (>1 mM) and robust differentiation at lower nontoxic concentrations. NaB did not alter MITF protein levels; however, it stimulated tyrosinase protein synthesis and inhibited tyrosinase activity, with no changes in cellular melanin. NaB did not affect oxidative stress, although it induced significant levels of the pro-inflammatory cytokine IL-6.

The Yiqi Qubai (YQ) formula is a hospital preparation for treating vitiligo in China that has had reliable efficacy for decades. The formula consists of four herbs; however, the extraction process to produce the formula is obsolete and the active ingredients and mechanisms remain unknown. Therefore, in this paper, fingerprints were combined with the chemometrics method to screen high-quality herbs for the preparation of the YQ standard decoction (YQD). Then, the YQD preparation procedure was optimized using response surface methodology. A total of 44 chemical constituents, as well as 36 absorption components (in rat plasma) of YQD, were identified via UPLC-Q-TOF/MS. Based on the ingredients, the quality control system of YQD was optimized by establishing the SPE-UPLC-Q-TOF/MS identification method and the HPLC quantification method. Network pharmacological analysis and molecular docking showed that carasinaurone, calycosin-7-O-β-d-glucoside, methylnissolin-3-O-glucoside, genkwanin, akebia saponin D, formononetin, akebia saponin B, and apigenin may be the key active components for treating vitiligo; the core targets associated with them were AKT1, MAPK1, and mTOR, whereas the related pathways were the PI3K-Akt, MAPK, and FoxO signaling pathways. Cellular assays showed that YQD could promote melanogenesis and tyrosinase activity, as well as the transcription and expression of tyrosinase-associated proteins (i.e., TRP-1) in B16F10 cells. In addition, YQD also increased extracellular tyrosinase activity. Further efficacy validation showed that YQD significantly promotes melanin production in zebrafish. These may be the mechanisms by which YQD improves the symptoms of vitiligo. This is the first systematic study of the YQ formula that has optimized the standard decoction preparation method and investigated the active ingredients, quality control, efficacy, and mechanisms of YQD. The results of this study lay the foundations for the clinical application and further development of the YQ formula.

UNASSIGNED: Dairy products have long been regarded as a controversial nutrient for the skin. However, a clear demonstration of donkey milk (DM) on skincare is required.
UNASSIGNED: In this study, spectrum and chemical component analyses were applied to DM. Then, the effects of DM on UVB-induced skin barrier damage and melanin pigmentation were first evaluated in vitro and in vivo. Cell survival, animal models, and expression of filaggrin (FLG) were determined to confirm the effect of DM on UVB-induced skin barrier damage. Melanogenesis and tyrosinase (TYR) activity were assessed after UVB irradiation to clarify the effect of DM on whitening activities. Further, a network pharmacology method was applied to study the interaction between DM ingredients and UVB-induced skin injury. Meanwhile, an analysis of the melanogenesis molecular target network was developed and validated to predict the melanogenesis regulators in DM.
UNASSIGNED: DM was rich in cholesterols, fatty acids, vitamins and amino acids. The results of evaluation of whitening activities in vitro and in vivo indicated that DM had a potent inhibitory effect on melanin synthesis. The results of effects of DM on UVB‑induced skin barrier damage indicated that DM inhibited UVB-induced injury and restored skin barrier function via up-regulation expression of FLG (filaggrin). The pharmacological network of DM showed that DM regulated steroid biosynthesis and fatty acid metabolism in keratinocytes and 64 melanin targets which the main contributing role of DM might target melanogenesis, cell adhesion molecules (CAMs), and Tumor necrosis factor (TNF) pathway.
UNASSIGNED: These results highlight the potential use of DM as a promising agent for whitening and anti-photoaging applications.

UNASSIGNED: Melanin is the predominant pigment responsible for the color of skin, hair, iris of eyes, and oral mucosa. Tyrosinase (TYR) is the key enzyme involved in melanin synthesis. Studies in dermatology have shown a positive correlation between TYR enzyme levels and melanin pigmentation of the skin. However, no study has been conducted to assess TYR levels in the gingiva. Hence the present study was conducted to assess TYR levels in gingival melanin hyperpigmentation.
UNASSIGNED: To assess the TYR gene expression in gingiva in individuals with moderate to severe gingival melanin hyperpigmentation.
UNASSIGNED: Subjects with a chief complaint of blackish appearance of gums with an unesthetic smile were included in the study. Informed consent was obtained. Scaling and root planning were done and subjects were recalled after 2 weeks. The gingival depigmentation procedure was performed using the conventional scalpel technique under adequate local anesthesia. The selected sites underwent conventional gingival depigmentation technique using Bard-Parker handle no: 3 and blade no: 11. The excised layer of epithelium along with a thin layer of underlying connective was sent to the laboratory to assess the TYR gene expression by real-time polymerase chain reaction technique.
UNASSIGNED: The levels of the TYR enzyme activity in the gingival tissues from the selected sites were assessed. Table 1 and Graph 1 show the levels of TYR enzyme gene expression in the gingival tissue.
UNASSIGNED: TYR gene expression and the degree of gingival melanin hyperpigmentation are positively correlated. Hence the assessment of TYR enzyme activity in gingiva could be of great value in today\'s cosmetologically conscious individuals.

Psoralen, a major furocoumarin component of the Fructus Psoralen (FP), in combination with ultraviolet radiation, cures abnormal pigmentation disorder. In a previous study, we synthesized a series of linear furocoumarins with different substituents, out of which 5-((diethylamino)methyl)-3-phenyl-7H-furo [3,2-g] chromen-7-one (encoded as 5D3PC) showed better pigmenting effect than others in B16 cells. In this study, we examined the mechanism underlying the melanogenic effect of 5D3PC both in vivo and in vitro. To examine the pigmentation effect, the B16 and human melanocyte cell lines, PIG1 and PIG3V melanocytes were incubated with 5D3PC. In animal experiments, C57BL/6 mice received 5% hydroquinone and were administrated with 5D3PC for 30 days. 5D3PC upregulated the melanin synthesis and tyrosinase in B16 cell, PIG1 and PIG3V. The expression level of tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1) and tyrosinase-related protein-2 (TRP-2), microphthalmia-associated transcription factor (MITF), cyclic adenosine monophosphate (cAMP), phosphorylation of cAMP-responsive element binding protein (p-CREB), phosphorylation of p38 mitogen-activated protein kinase (MAPK), c- phosphorylation of Jun N-terminal kinase (p-JNK) was significantly higher in 5D3PC-treated B16 cells. The oral administration of 5D3PC attenuated the depigmentation of the C57BL/6 vitiligo mice model by increasing the numbers of melanin-containing hair follicles, melanogenic protein, and melanogenesis-relative genes expression in skin tissues.

Tyrosinase is a copper-containing key substance in the pigmentation of mammalian hair and skin. Melanin synthesis is influenced by a variety of extrinsic and internal variables, including hormone fluctuations, inflammation, ageing, and subsequent ultraviolet light exposure. Melasma, senile lentigines, freckles, and diminished colour are all undesirable side effects of excessive melanin production. The current review provides the pursuit of effective and safe tyrosinase inhibitors derived from medicinal plants and ascribes updated inferences on current practices. Commercially available tyrosinase inhibitors provide an even skin tone and are used clinically to treat hyperpigmentation and related disorders. This review focuses on the mechanism of melanogenesis and on experimentally verified potent and natural tyrosinase inhibitors. Bioactive compounds such as phenols, flavonoids, stilbenes, and few traditional herbal formulations from the Indian system of medicine, have been used for long in India and subcontinents for the effective management of melanogenesis and related problems. Scientific information was gathered from different sources of databases such as PubMed, Google Scholar, Springer, Scopus, and Science Direct, as well as the literature found in medicinal plant books. This critically summarized review ensures to aid researchers and enterprises working on tyrosinase inhibitors and on conditions associated with melanogenesis, to get one-step solutions for identifying more safe and effective natural remedies.

Vitiligo is a common chronic dermatological abnormality that afflicts tens of millions of people. Furocoumarins isolated from Uygur traditional medicinal material Psoralen corylifolia L. have been proven to be highly effective for the treatment of vitiligo. Although many furocoumarin derivatives with anti-vitiligo activity have been synthesized, their targets with respect to the disease are still ambiguous. Fortunately, the JAKs were identified as potential targets for the disease and its inhibitors have been proved to be effective in the treatment of vitiligo in many clinical trials. Thus, sixty-five benzene sulfonate and benzoate derivatives of furocoumarins (7a-7ad, 8a-8ag) with superior anti-vitiligo activity targeting JAKs were designed and synthesized based on preliminary research. The SAR was characterized after the anti-vitiligo-activity evaluation in B16 cells. Twenty-two derivatives showed more potent effects on melanin synthesis in B16 cells than the positive control (8-MOP). Among them, compounds 7y and 8 not only could increase melanin content, but they also improved the catecholase activity of tyrosinase in a concentration-dependent manner. The docking studies indicated that they were able to interact with amino acid residues in JAK1 and JAK2 via hydrogen bonds. Furthermore, candidate 8 showed a moderate inhibition of CXCL-10, which plays an important role in JAK-STAT signaling. The RT-PCR and Western blotting analyses illustrated that compounds 7y and 8 promoted melanogenesis by activating the p38 MAPK and Akt/GSK-3β/β-catenin pathways, as well as increasing the expressions of the MITF and tyrosinase-family genes. Finally, furocoumarin derivative 8 was recognized as a promising candidate for the fight against the disease and worthy of further research in vivo.