In Silico Identification and Molecular Mechanism of Novel Tyrosinase Inhibitory Peptides Derived from Nacre of Pinctada martensii.

Pearl and nacre powders have been valuable traditional Chinese medicines with whitening properties for thousands of years. We utilized a high-temperature and high-pressure method along with compound enzyme digestion to prepare the enzymatic hydrolysates of nacre powder of Pinctada martensii (NP-PMH). The peptides were identified using LC-MS/MS and screened through molecular docking and molecular dynamics simulations. The interactions between peptides and tyrosinase were elucidated through enzyme kinetics, circular dichroism spectropolarimetry, and isothermal titration calorimetry. Additionally, their inhibitory effects on B16F10 cells were explored. The results showed that a tyrosinase-inhibitory peptide (Ala-His-Tyr-Tyr-Asp, AHYYD) was identified, which inhibited tyrosinase with an IC50 value of 2.012 ± 0.088 mM. The results of the in vitro interactions showed that AHYYD exhibited a mixed-type inhibition of tyrosinase and also led to a more compact enzyme structure. The binding reactions of AHYYD with tyrosinase were spontaneous, leading to the formation of a new set of binding sites on the tyrosinase. The B16F10 cell-whitening assay revealed that AHYYD could reduce the melanin content of the cells by directly inhibiting the activity of intracellular tyrosinase. Additionally, it indirectly affects melanin production by acting as an antioxidant. These results suggest that AHYYD could be widely used as a tyrosinase inhibitor in whitening foods and pharmaceuticals.

Comparative Analysis of Olive-Derived Phenolic Compounds' Pro-Melanogenesis Effects on B16F10 Cells and Epidermal Human Melanocytes.

Olive leaf contains plenty of phenolic compounds, among which oleuropein (OP) is the main component and belongs to the group of secoiridoids. Additionally, phenolic compounds such as oleocanthal (OL) and oleacein (OC), which share a structural similarity with OP and two aldehyde groups, are also present in olive leaves. These compounds have been studied for several health benefits, such as anti-cancer and antioxidant effects. However, their impact on the skin remains unknown. Therefore, this study aims to compare the effects of these three compounds on melanogenesis using B16F10 cells and human epidermal cells. Thousands of gene expressions were measured by global gene expression profiling with B16F10 cells. We found that glutaraldehyde compounds derived from olive leaves have a potential effect on the activation of the melanogenesis pathway and inducing differentiation in B16F10 cells. Accordingly, the pro-melanogenesis effect was investigated by means of melanin quantification, mRNA, and protein expression using human epidermal melanocytes (HEM). This study suggests that secoiridoid and its derivates have an impact on skin protection by promoting melanin production in both human and mouse cell lines.

Polysaccharide extracted from the Sargassum fusiforme induces cell cycle arrest and apoptosis of B16F10 melanoma cells through the PI3K/AKT pathway.

BACKGROUND: SARGASSUM FUSIFORME: (S. fusiforme) is a brown alga that has been utilized as a medicine for a long time. Polysaccharides extracted from S. fusiforme demonstrate antitumor activities. METHODS: The impact of S. fusiforme polysaccharides (SFPS 191,212) on the proliferation, apoptosis, and cell cycle kinetics of B16F10 murine melanoma cells were thoroughly investigated in this work. The anticancer activities of the SFPS 191,212 compounds were assayed in the B16F10 cells at both transcriptional and translational levels. RESULTS: The compound exhibited concentration-dependent effects. Moreover, SPFS 191,212 increased the numbers of apoptotic cells and arrested the cell cycle in the S phase of the quantitative real-time PCR. From western blotting, it was verified that the SFPS 191,212 treatment improved the expression of Bax, Caspase-9, and Caspase-3 genes and proteins, while it reduced phosphatidylinositol 3 kinase and Bcl-2 genes and proteins, suggesting the involvement of mitochondria. CONCLUSION: Overall, SFPS 191,212 can be further explored as a potential functional food or adjuvant agent for the prevention or treatment of melanoma.

Istradefylline modulates purinergic enzymes and reduces malignancy-associated factors in B16F10 melanoma cells.

ATP and adenosine exert pivotal roles in the development, maintenance, and metastatic spreading of melanoma. The action of such key melanoma tumor microenvironment (TME) constituents might be complementary or opposed, and their effects are not exclusive to immune cells but also to other host cells and tumor cells. The effects of ATP are controlled by the axis CD39/73, resulting in adenosine, the main actor in the TME, and A2A is the crucial mediator of its effects. We evaluated ATP and adenosine signaling through A2A on B16F10 melanoma cells using istradefylline (IST) (antiparkinsonian A2A antagonist) and caffeine (CAF) treatments after exposure to ATP and adenosine. Adenosine increased melanoma cell viability and proliferation in a concentration-dependent manner. ATP increases viability only as a substrate by CD39 to produce adenosine. Both IST and CAF are toxic to B16F10 cells, but only IST potentialized paclitaxel-induced cytotoxic effects, even decreasing its IC50 value. IST positively modulated CD39 and CD73 expression. CD39 activity was increased, and E-ADA was reduced, indicating that the melanoma cells promoted compensatory feedback in the production and maintenance of adenosine levels. A2A antagonism by IST reduced the factors associated with malignancy, like migration, adhesion, colony formation, and the capacity to produce melanin. Moreover, IST significantly increases nitric oxide (NO) production, which correlates to a decline in melanoma cell viability by apoptotic events. Altogether, our results suggest that adenosine signaling through A2A is essential for B16F10 cells, and its inhibition by IST causes compensatory purinergic enzymatic modulations. Furthermore, IST is a promising therapy that provides new ways to improve current melanoma treatments.

Anti-genotoxic and anti-mutagenic effects of melatonin supplementation in a mouse model of melanoma.

Melanoma, an aggressive skin cancer originating from melanocytes, can metastasize to the lungs, liver, cortex, femur, and spinal cord, ultimately resulting in DNA mutagenic effects. Melatonin is an endogenous hormone and free radical scavenger that possesses the ability to protect the DNA and to exert anti-proliferative effects in melanoma cells. The aim of this study was to evaluate the effects of B16F10 melanoma cells and the effects of melatonin supplementation on genotoxic parameters in murine melanoma models. Thirty-two male C57Bl/6 mice were divided in the following four groups: PBS + vehicle (n = 6), melanoma + vehicle (n = 10), PBS + melatonin (n = 6), and melanoma + melatonin (n = 10). The melanoma groups received a B16F10 cell injection, and melatonin was administered during 60 days. After treatment, tumor sizes were evaluated. DNA damage within the peripheral blood, lungs, liver, cortex, and spinal cord was determined using comet assay, and the mutagenicity within the bone marrow was determined using the micronucleus test. B16F10 cells effectively induced DNA damage in all tissues, and melatonin supplementation decreased DNA damage in the blood, liver, cortex, and spinal cord. This hormone exerts anti-tumor activity via its anti-proliferative, antioxidative, and pro-apoptotic effects. As this result was not observed within the lungs, we hypothesized that melatonin can induce apoptosis in cancer cells, and this was not evaluated by comet assay. This study provides evidence that melatonin can reduce the genotoxicity and mutagenicity caused by B16F10 cells.

Fraxinol Stimulates Melanogenesis in B16F10 Mouse Melanoma Cells through CREB/MITF Signaling.

Melanin pigment produced in melanocytes plays a protective role against ultraviolet radiation. Selective destruction of melanocytes causes chronic depigmentation conditions such as vitiligo, for which there are very few specific medical treatments. Here, we found that fraxinol, a natural coumarin from Fraxinus plants, effectively stimulated melanogenesis. Treatment of B16-F10 cells with fraxinol increased the melanin content and tyrosinase activity in a concentration-dependent manner without causing cytotoxicity. Additionally, fraxinol enhanced the mRNA expression of melanogenic enzymes such as tyrosinase, tyrosinase-related protein-1, and tyrosinase-related protein-2. Fraxinol also increased the expression of microphthalmia-associated transcription factor at both mRNA and protein levels. Fraxinol upregulated the phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB). Furthermore, H89, a cAMP-dependent protein kinase A inhibitor, decreased fraxinol-induced CREB phosphorylation and microphthalmia-associated transcription factor expression and significantly attenuated the fraxinol-induced melanin content and intracellular tyrosinase activity. These results suggest that fraxinol enhances melanogenesis via a protein kinase A-mediated mechanism, which may be useful for developing potent melanogenesis stimulators.

0D/2D heteronanostructure-integrated bimetallic CoCu-ZIF nanosheets and MXene-derived carbon dots for impedimetric cytosensing of melanoma B16-F10 cells.

A novel heterogeneous architecture has been constructed integrating two-dimensional (2D) bimetallic CoCu-zeolite imidazole framework (CoCu-ZIF) and zero-dimensional (0D) Ti3C2Tx MXene-derived carbon dots (CDs) (represented by CoCu-ZIF@CDs). The prepared CoCu-ZIF@CDs were further explored as sensitive layer for anchoring B16-F10 cell-targeted aptamer strands and detecting B16-F10 cells from the biological environment. Basic characterization showed that CDs were homogeneously embedded within CoCu-ZIF NSs owing to their π-π stacking interaction, leading to outstanding fluorescence performance of the 0D/2D CoCu-ZIF@CD nanohybrid. As such, the CoCu-ZIF@CD-based cytosensor was applied to detect living B16-F10 cells through electrochemical techniques and cell imaging. Compared with CoCu-ZIF- and CD-based cytosensors, the constructed CoCu-ZIF@CD-based one showed superior sensing performance, with an extremely low limit of detection (LOD) of 33 cells∙mL-1 and a wide range of suspension concentration of 1 × 102-1 × 105 cells∙mL-1 B16-F10 cells. The developed cytosensor also demonstrated excellent detection performance, including cell imaging properties, good selectivity, high stability, and good reproducibility. By anchoring other probe molecules, the constructed CoCu-ZIF@CD-based biosensor can be extensively explored for early diagnosis of other analytes, thereby widening the applications of porous organic frameworks in biosensing and biomedical fields. A novel sensing system for melanoma B16-F10 cells based on a novel CoCu-ZIF@CD nanohybrid has been developed. The CoCu-ZIF@CDs-based cytosensor displayed an extremely low limit of detection (LOD) of 33 cells∙mL-1 within the wide range of B16-F10 cell concentration from 1 × 102 to 1 × 105 cells∙mL-1, accompanying with cell imaging properties, good selectivity, high stability, and well reproducibility.

Verteporfin-Loaded Mesoporous Silica Nanoparticles' Topical Applications Inhibit Mouse Melanoma Lymphangiogenesis and Micrometastasis In Vivo.

Photodynamic therapy (PDT) has been pointed out as a candidate for improving melanoma treatment. Nanotechnology application in PDT has increased its efficacy by reducing side effects. Herein, mesoporous silica nanoparticles (MSNs) conjugated with verteporfin (Ver-MSNs), in use with PDT, were administered in mice to evaluate their efficacy on lymphoangiogenesis and micrometastasis in melanoma. Melanoma was induced in mice by the subcutaneous injection of B16-F10 cells. The mice were transcutaneously treated with MSNs, Ver-MSNs, or glycerol and exposed to red light. The treatment was carried out four times until day 20. Lymphangiogenesis and micrometastasis were identified by the immunohistochemical method. Lymphoangiogenesis was halved by MSN treatment compared with the control animals, whereas the Ver-MSN treatment almost abolished it. A similar reduction was also observed in lung micrometastasis. PDT with topically administrated Ver-MSNs reduced melanoma lymphoangiogenesis and lung micrometastasis, as well as tumor mass and angiogenesis, and therefore their use could be an innovative and useful tool in melanoma clinical therapy.

S-petasin induces apoptosis and inhibits cell migration through activation of p53 pathway signaling in melanoma B16F10 cells and A375 cells.

Melanoma is a dangerous type of skin cancer that develops from the melanocytes. Activation of p53 in melanoma cells has been validated as a strategy for melanoma therapy. S-Petasin, a dietary sesquiterpene isolated from Petasites japonicus, has been shown to possess multiple biological effects. However, no studies have reported that s-petasin exerted anti-melanoma or inhibited activity in melanoma cells. We investigated the effect of s-petasin in B16F10 cells and A375 cells and the underlying molecular mechanism. S-Petasin exerted a significant anti-proliferation effect on B16F10 cells and A375 cells as measured by the MTT assay and crystal violet staining assay. S-Petasin induced cell apoptosis in B16F10 cells and A375 cells as evidenced by flow cytometry assay and western blot assay. Wound healing assay and transwell cell migration and invasion assay revealed that s-petasin suppressed B16F10 cells and A375 cells migration in vitro. For mechanism study, western blot assay indicated that s-petasin activated the p53 pathway signaling. Furthermore, expression of Bcl-2, Bcl-XL, Bax, MMP-2, MMP-9, p21, CDK4 and cyclin D1 were regulated by s-petasin. Taken together, our data suggest that s-petasin is a novel compound which can induce apoptosis and inhibit cell migration through activation of the p53 pathway signaling in melanoma B16F10 cells and A375 cells.

Argania Spinosa Fruit Shell Extract-Induced Melanogenesis via cAMP Signaling Pathway Activation.

We have previously reported that argan oil and argan press-cake from the kernels of Argania spinosa have an anti-melanogenesis effect. Here, the effect of argan fruit shell ethanol extract (AFSEE) on melanogenesis in B16F10 cells was determined, and the mechanism underlying its effect was elucidated. The proliferation of AFSEE-treated B16F10 cells was evaluated using the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay, while the melanin content was quantified using a spectrophotometric method. The expression of melanogenesis-related proteins was determined by Western blot and real-time PCR, while global gene expression was determined using a DNA microarray. In vitro analysis results showed that the melanin content of B16F10 cells was significantly increased by AFSEE, without cytotoxicity, by increasing the melanogenic enzyme tyrosinase (TRY), tyrosinase related-protein 1 (TRP1), and dopachrome tautomerase (DCT) protein and mRNA expression, as well as upregulating microphthalmia-associated transcription factor (MITF) expression through mitogen-activated protein kinases (MAPKs) extracellular signal-regulated kinase (ERK) and p38, and the cyclic adenosine monophosphate (cAMP) signaling pathway, as indicated by the microarray analysis results. AFSEE's melanogenesis promotion effect is primarily attributed to its polyphenolic components. In conclusion, AFSEE promotes melanogenesis in B16F10 cells by upregulating the expression of the melanogenic enzymes through the cAMP-MITF signaling pathway.AFSEE may be used as a cosmetics product component to promote melanogenesis, or as a therapeutic against hypopigmentation disorders.

Asoprisnil, a Selective Progesterone Receptor Modulator (SPRM), Inhibits Melanosome Export in B16F10 Cells and HEMn-DP Melanocytes.

Previous studies have reported that estrogen hormone promotes melanogenesis while progesterone inhibits it. A selective estrogen receptor modulator (SERM), tamoxifen, has been shown to promote melanogenesis; however, to date, there have been no reports on the effects of a selective progesterone receptor modulator (SPRM) on melanogenesis. In the present study, we hypothesized that asoprisnil (AP), a SPRM, inhibits melanogenesis. AP was tested for cytotoxicity to B16F10 mouse melanoma cells for screening the nontoxic concentrations using MTS cytotoxicity assay. Extracellular and intracellular melanin levels were estimated at nontoxic concentrations of AP. To evaluate the direct effect of AP on tyrosinase enzyme, tyrosinase activity and copper chelating activities were measured. Next, the effects of AP on melanogenesis were tested in normal human melanocytes, neonatal, darkly pigmented (HEMn-DP). Our results demonstrate that AP was nontoxic at a concentration range of 10-50 µM in B16F10 cells; AP at 50 µM significantly suppressed extracellular melanin levels comparable to kojic acid at 500 µM, with no significant effect on intracellular melanin levels. The mechanism of melanogenesis inhibition was studied to assess if AP downregulated tyrosinase activity in cell lysates or in a cell-free system. However, AP was found to increase intracellular tyrosinase activity without any effect on tyrosinase enzyme activity or copper chelating activity in a cell-free system, indicating that AP inhibits melanogenesis by mechanisms other than direct effects on tyrosinase enzyme activity. The capacity of AP to inhibit melanosome export was further validated in HEMn-DP cells; AP significantly suppressed dendricity at concentrations of 20 and 30 µM in the absence of effects on melanin synthesis or intracellular tyrosinase activity. In addition, AP was nontoxic to human keratinocytes (HaCaT) at these concentrations, validating its safety for topical use. Taken together, our preliminary results demonstrate that AP might be repurposed as a candidate therapeutic for treatment of hyperpigmentation disorders via a unique mechanism, which encompasses a selective inhibition of melanosome export.

Citrus unshiu peel suppress the metastatic potential of murine melanoma B16F10 cells in vitro and in vivo.

The peel of Citrus unshiu Marcow. fruits (CU) has long been used as a traditional medicine that has therapeutic effects against pathogenic diseases, including asthma, vomiting, dyspepsia, blood circulation disorders, and various types of cancer. In this study, we investigated the effect of CU peel on metastatic melanoma, a highly aggressive skin cancer, in B16F10 melanoma cells, and in B16F10 cells inoculated-C57BL/6 mice. Our results show that ethanol extracts of CU (EECU) inhibited cell growth and increased the apoptotic cells in B16F10 cells. EECU also stimulated the induction of mitochondria-mediated intrinsic pathway, with reduced mitochondrial membrane potential and increased generation of intracellular reactive oxygen species. Furthermore, EECU suppressed the migration, invasion, and colony formation of B16F10 cells. In addition, the oral administration of EECU reduced serum lactate dehydrogenase activity without weight loss, hepatotoxicity, nor nephrotoxicity in B16F10 cell-inoculated mice. Moreover, EECU markedly suppressed lung hypertrophy, the number and expression of metastatic tumor nodules, and the expression of inflammatory tumor necrosis factor-alpha in lung tissue. In conclusion, our findings suggest that the inhibitory effect of EECU on the metastasis of melanoma indicates that it may be regarded as a potential therapeutic herbal drug for melanoma.

Synthesis of novel C4-benzazole naphthalimide derivatives with potent anti-tumor properties against murine melanoma.

Novel C4-benzazole naphthalimide derivatives were synthesized and tested in vitro and in vivo as anti-cancer drugs. Among these synthetic molecules, compounds 9 and 10 exhibited cytotoxicity against murine B16F10 melanoma cells. In addition, the above-mentioned compounds significantly suppressed lung tumor metastasis with no visible sign of toxicity.

Taurine Attenuates Doxorubicin-Induced Toxicity on B16F10 Cells.

This study aimed to investigate the effect of doxorubicin co-treatment with taurine on B16F10 melanoma cells. Frequently, Doxorubicin is used in the treatments of many different kinds of cancers, some of which are soft tissue sarcomas, hematological malignancies and carcinomas. However, the clinical application of doxorubicin is compromised by its severe adverse effects, including cardiotoxicity. In the present study, the efficacy of doxorubicin co-treatment with taurine was investigated. B16F10 cell viability was evaluated using MTT assays, trypan blue dye exclusion assays, and fluorescent staining technique. Apoptotic cells were detected by flow cytometry and the proteins associated with apoptosis and cellular differentiations were assessed by immunoblotting. Doxorubicin inhibited cell growth and induced cell death in B16F10 cells. Interestingly, doxorubicin co-treatment with taurine inhibited apoptosis in B16F10 cells. These results indicate that doxorubicin co-treatment with taurine attenuates doxorubicin-induced cytotoxicity and reduces ROS production in B16F10 cells.

Casticin impairs cell migration and invasion of mouse melanoma B16F10 cells via PI3K/AKT and NF-κB signaling pathways.

Casticin, a polymethoxyflavone, is one of the major active components obtained from Fructus viticis, which have been shown to have anticancer activities including induce cell apoptosis in human cancer cells. The aim of this study was to investigate the molecular mechanisms by which casticin inhibits cell migration and invasion of mouse melanoma B16F10 cells. Cell viability was examined by MTT assay and the results indicated that casticin decreased the total percentages of viable cells in dose-dependent manners. Casticin affected cell migration and invasion in B16F10 cells were examined by wound healing mobility assay and Boyden chamber migration and invasion assay and results indicated that casticin inhibited cell migration and invasion in dose-dependent manners. Western blotting was used to examine the protein expression of B16F10 cells after exposed to casticin and the results showed that casticin decreased the expressions of MMP-9, MMP-2, MMP-1, FAK, 14-3-3, GRB2, Akt, NF-κB p65, SOS-1, p-EGFR, p-JNK 1/2, uPA, and Rho A in B16F10 cells. Furthermore, cDNA microarray assay was used to show that casticin affected associated gene expression of cell migration and invasion and the results indicated that casticin affected some of the gene expression such as increased SCN1B (cell adhesion molecule 1) and TIMP2 (TIMP metallopeptidase inhibitor 2) and decreased NDUFS4 (NADH dehydrogenase (ubiquinone) Fe-S protein4), VEGFA (vascular endothelial growth factor A), and DDIT3 (DNA-damage-inducible transcript 3) which associated cell migration and invasion in B16F10 cells. Based on those observations, we suggest that casticin could be used as a novel anticancer metastasis of melanoma cancer in the future.

In vitro and in vivo anti-melanoma effects of Daphne gnidium aqueous extract via activation of the immune system.

The purpose of this study was to assess the antitumor and immunomodulatory effects of the aqueous extract from Daphne gnidium in mice-bearing melanoma tumor. Balb/C mice were subcutaneously implanted with B16-F10 cells and treated intraperitoneally with the aqueous extract at 200 mg/Kg b.w for 21 days. After euthanization on day 22, the tumors were weighed; lymphocyte proliferation, cytotoxic T lymphocyte (CTL), and natural killer (NK) cell activities were evaluated using the MTT assay. Macrophage phagocytosis was studied by measuring the lysosomal activity. In addition to its potential to inhibit the growth of the transplantable tumor, the aqueous extract remarkably induced splenocyte proliferation and both NK and CTL activities in tumor-bearing mice. The aqueous extract was also seen to have promoted lysosomal activity of host macrophages.

Estradiol differently affects melanin synthesis of malignant and normal melanocytes: a relationship with clock and clock-controlled genes.

Melanin production within melanocytes is regulated, among others, by estradiol, whose effects on melanogenesis are still not completely elucidated. Here we show that although 10(-7) M 17ß-estradiol (E2) increased tyrosinase mRNA levels in B16-F10 malignant melanocytes, there was a transient decrease and abolishment of the temporal variation of melanin content. Both parameters were much higher in the malignant than in normal Melan-a cells. Considering that silencing clock machinery in human melanocytes increases melanogenesis, we investigated clock gene expression in those cell lines. Except for Melan-a Bmal1 and B16-F10 Per2 expression of control cells, Per1, Per2, and Bmal1 expression increased independently of cell type or E2 treatment after 24 h. However, melanoma cells showed a marked increase in Per1 and Bma11 expression in response to E2 at the same time points, what may rule out E2 as a synchronizer agent since the expression of those genes were not in antiphase. Next, we investigated the expression of Xpa, a clock-controlled gene, which in Melan-a cells, peaked at 18 h, and E2 treatment shifted this peak to 24 h, whereas B16-F10 Xpa expression peaked at 24 h in both control and E2 group, and it was higher compared to Melan-a cells in both groups. Therefore, malignant and normal melanocytes display profound differences on core elements of the local clock, and how they respond to E2, what is most probably determinant of the differences seen on melanin synthesis and Tyrosinase and Xpa expression. Understanding these processes at the molecular level could bring new strategies to treat melanoma.

Calcitonin gene-related peptide cooperates with substance P to inhibit melanogenesis and induces apoptosis of B16F10 cells.

Skin is the largest organ in human body and works as biologically active barrier to provide critical preservation of body homeostasis. The skin is highly innervated by a plenitude of nerve fiber subpopulations, each carrying one or more neuronal mediators. Melanocyte itself also intimately contact with nerve fibers to form 'synaptic-like structure' and its functions may be directly regulated by the mediators contained in terminals of intra-epidermal nerve fibers. Clinical and biochemical studies have suggested that calcitonin gene-related peptide (CGRP) is involved in vitiligo skin. The present study was designed to investigate the effect of CGRP on epidermal melanocytes. After treatment with CGRP ranging from 0 to 500 ng/mL for 48 h, tyrosinase activity and melanogenesis were with little changes compared to treatment with medium only in B16F10 cells. Treatment with 500 ng/mL of CGRP cooperates with substance P (SP) (0.1-10 nM) to decrease tyrosinase activity and decrease melanin biosynthesis in B16F10 cells in a concentration-dependent manner. Furthermore, CGRP (8-37) antagonizes the synergistic effect of CGRP. The effect of CGRP on the cell apoptosis was examined. Treatments with 0-500 ng/mL of CGRP for 24 h, the expression levels of cleaved caspase-3, total caspase-3, cleaved caspase-9 and total caspase-9 were increased in a concentration-dependent manner. And 500 ng/mL of CGRP induced B16F10 cell apoptosis showed by TUNEL assay. In addition, Bax expression was up-regulated and Bcl-2 down-regulated in response to CGRP treatment. Hence, the Bax/Bcl-2 ratio was significantly increased. These in vitro observations indicate the pro-apoptotic impact of CGRP on B16F10 cell.

Layer-by-layer polymer coated gold nanoparticles for topical delivery of imatinib mesylate to treat melanoma.

The aim of this study was to investigate the feasibility of using layer-by-layer polymer coated gold nanoparticles (AuNP) as a carrier for topical iontophoretic delivery of imatinib mesylate (IM). AuNP were prepared by the Turkevich method and were stabilized and functionalized using polyvinylpyrrolidone and polyethylene imine. The functionalized AuNP were then sequentially coated with anionic poly(styrenesulfonate) and cationic polyethylene imine and loaded with IM. The layer-by-layer polymer coated AuNP (LbL-AuNP) showed average particle size and zeta-potential of 98.5 ± 4.3 nm and 32.3 ± 1.3 mV respectively. After LbL coating of AuNP, the surface plasmon resonance wavelength shifted from 518 to 530 nm. The loading efficiency of IM in LbL-AuNP was found to be 28.3 ± 2.3%, which was greatest for any small molecule loaded in AuNP. In vitro skin penetration studies in excised porcine ear skin showed that iontophoresis (0.47 mA/cm(2)) application enhanced the skin penetration of IM loaded AuNP by 6.2-fold compared to passive application. Tape stripping studies showed that iontophoresis of IM loaded LbL-AuNP retained 7.8- and 4.9-fold greater IM in stratum corneum and viable skin respectively compared with iontophoresis of free IM. LbL-AuNP were taken up rapidly (15 min) by B16F10 murine melanoma cells. Furthermore, IM loaded LbL-AuNP significantly (p < 0.001) decreased B16F10 cell viability compared to free IM. We have shown for the first time that IM can be delivered by topical application using LbL coated gold nanoparticles to treat melanoma.

Therapeutic Potential of Silver Nitroprusside Nanoparticles for Melanoma.

Melanoma has gained considerable attention due to its high mortality and morbidity rate worldwide. The currently available treatment options are associated with several limitations such as nonspecificity, drug resistance, easy clearance, low efficacy, toxicity-related issues, etc. To this end, nanotechnology has garnered significant attention for the treatment of melanoma. In the present manuscript, we have demonstrated the in vitro and in vivo anticancer activity of silver nitroprusside nanoparticles (abbreviated as AgNNPs) against melanoma. The AgNNPs exhibit cytotoxicity against B16F10 cells, which has been investigated by several in vitro experiments including [methyl 3H]-thymidine incorporation assay, cell cycle and apoptosis analysis by flow cytometry, and ROS generation through DCFDA, DHE, and DAF2A reagents. Further, the internalization of nanoparticles was determined by ICPOES analysis, while their colocalization was analyzed by confocal microscopy. Additionally, JC-1 staining is performed to examine mitochondrial membrane potential (MMP). Cytoskeleton integrity was observed by phalloidin staining. Expression of different markers (Ki-67, cytochrome c, and E-cadherin) was checked using an immunofluorescence assay. The in vivo therapeutic efficacy of AgNNPs has been validated in the melanoma model established by inoculating B16F10 cells into the dorsal right abdomen of C57BL/6J mice. The intraperitoneal administration of AgNNPs reduced melanoma growth and increased the survivability of tumor-bearing mice. The in vivo immunofluorescence studies (Ki-67, CD31, and E-cadherin) and TUNEL assay support the inhibitory and apoptotic nature of AgNNPs toward melanoma, respectively. Furthermore, the various signaling pathways and molecular mechanisms involved in anticancer activity are evaluated by Western blot analysis. These findings altogether demonstrate the promising anticancer potential of AgNNPs toward melanoma.