Quercetin Inhibits Proliferation and Induces Apoptosis of B16 Melanoma Cells In Vitro

Bioactive compounds from Actinidia arguta fruit as a new strategy to fight glioblastoma

In recent years, there has been a significant demand for natural products as a mean of disease prevention or as an alternative to conventional medications. The driving force for this change is the growing recognition of the abundant presence of valuable bioactive compounds in natural products. On recent years Actinia arguta fruit, also known as kiwiberry, has attracted a lot of attention from scientific community due to its richness in bioactive compounds, including phenolic compounds, organic acids, vitamins, carotenoids and fiber. These bioactive compounds contribute to the fruit's diverse outstanding biological activities such as antioxidant, anti-inflammatory, neuroprotective, immunomodulatory, and anti-cancer properties. Due to these properties, the fruit may have the potential to be used in the treatment/prevention of various types of cancer, including glioblastoma. Glioblastoma is the most aggressive form of brain cancer, displaying 90 % of recurrence rate within a span of 2 years. Despite the employment of an aggressive approach, the prognosis remains unfavorable, emphasizing the urgent requirement for the development of new effective treatments. The preclinical evidence suggests that kiwiberry has potential impact on glioblastoma by reducing the cancer self-renewal, modulating the signaling pathways involved in the regulation of the cell phenotype and metabolism, and influencing the consolidation of the tumor microenvironment. Even though, challenges such as the imprecise composition and concentration of bioactive compounds, and its low bioavailability after oral administration may be drawbacks to the development of kiwiberry-based treatments, being urgent to ensure the safety and efficacy of kiwiberry for the prevention and treatment of glioblastoma. This review aims to highlight the potential impact of A. arguta bioactive compounds on glioblastoma, providing novel insights into their applicability as complementary or alternative therapies.

Spice-Derived Phenolic Compounds: Potential for Skin Cancer Prevention and Therapy

Skin cancer is a condition characterized by the abnormal growth of skin cells, primarily caused by exposure to ultraviolet (UV) radiation from the sun or artificial sources like tanning beds. Different types of skin cancer include melanoma, basal cell carcinoma, and squamous cell carcinoma. Despite the advancements in targeted therapies, there is still a need for a safer, highly efficient approach to preventing and treating cutaneous malignancies. Spices have a rich history dating back thousands of years and are renowned for their ability to enhance the flavor, taste, and color of food. Derived from various plant parts like seeds, fruits, bark, roots, or flowers, spices are important culinary ingredients. However, their value extends beyond the culinary realm. Some spices contain bioactive compounds, including phenolic compounds, which are known for their significant biological effects. These compounds have attracted attention in scientific research due to their potential health benefits, including their possible role in disease prevention and treatment, such as cancer. This review focuses on examining the potential of spice-derived phenolic compounds as preventive or therapeutic agents for managing skin cancers. By compiling and analyzing the available knowledge, this review aims to provide insights that can guide future research in identifying new anticancer phytochemicals and uncovering additional mechanisms for combating skin cancer.

Potential Therapeutic Targets of Quercetin in the Cutaneous Melanoma Model and Its Cellular Regulation Pathways: A Systematic Review

Melanoma is a skin cancer with a high mortality rate due to its invasive characteristics. Currently, immunotherapy and targeted therapy increase patient survival but are ineffective in the advanced stages of the tumor. Quercetin (Que) is a natural compound that has demonstrated chemopreventive effects against different types of tumors. This review provides evidence for the therapeutic potential of Que in melanoma and identifies its main targets. The Scopus, Web of Science, and PubMed databases were searched, and studies that used free or encapsulated Que in melanoma models were included, excluding associations, analogs, and extracts. As a result, 73 articles were retrieved and their data extracted. Que has multiple cellular targets in melanoma models, and the main regulated pathways are cell death, redox metabolism, metastasis, and melanization. Que was also able to regulate important targets of signaling pathways, such as PKC, RIG-I, STAT, and P53. In murine models, treatment with Que reduced tumor growth and weight, and decreased metastatic nodules and angiogenic vasculature. Several studies have incorporated Que into carriers, demonstrating improved efficacy and delivery to tumors. Thus, Que is a promising therapeutic agent for the treatment of melanoma; however, further studies are needed to evaluate its effectiveness in clinical trials.

Flavonoids as Promising Natural Compounds in the Prevention and Treatment of Selected Skin Diseases

Phytochemicals represent a large and diverse group of naturally occurring compounds, bioactive nutrients, or phytonutrients produced by plants, widely found in fruits, vegetables, whole grains products, legumes, beans, herbs, seeds, nuts, tea, and dark chocolate. They are classified according to their chemical structures and functional properties. Flavonoids belong to the phenolic class of phytochemicals with potential solid pharmacological effects as modulators of multiple signal transduction pathways. Their beneficial effect on the human body is associated with their antioxidant, anti-inflammatory, antimutagenic, and anticarcinogenic properties. Flavonoids are also widely used in various nutritional, pharmaceutical, medical, and cosmetic applications. In our review, we discuss the positive effect of flavonoids on chronic skin diseases such as vitiligo, psoriasis, acne, and atopic dermatitis.

Phytochemical Constituents and Derivatives of Cannabis sativa; Bridging the Gap in Melanoma Treatment

Melanoma is deadly, physically impairing, and has ongoing treatment deficiencies. Current treatment regimens include surgery, targeted kinase inhibitors, immunotherapy, and combined approaches. Each of these treatments face pitfalls, with diminutive five-year survival in patients with advanced metastatic invasion of lymph and secondary organ tissues. Polyphenolic compounds, including cannabinoids, terpenoids, and flavonoids; both natural and synthetic, have emerging evidence of nutraceutical, cosmetic and pharmacological potential, including specific anti-cancer, anti-inflammatory, and palliative utility. Cannabis sativa is a wellspring of medicinal compounds whose direct and adjunctive application may offer considerable relief for melanoma suffers worldwide. This review aims to address the diverse applications of C. sativa's biocompounds in the scope of melanoma and suggest it as a strong candidate for ongoing pharmacological evaluation.

Investigation of the mechanism of the anti-cancer effects of Astragalus propinquus Schischkin and Pinellia pedatisecta Schott (A&P) on melanoma via network pharmacology and experimental verification

Melanoma is a commonly malignant cutaneous tumor in China. Astragalus propinquus Schischkin and Pinellia pedatisecta Schott (A&P) have been clinically used as adjunctive drugs in the treatment of malignant melanoma. However, the effect and mechanism of A&P on melanoma have yet to be explored. The current investigation seeks to characterize the active components of A&P and their potential roles in treating malignant melanoma using network pharmacology and in vitro and in vivo experiments. We first used the traditional Chinese medicine systems pharmacology (TCMSP) database and high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) to identify a total of 13 effective compounds within A&P. 70 common genes were obtained by matching 487 potential genes of A&P with 464 melanoma-related genes, and then we built up protein-protein interaction (PPI) network of these 70 genes, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The results revealed that A&P might influence the pathobiology of melanoma through the PI3K/Akt pathway. Molecular docking also confirmed that higher content of ingredients in A&P, including hederagenin, quercetin, beta-sitosterol and stigmasterol, had a strong binding activity (affinity < −5 kcal/mol) with the core targets AKT1, MAPK3 and ESR1. Furthermore, we confirmed A&P could inhibit melanoma cells proliferation and induce cells apoptosis through suppressing the PI3K/Akt signaling pathway by in vitro and in vivo xenograft model experiments. These findings indicate that A&P may function as a useful therapy for melanoma through the PI3K/Akt pathway.

Quercetin-Rich Extracts from Onions (Allium cepa) Play Potent Cytotoxicity on Adrenocortical Carcinoma Cell Lines, and Quercetin Induces Important Anticancer Properties

Adrenocortical carcinoma (ACC) is a rare subtype of cancer, with a poor prognosis in children and adults. Mitotane is the only approved adrenolytic drug for the treatment of ACC, which has controversies regarding its efficacy and side effects on patients. Onion (Allium cepa), a worldwide consumed food, is associated with many health benefits. Along with its glycosides, the flavonoid quercetin is abundant in onions. After evaluating the cytotoxicity of A. cepa extracts on adrenocortical carcinoma cell line (H295R), the rich quercetin fractions had better results. Then, we aimed to compare the quercetin vs. mitotane effectiveness, using adrenocortical carcinoma cell lines H295R and SW-13. Quercetin showed a higher cytotoxicity response on both cancerous cell lines after 10 µM concentration, while mitotane only after 30 µM. Cell cycle dynamics were altered upon quercetin treatments, with G2 phase increase with 30 µM of quercetin on H295R cell line and G1 arrest on SW-13 cell line with 15 µM. Early and late apoptosis, alongside intracellular calcium, were increased on SW-13 treated with 30 µM of quercetin, and ROS rates were reduced by quercetin on H295R. Therefore, quercetin-rich onions have the potential to be a natural source of anticancer agents for adrenocortical carcinoma.

Ethosomes and Transethosomes as Cutaneous Delivery Systems for Quercetin: A Preliminary Study on Melanoma Cells

The present study is aimed to design ethosomes and transethosomes for topical administration of quercetin. To overcome quercetin low bioavailability, scarce solubility and poor permeability that hamper its pharmaceutical use, the drug was loaded in ethosomes and transethosomes based on different concentrations of phosphatidylcholine. Vesicle morphology was studied by cryogenic transmission electron microscopy, while size distribution and quercetin entrapment capacity were evaluated up to 3 months, respectively, by photon correlation spectroscopy and high-performance liquid chromatography. The antioxidant property was studied by photochemiluminescence test. Quercetin release and permeation was investigated in vitro, using Franz cells associated to different membranes. In vitro assays were conducted on human keratinocytes and melanoma cells to study the behavior of quercetin-loaded nano-vesicular forms with respect to cell migration and proliferation. The results evidenced that both phosphatidylcholine concentration and quercetin affected the vesicle size. Quercetin entrapment capacity, antioxidant activity and size stability were controlled using transethosomes produced by the highest amount of phosphatidylcholine. In vitro permeation studies revealed an enhancement of quercetin permeation in the case of transethosomes with respect to ethosomes. Notably, scratch wound and migration assays suggested the potential of quercetin loaded-transethosomes as adjuvant strategy for skin conditions.

Quercetin increases mitochondrial proteins (VDAC and SDH) and downmodulates AXL and PIM-1 tyrosine kinase receptors in NRAS melanoma cells

Melanoma is a type of skin cancer with low survival rates after it has metastasized. In order to find molecular differences that could represent targets of quercetin in anti-melanoma activity, we have chosen SKMEL-103 and SKMEL-28 melanoma cells and human melanocytes as models. Firstly, we observed that quercetin was able in reducing SKMEL-103 cell viability, but not in SKMEL-28. Besides that, quercetin treatment caused inhibition of AXL in both cell lines, but upregulation of PIM-1 in SKMEL-28 and downregulation in SKMEL-103. Moreover, HIF-1 alpha expression decreased in both cell lines. Interestingly, quercetin was more effective against SKMEL-103 than kinases inhibitors, such as Imatinib, Temsirolimus, U0126, and Erlotinib. Interestingly, we observed that while the levels of succinate dehydrogenase and voltage-dependent anion channel increased in SKMEL-103, both proteins were downregulated in SKMEL-28 after quercetin's treatment. Furthermore, AKT, AXL, PIM-1, ABL kinases were much more active and chaperones HSP90, HSP70 and GAPDH were highly expressed in SKMEL-103 cells in comparison with melanocytes. Our findings indicate, for the first time, that the efficacy of quercetin to kill melanoma cells depends on its ability in inhibiting tyrosine kinase and upregulating mitochondrial proteins, at least when SKMEL-103 and SKMEL-28 cells response were compared.

Phytochemicals from Indian Ethnomedicines: Promising Prospects for the Management of Oxidative Stress and Cancer

Oxygen is indispensable for most organisms on the earth because of its role in respiration. However, it is also associated with several unwanted effects which may sometimes prove fatal in the long run. Such effects are more evident in cells exposed to strong oxidants containing reactive oxygen species (ROS). The adverse outcomes of oxidative metabolism are referred to as oxidative stress, which is a staple theme in contemporary medical research. Oxidative stress leads to plasma membrane disruption through lipid peroxidation and has several other deleterious effects. A large body of literature suggests the involvement of ROS in cancer, ageing, and several other health hazards of the modern world. Plant-based cures for these conditions are desperately sought after as supposedly safer alternatives to mainstream medicines. Phytochemicals, which constitute a diverse group of plant-based substances with varying roles in oxidative reactions of the body, are implicated in the treatment of cancer, aging, and all other ROS-induced anomalies. This review presents a summary of important phytochemicals extracted from medicinal plants which are a part of Indian ethnomedicine and Ayurveda and describes their possible therapeutic significance.

Recent Advances in Phenolic Metabolites and Skin Cancer

Skin cancer represents any tumor development from the cutaneous structures within the epidermis, dermis or subcutaneous tissue, and is considered to be the most prevalent type of cancer. Compared to other types of cancer, skin cancer is proven to have a positive growth rate of prevalence and mortality. There are available various treatments, including chemotherapy, immunotherapy, radiotherapy and targeted therapy, but because of the multidrug resistance development, a low success has been registered. By this, the importance of studying naturally occurring compounds that are both safe and effective in the chemoprevention of skin cancer is emphasized. This review focuses on melanoma because it is the deadliest form of skin cancer, with a significantly increasing incidence in the last decades. As chemopreventive agents, we present polyphenols and their antioxidant activity, anti-inflammatory effect, their ability to balance the cell cycle and to induce apoptosis and their various other effects on skin melanoma. Besides chemoprevention, studies suggest that polyphenols can have treating abilities in some conditions. The limitations of using polyphenols are also pointed out, which are related to their poor bioavailability and stability, but as the technology is well developed, it is possible to augment the efficacy of polyphenols in the case of melanoma.

Synthesis of cinnamoyl glucoside derivatives and their antiproliferation activities against murine melanoma B16-F10 cell line

Twelve cinnamoyl glucoside derivatives were prepared by glycosylation of glucosyl trichloroacetimidate and cinnamic acid derivatives, followed by dechloroacetylation with a pyridine/H2O mixture. Their structures were characterized by 1H and 13C NMR, as well as mass analysis. All the products were tested for their antiproliferation activities against murine melanoma B16-F10 cell line. Compounds 4e-4j were able to inhibit the proliferation of murine melanoma B16-F10 cell line with IC50 values of 17.38 ± 0.07, 9.87 ± 0.09, 9.69 ± 0.12, 29.42 ± 0.04, 32.95 ± 0.08, 25.68 ± 0.09 μM, respectively.

The Role of Senescent Cells in Acquired Drug Resistance and Secondary Cancer in BRAFi-Treated Melanoma

Simple Summary

Advances in melanoma treatment include v-Raf murine sarcoma viral oncogene homolog B (BRAF) inhibitors that target the predominant oncogenic mutation found in malignant melanoma. Despite initial success of the BRAF inhibitor (BRAFi) therapies, resistance and secondary cancer often occur. Mechanisms of resistance and secondary cancer rely on upregulation of pro-survival pathways that circumvent senescence. The repeated identification of a cellular senescent phenotype throughout melanoma progression demonstrates the contribution of senescent cells in resistance and secondary cancer development. Incorporating senotherapeutics in melanoma treatment may offer a novel approach for potentially improving clinical outcome.

Abstract

BRAF is the most common gene mutated in malignant melanoma, and predominately it is a missense mutation of codon 600 in the kinase domain. This oncogenic BRAF missense mutation results in constitutive activation of the mitogen-activate protein kinase (MAPK) pro-survival pathway. Several BRAF inhibitors (BRAFi) have been developed to specifically inhibit BRAF^V600 mutations that improve melanoma survival, but resistance and secondary cancer often occur. Causal mechanisms of BRAFi-induced secondary cancer and resistance have been identified through upregulation of MAPK and alternate pro-survival pathways. In addition, overriding of cellular senescence is observed throughout the progression of disease from benign nevi to malignant melanoma. In this review, we discuss melanoma BRAF mutations, the genetic mechanism of BRAFi resistance, and the evidence supporting the role of senescent cells in melanoma disease progression, drug resistance and secondary cancer. We further highlight the potential benefit of targeting senescent cells with senotherapeutics as adjuvant therapy in combating melanoma.

Quercetin nanoformulations: a promising strategy for tumor therapy

Phytochemicals as dietary constituents are being widely explored for the prevention and treatment of various diseases. Quercetin, a major constituent of various dietary products, has attracted extensive interest due to its anti-proliferative capability, reversal of multidrug resistance, autophagy promotion and tumor microenvironment modulation on different cancer types. Although quercetin has shown potent medical value, its application as an antitumor drug is limited. Problems like poor solubility, bioavailability and stability, short half-life and weak tumor-targeting biodistribution make quercetin an unreliable candidate for cancer therapy. Nanoparticle based platforms have shown a number of advantages in delivering a hydrophobic drug like quercetin to diseased tissues. Quercetin nanoparticles have demonstrated high encapsulation efficiency, stability, sustained release, prolonged circulation time, improved accumulation at tumor sites and therapeutic efficiency. Moreover, a combination of quercetin with other diagnostic or therapeutic agents in one nanocarrier has achieved enhancements in detecting or treating tumors. In this review, we have tried to summarize the pharmacological activities of quercetin with regard to tumor cells and microenvironments in vitro and in vivo. Furthermore, various nanoformulations have been highlighted for quercetin delivery for cancer treatment. These results suggest that quercetin nanoparticles may be a promising antitumor therapeutic agent.