In Vitro Anticancer Potential of Jasione montana and Its Main Components against Human Amelanotic Melanoma Cells

Using Flavonoid Substitution Status to Predict Anticancer Effects in Human Melanoma Cancers: An In Vitro Study

Skin cancers are a dominant type of cancer that impacts millions per year. Cancer is a heterogeneous disease triggered by the irreversible impairment of cellular homeostasis and function. In this study, we investigated the activity of 37 structurally diverse flavonoids to find potentially active substances using two melanoma cell lines: C32 and A375. First, the cytotoxic potential and DNA biosynthesis inhibition of flavonoids were tested to determine the most active compounds in cancer and normal cells. Second, the molecular mechanism of the anticancer activity of flavonoids was elucidated using Western blot and immunofluorescence analyses. Compounds 1, 6, 15, and 37 reduced the viability of A375 and C32 cell lines via the intrinsic and extrinsic pathways of apoptosis, whereas 16 and 17 acted in a higher degree via the inhibition of DNA biosynthesis. In our experiment, we demonstrated the anticancer activity of compound 15 (5,6-dihydroxyflavone) for the first time. The in vitro studies pointed out the importance of the flavonoid core in hydroxyl groups in the search for potential drugs for amelanotic melanoma.

Luteolin-Loaded Nanoparticles for the Treatment of Melanoma

Background and Purpose

Luteolin (LUT), a flavonoid found in various plants, has been reported to have potential therapeutic effects in melanoma. However, poor water solubility and low bioactivity have severely restricted the clinical application of LUT. Based on the high reactive oxygen species (ROS) levels in melanoma cells, we developed nanoparticles encapsulating LUT with the ROS-responsive material poly(propylene sulfide)-poly(ethylene glycol) (PPS-PEG) to enhance the water solubility of LUT, accelerate the release of LUT in melanoma cells, and further enhance its anti-melanoma effect, providing a viable solution for the application of LUT nano-delivery systems in melanoma therapy.

Methods

In this study, LUT-loaded nanoparticles were prepared with PPS-PEG and named as LUT-PPS-NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were applied to determine the size and morphology of LUT-PPS-NPs. In vitro studies were carried out to determine the uptake and mechanism of LUT-PPS-NPs by SK-MEL-28 melanoma cells. According to the CCK-8 assay, the cytotoxic effects of LUT-PPS-NPs on human skin fibroblasts (HSF) and SK-MEL-28 cells were assessed. Apoptosis assays, cell migration and invasion assays, and proliferation inhibition assays with low and normal density plating were also applied to test the in vitro anti-melanoma effect. Additionally, melanoma models were established utilizing BALB/c nude mice and initially evaluated the growth inhibitory impact following intratumoral injection of LUT-PPS-NPs.

Results

The size of LUT-PPS-NPs was 169.77 ± 7.33 nm with high drug loading (15.05 ± 0.07%). In vitro, cellular assays confirmed that LUT-PPS-NPs were efficiently internalized by SK-MEL-28 cells and showed low cytotoxicity against HSF. Moreover, LUT released from LUT-PPS-NPs significantly inhibited tumor cell proliferation, migration and invasion. Animal experiments showed that LUT-PPS-NPs inhibited tumor growth more than 2-fold compared with the LUT group.

Conclusion

In conclusion, the LUT-PPS-NPs developed in our study enhanced the anti-melanoma effect of LUT.

Glycerol and Natural Deep Eutectic Solvents Extraction for Preparation of Luteolin-Rich Jasione montana Extracts with Cosmeceutical Activity

Jasione montana is a plant from the family Campanulaceae rich in phenols with health-beneficial properties such as luteolin (LUT) derivatives. In this work, a glycerol-based ultrasound-assisted extraction method was developed and optimized for in total phenol (TP) and LUT content, as well as antiradical activity (RSA). The best conditions (glycerol content, temperature, plant material weight, and ultrasonication power) for the preparation of J. montana extracts richest in TP (OPT-TP), LUT (OPT-LUT), and having the best RSA (OPT-RSA) were determined. Furthermore, numerous natural deep eutectic solvents (NADES), containing proline, glycerol, betaine, urea, and glucose were prepared and used for the extraction of J. montana. Contents of TP, LUT, and RSA in the prepared extracts were established. Antioxidant and cosmeceutical activity of the prepared extracts was tested. The OPT-TP, OPT-LUT, and OPT-RSA, as well as the most efficient NADES-based extract, PG-50-TP, were excellent antioxidants and Fe²⁺ ion chelators. In addition, they were potent inhibitors of collagenase and hyaluronidase, as well as good significant anti-elastase and -lipoxygenase activity. The observed antioxidant- and enzyme-inhibiting activity of J. montana extracts prepared using environmentally friendly methods and non-toxic solvents makes them promising ingredients of cosmeceutical products.

Flavonoids as tyrosinase inhibitors in in silico and in vitro models: basic framework of SAR using a statistical modelling approach

Flavonoids are widely distributed in plants and constitute the most common polyphenolic phytoconstituents in the human diet. In this study, the in vitro inhibitory activity of 44 different flavonoids (1-44) against mushroom tyrosinase was studied, and an in silico study and type of inhibition for the most active compounds were evaluated too. Tyrosinase inhibitors block melanogenesis and take part in melanin production or distribution leading to pigmentation diseases. The in vitro study showed that quercetin was a competitive inhibitor (IC50=44.38 ± 0.13 µM) and achieved higher antityrosinase activity than the control inhibitor kojic acid. The in silico results highlight the importance of the flavonoid core with a hydroxyl at C7 as a strong contributor of interference with tyrosinase activity. According to the developed statistical model, the activity of molecules depends on hydroxylation at C3 and methylation at C8, C7, and C3 in the benzo-γ-pyrane ring of the flavonoids.

Recent Updates on Source, Biosynthesis, and Therapeutic Potential of Natural Flavonoid Luteolin: A Review

Nature gives immense resources that are beneficial to humankind. The natural compounds present in plants provide primary nutritional values to our diet. Apart from food, plants also provide chemical compounds with therapeutic values. The importance of these plant secondary metabolites is increasing due to more studies revealing their beneficial properties in treating and managing various diseases and their symptoms. Among them, flavonoids are crucial secondary metabolite compounds present in most plants. Of the reported 8000 flavonoid compounds, luteolin is an essential dietary compound. This review discusses the source of the essential flavonoid luteolin in various plants and its biosynthesis. Furthermore, the potential health benefits of luteolins such as anti-cancer, anti-microbial, anti-inflammatory, antioxidant, and anti-diabetic effects and their mechanisms are discussed in detail. The activity of luteolin and its derivatives are diverse, as they help to prevent and control many diseases and their life-threatening effects. This review will enhance the knowledge and recent findings regarding luteolin and its therapeutic effects, which are certainly useful in potentially utilizing this natural metabolite.

LC-PDA-MS and GC-MS Analysis of Scorzonera hispanica Seeds and Their Effects on Human Breast Cancer Cell Lines

Scorzonera hispanica is an herbaceous perennial cultivated in Central and Southern Europe. This study aimed to qualitatively and quantitatively evaluate the composition of oil, extracts, and fractions (SH1-SH12) obtained from S. hispanica seeds. Furthermore, an evaluation of biological activities in breast cancer cell lines was also performed. GC-MS analysis revealed that the primary components of the seed oil (SH12) were fatty acids and β-sitosterol. In the evaluation of extracts (SH1-SH3, SH8-SH10) and fractions (SH4-SH7, SH11) composition, the presence of apigenin, derivatives of p-coumaric and caffeic acids, was reported. In the biological assays, methanolic extract (SH1), diethyl ether (SH4), and chloroform (SH11) fractions exhibited cytotoxicity toward cells. The highest activity was observed for fatty acids- and 3,4-dimethoxycinnamate-rich SH11 (IC₅₀: 399.18 μg/mL for MCF-7, 781.26 μg/mL for MDA-MB-231). SH11 was also observed to induce apoptosis in MCF-7 cells (52.4%). SH1, SH4, and SH11 attenuate signaling pathways and affect the expression of apoptosis-, autophagy-, and inflammation-related proteins. SH12 was non-toxic toward either cancer or normal cell lines in concentrations up to 1 mg/mL. The results suggest that S. hispanica seeds exhibit a wide range of potential uses as a source of oil and bioactive compounds for complementary therapy of breast cancer.

Neochamaejasmin B extracted from Stellera chamaejasme L. induces apoptosis through caspase-10-dependent way in insect neuronal cells

To explore the toxicity mechanisms of neochamaejasmin B (NCB) extracted from Stellera chamaejasme L., we first evaluated its cytotoxicity in neuronal cells of Helicoverpa zea (AW1 cells). NCB inhibited cell growth and was cytotoxic to AW1 cells in a dose-dependent manner. Further, transmission electron microscopy (TEM) was used to analyze the microstructure, and typical apoptotic characteristics were observed in AW1 cells treated with NCB. Moreover, the NCB-induced apoptosis was dose dependent. Subsequently, we explored the mechanism of apoptosis. A decline in the mitochondrial membrane potential (MMP) was found. Also, the levels of Bax were increased with increases in drug concentration, but there was no statistical difference in Bcl-2 levels at different NCB doses. Caspase-3 and caspase-10 activity was increased. These findings confirmed that NCB induced apoptosis in AW1 cells through a caspase-10-dependent mechanism. The results provide the basic information needed for understanding the toxicity and mechanisms of action of NCB, which could potentially be used to develop NCB as a new insecticide.

Wound Healing Properties of Jasione montana Extracts and Their Main Secondary Metabolites

The effects of different extracts obtained from Jasione montana L. (JM1-JM6) and their main metabolites on biological processes during wound healing were evaluated. The effect on wound closure in the scratch test was established, and collagen type I synthesis and anti-inflammatory effects were assessed by flow cytometry in a human dermal fibroblast model (PCS-201-012). Additionally, the antioxidant activity (DPPH and FRAP) and degree of inhibition of elastase participating in the proliferation processes of skin fibroblasts were determined in an in vitro model. The extracts and fractions were analyzed using high-performance liquid chromatography-photodiode array detection (HPLC-PDA) to quantitatively characterize their main polyphenolic compounds. The high antioxidant activity of the JM4-JM5 fractions correlated with the content of luteolin and its derivative 7-O-glucoside. Luteolin also showed the highest anti-elastase activity with an IC50 value of 39.93 ± 1.06 μg/mL, and its substantial content in the JM4 fraction presumably determines its activity (359.03 ± 1.65 μg/mL). At lower concentrations (<50 μg/mL) of all extracts, cell proliferation and migration were significantly stimulated after 24 h of treatment. The stimulation of cell migration was comparable with that of allantoin, which was used as a positive control. However, most of the tested extracts showed limited capacity to affect collagen type I biosynthesis. Moreover, the tested samples exhibited a complex effect on cytokine secretion, and the strongest anti-inflammatory activity through the moderation of IL-1β, IL-6 and IL-8 was observed for JM4 and luteolin. Based on the obtained results of the quantitative analysis, the anti-inflammatory activity of JM4 may be due to the high content of luteolin. In summary, extracts from J. montana, which is flavonoid-rich, promote the viability and accelerate the migration of fibroblasts as well as moderate oxidant and inflammatory processes and elastase activity. Hence, they may be potentially useful for topical therapeutic applications to stimulate the wound healing process.

Skin cancer, including related pathways and therapy and the role of luteolin derivatives as potential therapeutics

Cutaneous malignant melanoma is the fastest growing and the most aggressive form of skin cancer that is diagnosed. However, its incidence is relatively scarce compared to the highest mortality rate of all skin cancers. The much more common skin cancers include nonmelanoma malignant skin cancers. Moreover, over the past several decades, the frequency of all skin cancers has increased much more dynamically than that of almost any other type of cancer. Among the available therapeutic options for skin cancers, chemotherapy used immediately after the surgical intervention has been an essential element. Unfortunately, the main problem with conventional chemopreventive regimens involves the lack of response to treatment and the associated side effects. Hence, there is a need for much more effective anticancer drugs. Correspondingly, the targeted alternatives have involved phytochemicals, which are safer chemotherapeutic agents and exhibit competitive anticancer activity with high therapeutic efficacy. Among polyphenolic compounds, some flavonoids and their derivatives, which are mostly found in medicinal plants, have been demonstrated to influence the modulation of signaling pathways at each stage of the carcinogenesis process, which is also important in the context of skin cancers. Hence, this review focuses on an exhaustive overview of the therapeutic effects of luteolin and its derivatives in the treatment and prevention of skin cancers. The bioavailability and structure–activity relationships of luteolin derivatives are also discussed. This review is the first such complete account of all of the scientific reports concerning this particular group of natural compounds that target a specific area of neoplastic diseases.

Plumbagin Elicits Cell-Specific Cytotoxic Effects and Metabolic Responses in Melanoma Cells

Melanoma is one of the most malignant skin cancers that require comprehensive therapies, including chemotherapy. A plant-derived drug, plumbagin (PLB), exhibits an anticancer property in several cancers. We compared the cytotoxic and metabolic roles of PLB in A375 and SK-MEL-28 cells, each with different aggressiveness. In our results, they were observed to have distinctive mitochondrial respiratory functions. The primary reactive oxygen species (ROS) source of A375 can be robustly attenuated by cell membrane permeabilization. A375 cell viability and proliferation, migration, and apoptosis induction are more sensitive to PLB treatment. PLB induced metabolic alternations in SK-MEL-28 cells, which included increasing mitochondrial oxidative phosphorylation (OXPHOS), mitochondrial ATP production, and mitochondrial mass. Decreasing mitochondrial OXPHOS and total ATP production with elevated mitochondrial membrane potential (MMP) were observed in PLB-induced A375 cells. PLB also induced ROS production and increased proton leak and non-mitochondria respiration in both cells. This study reveals the relationship between metabolism and cytotoxic effects of PLB in melanoma. PLB displays stronger cytotoxic effects on A375 cells, which exhibit lower respiratory function than SK-MEL-28 cells with higher respiratory function, and triggers cell-specific metabolic changes in accordance with its cytotoxic effects. These findings indicate that PLB might serve as a promising anticancer drug, targeting metabolism.