Vaccinium myrtillus L. extract and its native polyphenol‐recombined mixture have anti‐proliferative and pro‐apoptotic effects on human prostate cancer cell lines

A Review with a Focus on Vaccinium-Berries-Derived Bioactive Compounds for the Treatment of Reproductive Cancers

Cancers of the reproductive organs, including prostate, bladder, ovarian, and cervical cancers, are considered the most common causes of death in both sexes worldwide. The genus Vaccinium L. (Ericaceae) comprises fleshy berry crop species, including cranberries, blueberries, lingonberries, bilberries, and bog bilberries, and are widely distributed in many countries. Flavonols, anthocyanins (ACNs), proanthocyanidins (PACs), and phenolic acids are the most bioactive compounds naturally found in Vaccinium berries and have been extensively used as anticancer agents. However, it remains uncertain whether Vaccinium bioactives have a therapeutic role in reproductive cancers (RCs), and how these bioactives could be effective in modulating RC-related signalling pathways/molecular genes. Therefore, this article aims to review existing evidence in the PubMed/MEDLINE database on Vaccinium berries' major bioactive compounds in RC treatment and unravel the mechanisms underlying this process.

Src Tyrosine Kinase Inhibitory and Antioxidant Activity of Black Chokeberry and Bilberry Fruit Extracts Rich in Chlorogenic Acid

Edible berries such as the fruits of black chokeberry (Aronia melanocarpa (Michx.) Elliott) and bilberry (Vaccinium myrtillus L.) are considered to be rich in phenolic compounds, which are nowadays attracting great interest due to their promising health benefits. The main objective of our study was to investigate, for the first time, their inhibitory properties on Src tyrosine kinase activity, as this enzyme plays an important role in multiple cellular processes and is activated in both cancer and inflammatory cells. In hydroethanolic fruit extracts, 5.0-5.9% of total polyphenols were determined spectrophotometrically, including high amounts of hydroxycinnamic acid derivatives. HPLC analysis revealed that the black chokeberry and bilberry extracts contained 2.05 mg/g and 2.54 mg/g of chlorogenic acid, respectively. Using a time-resolved fluorescence resonance energy transfer (TR-FRET) assay, the extracts studied were found to have comparable inhibitory effects on Src tyrosine kinase, with IC50 values of 366 µg/mL and 369 µg/mL, respectively. The results also indicated that chlorogenic acid contributes significantly to the observed effect. In addition, both fruit extracts exhibited antioxidant activity by scavenging DPPH and NO radicals with SC50 values of 153-352 µg/mL. Our study suggested that black chokeberry and bilberry fruits may be beneficial in cancer and other inflammation-related diseases.

Single-Cell Analysis Reveals Transcriptomic Features of Drug-Tolerant Persisters and Stromal Adaptation in a Patient-Derived EGFR-Mutated Lung Adenocarcinoma Xenograft Model

INTRODUCTION

Targeted therapies require life-long treatment, as drug discontinuation invariably leads to tumor recurrence. Recurrence is mainly driven by minor subpopulations of drug-tolerant persister (DTP) cells that survive the cytotoxic drug effect. In lung cancer, DTP studies have mainly been conducted with cell line models.

METHODS

We conducted an in vivo DTP study using a lung adenocarcinoma patient-derived xenograft tumor driven by an EGFR mutation. Daily treatment of tumor-bearing mice for 5 to 6 weeks with the EGFR inhibitor erlotinib markedly shrunk tumors and generated DTPs, which were analyzed by whole exome, bulk population transcriptome, and single-cell RNA sequencing.

RESULTS

The DTP tumors maintained the genomic clonal architecture of untreated baseline (BL) tumors but had reduced proliferation. Single-cell RNA sequencing identified a rare (approximately 4%) subpopulation of BL cells (DTP-like) with transcriptomic similarity to DTP cells and intermediate activity of pathways that are up-regulated in DTPs. Furthermore, the predominant transforming growth factor-β activated cancer-associated fibroblast (CAF) population in BL tumors was replaced by a CAF population enriched for IL6 production. In vitro experiments indicate that these populations interconvert depending on the levels of transforming growth factor-β versus NF-κB signaling, which is modulated by tyrosine kinase inhibitor presence. The DTPs had signs of increased NF-κB and STAT3 signaling, which may promote their survival.

CONCLUSIONS

The DTPs may arise from a specific preexisting subpopulation of cancer cells with partial activation of specific drug resistance pathways. Tyrosine kinase inhibitor treatment induces DTPs revealing greater activation of these pathways while converting the major preexisting CAF population into a new state that may further promote DTP survival.

Vaccinium Species (Ericaceae): Phytochemistry and Biological Properties of Medicinal Plants

The Vaccinium L. (Ericaceae) genus consists of a globally widespread and diverse genus of around 4250 species, of which the most valuable is the Vaccinioidae subfamily. The current review focuses on the distribution, history, bioactive compounds, and health-related effects of three species: cranberry, blueberry, and huckleberry. Several studies highlight that the consumption of Vaccinium spp. presents numerous beneficial health-related outcomes, including antioxidant, antimicrobial, anti-inflammatory, and protective effects against diabetes, obesity, cancer, neurodegenerative diseases and cardiovascular disorders. These plants' prevalence and commercial value have enhanced in the past several years; thus, the generated by-products have also increased. Consequently, the identified phenolic compounds found in the discarded leaves of these plants are also presented, and their impact on health and economic value is discussed. The main bioactive compounds identified in this genus belong to anthocyanins (cyanidin, malvidin, and delphinidin), flavonoids (quercetin, isoquercetin, and astragalin), phenolic acids (gallic, p-Coumaric, cinnamic, syringic, ferulic, and caffeic acids), and iridoids.

Behind the Scenes of Anthocyanins-From the Health Benefits to Potential Applications in Food, Pharmaceutical and Cosmetic Fields

Anthocyanins are widespread and biologically active water-soluble phenolic pigments responsible for a wide range of vivid colours, from red (acidic conditions) to purplish blue (basic conditions), present in fruits, vegetables, and coloured grains. The pigments' stability and colours are influenced mainly by pH but also by structure, temperature, and light. The colour-stabilizing mechanisms of plants are determined by inter- and intramolecular co-pigmentation and metal complexation, driven by van der Waals, π-π stacking, hydrogen bonding, and metal-ligand interactions. This group of flavonoids is well-known to have potent anti-inflammatory and antioxidant effects, which explains the biological effects associated with them. Therefore, this review provides an overview of the role of anthocyanins as natural colorants, showing they are less harmful than conventional colorants, with several technological potential applications in different industrial fields, namely in the textile and food industries, as well as in the development of photosensitizers for dye-sensitized solar cells, as new photosensitizers in photodynamic therapy, pharmaceuticals, and in the cosmetic industry, mainly on the formulation of skin care formulations, sunscreen filters, nail colorants, skin & hair cleansing products, amongst others. In addition, we will unveil some of the latest studies about the health benefits of anthocyanins, mainly focusing on the protection against the most prevalent human diseases mediated by oxidative stress, namely cardiovascular and neurodegenerative diseases, cancer, and diabetes. The contribution of anthocyanins to visual health is also very relevant and will be briefly explored.

Quality by Design in optimizing the extraction of (poly)phenolic compounds from Vaccinium myrtillus berries

Quality by Design was adopted for developing an effective extraction procedure of (poly)phenolic compounds from bilberry (Vaccinium myrtillus L.) fruits, using a pooled sample of berries from different regions of Ukraine. Mechanical solvent extraction, microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) were investigated by screening matrices. Extraction time (Time, from 5 to 15 min), organic solvent type (OS type, methanol, ethanol and acetone), organic solvent percentage (OS%, from 50% to 90%), sample/extractant ratio (S/E ratio, from 0.025 to 0.1 g mL^-1), and, only for MAE, extraction temperature (T, from 30 to 60°C), were selected as critical method parameters (CMPs). The spectrophotometric assays total soluble polyphenols (TSP), total monomeric anthocyanins (TMA), and radical scavenging activity (evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), the 2,2'-azino-di-(3-ethylbenzthiazoline sulfonic acid), and the ferric reducing antioxidant power methods) were chosen as critical method attributes (CMAs). The screening procedure allowed for selecting UAE and methanol, while the other CMPs underwent further optimization through Response Surface Methodology. Target values for TSP, TMA and DPPH were selected and the method operable design region (MODR) was defined by means of Monte-Carlo simulations. The optimized conditions, with the corresponding MODR intervals in bracket, were the following: (i) Time, 17 min (15-23 min); OS%, 56% (44-59%); S/E ratio, 0.030 (0.022-0.034) g mL^-1. Under these experimental conditions, CMAs values of the pooled sample were the following (n = 3): TSP=4433±176 mg (+)-catechin eq/100 g dry weight (d.w.); TMA=3575±194 mg cyanidin-3-glucoside eq/100 g d.w.; DPPH=273±5 μg DPPH inhib./mg d.w. The optimized extraction method was tested for matrix effect (ME%) in the UHPLC-MS/MS analysis of 15 anthocyanins and 20 non-anthocyanins individual (poly)phenols commonly found in bilberries, as well as for luteolin, sinapic acid, and pelargonidin-3-glucoside, absent in this fruit and therefore added to the extracts as surrogate standards for evaluating apparent recovery (AR%). |ME%| was in any case ≤ 23% and AR% of the surrogate standards in the range 91-95%, confirming the very good performances of the optimized extraction method.

Bilberries: Curative and Miraculous – A Review on Bioactive Constituents and Clinical Research

Bilberry (Vaccinium myrtillus L.) fruits are an important part of local diets in many countries and are used as a medicinal herb to treat various disorders. Extracts from fruits are often a part of eye health-promoting supplements, whereas extracts from leaves are advertised for type 2 diabetes mellitus and glycemic control. This review provides an overview of the current knowledge of the phytochemical contents of bilberry fruits and leaves and their bioactivities, critically summarizes origins of the health claims and the outcome of clinical trials, with special attention towards those published in the past 10 years. Overall, the three most referenced indications, which are type 2 diabetes mellitus, vision disorders and circulatory diseases, all include contradictory results with no clear conclusion as to the benefits and recommended dosages. Moreover, the indications for vision disorders and diabetes originate from unproven or false claims that have been repeated in research since the 20th century without consistent fact-checking. Beneficial clinical results have been attested for the treatment of dyslipidemia and chronic inflammatory disorders when applied as dietary supplementation of fresh bilberries or as anthocyanin-rich bilberry fruit extracts. However, there is a general lack of double-blinded controlled research with larger sample sizes.

Dietary Polyphenols: Extraction, Identification, Bioavailability, and Role for Prevention and Treatment of Colorectal and Prostate Cancers

Fruits, vegetables, and other edible plants in our diet have numerous health benefits, due to the bioactive compounds in these food items, including polyphenols. These plants are a rich and promising source of natural products and phytochemicals that can be used to treat and prevent numerous diseases and prevent the progression of cancer. Dietary polyphenols exhibit chemo-preventive and therapeutic effects against various ailments, including several types of cancer. The current study focuses on polyphenol’s traditional and advanced extraction methods, with supercritical extraction as a novel approach. It also deals with their identification, bioavailability, and role in preventing and treating colorectal and prostate cancers. Additionally, the article covers the literature that deals with the anticancer activities of polyphenols, as well as their potential use as anticancer agents.

Electrochemical sensors based on sewage sludge-derived biochar for the analysis of anthocyanins in berry fruits

The reutilization of waste and the reduction of the general environmental impact of every production are fundamental goals that must be achieved in the framework of a circular economy. Recycled carbon-rich materials may represent a promising alternative to other less-sustainable carbonaceous materials used in the production of electrochemical sensing platforms. Herein, we propose an innovative carbon paste electrode (CPE) composed of biochar derived from biological sludge obtained from municipal and industrial wastewater treatment plants. The physicochemical properties of the biochar after a chemical treatment with an acidic solution obtained from industrial by-products were investigated. The electrode surface characterization was carried out by analyzing common redox probes and multiple phenols bearing varying numbers of –OH and –OCH₃ groups in their structure. Furthermore, the CPE was also tested on the evaluation of the phenolic fingerprints of Vaccinium myrtillus, Vaccinium uliginosum subsp. gaultherioides, and Fragaria × ananassa. Standard anthocyanin mixtures and extracts of the aforementioned fruits were analyzed to provide a phenolic characterization of real samples. The obtained results show that the sewage sludge–derived biochar can be a promising material for the development of electroanalytical sensors.

The Promising Therapeutic and Preventive Properties of Anthocyanidins/Anthocyanins on Prostate Cancer

As water-soluble flavonoid derivatives, anthocyanidins and anthocyanins are the plants pigments mostly rich in berries, pomegranate, grapes, and dark color fruits. Many bioactivity properties of these advantageous phytochemicals have been reported; among them, their significant abilities in the suppression of tumor cells are of the promising therapeutic features, which have recently attracted great attention. The prostate malignancy, is considered the 2nd fatal and the most distributed cancer type in men worldwide. The present study was designated to gather the preclinical and clinical studies evaluating potencies of anthocyanidins/anthocyanins for the treatment and prevention of this cancer type for the first time. In general, findings confirm that the anthocyanins (especifically cyanidin-3-O-glucoside) indicated higher activity against prostatic neoplasms compared to their correlated anthocyanidins (e.g., delphinidin); in which potent anti-inflammatory, apoptosis, and anti-proliferative activities were analyzed. Complementary anti-prostate cancer assessment of diverse naturally occurred anthocyanidins/anthocyanins and their synthetically optimized derivatives through preclinical experiments and eventually confirmed by clinical trials can promisingly lead to discover natural-based chemotherapeutic drug options.

Phytochemical and pharmacological anti-diabetic properties of bilberries (Vaccinium myrtillus), recommendations for future studies

Nowadays, extensive attention has focused on dietary constituents that may be valuable for treating, eating, and preventing diabetes. Numerous studies have shown that anthocyanin's are one of the most important nutritional factors associated with diabetes. Anthocyanin's are the leading group of water-soluble pigments in the plant kingdom, and they are generally available in some human diet in fruits, vegetables, cereals, beans. Amongst, bilberries (Vaccinium myrtillus), is one of the essential sources for dietary anthocyanin consumption containing vast amounts of anthocyanin's, making them the main plant in the treatment and prevention of diabetes. Although the bilberries have other valuable properties such as anti-cancer, anti-inflammatory, and antioxidant, the main focus of the present study is to present the effects of bilberries (V. myrtillus) on the prevention and treatment of diabetes.

Comparison of chemometric strategies for potential exposure marker discovery and false-positive reduction in untargeted metabolomics: application to the serum analysis by LC-HRMS after intake of Vaccinium fruit supplements

Untargeted liquid chromatographic-high-resolution mass spectrometric (LC-HRMS) metabolomics for potential exposure marker (PEM) discovery in nutrikinetic studies generates complex outputs. The correct selection of statistically significant PEMs is a crucial analytical step for understanding nutrition-health interactions. Hence, in this paper, different chemometric selection workflows for PEM discovery, using multivariate or univariate parametric or non-parametric data analyses, were comparatively tested and evaluated. The PEM selection protocols were applied to a small-sample-size untargeted LC-HRMS study of a longitudinal set of serum samples from 20 volunteers after a single intake of (poly)phenolic-rich Vaccinium myrtillus and Vaccinium corymbosum supplements. The non-parametric Games-Howell test identified a restricted group of significant features, thus minimizing the risk of false-positive retention. Among the forty-seven PEMs exhibiting a statistically significant postprandial kinetics, twelve were successfully annotated as purine pathway metabolites, benzoic and benzodiol metabolites, indole alkaloids, and organic and fatty acids, and five (i.e. octahydro-methyl-β-carboline-dicarboxylic acid, tetrahydro-methyl-β-carboline-dicarboxylic acid, citric acid, caprylic acid, and azelaic acid) were associated to Vaccinium berry consumption for the first time. The analysis of the area under the curve of the longitudinal dataset highlighted thirteen statistically significant PEMs discriminating the two interventions, including four intra-intervention relevant metabolites (i.e. abscisic acid glucuronide, catechol sulphate, methyl-catechol sulphate, and α-hydroxy-hippuric acid). Principal component analysis and sample classification through linear discriminant analysis performed on PEM maximum intensity confirmed the discriminating role of these PEMs.

HPLC/ESI-MS and NMR Analysis of Chemical Constitutes in Bioactive Extract from the Root Nodule of Vaccinium emarginatum

Vaccinium emarginatum Hayata is a medicinal plant that has been historically used in ethnopharmacy to treat diseases in Taiwan. The objective of this study is to evaluate the anti-cancer and anti-bacterial constitutes from the root nodule extract of V. emarginatum. The chemical composition of V. emarginatum fractions was analyzed by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) and the chemical constitutes were isolated and structurally identified by nuclear magnetic resonance (NMR) spectroscopy. Bioassay-guided chromatography showed that the ethyl acetate (EA) fraction was bioactive on the hepatocellular carcinoma (HepG2). By LC-ESI-MS/MS analysis, twenty peaks of EA fraction were partially identified and the phytochemical investigation of the fractions led to the isolation and identification of protocatuchuic acid (1), epicatechin (2), catechin (3), procyanidin B3 (4), procyanidin A1 (5), hyperin (6), isoquercetin (7), quercetin (8), lupeol (9), beta-amyrin (10), and alpha-amyrin (11). Both procyanidin B3 and A1 exhibited anti-proliferative activity against HepG2 and gastric adenocarcinoma (AGS) cells at IC₅₀ values between 38.4 and 41.1 μM and 79.4 and 83.8 μM, respectively. In addition, isoquercetin displayed the strongest anti-proliferative activity against the HepG2, lung carcinoma (A549), and AGS cell at 18.7, 24.6 and 68.5 μM, respectively. Among the triterpenoids, only lupeol showed the inhibitory activity against all tested tumor cell lines at IC₅₀ values between 72.9 and 146.8 μM. Furthermore, procyanidins B3, A1 and isoquercetin displayed moderate anti-bacterial activity against Staphylococcus aureus. In conclusion, this study provides background information on the exploitation of V. emarginatum as a potential natural anti-cancer and anti-bacterial agent in pharmaceutical research.

Real-time fluorescence imaging of anthocyanins complexed with diphenylboric acid 2-aminoethyl inside B16-F10 melanoma cells

Anthocyanins (AN), natural compounds daily consumed by humans, have outstanding therapeutical potential if administered topically in melanoma pathology. However, the search for efficient therapy development is still in progress, owing to the lack of complete understanding of the AN intracellular path, once they are uptaken by the cells. This target is constrained by the need for an imaging strategy that would enable their intracellular detection and localization in-situ. In this light, diphenylboric acid 2-aminoethyl (DPBA), a non-fluorescent reagent, was here successfully used to form fluorescent complexes with AN. The AN used are the cyanidin aglycon as a free standard molecule (CY), and the glycosylated compounds, extracted and purified from chokeberry fruits (AE). In solution, it was observed that the fluorescence emission increased by 39% (CY@DPBA), and by 34% (AE@DPBA), which concludes that AN form fluorescent complexes with DPBA (CY@DPBA and AE@DPBA). In addition, using NMR (nuclear magnetic resonance) spectroscopy, and HRMS (high-resolution mass spectrometry) analysis, the structure of the CY@DPBA complex was efficiently elucidated. In-vitro experiments showed that the complexes formed after the treatment proved to be non-toxic on B16-F10 cells. The sub-cellular visualization of all AN was monitored by fluorescence microscopy and flow cytometry, demonstrating detectable signals of the non-metabolized CY and glycosylated CY inside melanoma cells. This study reports that the use of DPBA to image AN intracellularly is a sensitive, non-invasive and successful method that can extend its application in broad fields like drug development or metabolism-associated mechanisms.

Liquid Chromatographic Quadrupole Time-of-Flight Mass Spectrometric Untargeted Profiling of (Poly)phenolic Compounds in Rubus idaeus L. and Rubus occidentalis L. Fruits and Their Comparative Evaluation

This study provided a detailed profiling of the antioxidant and bioactive compounds occurring in three varieties of Rubus idaeus L. fruits (“Fall Gold”, “Glen Ample” and “Tulameen”) compared to Rubus occidentalis L. black raspberry (“Jewel” cultivar), adopting a comprehensive untargeted metabolomics approach developed with UHPLC analysis coupled with quadrupole/time-of-flight high resolution mass spectrometry, using the SWATH^® acquisition protocol. The feature selection and annotation workflow, applied to the analysis of raspberry extracts in both polarities, allowed identifying 68 bioactive compounds mainly belonging to the classes of (poly)phenolic compounds. Interestingly, some of these identifications (e.g., ferulic acid glycosides and the ellagitannin-like nobotanin/malabathrin) represent the first report in raspberry fruits. Principal component analysis made possible highlighting the features more related to the expression of a genotype effect within the R. idaeus species or between the two raspberry species herein investigated. Overall, flavanols were the most discriminating features for the Fall Gold variety, whereas ellagitannins and flavonol glycosides represent more distinctive metabolic traits in Glen Ample and Tulameen fruits. Moreover, R. occidentalis Jewel variety was strongly characterized by the occurrence of anthocyanins, such as cyanidin, pelargonidin and delphinidin glycosides.