Enhancing the Cancer Cell Growth Inhibitory Effects of Table Grape Anthocyanins

Design and development of locust bean gum-endowed/Phyllanthus reticulatus anthocyanin- functionalized biogenic gold nanosystem for enhanced antioxidative and anticancer chemotherapy

Herein, the design and fabrication of an anticancer nanoplatform (LBG/PRA-NG) based on locust bean gum-stabilized nanogold and functionalized with Phyllanthus reticulatus anthocyanins was described. LBG/PRA-NG was prepared in an eco-friendly, one-pot approach at room temperature, mediated by the anthocyanins and gum as bio-reductant and stabilizer, respectively. The nanostructure was elaborately characterized by FESEM, TEM, UV-visible, DLS, Zeta potential, FTIR, XRD, TGA/DTG, and XPS analysis. Its anticancer attributes were examined based on cytotoxicity on MCF-7 and MDA-MB-231 breast cancer cell lines, as well as the generation of intracellular reactive oxygen species. The results revealed the successful formation of a homogenous and highly stable nanocomposite (LBG/PRA-NG), with quasi-spherical shape, small size (14.73 nm), Zeta potential and PDI values of -58.30 mV and 0.237, respectively. The presence of a plasmonic peak at 525 nm was indicative of AuNPs. Compared to the galactomannan and anthocyanin, LBG/PRA-NG exhibited superior antioxidative properties with IC50 values of 35.44 μg/mL against DPPH and 24.55 μg/mL against ABTS+. Notably, LBG/PRA-NG also demonstrated enhanced anticancer properties relative to LBG and anthocyanins, with IC50 values of 16.17 μg/mL and 25.06 μg/mL against MCF-7 and MDA-MB-231 cells. Meanwhile, the normal cells (HEK-293 and L929) resisted the innocuous effects of LBG/PRA-NG. Furthermore, treatment of breast cancer cells with LBG/PRA-NG drastically elevated the intracellular ROS levels. This suggested that the anticancer activity of LBG/PRA-NG may be mediated via amplification of ROS/oxidative stress-induced apoptosis. Altogether, these findings indicate the remarkable potential of LBG/PRA-NC in the development of anticancer therapy.

Causal relationship between dietary factors and breast cancer risk: A Mendelian randomization study

Background

Previous studies have discovered an association between dietary factors and breast cancer. However, few studies have used Mendelian randomization (MR) to assess the potential causal relationship between dietary factors and breast cancer.

Methods

The exposure datasets for fresh fruit intake, dried fruit intake, salad/raw vegetable intake, cooked vegetable intake, oily fish intake, non-oily fish intake, cheese intake, and bread intake were obtained from the UK Biobank. The outcome dataset was extracted from the Breast Cancer Association Consortium (BCAC). We used the inverse variance weighted (IVW) method as the primary approach for the two-sample MR analysis. To ensure the accuracy of the results, we conducted heterogeneity and horizontal pleiotropy analyses. Additionally, multivariable MR analysis was conducted to ensure the stability of the results.

Results

Dried fruit intake was found to be a protective factor for overall breast cancer (outliers excluded: OR: 0.549; 95 % CI: 0.429-0.702; p = 1.75 × 10-6). Subtype analyses showed that dried fruit intake was inversely associated with both estrogen receptor-positive (ER+) breast cancer (outliers excluded: OR: 0.669; 95 % CI: 0.512-0.875; p = 0.003) and ER-negative (ER-) breast cancer (OR: 0.559; 95 % CI: 0.379-0.827; p = 0.004), while fresh fruit intake was inversely associated with ER- breast cancer (excluded outliers: OR: 0.510; 95 % CI: 0.308-0.846; p = 0.009). No significant causal relationship was found between other dietary intakes and breast cancer. After adjusting for the effects of possible confounders, the causal relationships found by the two-sample MR analysis remained.

Conclusion

Our study provides evidence that dried fruit intake may reduce the risk of both ER+ and ER- breast cancer, and fresh fruit intake may reduce the risk of ER- breast cancer. Other factors included in this study were not linked to breast cancer.

The preventive and therapeutic effects of anthocyanins on colorectal cancer: A comprehensive review based on up-to-date experimental studies

Colorectal cancer (CRC) is the second most lethal and the third most diagnosed type of cancer worldwide. More than 75% of CRC cases are sporadic and lifestyle-related. Risk factors include diet, physical inactivity, genetics, smoking, alcohol, changes in the intestinal microbiota, and inflammation-related diseases such as obesity, diabetes, and inflammatory bowel diseases. The limits of conventional treatments (surgery, chemotherapy, radiotherapy), as demonstrated by the side effects and resistance of many CRC patients, are making professionals search for new chemopreventive alternatives. In this context, diets rich in fruits and vegetables or plant-based products, which contain high levels of phytochemicals, have been postulated as complementary therapeutic options. Anthocyanins, phenolic pigments responsible for the vivid colors of most red, purple, and blue fruits and vegetables, have been shown protective effects on CRC. Berries, grapes, Brazilian fruits, and vegetables such as black rice and purple sweet potato are examples of products rich in anthocyanins, which have been able to reduce cancer development by modulating signaling pathways associated with CRC. Therefore, this review has as main objective to present and discuss the potential preventive and therapeutic effects of anthocyanins present in fruits and vegetables, in plant extracts, or in their pure form on CRC, taking into account up-to-date experimental studies (2017-2023). Additionally, a highlight is given towards the mechanisms of action of anthocyanins on CRC.

Anti-cancer effect of entacaponeon esophageal cancer cells via apoptosis induction and cell cycle modulation

BACKGROUND

Esophageal cancer (EC) is the sixth leading cause of cancer-related death, despite many advances in treatment, the survival of patients still remains poor. In recent years, the N6-methyladenosine (m6A) has been introduced as one of the most important modifications at the epitranscriptome level, with an important role in the mRNA regulation in various diseases, such as cancers. The m6A is regulated by different factors, including FTO as a demethylase. The m6A modification, especially through FTO overexpression has an oncogenic role in different cancer types such as EC. Recent studies showed that entacapone, a catechol-o-methyl transferase (COMT) inhibitor currently applied for Parkinson's disease, can inhibit FTO enzyme.

AIMS

In this study, we aimed to investigate the effect of entacapone as an FTO inhibitor on the m6A level and also apoptosis and cell cycle response in KYSE-30 and YM-1 of esophageal squamous cancer cell (ESCC) lines.

METHODS

Cell toxicity and IC50 of entacapone were evaluated using The MTT assay in YM-1 and KYSE-30 cells. Cells were treated into two groups: DMSO (control) and entacapone (mean IC₅₀ ). Total RNA was extracted, and m6A levels were measured via the ELISA method. Subsequently, the apoptosis and cell cycle dys-regulation were detected by annexin-V-FITC/PI staining and PI staining via flow cytometry.

RESULTS

Entacapone has the cytotoxicity effect on both esophageal cancer cell lines compared to normal PBMC cells. As well, entacapone treatment (140 μM) can induce apoptosis (KYSE-30: 50%. YM-1:22.6%) and has a modulatory effect on cell cycle progression in both YM-1 and KYSE-30 cells (p-value<.05). However, no significant difference in the m6A concentration was observed.

CONCLUSION

Our findings suggested that entacapone has the inhibitory effect on ESCC cell lines through induction of the apoptosis and modulation of the cell cycle without toxicity on the normal PBMC.

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.

Main Determinants Affecting the Antiproliferative Activity of Stilbenes and Their Gut Microbiota Metabolites in Colon Cancer Cells: A Structure-Activity Relationship Study

trans-Resveratrol can be catabolized by the gut microbiota to dihydroresveratrol, 3,4'-dihydroxy-trans-stilbene, lunularin, and 4-hydroxydibenzyl. These metabolites can reach relevant concentrations in the colon. However, not all individuals metabolize RSV equally, as it depends on their RSV gut microbiota metabotype (i.e., lunularin producers vs. non-producers). However, how this microbial metabolism affects the cancer chemopreventive activity of stilbenes and their microbial metabolites is poorly known. We investigated the structure-antiproliferative activity relationship of dietary stilbenes, their gut microbial metabolites, and various analogs in human cancer (Caco-2 and HT-29) and non-tumorigenic (CCD18-Co) colon cells. The antiproliferative IC₅₀ values of pterostilbene, oxy-resveratrol, piceatannol, resveratrol, dihydroresveratrol, lunularin, 3,4'-dihydroxy-trans-stilbene, pinosylvin, dihydropinosylvin, 4-hydroxy-trans-stilbene, 4-hydroxydibenzyl, 3-hydroxydibenzyl, and 4-trans-stilbenemethanol were calculated. IC₅₀ values were correlated with 34 molecular characteristics by bi- and multivariate analysis. Little or no activity on CCD18-Co was observed, while Caco-2 was more sensitive than HT-29, which was explained by their different capacities to metabolize the compounds. Caco-2 IC₅₀ values ranged from 11.4 ± 10.1 μM (4-hydroxy-trans-stilbene) to 73.9 ± 13.8 μM (dihydropinosylvin). In HT-29, the values ranged from 24.4 ± 11.3 μM (4-hydroxy-trans-stilbene) to 96.7 ± 6.7 μM (4-hydroxydibenzyl). At their IC₅₀, most compounds induced apoptosis and arrested the cell cycle at the S phase, pterostilbene at G₂/M, while 4-hydroxy-trans-stilbene and 3,4'-dihydroxy-trans-stilbene arrested at both phases. Higher Connolly values (larger size) hindered the antiproliferative activity, while a lower pKa1 enhanced the activity in Caco-2, and higher LogP values (more hydrophobicity) increased the activity in HT-29. Reducing the styrene double bond in stilbenes was the most critical feature in decreasing the antiproliferative activity. These results (i) suggest that gut microbiota metabolism determines the antiproliferative effects of dietary stilbenes. Therefore, RSV consumption might exert different effects in individuals depending on their gut microbiota metabotypes associated with RSV metabolism, and (ii) could help design customized drugs with a stilbenoid and (or) dibenzyl core against colorectal cancer.

Chemopreventive and therapeutic properties of anthocyanins in breast cancer: A comprehensive review

Anthocyanins have received the attention of the scientific community because of their antioxidant, antimetastatic, and cancer-inhibitory properties. The aim of this review is to comprehensively summarize the possible mechanisms by which anthocyanins exhibit anticarcinogenic properties in breast cancer (BC) cell lines and animal models. Anthocyanins inhibit proinflammatory, signal transducer and activator of transcription 3, and nuclear factor kappa-light-chain-enhancer of activated B cell pathways and increase the activities of detoxification enzymes. In addition, downregulation of metalloproteinases by anthocyanins inhibits tumor invasion and metastatic processes in experimental systems. Anthocyanins mediate anticancer and angiogenic effects by modifying multiple receptor families. Furthermore, inhibition of cell-cycle upstream polo-like kinase signaling, the chromosomal replication checkpoint, and ataxia telangiectasia mutated signaling may contribute to the anticarcinogenic effects of anthocyanins. Finally, anthocyanins induce mitochondrial-mediated apoptosis and downregulate the phosphatidylinositol-3-kinase/AKT/mTOR pathway. In conclusion, anthocyanins have been shown to exert potential antitumor effects against breast carcinogenesis in vitro and in vivo, providing insights into the use of anthocyanins as a natural chemopreventive intervention in BC.

Stability and Antiproliferative Activity of Malvidin-Based Non-Oxonium Derivative (Oxovitisin A) Compared with Precursor Anthocyanins and Pyranoanthocyanins

Oxovitisins are a unique group of anthocyanin derivatives with a non-oxonium nature and α-pyranone (lactone) D ring on the structure. In this study, oxovitisin A was synthesized through the micro-oxidative reaction of carboxypyranomalvidin-3-O-glucoside (vitisin A) with water, and its thermostability, pH, and SO₂ color stability were studied compared with its two precursors, malvidin-3-O-glucoside (Mv3glc) and vitisin A, as well as methylpyrano-malvidin-3-O-glucoside (Me-py). Results showed that oxovitisin A exhibited the highest stabilities, which were inseparably related to its noncharged structure and the additional carbonyl group on the D ring. Moreover, the antiproliferative capacity of oxovitisin A was comparatively evaluated against two human gastrointestinal cancer cell lines. Interestingly, oxovitisin A presented the strongest antiproliferative ability on MKN-28 (IC₅₀ = 538.42 ± 50.06 μM) and Caco-2 cells (IC₅₀ = 434.85 ± 11.87 μM) compared with two other pyranoanthocyanins. Therefore, we conclude that oxovitisin A as a highly stable anthocyanin derivative still exhibits a satisfactory antiproliferative ability.

Anthocyanins as Key Phytochemicals Acting for the Prevention of Metabolic Diseases: An Overview

Anthocyanins are water-soluble pigments present in fruits and vegetables, which render them an extensive range of colors. They have a wide distribution in the human diet, are innocuous, and, based on numerous studies, have supposed preventive and therapeutical benefits against chronic affections such as inflammatory, neurological, cardiovascular, digestive disorders, diabetes, and cancer, mostly due to their antioxidant action. Despite their great potential as pharmaceutical applications, they have a rather limited use because of their rather low stability to environmental variations. Their absorption was noticed to occur best in the stomach and small intestine, but the pH fluctuation of the digestive system impacts their rapid degradation. Urine excretion and tissue distribution also occur at low rates. The aim of this review is to highlight the chemical characteristics of anthocyanins and emphasize their weaknesses regarding bioavailability. It also targets to deliver an update on the recent advances in the involvement of anthocyanins in different pathologies with a focus on in vivo, in vitro, animal, and human clinical trials.

Anthocyanins in Colorectal Cancer Prevention Review

Colorectal cancer (CRC) is still a big health burden worldwide. Nutrition and dietary factors are known to affect colorectal cancer development and prognosis. The protective roles of diets rich in fruits and vegetables have been previously reported to contain high levels of cancer-fighting phytochemicals. Anthocyanins are the most abundant flavonoid compounds that are responsible for the bright colors of most blue, purple, and red fruits and vegetables, and have been shown to contribute to the protective effects of fruits and vegetables against cancer and other chronic diseases. Berries and grapes are the most common anthocyanin-rich fruits with antitumor effects. The antitumor effects of anthocyanins are determined by their structures and bioavailability as well as how they are metabolized. In this review, we aimed to discuss the preventive as well as therapeutic potentials of anthocyanins in CRC. We summarized the antitumor effects of anthocyanins and the mechanisms of action. We also discussed the potential pharmaceutical application of anthocyanins in practice.

Hydroethanolic Extracts of the Aristotelia Chilensis (Maqui) Berry Reduces Cellular Viability and Invasiveness in the Endometrial Cancer Cell Line Ishikawa

Cancer of the reproductive tract includes diseases with higher prevalence in the female population. This investigation examined whether an anthocyanin-enriched extract of Aristotelia chilensis, commonly known as "maqui," could affect some hallmarks of endometrial cancer. Cultures of the human endometrial cancer cell line Ishikawa were treated with a hydroethanolic maqui extract at 1, 3, 10, 30, 100, 300, or 1000 µg/mL to determine the effect on cell viability by MTT assay. Then, we used the 50% Effective Concentration (EC50) to evaluate whether the effect of the maqui extract is mediated via an arrest of the cell cycle or induction of apoptosis using flow cytometry or Annexin V-FITC assays, respectively. The effects of sublethal doses of the maqui extract on migration and invasiveness of Ishikawa cells were also evaluated by the wound healing and Boyden Chamber assay, respectively. Our results show that the hydroethanolic maqui extract inhibits the cell viability with an EC50 of 472.3 µg/mL via increased apoptosis, and that reduces the invasive capacity but not migration of Ishikawa cells. These findings suggest that the hydroethanolic maqui extract has antineoplastic properties for endometrial cancer and merits further studies to corroborate its efficiency as anticancer therapy in reproductive organs.

Anthocyanin supplement as a dietary strategy in cancer prevention and management: A comprehensive review

Anthocyanins are natural pigments proven to be beneficial in the vast majority of health problems with no side effects. In this review, the latest progress on the cancer prevention and management of anthocyanins in treating cancers ranked in the top 5 of incidence and mortality was summarized, and the interaction and corresponding mechanisms were established based on a systematic review of electronic libraries. Several studies have revealed that anthocyanins have positive impact on human health with anti-cancer capacity. This review aimed to accumulate the evidence on the anti-cancer effects of anthocyanins, corresponding mechanisms and limitation of anthocyanins on cancer prevention and management. Notably, this review updated the latest studies on cancer prevention and management of anthocyanins and also inputted the future perspectives and the demanding questions for the possible contribution of anthocyanins as anti-cancer adjuvant.

Investigation on the biological activity of anthocyanins and polyphenols in blueberry

Blueberry (Vaccinium spp.) is a fruit recognized in the world as healthy, and many of its active ingredients have important physiological functions. This study analyzed the antioxidant activity, antitumor activity, and immune function of anthocyanins and polyphenols extracted from blueberries. The crude extracts of anthocyanins and polyphenols were obtained from blueberries and then purified, and the extract exhibited excellent dose-dependent antitumor activity and antioxidant activity in vivo and in vitro. The purified anthocyanins and polyphenol compounds showed higher antioxidant activity, whereas the crude extract had a better inhibitory effect on tumor proliferation than pure extract, and the blueberry anthocyanin and polyphenol crude product mixture showed a more powerful tumor suppressor, which may be the result of the synergistic effect of multiple compounds. The crude extracts were also more efficient at improving immune function, as reflected by measurements of change in body weight, thymus and spleen indices, macrophage phagocytosis, lymphocyte transformation capacity, superoxide dismutase activity, malondialdehyde content, and serum nitric oxide levels. These results indicate that blueberry anthocyanins and polyphenol extracts can improve immune function and reduce the metastasis and proliferation of cancer cells. This study reveals the functions of important active substances in blueberries and provides support for the development of functional health products and therapeutic drugs. PRACTICAL APPLICATION: We compared the biological activity of crude and purified anthocyanins and polyphenol extracts from blueberries and tested their effects on improving immune function. This study contributes to a better understanding of the bioactivity of blueberry extracts and is valuable for further applications of blueberries in medicine.

Grapevine as a Rich Source of Polyphenolic Compounds

Grapes are rich in primary and secondary metabolites. Among the secondary metabolites, polyphenolic compounds are the most abundant in grape berries. Besides their important impacts on grape and wine quality, this class of compounds has beneficial effects on human health. Due to their antioxidant activity, polyphenols and phenolic acids can act as anti-inflammatory and anticancerogenic agents, and can modulate the immune system. In grape berries, polyphenols and phenolic acids can be located in the pericarp and seeds, but distribution differs considerably among these tissues. Although some classes of polyphenols and phenolic acids are under strict genetic control, the final content is highly influenced by environmental factors, such as climate, soil, vineyard, and management. This review aims to present the main classes of polyphenolic compounds and phenolic acids in different berry tissues and grape varieties and special emphasis on their beneficial effect on human health.

Cyanidin-3-O-glucoside inhibits epithelial-to-mesenchymal transition, and migration and invasion of breast cancer cells by upregulating KLF4

Background

Anthocyanins (ACNs) are capable of suppressing breast cancer growth; however, investigation on the effect and mechanism of ACNs on epithelial-to-mesenchymal transition (EMT), and cell migration and invasion in breast cancer cells is limited. A complete understanding of those properties may provide useful information on of how to use these natural compounds for cancer prevention and treatment.

Objectives

The aim of this work was to investigate the role of cyanidin-3-O-glucoside (Cy3G), one of the most widely distributed ACNs in edible fruits, in the EMT process, and cell migration and invasion of breast cancer cells, and its underlying molecular mechanisms of how Cy3G establishes these functional roles in these cells.

Methods

MDA-MB-231 and MDA-MB-468 breast cancer cells were treated with Cy3G (20 μM) for 24 h, and then the cells were used for cell migration and invasion assay. Western blotting, luciferase assay, ubiquitination assay, gene knockdown, and cycloheximide chase assay were performed to analyze the molecular mechanisms of Cy3G in suppressing EMT, and cell migration and invasion.

Results

Cy3G inhibited the EMT process in these cells and significantly suppressed the migration and invasion of breast cancer cells (P ≤ 0.05) by upregulating Krüppel-like factor 4 (KLF4) expression at protein level. KLF4 knockdown in MDA-MB-231 cells did not reveal any change in EMT marker expression, and cell migration and invasion upon treatment with Cy3G (P ≥ 0.05), which strongly indicated that the effects of Cy3G were mediated by KLF4. Furthermore, we determined that Cy3G indirectly upregulated KLF4 expression by downregulating FBXO32, which is the E3 ligase of KLF4.

Conclusion

Cy3G is a potential anticancer reagent as it can inhibit EMT and breast cancer cell migration and invasion by upregulating KLF4.

Preparation of Lipid-Soluble Bilberry Anthocyanins through Acylation with Cinnamic Acids and their Antioxidation Activities

To enable the use of anthocyanins in food with high oil content, bilberry anthocyanins were acylated with cinnamic acids to address their poor lipid solubility. Structural analyses based on Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ¹H nuclear magnetic resonance analyses indicated that cinnamic acids were efficiently grafted onto 6-OH of glucoside and galactoside and 5-OH of arabinose through an esterification reaction. The higher the dose of the acylating agent, the higher the acylation degree (AD) and the lower the total anthocyanidin content (TAC) of bilberry anthocyanins. An-Ci4 presented the highest AD value (6.61%), and An-Ci3 exhibited the lowest TAC value (50.16 mg/g). After acylating with lipophilic cinnamic acids, the lipid solubility of acylated bilberry anthocyanins significantly improved. The color of the native bilberry anthocyanin solution dissolved in ethyl acetate and dioxane was transparent. By contrast, the acylated anthocyanin solution dissolved in these solvents was unmistakably red. In terms of the antioxidant activity, acylated bilberry anthocyanins demonstrated inferior performance in 2,2-diphenyl-1-picrylhydrazyl (DPPH) clearance but a better inhibition ratio in β-carotene bleaching assay compared with native bilberry anthocyanins. As AD value increased, the DPPH clearance of acylated anthocyanins decreased and their inhibition ratio increased in β-carotene bleaching assay.

The Multifunctional Benefits of Naturally Occurring Delphinidin and Its Glycosides

Delphinidin (Del) and its glycosides are water-soluble pigments, belonging to a subgroup of flavonoids. They are health-promoting candidates for pharmaceutical and nutraceutical uses, as indicated by exhibiting antioxidation, anti-inflammation, antimicroorganism, antidiabetes, antiobesity, cardiovascular protection, neuroprotection, and anticancer properties. Glycosylation modification of Del is associated with increased stability and reduced biological activity. Del and its glycosides can be the alternative inhibitors of CBRs, ERα/β, EGFR, BCRP, and SGLT-1, and virtual docking indicates that the sugar moiety may not effectively interact with the active sites of the targets. Structure-based characteristics confer the multifunctional properties of Del and its glycosides. Because of their health-promoting effects, Del and its glycosides are promising and have been developed as potential pharmaceuticals. However, more investigation on the underlying mechanisms of Del and its glycosides in mediating cellular processes with high specificity are still needed. The research progression of Del and its glycosides over the last 10 years is comprehensively reviewed in this article.

Delphinidin suppresses breast carcinogenesis through the HOTAIR/microRNA-34a axis

Delphinidin, one of the main anthocyanidins, has potent anti-cancer properties. In this study, we investigated the effect of delphinidin on 1-methyl-1-nitrosourea (MNU)-induced breast carcinogenesis on rats and the mechanism of delphinidin via negative regulation of the HOTAIR/microRNA-34a axis. We found administration of delphinidin could effectively suppress MNU-induced mammal breast carcinogenesis. Delphinidin downregulated the level of HOTAIR and upregulated miR-34a in breast carcinogenesis. Western blot analysis confirmed that delphinidin treatment can significantly decrease the expression of β-catenin, glycogen synthase kinase-3β (Gsk3β), c-Myc, cyclin-D1, and matrix metalloproteinase-7(MMP-7) expression in breast cancer cells, and inhibition of miR-34a significantly reduced the effect of delphinidin on c-Myc, cyclin-D1, and MMP-7. HOTAIR overexpression also blocked the effect of delphinidin on miR-34a and the Wnt/β-catenin signaling pathway in MDA-MB-231 cells. RNA immunoprecipitation (RIP) assay and chromatin immunoprecipitation (ChIP) assay results showed that delphinidin upregulated miR-34a by inhibiting HOTAIR, coupled with enhancement of the zeste homolog 2 (EZH2) and histone H3 Lys27 trimethylation (H3K27me3). This study indicated that delphinidin may potentially suppress breast carcinogenesis and exert its anti-cancer effect through the HOTAIR/miR-34a axis. These findings provided new evidence for the use of delphinidin in preventing breast carcinogenesis.

Natural flavonoids for the prevention of colon cancer: A comprehensive review of preclinical and clinical studies

Flavonoids comprise a group of natural polyphenols consisting of more than 5,000 subtypes mostly existing in fruits and vegetables. Flavonoids consumption could potentially attenuate the incidence and recurrence risk of colorectal cancers through their antiperoxidative, antioxidant, and anti-inflammatory effects. In addition, these compounds regulate the mitochondrial function, balance the bacterial flora and promote the apoptosis process in cancerous cells. However, some previous data failed to show the effectiveness of flavonoids in reducing the risk of colorectal cancer. In this study, we have reviewed the efficacy of different flavonoids subtypes on the risk of colon cancer and molecular mechanisms involved in this process in both clinical and animal studies. In addition, we tried to elucidate the potential synergy between these compounds and current colorectal cancer treatments.

Chemoprevention of Colorectal Cancer by Dietary Compounds

Colorectal cancer is one of the leading causes of death, and the third most diagnosed type of cancer, worldwide. It is most common amongst men and women over 50 years old. Risk factors include smoking, alcohol, diet, physical inactivity, genetics, alterations in gut microbiota, and associated pathologies (diabetes, obesity, chronic inflammatory bowel diseases). This review will discuss, in detail, the chemopreventive properties of some dietary compounds (phenolic compounds, carotenoids, iridoids, nitrogen compounds, organosulfur compounds, phytosterols, essential oil compounds, polyunsaturated fatty acids and dietary fiber) against colorectal cancer. We present recent data, focusing on in vitro, laboratory animals and clinical trials with the previously mentioned compounds. The chemopreventive properties of the dietary compounds involve multiple molecular and biochemical mechanisms of action, such as inhibition of cell growth, inhibition of tumor initiation, inhibition of adhesion, migration and angiogenesis, apoptosis, interaction with gut microbiota, regulation of cellular signal transduction pathways and xenobiotic metabolizing enzymes, etc. Moreover, this review will also focus on the natural dietary compounds' bioavailability, their synergistic protective effect, as well as the association with conventional therapy. Dietary natural compounds play a major role in colorectal chemoprevention and continuous research in this field is needed.