Chemopreventive Effect of Dietary Anthocyanins against Gastrointestinal Cancers: A Review of Recent Advances and Perspectives

Bioengineered Anthocyanin-Enriched Tomatoes: A Novel Approach to Colorectal Cancer Prevention

Colorectal cancer (CRC) remains a significant global health challenge, with barriers to effective prevention and treatment including tumor recurrence, chemoresistance, and limited overall survival rates. Anthocyanins, known for their strong anti-cancer properties, have shown promise in preventing and suppressing various cancers, including CRC. However, natural sources of anthocyanins often fail to provide sufficient quantities needed for therapeutic effects. Bioengineered crops, particularly anthocyanin-enriched tomatoes, offer a viable solution to enhance anthocyanin content. Given its large-scale production and consumption, tomatoes present an ideal target for bioengineering efforts aimed at increasing dietary anthocyanin intake. This review provides an overview of anthocyanins and their health benefits, elucidating the mechanisms by which anthocyanins modulate the transcription factors involved in CRC development. It also examines case studies demonstrating the successful bioengineering of tomatoes to boost anthocyanin levels. Furthermore, the review discusses the effects of anthocyanin extracts from bioengineered tomatoes on CRC prevention, highlighting their role in altering metabolic pathways and reducing tumor-related inflammation. Finally, this review addresses the challenges associated with bioengineering tomatoes and proposes future research directions to optimize anthocyanin enrichment in tomatoes.

Anthocyanin-Rich Berry Extracts Affect SN-38-Induced Response: A Comparison of Non-Tumorigenic HCEC-1CT and HCT116 Colon Carcinoma Cells

Chemotherapy with irinotecan (CPT-11), the pro-drug of the highly cytotoxic SN-38, is among the standard-of-care treatments for colorectal cancer. To counteract undesired toxic side effects on healthy tissue such as the intestinal epithelium, the use of preparations rich in polyphenols with anti-oxidative and anti-inflammatory properties such as anthocyanins has been proposed. In the present study, the question of whether non-tumorigenic human epithelium cells (HCEC-1CT) can be protected against the cytotoxic impact of SN-38 by anthocyanin-rich polyphenol extracts without compromising the desired therapeutic effect against tumor cells (HCT-116) was addressed. Hence, single and combinatory effects of anthocyanin-rich polyphenol extracts of elderberry (EB), bilberry (Bil), blackberry (BB) and black currant (BC) with the chemotherapeutic drug SN-38 were investigated. Out of the extracts, BB showed the most potent concentration-dependent cytotoxicity alone and in combination with SN-38, with even stronger effects in non-tumorigenic HCEC-1CT cells. In cytotoxic concentrations, BB decreased the level of DNA/topoisomerase I covalent complexes in HCEC-1CT cells below base level but without concomitant reduction in SN-38-induced DNA strand breaks. The herein reported data argue towards an interference of anthocyanins with successful treatment of cancer cells and a lack of protective properties in healthy cells.

Dietary Supplementation of Haskap Berry (Lonicera caerulea L.) Anthocyanins and Probiotics Attenuate Dextran Sulfate Sodium-Induced Colitis: Evidence from an Experimental Animal Model

Haskap berry (Lonicera caerulea L.) is a rich dietary source of anthocyanins with potent anti-inflammatory properties. In this study, isolated haskap berry anthocyanins were encapsulated in maltodextrin and inulin (3:1) by freeze-drying to improve stability and bioavailability. The structural properties of microcapsules, encapsulation yield, efficiency, recovery, and powder retention were evaluated. The microcapsules that exhibited the highest encapsulation efficiency (60%) and anthocyanin recovery (89%) were used in the dextran sulfate sodium (DSS)-induced acute colitis in mice. Thirty-five BALB/c male mice of seven weeks old were divided into seven dietary supplementation groups (n = 5) to receive either free anthocyanins, encapsulated anthocyanins (6.2 mg/day), or probiotics (1 × 109 CFU/day) alone or as combinations of anthocyanin and probiotics. As observed by clinical data, free anthocyanin and probiotic supplementation significantly reduced the severity of colitis. The supplementary diets suppressed the DSS-induced elevation of serum inflammatory (interleukin (IL)-6 and tumor necrosis factor) and apoptosis markers (B-cell lymphoma 2 and Bcl-2-associated X protein) in mice colon tissues. The free anthocyanins and probiotics significantly reduced the serum IL-6 levels. In conclusion, the dietary supplementation of haskap berry anthocyanins and probiotics protects against DSS-induced colitis possibly by attenuating mucosal inflammation, and this combination has the potential as a health-promoting dietary supplement and nutraceutical.

An overview on the cellular mechanisms of anthocyanins in maintaining intestinal integrity and function

Structural and functional changes of the intestinal barrier, as a consequence of a number of (epi)genetic and environmental causes, have a main role in penetrations of pathogens and toxic agents, and lead to the development of inflammation-related pathological conditions, not only at the level of the GI tract but also in other extra-digestive tissues and organs. Anthocyanins (ACNs), a subclass of polyphenols belonging to the flavonoid group, are well known for their health-promoting properties and are widely distributed in the human diet. There is large evidence about the correlation between the human intake of ACN-rich products and a reduction of intestinal inflammation and dysfunction. Our review describes the more recent advances in the knowledge of cellular and molecular mechanisms through which ACNs can modulate the main mechanisms involved in intestinal dysfunction and inflammation, in particular the inhibition of the NF-κB, JNK, MAPK, STAT3, and TLR4 proinflammatory pathways, the upregulation of the Nrf2 transcription factor and the expression of tight junction proteins and mucins.

Chalcone-Synthase-Encoding RdCHS1 Is Involved in Flavonoid Biosynthesis in Rhododendron delavayi

Flower color is an important ornamental feature that is often modulated by the contents of flavonoids. Chalcone synthase is the first key enzyme in the biosynthesis of flavonoids, but little is known about the role of R. delavayi CHS in flavonoid biosynthesis. In this paper, three CHS genes (RdCHS1-3) were successfully cloned from R. delavayi flowers. According to multiple sequence alignment and a phylogenetic analysis, only RdCHS1 contained all the highly conserved and important residues, which was classified into the cluster of bona fide CHSs. RdCHS1 was then subjected to further functional analysis. Real-time PCR analysis revealed that the transcripts of RdCHS1 were the highest in the leaves and lowest in the roots; this did not match the anthocyanin accumulation patterns during flower development. Biochemical characterization displayed that RdCHS1 could catalyze p-coumaroyl-CoA and malonyl-CoA molecules to produce naringenin chalcone. The physiological function of RdCHS1 was checked in Arabidopsis mutants and tobacco, and the results showed that RdCHS1 transgenes could recover the color phenotypes of the tt4 mutant and caused the tobacco flower color to change from pink to dark pink through modulating the expressions of endogenous structural and regulatory genes in the tobacco. All these results demonstrate that RdCHS1 fulfills the function of a bona fide CHS and contributes to flavonoid biosynthesis in R. delavayi.

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.

Blackberries and Mulberries: Berries with Significant Health-Promoting Properties

Blackberries and mulberries are small and perishable fruits that provide significant health benefits when consumed. In reality, both are rich in phytochemicals, such as phenolics and volatile compounds, and micronutrients, such as vitamins. All the compounds are well-known thanks to their medicinal and pharmacological properties, namely antioxidant, anti-inflammatory, anti-cancer, antiviral, and cardiovascular properties. Nevertheless, variables such as genotype, production conditions, fruit ripening stage, harvesting time, post-harvest storage, and climate conditions influence their nutritional composition and economic value. Given these facts, the current review focuses on the nutritional and chemical composition, as well as the health benefits, of two blackberry species (Rubus fruticosus L., and Rubus ulmifolius Schott) and one mulberry species (Morus nigra L.).

Identification and Expression Analysis of DFR Gene Family in Brassica napus L

Dihydroflavonol 4-reductase (DFR) is a key enzyme in the flavonoid biosynthetic pathway and is essential for the formation of plants' color. In this study, 26 BnDFR genes were identified using 6 Arabidopsis DFR genes as reference. The physicochemical properties, subcellular localization, and conserved structure of BnDFR proteins were analyzed; the evolutionary relationship, collinearity analysis, and expression characteristics of BnDFR genes were studied; and the correlation between the expression level of BnDFR genes and anthocyanin content in rape petals were analyzed. The results showed that the 26 BnDFRs were located in chloroplasts, cytoplasm, nuclei, and mitochondria, distributed on 17 chromosomes, and divided into 4 groups; members of the same group have a similar function, which may be related to the environmental response elements and plant hormone response elements. Intraspecific collinearity analysis showed 51 pairs of collinear genes, and interspecific collinearity analysis showed 30 pairs of collinear genes. Analysis of the expression levels of BnDFRs and anthocyanin content in different color rape petals showed that BnDFR6 and BnDFR26 might play an important role in the synthesis of anthocyanins in rape petals. This provides theoretical guidance for further analysis of the anthocyanin anabolism mechanism involved in the DFR gene in Brassica napus.

Black rice and its by-products: anthocyanin-rich extracts and their biological potential

Recently, growing demand for products enriched with natural compounds that support human health has been observed. Black rice, its by-products, and residues are known to have in their composition a large amount of these compounds with biological potential, mainly anthocyanins. These compounds have reported effects on anti-obesity, antidiabetic, antimicrobial, anticancer, neuroprotective, and cardiovascular disease. Therefore, the extract from black rice or its by-products have great potential for application as ingredients in functional foods, supplements, or pharmacological formulations. This overview summarizes the methods employed for the extraction of anthocyanins from both black rice and its by-products. In addition, trends in applications of these extracts are also evaluated regarding their biological potential. Commonly, the extraction methods used to recover anthocyanins are conventional (maceration) and some emerging technologies (Ultrasound-Assisted Extraction - UAE, and Microwave-Assisted Extraction - MAE). Anthocyanin-rich extracts from black rice have presented a biological potential for human health. In vitro and in vivo assays (in mice) showed these compounds mainly with anti-cancer properties. However, more clinical trials are still needed to prove these potential biological effects. Extracts from black rice and its by-products have great potential in applying functional products with beneficial characteristics to humans and reducing agro-industrial residues.

The Extraction and High Antiproliferative Effect of Anthocyanin from Gardenblue Blueberry

Blueberries are rich in flavonoids, anthocyanins, phenolic acids, and other bioactive substances. Anthocyanins are important functional components in blueberries. We collected 65 varieties of blueberries to investigate their nutritional and functional values. Among them, Gardenblue had the highest anthocyanin content, with 2.59 mg/g in fresh fruit. After ultrasound-assisted solvent extraction and macroporous resin absorption, the content was increased to 459.81 mg/g in the dried powder. Biological experiments showed that Gardenblue anthocyanins (L¹) had antiproliferative effect on cervical cancer cells (Hela, 51.98 μg/mL), liver cancer cells (HepG2, 23.57 μg/mL), breast cancer cells (MCF-7, 113.39 μg/mL), and lung cancer cells (A549, 76.10 μg/mL), and no apparent toxic effects were indicated by methyl thiazolyl tetrazolium (MTT) assay, especially against HepG2 cells both in vitro and in vivo. After combining it with DDP (cisplatin) and DOX (doxorubicin), the antiproliferative effects were enhanced, especially when combined with DOX against HepG2 cells; the IC₅₀ value was 0.02 μg/mL. This was further evidence that L¹ could inhibit cell proliferation by inducing apoptosis. The detailed mechanism might be L¹ interacting with DNA in an intercalation mode that changes or destroys DNA, causing apoptosis and inhibiting cell proliferation. The findings of this study suggest that L¹ extract can be used as a functional agent against hepatoma carcinoma cells.

Transcriptome and metabolome analyses reveal molecular mechanisms of anthocyanin-related leaf color variation in poplar (Populus deltoides) cultivars

INTRODUCTION

Colored-leaf plants are increasingly popular for their aesthetic, ecological, and social value, which are important materials for research on the regulation of plant pigments. However, anthocyanin components and the molecular mechanisms of anthocyanin biosynthesis in colored-leaf poplar remain unclear. Consequently, an integrative analysis of transcriptome and metabolome is performed to identify the key metabolic pathways and key genes, which could contribute to the molecular mechanism of anthocyanin biosynthesis in the colored-leaf cultivars poplar.

METHODS

In this study, integrated metabolite and transcriptome analysis was performed to explore the anthocyanin composition and the specific regulatory network of anthocyanin biosynthesis in the purple leaves of the cultivars 'Quanhong' (QHP) and 'Zhongshanyuan' (ZSY). Correlation analysis between RNA-seq data and metabolite profiles were also performed to explore the candidate genes associated with anthocyanin biosynthesis. R2R3-MYB and bHLH TFs with differential expression levels were used to perform a correlation analysis with differentially accumulated anthocyanins.

RESULTS AND DISCUSSION

A total of 39 anthocyanin compounds were detected by LC-MS/MS analysis. Twelve cyanidins, seven pelargonidins, five delphinidins, and five procyanidins were identified as the major anthocyanin compounds, which were differentially accumulated in purple leaves of QHP and ZSY. The major genes associated with anthocyanin biosynthesis, including structural genes and transcription factors, were differentially expressed in purple leaves of QHP and ZSY through RNA-sequencing (RNA-seq) data analysis, which was consistent with quantitative real-time PCR analysis results. Correlation analysis between RNA-seq data and metabolite profiles showed that the expression patterns of certain differentially expressed genes in the anthocyanin biosynthesis pathway were strongly correlated with the differential accumulation of anthocyanins. One R2R3-MYB subfamily member in the SG5 subgroup, Podel.04G021100, showed a similar expression pattern to some structural genes. This gene was strongly correlated with 16 anthocyanin compounds, indicating that Podel.04G021100 might be involved in the regulation of anthocyanin biosynthesis. These results contribute to a systematic and comprehensive understanding of anthocyanin accumulation and to the molecular mechanisms of anthocyanin biosynthesis in QHP and ZSY.

Impact of anthocyanin on genetic stability in mammary adenocarcinoma-induced mice treated with methotrexate

Background

Genetic instability leads to genome mutations, changes in nucleotide sequences, rearrangements, and gains or losses of part of the chromosomes. This instability can initiate and develop cancer. This study evaluated genomic stability in methotrexate and anthocyanin-treated mammary adenocarcinoma model. Seventy albino mice were divided into seven groups: negative control, anthocyanin, methotrexate, Ehrlich’s solid tumor; Ehrlich’s solid tumor and methotrexate; Ehrlich’s solid tumor and anthocyanin; and Ehrlich’s solid tumor, methotrexate, and anthocyanin groups.

Results

Tumor weight and size were evaluated. Serum arylesterase activity was low in all the induced tumors and those treated with anthocyanin, methotrexate, or both. Poly[adenosine diphosphate (ADP)-ribose] polymerase activity was high, and glutathione S-transferase activity was low in the tumors treated with anthocyanin, methotrexate, or both, compared with that of the untreated tumor. There was an increase in DNA damage in the mice with solid tumors and those injected with methotrexate or methotrexate and anthocyanin, compared with that in the untreated mice.

Conclusions

There was a decrease in genetic instability and DNA damage in the tumor-bearing mice treated with anthocyanin, with a concomitant increase in nuclear poly[adenosine diphosphate (ADP)-ribose] polymerase activity, compared with those of the untreated group. Anthocyanin exerted positive effects in the treatment of mammary adenocarcinoma.

Communication in non-communicable diseases (NCDs) and role of immunomodulatory nutraceuticals in their management

Conveyance of pathogens between organisms causes communicable diseases. On the other hand, a non-communicable disease (NCD) was always thought to have no causative transmissible infective agents. Today, this clear distinction is increasingly getting blurred and NCDs are found to be associated with some transmissible components. The human microbiota carries a congregation of microbes, the majority and the most widely studied being bacteria in the gut. The adult human gut harbors ginormous inhabitant microbes, and the microbiome accommodates 150-fold more genes than the host genome. Microbial communities share a mutually beneficial relationship with the host, especially with respect to host physiology including digestion, immune responses, and metabolism. This review delineates the connection between environmental factors such as infections leading to gut dysbiosis and NCDs and explores the evidence regarding possible causal link between them. We also discuss the evidence regarding the value of appropriate therapeutic immunomodulatory nutritional interventions to reduce the development of such diseases. We behold such immunomodulatory effects have the potential to influence in various NCDs and restore homeostasis. We believe that the beginning of the era of microbiota-oriented personalized treatment modalities is not far away.

The anticancer effects of cyanidin 3-O-glucoside combined with 5-fluorouracil on lung large-cell carcinoma in nude mice

The haskap (Lonicera caerulea L., Caprifoliaceae) berry has been widely used in traditional medicine in Kuril Islands, Russia, Japan, and China. Cyanidin-3-O-glucoside (C3G) is the most abundant anthocyanin in haskap berries, and C3G induces antiproliferative pharmacological activity in various cancer cells. However, no study has investigated its anti-lung large-cell carcinoma (LCC) pharmacological role. Therefore, this study determined whether C3G alone or C3G combined with 5-fluorouracil (5-FU) inhibits human lung LCC. We determined the tumor growth, apoptosis, inflammation, and metastasis in the H661 lung LCC lines xenografted into BALB/c nude mice. The mice were administered saline (control), 5-FU, C3G, or both C3G and 5-FU. Relative to the control mice, those treated with C3G alone or both C3G and 5-FU exhibited impaired tumor growth; increased tumor apoptosis; decreased inflammatory cytokine levels (e.g., IL-1β, TNF-α, C-reactive protein, and IL-6); decreased inflammation-related factors, including cyclooxygenase-2 protein and nuclear factor-κB (NF-κB) mRNA; increased inhibition of NF-κB kinase α mRNA; and downregulated metastasis-related factors, such as transforming growth factor-β, CD44, epidermal growth factor receptor, and vascular endothelial growth factor. In addition, C3G alone or combined with 5-FU affected the expression of the tumor microenvironment-related factors Ki67, CD45, PDL1, and CD73. Compared with the mice treated with 5-FU or C3G alone, those treated with both C3G and 5-FU exhibited significantly impaired tumor growth, decreased tumor sizes, and increased tumor inhibition. This in vivo study demonstrated that C3G alone or combined with 5-FU may impair the growth of lung LCC and inhibit tumorigenesis. The findings indicate that C3G alone or C3G combined with 5-FU may be beneficial for treating human lung LCC.

Association between Dietary Anthocyanidins and Risk of Lung Cancer

Background: Anthocyanidins are a kind of water-soluble flavonoids widely found in flowers and fruits of many plants. Although the beneficial effect of anthocyanidins in cancer prevention has been discussed, the value of anthocyanidins in lung cancer prevention requires further investigation. In this study, we aimed to explore the role of dietary anthocyanidins in the prevention of lung cancer in population-based prospective studies. Methods: Data of participants in this study were collected from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated in Cox proportional hazards regression for the association of dietary anthocyanidins and lung cancer risk. The dose-response relationship was explored between total anthocyanidins and the incidence of lung cancer. Results: A total of 97,993 participants were included in this study. The calculated HRs showed a trend that a higher quartile of total anthocyanidins indicated lower risk of lung cancer after adjusting for covariates (HRQ4vsQ1: 0.63; 95% CI: 0.55,0.73; p for trend < 0.001). A non-linear association between total anthocyanidins and lung cancer risk was found in the restricted cubic spline model. Conclusion: A protective association between dietary anthocyanidins and risk of lung cancer in Americans was investigated.

How We Can Change Clinical Practice Using Antioxidant Molecules?

The collection of studies in this Special Issue, “The Role of Antioxidant Molecules and Melatonin in Cellular Protection”, published in Antioxidants (accessed on 30 April 2021; https://www [...]

Current knowledge of anthocyanin metabolism in the digestive tract: absorption, distribution, degradation, and interconversion

Potential roles for anthocyanins in preventing various chronic diseases have been reported. These compounds are highly sensitive to external conditions and are susceptible to degradation, which increases the complexity of their metabolism in vivo. This review discusses anthocyanin metabolism in the digestive tract, phase I and II metabolism, and enterohepatic circulation (EHC), as well as their distribution of anthocyanins in blood, urine, and several organs. In the oral cavity, anthocyanins are partly hydrolyzed by microbiota into aglycones which are then conjugated by glucuronidase. In stomach, anthocyanins are absorbed without deglycosylation via specific transporters, such as sodium-dependent glucose co-transporter 1 and facilitative glucose transporters 1, while in small intestine, they are mainly absorbed as aglycones. High polymeric anthocyanins are easily degraded into low-polymeric forms or smaller phenolic acids by colonic microbiota, which improves their absorption. Anthocyanins and their derivatives are modified by phase I and II metabolic enzymes in cells and are released into the blood via the gastrovascular cavity into EHC. Notably, interconversion can be occurred under the action of enzymes such as catechol-O-methyltransferase. Taking together, differences in anthocyanin absorption, distribution, metabolism, and excretion largely depend on their glycoside and aglycone structures.

The significant role of nutraceutical compounds in ulcerative colitis treatment

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) mainly affecting the colon and the rectum. Its main characters are represented by relapsing and remitting mucosal inflammation, starting in the rectum and typically extending continuously proximally through part or the entire colon. UC pathogenesis depends on multiple factors, such as genetic predisposition, defects in the epithelial barrier, dysregulated immune responses, and environmental causes. The most frequent symptoms are abdominal pain, weight loss, mucus discharge, bloody diarrhoea, incontinence, nocturnal defecations, fever, and anemia. Existing therapies for UC include 5-aminosalicylic acid (5-ASA) and its derivatives, steroids, immunosuppressants and biological drugs. However, limited efficacy and unwanted adverse effects hardly limit these strategies of treatment. In the last decades, research studies have been driven towards complementary and alternative medicines for the treatment of UC. Various nutraceuticals have exhibited promising results in modulating intestinal inflammation meanwhile improving symptoms. These compounds possess a wide spectrum of positive health effects evidenced by in vitro studies, characterized by their involvement in antioxidant defenses, cell proliferation, and gene expression. The present review analyzes the available data about the different types of nutraceuticals and their potential effectiveness as adjuvant therapy of IBD, with particular emphasis to UC.

Characterization and functional analysis of RdDFR1 regulation on flower color formation in Rhododendron delavayi

Rhododendron delavayi is a popular ornamental plant with globular flowers noted for their bright red color, but very limited studies have been reported on its flower color formation. In this study, we successfully isolated a novel DFR gene (RdDFR1) from red flowers of Rhododendron delavayi. Multiple sequence alignments revealed that RdDFR1 had the conserved NADP and substrate binding domain, and was classified into Asn-type DFR. Meanwhile, quantitative real-time PCR analysis showed that transcript levels of RdDFR1 matched the accumulation patterns of anthocyanins during flower development, hinting its potential role involved in anthocyanin biosynthesis. Then in vitro enzymatic analysis indicated that recombinant RdDFR1 protein could catalyze the production of leucoanthocyanidins from dihydroquercetin and dihydromyricetin. Furthermore, the in planta assay, using Arabidopsis thaliana dfr mutant (tt3-1) and tobacco, displayed that RdDFR1 transgenes recovered the defective proanthocyanidin and anthocyanin biosynthesis at seed coats, hypocotyl as well as cotyledon, and altered the flowers color of tobacco from pale pink to dark pink which demonstrated its function as dihydroflavonol 4-reductase in vivo. In summary, our findings suggest that RdDFR1 plays a crucial role in the biosynthesis of anthocyanin and will also make a contribution to understand the mechanisms of flower color formation in Rhododendron delavayi.

Functional analysis of a dihydroflavonol 4-reductase gene in Ophiorrhiza japonica (OjDFR1) reveals its role in the regulation of anthocyanin

Dihydroflavonol 4-reductase (DFR), a key regulatory enzyme, participated in the biosynthesis of anthocyanins, proanthocyanidins and other flavonoids that essential for plant survival and human health. However, the role of this enzyme in Ophiorrhiza japonica is still unknown. Here, three putative DFR-like genes were firstly isolated from O. japonica. Phylogenetic analysis indicated that OjDFR1 was classified into DFR subgroup, while the rest two were clustered into other NADPH-dependent reductases. Then, functions of the three genes were further characterized. Expression analysis showed that OjDFR1 transcripts had strong correlations with the accumulation pattern of anthocyanin during the flower developmental, whereas other two were not, this suggested the potential roles of OjDFR1 in anthocyanin biosynthesis. Subsequently, all three clones were functionally expressed in Escherichia coli, but confirming that only OjDFR1 encode active DFR proteins that catalyzed the reduction of dihydroflavonols to leucoanthocyanidin. Consistant with the biochemical assay results, overexpressing OjDFR1 in Arabidopsis tt3-1 mutant successfully restored the deficiency of anthocyanin and proanthocyanidin, hinting its function as DFR in planta. Additionally, heterologous expression of OjDFR1 in transgenic tobacco contributed to darker flower color via up-regulating the expressions of endogenous NtANS and NtUFGT, which suggested that OjDFR1 was involved in flower color development. In summary, this study validates the functions of OjDFR1 and expands our understanding of anthocyanin biosynthesis in O. japonica.

Delphinidin and Its Glycosides' War on Cancer: Preclinical Perspectives

Until now, several studies have looked at the issue of anthocyanin and cancer, namely the preventive and inhibitory effects of anthocyanins, as well as the underlying molecular processes. However, no targeted review is available regarding the anticarcinogenic effects of delphinidin and its glycosides on various cancers and their plausible molecular mechanisms. Considerable evidence shows significant anticancer properties of delphinidin-rich preparations and delphinidin alone both in vitro and in vivo. This review covers the in vitro and preclinical implications of delphinidin-mediated cell protection and cancer prevention; thus, we strongly recommend that delphinidin-rich preparations be further investigated as potential functional food, dietary antioxidant supplements, and natural health products targeting specific chronic diseases, including cancer. In addition to in vitro investigations, future research should focus on more animal and human studies to determine the true potential of delphinidin.

A Presurgical Study of Curcumin Combined with Anthocyanin Supplements in Patients with Colorectal Adenomatous Polyps

Adenomatous polyps are precancerous lesions associated with a higher risk of colorectal cancer (CRC). Curcumin and anthocyanins have shown promising CRC-preventive activity in preclinical and epidemiological studies. The objective of this window-of-opportunity, proof-of principle trial was to evaluate the effect of curcumin combined with anthocyanin supplements on tissue biomarkers of colorectal adenomatous polyps. Eligible patients received either anthocyanin and curcumin supplementation or related matching placebo for 4-6 weeks before polyp removal. Adenomatous polyps and adjacent tissue biopsies were collected at baseline and after supplementation for immunohistochemical assessment of β-catenin, NF-kappa B (NF-κB), Ki-67, P53, and dysplasia. No differences were observed in baseline biomarker expression between normal and dysplastic tissues. The combination of anthocyanins and curcumin resulted in a significant borderline reduction of NF-κB immunohistochemistry (IHC) expression in adenoma tissue (geometric mean ratio (GMR): 0.72; 95% confidence interval (CI): 0.51-1.00; p-value: 0.05) and a trend to a reduction of Ki-67 (GMR: 0.73; 95% CI: 0.50-1.08; p-value: 0.11). No significant modulation of biomarkers in normal adjacent mucosa was observed. We concluded that the combined supplementation of anthocyanins and curcumin seems to lead to a potentially favorable modulation of tissue biomarkers of inflammation and proliferation in colon adenomas.

Cyanidin-3-O-glucoside and its phenolic metabolites ameliorate intestinal diseases via modulating intestinal mucosal immune system: potential mechanisms and therapeutic strategies

The incidence of the intestinal disease is globally increasing, and the intestinal mucosa immune system is an important defense line. A potential environmental cause to regulate gut health is diet. Cyanidin-3-O-glucoside is a natural plant bioactive substance that has shown rising evidence of improving intestinal disease and keeping gut homeostasis. This review summarized the intestinal protective effect of Cyanidin-3-O-glucoside in vivo and in vitro and discussed the potential mechanisms by regulating the intestinal mucosal immune system. Cyanidin-3-O-glucoside and phenolic metabolites inhibited the presence and progression of intestinal diseases and explained from the aspects of repairing the intestinal wall, inhibiting inflammatory reaction, and regulating the gut microbiota. Although the animal and clinical studies are inadequate, based on the accumulated evidence, we propose that the interaction of Cyanidin-3-O-glucoside with the intestinal mucosal immune system is at the core of most mechanisms by which affect host gut diseases. This review puts forward the potential mechanism of action and targeted treatment strategies.

Dietary Effects of Anthocyanins in Human Health: A Comprehensive Review

In recent years, the consumption of natural-based foods, including beans, fruits, legumes, nuts, oils, vegetables, spices, and whole grains, has been encouraged. This fact is essentially due to their content in bioactive phytochemicals, with the phenolic compounds standing out. Among them, anthocyanins have been a target of many studies due to the presence of catechol, pyrogallol, and methoxy groups in their chemical structure, which confer notable scavenging, anti-apoptotic, and anti-inflammatory activities, being already recommended as supplementation to mitigate or even attenuate certain disorders, such as diabetes, cancer, and cardiovascular and neurological pathologies. The most well-known anthocyanins are cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside. They are widespread in nature, being present in considerable amounts in red fruits and red vegetables. Overall, the present review intends to discuss the most recent findings on the potential health benefits from the daily intake of anthocyanin-rich foods, as well as their possible pharmacological mechanisms of action. However, before that, some emphasis regarding their chemical structure, dietary sources, and bioavailability was done.

Evidence of Polyphenols Efficacy against Dry Eye Disease

Dry eye disease is a multifactorial pathology compromising the quality of life of patients, resulting in significant damage of the ocular surface and discomfort. The current therapeutical strategies are not able to definitively resolve the underlying causes and stop the symptoms. Polyphenols are promising natural molecules that are receiving increasing attention for their activity/effects in counteracting the main pathologic mechanisms of dry eye disease and reducing its symptoms. In the present review, a deep literature search focusing on the main polyphenols tested against dry eye disease was conducted, analyzing related in vitro, in vivo, and clinical studies to provide a comprehensive and current review on the state of the art. Polyphenols present multiple effects against dry eye diseases-related ocular surface injury. In particular, the observed beneficial effects of polyphenols on corneal cells are the reduction of the pathological processes of inflammation, oxidative stress, and apoptosis and modulation of the tear film. Due to numerous studies reporting that polyphenols are effective and safe for treating the pathological mechanisms of this ocular surface disease, we believe that future studies should confirm and extend the evidence of polyphenols efficacy in clinical practice against dry eye disease and help to develop new ophthalmic drug(s).