Suppression of the kinase activity of receptor tyrosine kinases by anthocyanin-rich mixtures extracted from bilberries and grapes

Anthocyanins from pomegranate peel (Punica granatum), chili pepper fruit (Capsicum annuum), and bougainvillea flowers (Bougainvillea spectabilis) with multiple biofunctions: Antibacterial, antioxidant, and anticancer

Background

Natural colorants, including natural pigments, e.g., anthocyanins, carotenoids, and chlorophylls, in novel and attractive food matrixes have become a popular trend. They impart favorite colors to food products and provide significant therapeutic effects. This study is aimed at extracting and identifying some natural pigments from different plant sources and evaluating their ability as antibacterial, antioxidant, and anticancer activities.

Methods

The anthocyanin-rich extract (ARE) is derived from three natural plant sources: pomegranate peel (Punica granatum), chili pepper fruit (Capsicum annuum), and Bougainvillea flowers. Bougainvillea spectabilis are analyzed for biochemical composition, as well as antioxidant, antibacterial, and anticancer activity, HPLC, DPPH, FRAP, disc diffusion assay, MIC, MTT, VEGFR-2, and caspase-9 assays.

Results

All three extracts had varying total phenolic contents, ranging from 14 to 466 mg GAE/g extract, where Punica granatum was the highest (466 mg GAE/g extract), followed by Bougainvillea spectabilis (180 mg GAE/g extract), and then Capsicum annuum (14 mg GAE/g extract). The antioxidant activity rose steadily with raising concentration. The ARE of pomegranate peels recorded highest value, followed by Bougainvillea flowers and chili pepper fruit. The MTT assay revealed an inhibitory action of the tested extracts on the proliferation of HCT-116, MCF-7, and HepG2 in a concentration-based manner. Gene expression of caspase-9 transcripts was considerably multiplied by the application of ARE of pomegranate peels. All the tested extracts inhibited VEGFR-2, and the inhibition (%) expanded gradually with increasing concentrations, achieving the highest value (80 %) at 10 μg/mL. The ARE of pomegranate peels scored highest antibacterial activity, followed by ARE of chili pepper fruit and Bougainvillea flowers. The inhibition zone diameter escalated gradually with rising concentrations of the tested samples.

Conclusion

The AREs of the three studied plant sources can be used as multifunctional products with antioxidant, anticancer, and antibacterial activities that are natural, safe, and cheap.

An updated overview of cyanidins for chemoprevention and cancer therapy

Anthocyanins are colored polyphenolic compounds that belong to the flavonoids family and are largely present in many vegetables and fruits. They have been used in traditional medicine in many cultures for a long time. The most common and abundant anthocyanins are those presenting an O-glycosylation at C-3 (C ring) of the flavonoid skeleton to form -O-β-glucoside derivatives. The present comprehensive review summarized recent data on the anticancer properties of cyanidings along with natural sources, phytochemical data, traditional medical applications, molecular mechanisms and recent nanostrategies to increase the bioavailability and anticancer effects of cyanidins. For this analysis, in vitro, in vivo and clinical studies published up to the year 2022 were sourced from scientific databases and search engines such as PubMed/Medline, Google scholar, Web of Science, Scopus, Wiley and TRIP database. Cyanidins' antitumor properties are exerted during different stages of carcinogenesis and are based on a wide variety of biological activities. The data gathered and discussed in this review allows for affirming that cyanidins have relevant anticancer activity in vitro, in vivo and clinical studies. Future research should focus on studies that bring new data on improving the bioavailability of anthocyanins and on conducting detailed translational pharmacological studies to accurately establish the effective anticancer dose in humans as well as the correct route of administration.

Modulation of Cytoskeleton, Protein Trafficking, and Signaling Pathways by Metabolites from Cucurbitaceae, Ericaceae, and Rosaceae Plant Families

One promising frontier within the field of Medical Botany is the study of the bioactivity of plant metabolites on human health. Although plant metabolites are metabolic byproducts that commonly regulate ecological interactions and biochemical processes in plant species, such metabolites also elicit profound effects on the cellular processes of human and other mammalian cells. In this regard, due to their potential as therapeutic agents for a variety of human diseases and induction of toxic cellular responses, further research advances are direly needed to fully understand the molecular mechanisms induced by these agents. Herein, we focus our investigation on metabolites from the Cucurbitaceae, Ericaceae, and Rosaceae plant families, for which several plant species are found within the state of Florida in Hillsborough County. Specifically, we compare the molecular mechanisms by which metabolites and/or plant extracts from these plant families modulate the cytoskeleton, protein trafficking, and cell signaling to mediate functional outcomes, as well as a discussion of current gaps in knowledge. Our efforts to lay the molecular groundwork in this broad manner hold promise in supporting future research efforts in pharmacology and drug discovery.

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.

The ameliorating effects of anthocyanins on the cross-linked signaling pathways of cancer dysregulated metabolism

Cancer cells underlie the dysregulated metabolism of carbohydrate, lipid and protein and thereby, employ interconnected cross-linked signaling pathways to supply adequate energy for growth and related biosynthetic procedures. In the present study, a comprehensive review of cancer metabolism and anthocyanin's effect was conducted using the existing electronic databases, including Medline, PubMed, Scopus, and Web of Science, as well as related articles in the field. Such keywords as "cancer", and "cancer metabolism" in the title/abstract/keyword and all the "anthocyanins" in the whole text were used. Data were collected without time restriction until February 2020. The results indicated the involvement of several signaling pathways, including inflammatory PI3K/Akt/mTOR pathway, Bax/Bcl-2/caspases as apoptosis modulators, and NF-κB/Nrf2 as oxidative stress mediators in the cancer dysregulated metabolism. Compelling studies have shown that targeting these pathways, as critical hallmarks of cancer, plays a critical role in combating cancer dysregulated metabolism. The complexity of cancer metabolism signaling pathways, along with toxicity, high costs, and resistance to conventional drugs urge the need to investigate novel multi-target agents. Increasing evidence has introduced plant-derived secondary metabolites as hopeful anticancer candidates which target multiple dysregulated cross-linked pathways of cancer metabolism. Amongst these metabolites, anthocyanins have demonstrated positive anticancer effects by targeting inflammation, oxidative stress, and apoptotic signaling pathways. The current study revealed the cross-linked signaling pathways of cancer metabolism, as well as the promising pharmacological mechanisms of anthocyanins in targeting the aforementioned signaling mediators. To overcome the pharmacokinetic limitations of anthocyanins in cancer treatment, their interactions with gut microbiota and the need to develop related nano-formulations were also considered.

Cyanidin inhibits EMT induced by oxaliplatin via targeting the PDK1-PI3K/Akt signaling pathway

Anthocyanins have been shown to exhibit antitumor activity in several cancers in vitro and in vivo. Oxaliplatin is widely used as an anti-cancer drug. However, a large proportion of patients receiving platinum-based anti-cancer drug treatments will relapse because of metastasis and drug resistance. The aim of this study is to discover an effective anthocyanin that possesses the combinational anti-metastatic effects of oxaliplatin. Our results showed that cyanidin, one of the main constituents of anthocyanins, widely found in black rice, black bean, Hawthorn and other foods, could reverse drug resistance and enhance the effects of oxaliplatin on hepatic cellular cancer (HCC). Cyanidin inhibited migration and reversed EMT biomarker changes induced by low dose OXA. Moreover, 3-phosphoinositide-dependent protein kinase 1 (PDK1) can be considered a potential target and cyanidin significantly increased OXA sensitivity and inhibited the EMT induced by OXA via PI3K/Akt signaling in HCC.

Comparison of the effect of chemical composition of anthocyanin-rich plant extracts on colon cancer cell proliferation and their potential mechanism of action using in vitro, in silico, and biochemical assays

The objective was to compare the anti-proliferative effect of anthocyanin-rich plant extracts on human colon cancer cells and determine their mechanism of action. Eleven extracts were tested: red (RG) and purple grape, purple sweet potato, purple carrot, black and purple bean, black lentil (BL), black peanut, sorghum (SH), black rice, and blue wheat. HCT-116 and HT-29 inhibition correlated with total phenolics (r=0.87 and 0.77, respectively), delphinidin-3-O-glucoside concentration with HT-29 inhibition (r=0.69). The concentration inhibition fifty (IC₅₀) for BL, SH, RG on HT-29 and HCT-116 cell proliferation ranged 0.9-2.0mg/mL. Extracts decreased expression of anti-apoptotic proteins (survivin, cIAP-2, XIAP), induced apoptosis, and arrested cells in G1. Anthocyanins exhibited tyrosine kinase inhibitory potential in silico and biochemically; cyanidin-3-O-glucoside had one of the highest binding affinities with all kinases, especially ABL1 (-8.5kcal/mol). Cyanidin-3-O-glucoside and delphinidin-3-O-glucoside inhibited EGFR (IC₅₀=0.10 and 2.37µM, respectively). Cyanidin-3-O-glucoside was the most potent anthocyanin on kinase inhibition.

Effects of anthocyanins on the prevention and treatment of cancer

Anthocyanins are a class of water-soluble flavonoids, which show a range of pharmacological effects, such as prevention of cardiovascular disease, obesity control and antitumour activity. Their potential antitumour effects are reported to be based on a wide variety of biological activities including antioxidant; anti-inflammation; anti-mutagenesis; induction of differentiation; inhibiting proliferation by modulating signal transduction pathways, inducing cell cycle arrest and stimulating apoptosis or autophagy of cancer cells; anti-invasion; anti-metastasis; reversing drug resistance of cancer cells and increasing their sensitivity to chemotherapy. In this review, the latest progress on the anticancer activities of anthocyanins and the underlying molecular mechanisms is summarized using data from basic research in vitro and in vivo, from clinical trials and taking into account theory and practice.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

Bilberry extract, its major polyphenolic compounds, and the soy isoflavone genistein antagonize the cytostatic drug erlotinib in human epithelial cells

Erlotinib (Tarceva®) is a chemotherapeutic drug approved for the treatment of pancreatic cancer and non-small cell lung cancer. Its primary mode of action is the inhibition of the epidermal growth factor receptor (EGFR), a receptor tyrosine kinase (RTK). Recently, RTK-inhibiting polyphenols have been reported to interact synergistically with erlotinib. Furthermore some anthocyanidins and anthocyanin-rich berry extracts have been reported to inhibit tyrosine kinases, including the EGFR, which raises the question of potential interactions with erlotinib. Polyphenol-rich preparations such as berry- or soy-based products are commercially available as food supplements. In the present study we tested a bilberry extract, its major anthocyanin and potential intestinal degradation products, as well as genistein, with respect to possible interactions with erlotinib. Cell growth inhibition was assessed using the sulforhodamine B assay, while interactions with EGFR phosphorylation were analyzed by SDS-PAGE/western blotting with subsequent immunodetection. Genistein, bilberry extract, delphinidin-3-O-glucoside and delphinidin were found to antagonize erlotinib whereas phloroglucinol aldehyde was found to enhance cytostatic effects of the drug on human epithelial A431 cells. Genistein also antagonized the EGFR inhibitory effects of erlotinib, whereas bilberry anthocyanins showed no significant interactions in this regard. Our data indicate that different polyphenols are potentially able to impair the cytostatic effect of erlotinib in vitro. Genistein interacts via the modulation of erlotinib-mediated EGFR inhibition whereas bilberry anthocyanins modulated the growth-inhibitory effect of erlotinib without affecting EGFR phosphorylation, thus indicating a different mechanism of interference.

The inhibitory effect of anthocyanins on Akt on invasion and epithelial-mesenchymal transition is not associated with the anti-EGFR effect of the anthocyanins

Evidence suggests that anthocyanins inhibit EGFR and Akt activity. However, it is still unknown whether the inhibitory effect of anthocyanins on Akt is associated with the anti-EGFR effect. The effect of anthocyanins on epithelial-mesenchymal transition (EMT) has not been extensively studied. Therefore, we investigated the effects of anthocyanins from fruits of Vitis coignetiae Pulliat (AIMs) on EGF-induced EMT and the underlying molecular mechanisms. AIMs suppressed the invasion of A549 cells in a dose-dependent manner. AIMs inhibited the phosphorylation of Akt and EGFR, but the inhibitory effect on Akt was not derived from EGFR. EGF re-induced Akt phosphorylation at Thr308 in the AIM-treated cells, but not Akt phosphorylation at Ser473. AIMs also inhibited EMT of cancer cells. AIMs inhibited glycogen synthase kinase-3β phosphorylation and β-catenin expression that are invovled in EMT. We confirmed these findings with transforming growth factor (TGF)-β. In conclusion, these data suggest that the inhibitory effect of AIMs on Akt activity is independent of EGFR, and that AIMs suppressed invasion and migration at least in part by suppressing EMT by inhibiting Akt activity as well as EGFR. This study provides evidence that AIMs may have anticancer effects on human cancer cells.

Effect of microformulation on the bioactivity of an anthocyanin-rich bilberry pomace extract ( Vaccinium myrtillus L.) in vitro

In cell culture were compared the different release rates of anthocyanins from a bilberry pomace extract encapsulated either in food grade whey protein-based matrix capsules (WPC) or in pectin amid-based hollow spherical capsules (PHS). The impact of the formulations on typical anthocyanin-associated biological end points such as inhibition of the epidermal growth factor receptor (EGFR) and suppression of cell growth in HT29 colon carcinoma cells was assessed. The purpose was to find whether the release rates are sufficient to maintain biological activity and whether encapsulation affected EGFR inhibitory and growth suppressive properties of the extract. Even though anthocyanin release from extract-loaded capsules was proven under cell culture conditions, the inhibitory potential toward the EGFR was diminished. However, nonencapsulated extract as well as both extract-loaded encapsulation systems diminished the growth of HT29 cells to a comparable extent. The loss of EGFR inhibitory properties by encapsulation despite anthocyanin release indicates substantial contribution of other further constituents not monitored so far. Taken together, both applied encapsulation strategies allowed anthocyanin release and maintained biological activity with respect to growth inhibitory properties. However, the loss of EGFR inhibitory effects emphasizes the need for biological profiling to estimate process-induced changes of plant constituent's beneficial potencies.

Anthocyanins suppress the cleavable complex formation by irinotecan and diminish its DNA-strand-breaking activity in the colon of Wistar rats

In the present study, the question was addressed whether anthocyanins interfere with the topoisomerase I poison irinotecan in vivo. In vivo complexes of enzyme to DNA bioassay was used to detect irinotecan-induced stabilization of topoisomerase I/DNA complexes and single cell gel electrophoresis to determine DNA-strand-break induction in the colon of male Wistar rats. Furthermore, analysis of anthocyanin concentrations in rat plasma and rat colon was included in the testing, demonstrating that anthocyanins reach the colon and the concentrations do not differ between rats that only received anthocyanins and the anthocyanin/irinotecan group. Blackberry extract was found to significantly reduce irinotecan-mediated topoisomerase I/DNA cleavable complex formation. Overall, anthocyanins did not notably increase cleavable complex formation. However, a significant increase of DNA damage was shown after a single dose of irinotecan as well as the single compounds cyanidin (cy) and cyanidin-3-glucoside (cy-3-g). Furthermore, a significant reduction of irinotecan-induced DNA-strand breaks after a pretreatment with cy, cy-3-g and blackberry extract was observed. Thus, the question arises whether anthocyanin-rich preparations might interfere with chemotherapy or whether, due to low systemic bioavailability, the preparations might provide protective potential in the gastrointestinal tract.

Inhibition of lung tumor development by berry extracts in mice exposed to cigarette smoke

Cigarette smoke (CS) and dietary factors play a major role in cancer epidemiology. At the same time, however, the diet is the richest source of anticancer agents. Berries possess a broad array of health protective properties and were found to attenuate the yield of tumors induced by individual carcinogens in the rodent digestive tract and mammary gland but failed to prevent lung tumors induced by typical CS components in mice. We exposed whole-body Swiss ICR mice to mainstream CS, starting at birth and continuing daily for 4 months. Aqueous extracts of black chokeberry and strawberry were given as the only source of drinking water, starting after weaning and continuing for 7 months, thus mimicking an intervention in current smokers. In the absence of berries, CS caused a loss of body weight, induced early cytogenetical damage in circulating erythrocytes and histopathological alterations in lung (emphysema, blood vessel proliferation, alveolar epithelial hyperplasia and adenomas), liver (parenchymal degeneration) and urinary bladder (epithelial hyperplasia). Both berry extracts inhibited the CS-related body weight loss, cytogenetical damage, liver degeneration, pulmonary emphysema and lung adenomas. Protective effects were more pronounced in female mice, which may be ascribed to modulation by berry components of the metabolism of estrogens implicated in lung carcinogenesis. Interestingly, both the carcinogen and the chemopreventive agents tested are complex mixtures that contain a multitude of components working through composite mechanisms.

Lymphangiogenesis and hemangiogenesis: potential targets for therapy

This review updates historical background from century-old observations on embryonic lymphatic system development through current understanding of the molecular basis of lymphvasculogenesis/lymphangiogenesis ("molecular lymphology"), highlighting similarities and differences with analogous blood vasculature processes. Topics covered include molecular mechanisms in lymphatic development, structural adaptations of the lymphatic vasculature to particulate and cellular transport and trafficking, lymphogenous route of clinical cancer spread, preservation of delineated lymphatic pathways during cancer operations, and anti-lymphangiogenesis in cancer therapy.

Anthocyanin-rich red grape extract impedes adenoma development in the Apc(Min) mouse: pharmacodynamic changes and anthocyanin levels in the murine biophase

PURPOSE

Red grape pomace extract (oenocyanin) is a cheap and rich source of anthocyanins, the agents suggested to possess cancer chemopreventive properties. Here the hypothesis was tested that oenocyanin added to the diet can interfere with intestinal adenoma development in the Apc(Min) mouse, a model of intestinal carcinogenesis linked to an Apc mutation.

METHODS

Mice received oenocyanin (0.3%) in their diet until week 16, when adenoma number and burden were recorded. Expression of Akt and ERK proteins was studied by Western blot in adenomas to discover effects of anthocyanins on cellular signalling via the PI3 and MAP kinase pathways. Levels of anthocyanins were measured by HPLC with visible spectroscopic or mass spectrometric detection.

RESULTS

In mice which had consumed oenocyanin, overall adenoma burden was halved and adenoma number was marginally reduced when compared with mice on control diet. The proliferation index in colonic adenomatous crypts, as reflected by Ki-67 staining, was significantly decreased from 88.14% in control mice to 75.6+/-4% in mice on oenocyanin (P=0.014). Expression of Akt in small intestinal adenomas from Apc(Min) mice on oenocyanin was reduced by 54% (P=0.003), when compared to controls. Oenocyanin anthocyanins and glucuronide metabolites were found in the urine and intestine but not in plasma.

CONCLUSIONS

The results suggest that oenocyanin may be a viable and economical alternative to anthocyanin-rich berry extracts for chemopreventive intervention. Akt and pErk might be suitable biomarkers of anthocyanin target organ efficacy.