Anthocyanins and their role in cancer prevention

Flavonoids and darkness lower PCD in senescing Vitis vinifera suspension cell cultures

BACKGROUND

Senescence is a key developmental process occurring during the life cycle of plants that can be induced also by environmental conditions, such as starvation and/or darkness. During senescence, strict control of genes regulates ordered degradation and dismantling events, the most remarkable of which are genetically programmed cell death (PCD) and, in most cases, an upregulation of flavonoid biosynthesis in the presence of light. Flavonoids are secondary metabolites that play multiple essential roles in development, reproduction and defence of plants, partly due to their well-known antioxidant properties, which could affect also the same cell death machinery. To understand further the effect of endogenously-produced flavonoids and their interplay with different environment (light or dark) conditions, two portions (red and green) of a senescing grapevine callus were used to obtain suspension cell cultures. Red Suspension cell Cultures (RSC) and Green Suspension cell Cultures (GSC) were finally grown under either dark or light conditions for 6 days.

RESULTS

Darkness enhanced cell death (mainly necrosis) in suspension cell culture, when compared to those grown under light condition. Furthermore, RSC with high flavonoid content showed a higher viability compared to GSC and were more protected toward PCD, in accordance to their high content in flavonoids, which might quench ROS, thus limiting the relative signalling cascade. Conversely, PCD was mainly occurring in GSC and further increased by light, as it was shown by cytochrome c release and TUNEL assays.

CONCLUSIONS

Endogenous flavonoids were shown to be good candidates for exploiting an efficient protection against oxidative stress and PCD induction. Light seemed to be an important environmental factor able to induce PCD, especially in GSC, which lacking of flavonoids were not capable of preventing oxidative damage and signalling leading to senescence.

Muscadine Grape Skin Extract Induces an Unfolded Protein Response-Mediated Autophagy in Prostate Cancer Cells: A TMT-Based Quantitative Proteomic Analysis

Muscadine grape skin extract (MSKE) is derived from muscadine grape (Vitis rotundifolia), a common red grape used to produce red wine. Endoplasmic reticulum (ER) stress activates the unfolded protein response (UPR) that serves as a survival mechanism to relieve ER stress and restore ER homeostasis. However, when persistent, ER stress can alter the cytoprotective functions of the UPR to promote autophagy and cell death. Although MSKE has been documented to induce apoptosis, it has not been linked to ER stress/UPR/autophagy. We hypothesized that MSKE may induce a severe ER stress response-mediated autophagy leading to apoptosis. As a model, we treated C4-2 prostate cancer cells with MSKE and performed a quantitative Tandem Mass Tag Isobaric Labeling proteomic analysis. ER stress response, autophagy and apoptosis were analyzed by western blot, acridine orange and TUNEL/Annexin V staining, respectively. Quantitative proteomics analysis indicated that ER stress response proteins, such as GRP78 were greatly elevated following treatment with MSKE. The up-regulation of pro-apoptotic markers PARP, caspase-12, cleaved caspase-3, -7, BAX and down-regulation of anti-apoptotic marker BCL2 was confirmed by Western blot analysis and apoptosis was visualized by increased TUNEL/Annexin V staining upon MSKE treatment. Moreover, increased acridine orange, and LC3B staining was detected in MSKE-treated cells, suggesting an ER stress/autophagy response. Finally, MSKE-mediated autophagy and apoptosis was antagonized by co-treatment with chloroquine, an autophagy inhibitor. Our results indicate that MSKE can elicit an UPR that can eventually lead to apoptosis in prostate cancer cells.

Colorimetry Technique as a Tool for Determining Release Kinetics and Mass Transfer Parameters of Anthocyanins Encapsulated in W1/O/W2 Double Emulsions

Anthocyanin extract (AE) was encapsulated in W1/O/W2 double emulsions and colorimetry technique using the CIE L*a*b* system was used to determine the release kinetics. Parameters a* and b* better correlated the variations in color of emulsions due to the release of AE into the external phase. Chroma value (C*) was used for tracking these color variations and to determine the release kinetics. The emulsions showed high stability, droplet sizes didn’t change after 30 days of storage (D4,3=4.74±0.12 μm), and 2.7 % AE was released to the external phase after this time. The possible release mechanism of AE from the internal phase of the emulsion is diffusion controlled with good accordance to Fick’s first law (R2=0.9938) with a diffusion coefficient of 7.15×10−8 cm2/d.

Associations of dietary intakes of anthocyanins and berry fruits with risk of type 2 diabetes mellitus: a systematic review and meta-analysis of prospective cohort studies

To investigate the associations of dietary intakes of anthocyanins and berry fruits with type 2 diabetes mellitus (T2DM) risk and to evaluate the potential dose-response relationships based on prospective cohort studies. Cochrane library, Embase and PubMed databases were systematically searched up to Jan 2016 for relevant original studies. Summary relative risks (RRs) were calculated with a random effects model comparing the highest with lowest category. Dose-response was estimated using restricted cubic spline regression models. Three cohort studies reporting dietary anthocyanin intake with 200 894 participants and 12 611 T2DM incident cases, and five cohort studies reporting berry intake with 194 019 participants and 13 013 T2DM incident cases were investigated. Dietary anthocyanin consumption was associated with a 15% reduction of T2DM risk (summary RR=0.85; 95% confidence interval (CI): 0.80-0.91; I²=14.5%). Consumption of berries was associated with an 18% reduction of T2DM risk (summary RR=0.82, 95% CI: 0.76-0.89; I²=48.6%). Significant curvilinear associations were found between dietary intake of anthocyanins (P for nonlinearity=0.006) and berries (P for nonlinearity=0.028) and T2DM risk, respectively. The risk of T2DM was decreased by 5%, with a 7.5 mg/day increment of dietary anthocyanin intake (RR=0.95; 95% CI: 0.93-0.98; I²=0.00%) or with a 17 g/day increment of berry intake (RR=0.95, 95% CI: 0.91-0.99; I²=0.00%), respectively. Higher dietary intakes of anthocyanins and berry fruits are associated with a lower T2DM risk.

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.

Effect of YH0618 soup on chemotherapy-induced toxicity in patients with cancer who have completed chemotherapy: study protocol for a randomized controlled trial

Background

The incidence of cancer has been staying at a high level worldwide in recent years. With advances in cancer diagnosis and therapy strategy, the survival rate of patients with cancer has been increasing, but the side effects of these treatments, especially chemotherapy, are obvious even when the chemotherapy ceases. YH0618, a prescription, has showed efficacy in reducing chemotherapy-induced toxicity through long clinical practice. However, there is no scientific research exploring the effects of YH0618 in patients with cancer. Therefore, using a randomized controlled trial, this study will explore the efficacy of YH0618 on ameliorating chemotherapy-induced toxicity including dermatologic toxicity, myelosuppression, hepatotoxicity and nephrotoxicity and improving fatigue in cancer patients who have completed chemotherapy.

Methods/design

This is a prospective assessor-blinded, parallel, randomized controlled trial. Patients with cancer at any stage who have completed chemotherapy within two weeks will be randomly divided into group A (YH0618) and group B (wait-list) using a 1:1 allocation ratio. The chemotherapeutic agents include taxanes or anthracyclines. Subjects assigned to group A will receive YH0618 soup 6 days a week for 6 weeks and uncontrolled follow-up for 6 weeks, while group B are required to wait for 6 weeks before receiving YH0618 intervention. The primary outcome of this study is the incidence of protocol-specified grade ≥2 dermatologic toxicities graded by NCI CTCAE Chinese version 4.0 and changes of fingernail color, face skin color and tongue color evaluated by the L*a*b system within 6 weeks. There are some secondary outcomes associated with dermatologic toxicity including fatigue and clinical objective examination.

Discussion

There are few scientific and safe methods in ameliorating chemotherapy-induced toxicity. The proposed study may provide direct and convincing evidence to support YH0618 as an adjuvant treatment for reducing chemotherapy-induced toxicity, which could be introduced into clinical settings.

Trial registration

Chinese Clinical Trial Registry: ChiCTR-IOR-15006486. Registered on 21 May 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1443-9) contains supplementary material, which is available to authorized users.

Tissue biochemical diversity of 20 gooseberry cultivars and the effect of ethylene supplementation on postharvest life

The European gooseberry (Ribes uva-crispa) is still an understudied crop with limited data available on its biochemical profile and postharvest life. A variety of polyphenols were detected in the skin and flesh of 20 gooseberry cvs, representing mainly flavonol glycosides, anthocyanins and flavan-3-ols. In contrast, gooseberry seeds were for the first time characterised by the presence of considerable amounts of hydroxycinnamic acid glycosides tentatively identified by UPLC-QToF/MS. All cvs examined represented a good source of vitamin C while being low in sugar. Furthermore, the postharvest stability of bioactives was explored by supplementation of exogenous ethylene in air at 5 °C. Results suggest a low sensitivity of gooseberries to ethylene. The overall quality of gooseberries remained stable over two weeks, showing potential for extended bioactive life.

Flavonoids, Flavonoid Subclasses, and Esophageal Cancer Risk: A Meta-Analysis of Epidemiologic Studies

Flavonoids have been suggested to play a chemopreventive role in carcinogenesis. However, the epidemiologic studies assessing dietary intake of flavonoids and esophageal cancer risk have yielded inconsistent results. This study was designed to examine the association between flavonoids, each flavonoid subclass, and the risk of esophageal cancer with a meta-analysis approach. We searched for all relevant studies with a prospective cohort or case-control study design published from January 1990 to April 2016, using PUBMED, EMBASE, and Web of Science. Pooled odds ratios (ORs) were calculated using fixed or random-effect models. In total, seven articles including 2629 cases and 481,193 non-cases were selected for the meta-analysis. Comparing the highest-intake patients with the lowest-intake patients for total flavonoids and for each flavonoid subclass, we found that anthocyanidins (OR = 0.60, 95% CI: 0.49-0.74), flavanones (OR = 0.65, 95% CI: 0.49-0.86), and flavones (OR = 0.78, 95% CI 0.64-0.95) were inversely associated with the risk of esophageal cancer. However, total flavonoids showed marginal association with esophageal cancer risk (OR = 0.78, 95% CI: 0.59-1.04). In conclusion, our study suggested that dietary intake of total flavonoids, anthocyanidins, flavanones, and flavones might reduce the risk of esophageal cancer.

Effects of Black Raspberry Extract and Protocatechuic Acid on Carcinogen-DNA Adducts and Mutagenesis, and Oxidative Stress in Rat and Human Oral Cells

Effects of black raspberry (BRB) extract and protocatechuic acid (PCA) on DNA adduct formation and mutagenesis induced by metabolites of dibenzo[a,l]pyrene (DBP) were investigated in rat oral fibroblasts. The DBP metabolites, (±)-anti-11,12-dihydroxy-11,12,-dihydrodibenzo[a,l]pyrene (DBP-diol) and 11,12-dihydroxy-13,14-epoxy-11,12,13,14-tetrahydrodibenzo[a,l]pyrene (DBPDE) induced dose-dependent DNA adducts and mutations. DBPDE was considerably more potent, whereas the parent compound had no significant effect. Treatment with BRB extract (BRBE) and PCA resulted in reduced DBP-derived DNA adduct levels and reduced mutagenesis induced by DBP-diol, but only BRBE was similarly effective against (DBPDE). BRBE did not directly inactivate DBPDE, but rather induced a cellular response-enhanced DNA repair. When BRBE was added to cells 1 day after the DBP-diol, the BRBE greatly enhanced removal of DBP-derived DNA adducts. As oxidative stress can contribute to several stages of carcinogenesis, BRBE and PCA were investigated for their abilities to reduce oxidative stress in a human leukoplakia cell line by monitoring the redox indicator, 2',7'-dichlorodihydrofluorescein diacetate (H2DCF) in cellular and acellular systems. BRBE effectively inhibited the oxidation, but PCA was only minimally effective against H2DCF. These results taken together provide evidence that BRBE and PCA can inhibit initiation of carcinogenesis by polycyclic aromatic hydrocarbons; and in addition, BRBE reduces oxidative stress. Cancer Prev Res; 9(8); 704-12. ©2016 AACR.

Characterization of Arabidopsis thaliana FLAVONOL SYNTHASE 1 (FLS1) -overexpression plants in response to abiotic stress

Flavonoids are an important group of secondary metabolites that are involved in plant growth and contribute to human health. Many studies have focused on the biosynthesis pathway, biochemical characters, and biological functions of flavonoids. In this report, we showed that overexpression of FLS1 (FLS1-OX) not only altered seed coat color (resulting in a light brown color), but also affected flavonoid accumulation. Whereas fls1-3 mutants accumulated higher anthocyanin levels, FLS1-OX seedlings had lower levels than those of the wild-type. Besides, shoot tissues of FLS1-OX plants exhibited lower flavonol levels than those of the wild-type. However, growth performance and abiotic stress tolerance of FLS1-OX, fls1-3, and wild-type plants were not significantly different. Taken together, FLS1 can be manipulated (i.e., silenced or overexpressed) to redirect the flavonoid biosynthetic pathway toward anthocyanin production without negative effects on plant growth and development.

The Chemistry of Gut Microbial Metabolism of Polyphenols

Gut microbiota contribute to the metabolism of dietary polyphenols and affect the bioavailability of both the parent polyphenols and their metabolites. Although there is a large number of reports of specific polyphenol metabolites, relatively little is known regarding the chemistry and enzymology of the metabolic pathways utilized by specific microbial species and taxa, which is the focus of this review. Major classes of dietary polyphenols include monomeric and oligomeric catechins (proanthocyanidins), flavonols, flavanones, ellagitannins, and isoflavones. Gut microbial metabolism of representatives of these polyphenol classes can be classified as A- and C-ring cleavage (retro Claisen reactions), C-ring cleavage mediated by dioxygenases, dehydroxylations (decarboxylation or reduction reactions followed by release of H₂O molecules), and hydrogenations of alkene moieties in polyphenols, such as resveratrol, curcumin, and isoflavones (mediated by NADPH-dependent reductases). The qualitative and quantitative metabolic output of the gut microbiota depends to a large extent on the metabolic capacity of individual taxa, which emphasizes the need for assessment of functional analysis in conjunction with determinations of gut microbiota compositions.

Bioavailability studies and anticancer properties of malvidin based anthocyanins, pyranoanthocyanins and non-oxonium derivatives

In this study, the gastric transport efficiency of malvidin-3-glucoside and several derivatives was assayed on the MKN-28 cell model. The transport efficiency was found to increase for all compounds with the incubation time. Pyranoanthocyanins may slightly impair transport efficiency levels in comparison with native anthocyanins. Among the pyranoanthocyanin derivatives the presence of the carbonyl group and the absence of charge were important for the transport efficiency percentage of oxovitisin and apparently compensated the negative effect associated with the additional ring. Moreover, the antiproliferative properties of these compounds in the MCF-7 cancer cell line were assayed, oxovitisin being the most effective compound in inhibiting the proliferation of MCF-7 cells. Also, a kinetic incorporation of oxovitisin was assayed revealing that this pyranoanthocyanin is quickly incorporated into cells. This study confirms the importance of the natural micro-oxidative processes that occur during the ageing of anthocyanin-containing food and their impact on their bioavailability and bioactivity properties.

The Effects of Vaccinium myrtillus Extract on Hamster Pial Microcirculation during Hypoperfusion-Reperfusion Injury

Introduction

The present study was aimed to assess the in vivo hamster pial microvessel alterations due to 30 min transient bilateral common carotid artery occlusion (BCCAO) and reperfusion (60 min); moreover, the neuroprotective effects of Vaccinium myrtillus extract, containing 34.7% of anthocyanins, were investigated.

Materials and Methods

Two groups of male hamsters were used: the first fed with control diet and the other with Vaccinium myrtillus supplemented diet. Hamster pial microcirculation was visualized by fluorescence microscopy through an open cranial window. Pial arterioles were classified according to Strahler’s method.

Results

In age-matched control diet-fed hamsters, BCCAO caused a decrease in diameter of all arterioles. At the end of reperfusion, the reduction of diameter in order 3 arterioles was by 8.4 ± 3.1%, 10.8 ± 2.3% and 12.1 ± 1.1% of baseline in the 2, 4 and 6 month control diet-fed hamsters, respectively. Microvascular permeability and leukocyte adhesion were markedly enhanced, while perfused capillary length (PCL) decreased. The response to acetylcholine and papaverine topical application was impaired; 2’-7’-dichlorofluoresceine-diacetate assay demonstrated a significant ROS production. At the end of BCCAO, in age-matched Vaccinium myrtillussupplemented diet-fed hamsters, the arteriolar diameter did not significantly change compared to baseline. After 60 min reperfusion, order 3 arterioles dilated by 9.3 ± 2.4%, 10.6 ± 3.1% and 11.8 ± 2.7% of baseline in the 2, 4 and 6 month Vaccinium myrtillus supplemented diet-fed hamsters, respectively. Microvascular leakage and leukocyte adhesion were significantly reduced in all groups according to the time-dependent treatment, when compared with the age-matched control diet-fed hamsters. Similarly, the reduction in PCL was progressively prevented. Finally, the response to acetylcholine and papaverine topical application was preserved and there was no significant increase in ROS production in all groups.

Conclusions

In conclusion, Vaccinium myrtillusextract protected pial microcirculation during hypoperfusion-reperfusion, preventing vasoconstriction, microvascular permeability, leukocyte adhesion, reduction in PCL and preserving the endothelium function.

Effects of UV Rays and Thymol/Thymus vulgaris L. Extract in an ex vivo Human Skin Model: Morphological and Genotoxicological Assessment

Ultraviolet (UV) radiation is the major environmental factor affecting functions of the skin. Compounds rich in polyphenols, such as Thymus vulgaris leaf extract and thymol, have been proposed for the prevention of UV-induced skin damage. We compared the acute effects induced by UVA and UVB rays on epidermal morphology and proliferation, cytotoxicity, and genotoxicity. Normal human skin explants were obtained from young healthy women (n = 7) after informed consent and cultured at the air-liquid interface overnight. After 24 h, the samples were divided in 2 groups: the former exposed to UVA (16 or 24 J/cm2) and the latter irradiated with UVB (0.24 or 0.72 J/cm2). One hour after the end of irradiation, supernatants were collected for evaluation of the lactate dehydrogenase activity. Twenty-four hours after UVB exposure, biopsies were processed for light and transmission electron microscopy analysis, proliferation, cytotoxicity, and genotoxicity. UVB and UVA rays induced early inhibition of cell proliferation and DNA damage compared to controls. In particular, UVB rays were always more cytotoxic and genotoxic than UVA ones. For this reason, we evaluated the effect of either T. vulgaris L. extract (1.82 µg/ml) or thymol (1 µg/ml) on all samples treated for 1 h before UVB irradiation. While Thymus had a protective action for all of the endpoints evaluated, the action of the extract was less pronounced on epidermal proliferation and morphological features. The results presented in this study could be the basis for investigating the mechanism of thymol and T. vulgaris L. extract against the damage induced by UV radiation.

Delphinidin sensitizes prostate cancer cells to TRAIL-induced apoptosis, by inducing DR5 and causing caspase-mediated HDAC3 cleavage

TRAIL can induce apoptosis in some cancer cells and is an immune effector in the surveillance and elimination of developing tumors. Yes, some cancers are resistant to TRAIL. Delphinidin, a polyphenolic compound contained in brightly colored fruits and vegetables, has anti-inflammatory, anti-oxidant, and anti-tumorigenic activities. Here we showed that delphinidin sensitized TRAIL-resistant human prostate cancer cells to undergo apoptosis. Cells treated with delphinidin and TRAIL activated the extrinsic and intrinsic pathways of caspase activation. TRAIL-induced apoptosis in prostate cancer cells pretreated with delphinidin was dependent on death receptor 5 (DR5) and downstream cleavage of histone deacetylase 3 (HDAC3). In conclusion, delphinidin sensitizes prostate cancer cells to TRAIL-induced apoptosis by inducing DR5, thus causing caspase-mediated HDAC3 cleavage. Our data reveal a potential way of chemoprevention of prostate cancer by enabling TRAIL-mediated apoptosis.

Eugenia jambolana (Java Plum) Fruit Extract Exhibits Anti-Cancer Activity against Early Stage Human HCT-116 Colon Cancer Cells and Colon Cancer Stem Cells

The World Health Organization predicts over a 70% increase in cancer incidents in developing nations over the next decade. Although these nations have limited access to novel therapeutics, they do have access to foods that contain chemopreventive bioactive compounds such as anthocyanins, and as such, consumption of these foods can be encouraged to combat cancer. We and others have previously characterized the anti-colon cancer properties of dietary anthocyanins from different sources. Eugenia jambolana (Java plum) is a tropical medicinal fruit rich in anthocyanins, however, its anti-colon cancer properties are not well characterized. Furthermore, recent evidence suggests that colon cancer stem cells (colon CSCs) promote resistance to chemotherapy, relapse of tumors and contribute to poor prognosis. The objectives of this study were to 1) characterize the anthocyanin profile of Java plum using HPLC-MS; and 2) determine the anti-proliferative (cell counting and MTT) and pro-apoptotic (TUNEL and caspase 3/7 glo assay) properties of Java plum fruit extract (JPE) using HCT-116 colon cancer cell line and colon CSCs (positive for CD 44, CD 133 and ALDH1b1 markers). HPLC-MS analysis showed that JPE contains a variety of anthocyanins including glucosides of delphinidin, cyanidin, petunidin, peonidin and malvidin. JPE anthocyanins suppressed (p < 0.05) proliferation in HCT-116 cells and elevated (p < 0.05) apoptosis in both HCT-116 cells and colon CSCs. JPE also suppressed the stemness in colon CSCs as evaluated using colony formation assay. These results warrant further assessment of the anti-cancer activity of JPE, and its molecular mechanisms using pre-clinical models of colon cancer.

Delphinidin suppresses proliferation and migration of human ovarian clear cell carcinoma cells through blocking AKT and ERK1/2 MAPK signaling pathways

Delphinidin possesses the highest chemopreventive activity among the six components of anthocyanidin that are pigments from fruits and vegetables giving them blue, purple or red colors. Although delphinidin has anti-carcinogenic and apoptotic effects in various cancers, little is known about its functional roles in ovarian clear cell carcinoma (CCC) which shows poor prognosis with resistance to chemotherapy as compared with other subtypes of epithelial ovarian cancers (EOC). Results of present study revealed that cell survival rates of ES2 cells from ovarian CCC treated with delphinidin decreased in a dose-dependent manner. Also, delphinidin inhibited migration and induced apoptosis of ES2 cells. To investigate the molecular mechanisms responsible for biological effects of delphinidin, we analyzed the phosphorylation status of carcinogenic protein kinases related to development of CCC in a dose- and time-dependent manner. Phosphorylation of downstream targets of PI3K (AKT and p70S6K) and MAPKs (ERK1/2 and JNK) signaling was suppressed by treatment of ES2 cells with delphinidin. In addition, pharmacological inhibitors of PI3K/AKT and ERK1/2 MAPK pathway improved the anti-proliferative action of delphinidin on ES2 cells. Moreover, we compared the cancer preventive effects of delphinidin with traditional cisplatin- and paclitaxel-based chemotherapy on cell viability of ES2 cells. Results showed that delphinidin is as effective in its therapeutic activity against ES2 cells as cisplatin and placlitaxel. Collectively, these results indicated that delphinidin plays a critical role as a new chemotherapeutic agent to prevent development and progression of ES2 cells in CCC via inactivation of PI3K/AKT and ERK1/2 MAPK signal transduction cascades.

Gastroretentive systems - a proposed strategy to modulate anthocyanin release and absorption for the management of diabetes

Several reports have indicated a positive correlation between the consumption of anthocyanins (ACN) and biomarkers relating to the improvement of type 2 diabetes (T2D). However, the results from in vitro studies often do not translate into clinical evidence. Potential causes of these discrepancies are experimental conditions that lack physiological relevancy; extensive degradation of these compounds in vivo due to changes in pH and metabolism; and a short residence time in the absorption window in relation to the absorption rate. Here, gastroretentive systems (GRS) are proposed as a strategy to overcome the limitations in ACN delivery and to reduce the existing bench-to-subject gap. This review summarizes recent literature on the use of ACN for the management and control of T2D, followed by GRS platforms to promote a sustained release of ACN for increased health benefits.

Enzymatic Acylation of Anthocyanin Isolated from Black Rice with Methyl Aromatic Acid Ester as Donor: Stability of the Acylated Derivatives

The enzymatic acylation of anthocyanin from black rice with aromatic acid methyl esters as acyl donors and Candida antarctica lipase B was carried out under reduced pressure. The highest conversion of 91% was obtained with benzoic acid methyl ester as acyl donor; cyanidin 3-(6″-benzoyl)-glucoside, cyanidin 3-(6″-salicyloyl)-glucoside, and cyanidin 3-(6″-cinnamoyl)-glucoside were successfully synthesized. This is the first report on the enzymatic acylation of anthocyanin from black rice with methyl aromatic esters as acyl donors and lipase as biocatalyst. Furthermore, the acylation with aromatic carboxylic acids enhanced both the thermostability and light resistivity of anthocyanin. In particular, cyanidin 3-(6″-cinnamoyl)-glucoside was the most stable among the three acylated anthocyanins synthesized.

Effect of irrigation regime on anthocyanin content and antioxidant activity of Vitis vinifera L. cv. Syrah grapes under semiarid conditions

BACKGROUND

Irrigation management is a powerful technique to control grape and wine colour. However, water deficit effects on anthocyanins are often contrasting, depending on the severity of water restriction. In addition, the effect of irrigation on the antiradical capacity of grapes has not been extensively studied. In this work the effect of water availability on anthocyanin profile and content as well as the antioxidant activity of Syrah grapes was investigated in an irrigation trial under semiarid climate conditions.

RESULTS

Three irrigation treatments were applied in a 15-year-old Vitis vinifera cv. Syrah vineyard, starting at berry set through harvest of 2011 and 2012: full irrigation (FI) at 100% of crop evapotranspiration (ETc), deficit irrigation (DI) at 50% of ETc and non-irrigated (NI). NI grapes were characterized by increased individual anthocyanin content. However, differences among irrigation treatments were significant only around 18-24 days after veraison, when anthocyanin accumulation was maximum. The antioxidant activity of the skin extracts was not affected by irrigation.

CONCLUSION

Irrigation proved to be an effective technique to control anthocyanin content in Syrah grapes under semiarid conditions. However, anthocyanin accumulation pattern should be considered by winemakers to appropriately select harvest time for improved wine colour.

UV-B-induced anthocyanin accumulation in hypocotyls of radish sprouts continues in the dark after irradiation

BACKGROUND

Raphanus sativus L. cv. Yanghua sprouts are rich in health-promoting anthocyanins; thus hypocotyls show a red color under light. In this study, effects of UV-B irradiation at 5 W m(-2) on anthocyanin biosynthesis in the hypocotyls of radish sprouts were investigated.

RESULTS

Anthocyanins began to accumulate rapidly from 24 h irradiation and increased continuously until 48 h, showing a similar pattern to phenylalanine ammonia lyase (PAL) activity, with a correlation coefficient of 0.804. The expression of DFR and ANS paralleled the upward trend in anthocyanin accumulation, while CHS, CHI and F3H were upregulated before accumulation. When sprouts were moved into the dark from UV-B, the anthocyanin accumulation did not stop immediately. By contrast, anthocyanin accumulated continuously for more than 12 h in the dark, which was further supported by the significantly higher PAL activity monitored at 24 h after irradiation. Similarly, the transcript levels of anthocyanin biosynthesis-related genes were much higher over 6 h after 12 h UV-B irradiation.

CONCLUSION

UV-B-induced anthocyanin accumulation continues in the dark after irradiation, which was supported by unfading PAL activity and high levels of biosynthesis-related genes. This will provide evidence to produce high-quality sprouts with more anthocyanins but less energy wastage in practice.

Metabolic Profiling and Antioxidant Assay of Metabolites from Three Radish Cultivars (Raphanus sativus)

A total of 13 anthocyanins and 33 metabolites; including organic acids, phenolic acids, amino acids, organic compounds, sugar acids, sugar alcohols, and sugars, were profiled in three radish cultivars by using high-performance liquid chromatography (HPLC) and gas chromatography time-of-flight mass spectrometry (GC-TOFMS)-based metabolite profiling. Total phenolics and flavonoids and their in vitro antioxidant activities were assessed. Pelargonidins were found to be the major anthocyanin in the cultivars studied. The cultivar Man Tang Hong showed the highest level of anthocyanins (1.89 ± 0.07 mg/g), phenolics (0.0664 ± 0.0033 mg/g) and flavonoids (0.0096 ± 0.0004 mg/g). Here; the variation of secondary metabolites in the radishes is described, as well as their association with primary metabolites. The low-molecular-weight hydrophilic metabolite profiles were subjected to principal component analysis (PCA), hierarchical clustering analysis (HCA), Pearson's correlation analysis. PCA fully distinguished the three radish cultivars tested. The polar metabolites were strongly correlated between metabolites that participate in the TCA cycle. The chemometrics results revealed that TCA cycle intermediates and free phenolic acids as well as anthocyanins were higher in the cultivar Man Tang Hong than in the others. Furthermore; superoxide radical scavenging activities and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging were investigated to elucidate the antioxidant activity of secondary metabolites in the cultivars. Man Tang Hong showed the highest superoxide radical scavenging activity (68.87%) at 1000 μg/mL, and DPPH activity (20.78%), followed by Seo Ho and then Hong Feng No. 1. The results demonstrate that GC-TOFMS-based metabolite profiling, integrated with chemometrics, is an applicable method for distinguishing phenotypic variation and determining biochemical reactions connecting primary and secondary metabolism. Therefore; this study might provide information on the relationship between primary and secondary metabolites and a synergistic antioxidant ability derived from the secondary metabolites in the radish cultivars.

Functional Characterization of a Dihydroflavanol 4-Reductase from the Fiber of Upland Cotton (Gossypium hirsutum)

Dihydroflavanol 4-reductase (DFR) is a key later enzyme involved in two polyphenols' (anthocyanins and proanthocyanidins (PAs)) biosynthesis, however it is not characterized in cotton yet. In present reports, a DFR cDNA homolog (designated as GhDFR1) was cloned from developing fibers of upland cotton. Silencing GhDFR1 in cotton by virus-induced gene silencing led to significant decrease in accumulation of anthocyanins and PAs. More interestingly, based on LC-MS analysis, two PA monomers, (-)-epicatachin and (-)-epigallocatachin, remarkably decreased in content in fibers of GhDFR1-silenced plants, but two new monomers, (-)-catachin and (-)-gallocatachin were present compared to the control plants infected with empty vector. The ectopic expression of GhDFR1 in an Arabidopsis TT3 mutant allowed for reconstruction of PAs biosynthesis pathway and led to accumulation of PAs in seed coat. Taken together, these data demonstrate that GhDFR1 contributes to the biosynthesis of anthocyanins and PAs in cotton.

Anthocyanin can arrest the cone photoreceptor degeneration and act as a novel treatment for retinitis pigmentosa

Retinitis pigmentosa (RP) is a group of heterogeneous inherited retinal diseases that is characterized by primary death rod photoreceptors and the secondary loss of cones. The degeneration of cones causes gradual constriction of visual fields, leaving the central islands that are eventually snuffed out. Studies indicate that the hyperoxia causes oxidative damage in the retina and contributes to the cone death of RP. Moreover, abundant reactive oxidative species (ROS) which are generated in cones may result in mitochondria membrane depolarization, which has been ascribed a central role in the apoptotic process and has been proposed to act as a forward feeding loop for the activation of downstream cascades. Anthocyanin is a potent antioxidant which has been evidenced to be able to counteract oxidative damages, scavenge surplus ROS, and rectify abnormities in the apoptotic cascade. Taken together with its ability to attenuate inflammation which also contributes to the etiology of RP, it is reasonable to hypothesize that the anthocyanin could act as a novel therapeutic strategy to retard or prevent cone degeneration in RP retinas, particularly if the treatment is timed appropriately and delivered efficiently. Future pharmacological investigations will identify the anthocyanin as an effective candidate for PR therapy and refinements of that knowledge would ignite the hope of restoring the visual function in RP patients.

Studies on oxidants and antioxidants with a brief glance at their relevance to the immune system

Free radical generation occurs continuously within cells as a consequence of common metabolic processes. However, in high concentrations, whether from endogenous or exogenous sources, free radicals can lead to oxidative stress; a harmful process that cause serious damages to all biomolecules in our body hence impairs cell functions and even results in cell death and diseased states. Oxidative injuries accumulate over time and participate in cancer development, cardiovascular and neurodegenerative disorders as well as aging. Nature has bestowed the human body with a complex web of antioxidant defense system including enzymatic antioxidants like glutathione peroxidase and glutathione reductase, catalase and superoxide dismutase as well as non-enzymatic antioxidants such as thiol antioxidants, melatonin, coenzyme Q, and metal chelating proteins, which are efficient enough to fight against excessive free radicals. Also, nutrient antioxidants such as vitamin C, vitamin E, carotenoids, polyphenols, and trace elements are known to have high antioxidant potency to assist in minimizing harmful effects of reactive species. The immune system is also extremely vulnerable to oxidant and antioxidant balance as uncontrolled free radical production can impair its function and defense mechanism. The present paper reviews the ways by which free radicals form in the body and promote tissue damage, as well as the role of the antioxidants defense mechanisms. Finally, we will have a brief glance at oxidants and antioxidants relevance to the immune system.

A significant by-product of the industrial processing of pistachios: shell skin – RP-HPLC analysis, and antioxidant and enzyme inhibitory activities of the methanol extracts of Pistacia vera L. shell skins cultivated in Gaziantep, Turkey

The antioxidant and enzyme inhibitory activities of the methanol extracts of immature and mature shell skins ofPistacia veraL. were evaluated.

A polyamide resin based method for adsorption of anthocyanins from blackberries

A polyamide resin was successfully employed for the purification of blackberry anthocyanins and this proved to be an efficient and low-cost method.

Anthocyanins in obesity-associated thrombogenesis: a review of the potential mechanism of action

Platelet dysfunction, oxidative stress and dyslipidemia are important contributors to pro-thrombotic progression particularly in obese and hyper-cholesterolemic populations.

Effects of Heat Stress on Metabolite Accumulation and Composition, and Nutritional Properties of Durum Wheat Grain

Durum wheat (Triticum turgidum (L.) subsp. turgidum (L.) convar. durum (Desf.)) is momentous for human nutrition, and environmental stresses can strongly limit the expression of yield potential and affect the qualitative characteristics of the grain. The aim of this study was to determine how heat stress (five days at 37 °C) applied five days after flowering affects the nutritional composition, antioxidant capacity and metabolic profile of the grain of two durum wheat genotypes: "Primadur", an elite cultivar with high yellow index, and "T1303", an anthocyanin-rich purple cultivar. Qualitative traits and metabolite evaluation (by gas chromatography linked to mass spectrometry) were carried out on immature (14 days after flowering) and mature seeds. The effects of heat stress were genotype-dependent. Although some metabolites (e.g., sucrose, glycerol) increased in response to heat stress in both genotypes, clear differences were observed. Following the heat stress, there was a general increase in most of the analyzed metabolites in "Primadur", with a general decrease in "T1303". Heat shock applied early during seed development produced changes that were observed in immature seeds and also long-term effects that changed the qualitative and quantitative parameters of the mature grain. Therefore, short heat-stress treatments can affect the nutritional value of grain of different genotypes of durum wheat in different ways.

Anthocyanin composition and expression analysis of anthocyanin biosynthetic genes in kidney bean pod

Kidney bean (Phaseolus vulgaris L.) is an important dietary legume crop cultivated and consumed worldwide. A purple cultivar (Zi Bawang) and a green cultivar (Chun Qiu), the main difference of which is in the pod skin color, were selected for the study. Malvidin 3, 5-diglucoside is identified as the major anthocyanin in the pod skin of Zi Bawang by HPLC-ESI-MS/MS. Three regulatory genes PvMYB1, PvMYB2, PvTT8-1 and most structural genes are dramatically up-regulated in purple pod skin compared to those in other materials. Significantly decreased expression levels of all regulatory genes and most biosynthetic genes are also detected in the purple skin of pods covered with bags compared to non-covered ones. All the results suggest that PvMYB1, PvMYB2 and PvTT8-1 might play a critical role in transcriptional activation of most anthocyanin biosynthetic genes in purple kidney bean pod.

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes.

Temperature dependency of shelf and thermal stabilities of anthocyanins from corn distillers' dried grains with solubles in different ethanol extracts and a commercially available beverage

The objective was to determine the shelf and thermal stabilities of anthocyanins from distillers' dried grains with solubles (DDGS) extracted with different ethanol concentrations as well as a semi-purified Maiz Morado (purple corn) anthocyanin extract added to a commercially available beverage. Storage for 6 weeks of DDGS showed an overall reduction of anthocyanins from 6.8 to 73.7%. In DDGS, an ethanol increase from 0 to 25% resulted in less sensitivity of anthocyanin to temperature changes. Acylation resulted in faster degradation and higher reaction rate constants than their corresponding non-acylated forms. Anthocyanin changes were accompanied by an overall increase in lightness and a decrease in redness. Storage of beverage for 12 weeks at 4 °C resulted in a 25.5% reduction of anthocyanin. Results have important implications in selecting colored corn as an economical source of food colorants.