Effects of phenolic compounds in blueberries and muscadine grapes on HepG2 cell viability and apoptosis

Metabolomic Profiling and Assessment of Phenolic Compounds Derived from Vitis davidii Foex Cane and Stem Extracts

Phenolic extracts from berry seeds have been extensively studied for their health benefits. However, few studies have been conducted on the effects of phenolic extracts from Vitis L. canes and berry stems. The Chinese spine grape (V. davidii Foex) is an important and widely distributed wild species of Vitis L. The present study explored the metabolomic profile and evaluated the antioxidant activity of phenolic compounds in extracts from V. davidii Foex. canes and stems, with a focus on their role in preventing DNA damage caused by free radicals and inhibiting the growth of breast (MCF-7) and cervical (HeLa) cancer cells. Total phenolic compounds in the dried berry stems of spine grapes were higher than that in vine canes. Analysis of the extracts showed that proanthocyanins, epicatechin, catechin, and phenolic acid were the main phenolic compounds in V. davidii Foex, but in higher quantities in berry stems than in vine canes. However, trans-resveratrol and kaempferol 3-O-glucoside were present in the vine canes but not in the berry stems. Antioxidant analysis by FRAP and ABTS showed that extracts from berry stems and vine canes had a higher antioxidant activity than thinned young fruit shoots before flowering, leaves, peel, pulp, and seeds in V. davidii Foex. Moreover, the antioxidant activity of extracts from berry stems was higher than that in other grape species, except for muscadine. In vitro analyses further showed that the extracts significantly increased H₂O₂ scavenging ability and conferred a protective effect against DNA damage. Furthermore, a low concentration of phenolic compounds in extracts from the vine canes and berry stems of spine grapes inhibited the proliferation of the MCF-7 and Hela cancer cells. These research results provided some important useful information for the exploitation of V. davidii Foex canes and berry stems and indicated that canes and stems of V. davidii Foex had good antioxidant properties, anticancer activity and prevented DNA damage, providing evidence for medical utilization of V. davidii Foex.

Chitosan nanoparticles as a promising candidate for liver injury induced by 2-nitropropane: Implications of P53, iNOS, VEGF, PCNA, and CD68 pathways

The current article was designed to assess the role of chitosan nanoparticles (CNPs) in the management of hepatic injury induced by the hepatocarcinogen 2-nitropropane (2-NP). Rats were divided into three groups. The first group served as a control, the second group was injected with 2-NP, while the third group was treated with CNPs 1 h before 2-NP injection every other day for 4 weeks. The 2-NP injection upregulated serum AST and ALT activities, as well as hepatic TNF- α, IL-6, and MDA levels and the expression of vascular endothelial growth factor (VEGF) and caspase-3, whereas GSH contents and SOD activity were decreased. Immunohistochemistry investigations revealed that the hepatic protein expression of collagen I, inducible nitric oxide synthetase, proliferating cell nuclear antigen, cluster of differentiation, and p53 were upregulated. hematoxylin and eosin (H&E) and Masson's trichrome stains supported the previous parameters, and CNPs ameliorated most of the previous biochemical parameters. CNPs achieved promising results in the limitation of 2-NP hepatotoxicity.

Inhibition of Digestive Enzyme and Stimulation of Human Liver Cells (HepG2) Glucose Uptake by Date Seeds Extract

Type 2 diabetes mellitus is increasing worldwide, and the United Arab Emirates is presenting one of the world's highest prevalence rates. Dietary polyphenols exert an antidiabetic effect by modulating carbohydrates digestion and cellular glucose uptake. Due to their particularly high content in polyphenols, date seeds represent a potential antidiabetic agent. This study aims to determine if date seed polyphenols inhibit the activity of the enzymes (α-amylase and α-glucosidase), responsible for the digestion of carbohydrates and modulating the glucose uptake by human liver cells. In vitro activity of the intestinal α-glucosidase, pancreatic α-amylase, the glucose uptake by HepG2 cells, and the expression of GLUT4 and AMPK analyzed by western blotting (with and without date seeds extract). Our result showed that the maximum enzymes inhibition was obtained with 400 μg/mL and 900 μg/mL DSE for α-amylase and α-glucosidase, respectively. The HepG2 cell viability significantly decreased up to 80% at 4000 μg/mL DSE. The expression of GLUT4 was higher at 100 μg/mL DSE (with insulin and without insulin). However, the expressions of P-AMPK and AMPK were increased by DSE, mainly in a non-insulin-dependent manner. Therefore, DSE, by inhibiting carbohydrate digestion and stimulating glucose uptake by HepG2, can potentially demonstrate the therapeutic potential for diabetes management.

Chemopreventive Properties of Extracts Obtained from Blueberry (Vaccinium myrtillus L.) and Jabuticaba (Myrciaria cauliflora Berg.) in Combination with Probiotics

The association of probiotics and fruit extracts may influence the chemopreventive effect of colorectal cancer. In this context, antiproliferative activity was evaluated to select the best extracts that would be added probiotics, after addition of Bifidobacterium or Lactobacillus in the extracts the antiradical and antioxidant activity, quinone reductase (QR) assay and apoptosis assay were evaluated. Four extracts were isolated: E1: rich in total phenolic compounds; E2: rich in water-soluble phenolic compounds; E3: rich in most apolar phenolic compounds and E4: rich in anthocyanins. The antiproliferative results showed that the best extracts for blueberry and jabuticaba were, respectively the extract E4 and E2. After addition of the probiotic bacteria in these best extracts, it was observed that E2 from jabuticaba presented significantly higher antiradical and antioxidant activity values compared to E4 from blueberry before and after addition of probiotics. There was also a 9-fold increase in activity of QR by the E2 from jabuticaba with Lactobacillus (JL). Likewise, this same extract showed a significant increase both in apoptotic and necrotic cells for both cells. In conclusion, extract rich in water-soluble phenolic compounds (E2) from jabuticaba presented a greater chemopreventive effect compared to the others.

In Vitro Propagation and Variation of Antioxidant Properties in Micropropagated Vaccinium Berry Plants-A Review

The berry crops in genus Vacciniun L. are the richest sources of antioxidant metabolites which have high potential to reduce the incidence of several degenerative diseases. In vitro propagation or micropropagation has been attractive to researchers for its incredible potential for mass production of a selected genotype in a short time, all year round. Propagation techniques affect the antioxidant activity in fruits and leaves. Total antioxidant activity was higher in the fruit of in vitro propagated plants compare to the plants grown ex vivo. This review provides critical information for better understanding the micropropagation and conventional propagation methods, and their effects on antioxidant properties and morphological differentiation in Vaccinium species, and fills an existing gap in the literature.

Isolation of strawberry anthocyanin-rich fractions and their mechanisms of action against murine breast cancer cell lines

The aim of this study was the evaluation of the effects of strawberry anthocyanin extract treatment on two in vitro models of murine breast cancer cell lines, in an attempt to detect a specific pathway (AMP-activated protein kinase or AMPK) through which strawberries exert their anticancer activity. The anticancer activity of purified anthocyanin extracts from an Alba cultivar on two murine cancer cell lines, N202/1A (with high levels of the HER2/neu oncogene) and N202/1E (with low levels of the HER2/neu oncogene), was evaluated after 48 and 72 h of treatment. The cell viability and apoptosis, intracellular ROS rates, and cell oxidative damage were assessed. Western blot assays were performed to analyze the expression of several proteins related to apoptosis, autophagy, metastasis, the oxidative status, mitochondrial functionality, and the AMPK pathway. This study demonstrated that the anthocyanin extract of Alba strawberry shows an antiproliferative effect on cancer cells, through the induction of apoptosis and oxidative stress, by stimulating different molecular pathways. This study is one of the first studies that have tried to deepen the understanding of a candidate pathway for the explanation of the effects of strawberry on cancer cells. A relationship between the AMPK pathway and the anticancer effects of strawberries was demonstrated.

Crosstalk between GSK-3, c-Fos, NFκB and TNF-α signaling pathways play an ambitious role in Chitosan Nanoparticles Cancer Therapy

Nanotechnology is a promising era of medicine for developing targeted drug delivery system. Chitosan nanoparticles (CNPs) have attracted increasing attention for their wide applications as anticancer drugs. This article is concerned with the therapeutic index of chitosan nanoparticles against diethyl nitrosamine (DEN) induced hepatocellular carcinoma (HCC). HCC was induced in rats via repeated DEN administration in a dose of 200 mg/kg BW IP, 2 weeks later rats received (2 ml/kg BW) CCl4 orally for 2 months followed by daily treatment with chitosan nanoparticles in an oral dose of 12 mg/kg for 1 month. Then the gene expression of glycogen synthase kinase-3 (GSK-3), (c-FOS), nuclear factor kappa-B (NFκB) and tumor necrosis factor- α (TNF-α) were reported in rats sera and the correlation between GSK-3, C-Fos, NFƘB and TNF-α and liver tumorigenesis was investigated. The results elucidated that DEN significantly increased serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Marked increments in serum malondialdehyde (MDA) and nitric oxide (NOx) levels along with a slight reduction of glutathione (GSH) level were evidenced in HCC. Liver injury triggered an inflammatory response by enhancing the mRNA gene expression of NFκB and TNF-α. DEN effectively activated apoptotic markers GSK-3 and c-FOS. Oral administration of CNPs alleviated the oxidative, inflammatory and apoptotic hazards induced via DEN. The histopathological examination reinforced these results. The present study highlights the anti-inflammatory and anti-apoptotic potentials of CNPs against DEN-induced HCC.

Effects of Different Acyl Gellan Gums on the Rheological Properties and Colloidal Stability of Blueberry Cloudy Juice

In this study, gellan gums with different acyl contents were prepared, and their effects on blueberry cloudy juices were compared. The rheological properties, stability coefficients, sedimentations, color parameters and particle size distributions of blueberry cloudy juices with 0.035% (w/w) of gellan gum were measured. As the acyl content increased, the viscosity increased, and the sedimentation and stability coefficient values decreased. Gellan gums with higher acyl contents provided better beverage stabilizing capabilities through stricter enforcement of the molecular associations. Overall, this study provides valuable information for enhancing the gelation and stabilization of blueberry cloudy juices, confirms the superiority of high acyl gellan gums for inhibiting the color fading of anthocyanins, and further guides the development of novel product concepts.

PRACTICAL APPLICATION

Cloudy juices made from blueberries have many benefits. However, the particles in cloudy juices will flocculate during storage, resulting in an undesirable precipitate. In our work, gellan gums with different acyl contents were prepared and applied to blueberry juice to prevent aggregation. The results provide valuable information for enhancing the stabilization of blueberry juices, confirm the superiority of high acyl gellan for inhibiting color fading, and further guide the development of novel product concepts.

Beyond Conventional Medicine - a Look at Blueberry, a Cancer-Fighting Superfruit

Nearly 40% of men and women will be diagnosed with cancer during their lifetime. Thus, there is a rapidly growing need for novel therapies to combat this deadly disease. One such method is the consumption of blueberries. Long coveted for their powerful antioxidant properties, more recent studies have demonstrated that blueberries also exhibit inherent abilities to prevent carcinogenesis, inhibit the proliferation of neoplastic cells, and reduce the risks of recurrence in patients in remission. This review will focus on the specific activities of blueberry derivatives in cancer cells across many different forms of cancer. Ultimately, such research could be helpful in the development of new strategies to treat cancer.

Potential Benefits of Edible Berries in the Management of Aerodigestive and Gastrointestinal Tract Cancers: Preclinical and Clinical Evidence

Epidemiological reports as well as experimental studies have demonstrated the significant health benefits provided by regular berry consumption. Berries possess both prophylactic and therapeutic potential against several chronic illnesses, such as cardiovascular, neurodegenerative, and neoplastic diseases. Berries owe their health benefits to phytoconstituents, such as polyphenolic anthocyanins, ellagic acid, and a diverse array of phytochemicals bestowed with potent antioxidant and anti-inflammatory effects as well as the ability to engage a multitude of signaling pathways. This review highlights the principal chemical constituents present in berries and their primary molecular targets. The article presents and critically analyzes the chemopreventive and therapeutic potential of berry extracts, fractions, and bioactive components on various cancers of the gastrointestinal tract (GIT), including esophageal, stomach, intestinal, and colorectal cancers as well as cancers of the upper aerodigestive tract, such as oral cancer. The current status of clinical studies evaluating berry products in several aforementioned cancers is presented. Various emerging issues including dose-ranging and dosage forms, the role of synergy and the usage of combination therapy as well as other relevant areas essential for the development of berry phytoconstituents as mainstream chemopreventive and therapeutic agents against aerodigestive and GIT cancers are critically discussed.

Intermolecular binding of blueberry pectin-rich fractions and anthocyanin

Pectin was extracted from blueberry powder into three fractions of water soluble (WSF), chelator soluble (CSF) and sodium carbonate soluble (NSF). The fractions were incubated with cyanidin-3-glucoside (C3G), a mixture of five anthocyanidins (cyanidin, pelargonidin, malvidin, petunidin and delphinidin) or blueberry juice at pH 2.0-4.5. Free anthocyanins and bound anthocyanin-pectin mixtures were separated by ultrafiltration. WSF bound the least amount of anthocyanin at all pH values. CSF had stronger anthocyanin binding ability at pH 2.0-3.6, while NSF had stronger anthocyanin binding ability at pH 3.6-4.5. The pectin and anthocyanin binding was lowest at pH 4.5 and higher at pH 2.0-3.6. Nearly doubling C3G pigment content increased bound anthocyanin percentage by 16-23% at pH 3.6, which favored anthocyanin aromatic stacking, compared to 3-9% increase at pH 2.0. Ionic interaction between anthocyanin flavylium cations and free pectic carboxyl groups, and anthocyanin stacking may be two major mechanisms for pectin and anthocyanin binding.

Inhibition of oxidative stress and lipid peroxidation by anthocyanins from defatted Canarium odontophyllum pericarp and peel using in vitro bioassays

Canarium odontophyllum, also known as CO, is a highly nutritious fruit. Defatted parts of CO fruit are potent sources of nutraceutical. This study aimed to determine oxidative stress and lipid peroxidation effects of defatted CO pericarp and peel extracts using in vitro bioassays. Cell cytotoxic effect of the CO pericarp and peel extracts were also evaluated using HUVEC and Chang liver cell lines. The crude extracts of defatted CO peel and pericarp showed cytoprotective effects in t-BHP and 40% methanol-induced cell death. The crude extracts also showed no toxic effect to Chang liver cell line. Using CD36 ELISA, NAD(+) and LDL inhibition assays, inhibition of oxidative stress were found higher in the crude extract of defatted CO peel compared to the pericarp extract. Hemoglobin and LDL oxidation assays revealed both crude extracts had significantly reduced lipid peroxidation as compared to control. TBARS values among defatted CO pericarp, peel, and cyanidin-3-glucoside showed no significant differences for hemoglobin and LDL oxidation assays. The protective effects of defatted CO parts, especially its peel is related to the presence of high anthocyanin that potentially offers as a pharmaceutical ingredient for cardioprotection.

Effect of blueberry pretreatment on diethylnitrosamine-induced oxidative stress and liver injury in rats

Diethylnitrosamine (DEN) treatment increases the generation of reactive oxygen species (ROS), apoptosis, necrosis and proliferation in the liver. Blueberries (BB; Vaccinium corymbosum L.) contain polyphenols and other active components and have high antioxidant capacities. We investigated the effect of BB pretreatment on DEN-induced liver injury and oxidative and nitrosative stress in male rats. Rats were fed with 5% and 10% BB containing diet for six weeks and DEN (200mg/kg; i.p.) was applied two days before the end of this period. Liver function tests were determined in serum and histopathological evaluation was performed in the liver tissue. Apoptosis-related proteins, Bax and B cell lymphoma-2 (Bcl-2) and proliferating cell nuclear antigen (PCNA) expressions were also examined. Oxidative and nitrosative stress were evaluated in the liver by measuring thiobarbituric acid reactive substances, diene conjugate, protein carbonyl and nitrotyrosine levels, and glutathione levels and glutathione peroxidase, superoxide dismutase and glutathione transferase (GST) activities. Pretreatment with high dose of BB reduced apoptotic, necrotic and proliferative changes in the liver induced by DEN. Dietary BB also decreased hepatic lipid peroxidation, protein oxidation and nitrotyrosine levels together with increased GST activity. In conclusion, BB may have an inhibiting effect on acute liver injury by reducing apoptosis, necrosis, proliferation, oxidative and nitrosative stress in DEN-treated rats.

Investigation on the protective effects of cranberry against the DNA damage induced by benzo[a]pyrene

There are few reports that demonstrate the antigenotoxic potential of cranberries. Although the types of berry fruits consumed worldwide are many, this paper focuses on cranberries that are commonly consumed in Mexico (Vaccinium macrocarpon species). The purpose of the present study is to determine whether cranberry ethanolic extract (CEE) can prevent the DNA damage produced by benzo[a]pyrene (B[a]P) using an in vivo mouse peripheral blood micronucleus assay. The experimental groups were organized as follows: a negative control group (without treatment), a positive group treated with B[a]P (200 mg/kg), a group administered with 800 mg/kg of CEE, and three groups treated with B[a]P and CEE (200, 400, and 800 mg/kg) respectively. The CEE and benzo[a]pyrene were administered orally for a week, on a daily basis. During this period the body weight, the feed intake, and the determination of antigenotoxic potential were quantified. At the end of this period, we continued with the same determinations for one week more (recovery period) but anymore administration of the substances. The animals treated with B[a]P showed a weight increase after the first week of administration. The same phenomenon was observed in the lots combined with B[a]P and CEE (low and medium doses). The dose of 800 mg/kg of CEE showed similar values to the control group at the end of the treatment period. In the second part of the assay, when the substances were not administered, these experimental groups regained their normal weight. The dose of CEE (800 mg/kg) was not genotoxic nor cytotoxic. On the contrary, the B[a]P increases the frequency of micronucleated normochromatic erythrocytes (MNNE) and reduces the rate of polychromatic erythrocytes (PE) at the end of the treatment period. With respect to the combined lots, a significant decrease in the MN rate was observed from the sixth to the eighth day of treatment with the two high doses applied; the highest protection (60%) was obtained with 800 mg/kg of CEE. The same dose showed an anticytotoxic effect which corresponded to an improvement of 62.5% in relation to the animals administered with the B[a]P. In the second period, all groups reached values that have been seen in the control group animals. Our results suggest that the inhibition of clastogenicity of the cranberry ethanolic extract against B[a]P is related to the antioxidant capacity of the combination of phytochemicals present in its chemical composition.

Antibacterial activities of blueberry and muscadine phenolic extracts

Phenolics are one category of phyto-antimicrobials that refer to the antimicrobial substances extracted from plant sources. This study was undertaken to determine the influence of blueberry and muscadine phenolic extracts on the growths of 2 important foodborne bacterial pathogens, Salmonella Enteritidis and Listeria monocytogenes. Cells of S. Enteritidis (n = 4) or L. monocytogenes (n = 4) strains were inoculated (3 log CFU/mL) into tryptic soy broth (TSB) supplemented with 46.25 ppm of muscadine phenolics and 24 ppm of blueberry phenolics, respectively. The inoculated and un-inoculated broth with or without the supplemented phenolics were incubated at 37 °C for 24 h. Samples were drawn periodically, and cell populations of Salmonella and Listeria were determined on tryptic soy agar (TSA). It was observed that Salmonella was relatively more susceptible than Listeria to the phenolic extracts used in the study. The growth of Salmonella was significantly inhibited in all samples at all sampling points except for the sample that was supplemented with muscadine water extract and drawn at the 24-h sampling point. Blueberry phenolics were relatively more effective than muscadine phenolic extracts in inhibiting the growth of Salmonella. One tested strain of Listeria was more susceptible to ethanol than water phenolic extracts. The study revealed the potentials and limitations of using blueberry and muscadine phenolics to control the growths of selected Salmonella and Listeria strains.

Targets of Red Grapes: Oxidative Damage of DNA and Leukaemia Cells

Vitis vinifera is a widespread crop all over the world. The biophenols present in grapes have a remarkable influence on wine quality and also confer potential health-protecting properties to this fruit. The aim of the present work was to assess the beneficial properties of skin, seeds and pulp of red table grapes (RTG) ( Vitis vinifera, Palieri Cadiz variety). Two potential beneficial activities of red table grapes (RTG) were analyzed: (i) The maintenance of genomic stability studying their genotoxic/antigenotoxic effects, and (ii) the in vitro cytotoxic effect against tumor cells of RTG components.

The genotoxic and/or antigenotoxic effect was measured applying the somatic mutation and recombination test on wing imaginal discs of Drosophila melanogaster. The cytotoxic effect was monitored using the HL60 human leukemia model to evaluate the antiproliferative potential of the different parts of RTG. The three major parts (skin, seeds and pulp) are not genotoxic. When antigenotoxicity assays were performed using hydrogen peroxide as the oxidative genotoxin, skin, seed and pulp exerted a desmutagenic effect, with seeds and skin showing the most potent effect. The cytotoxicity tests using HL60 cells indicated that only skin and pulp fractions are able to inhibit the tumor growth, with skin having the lowest IC50 (1.8 mg/mL versus 8 mg/mL of pulp). These results suggest that RTG are potent anti-mutagens that protect DNA from oxidative damage as well as being cytotoxic toward the HL60 tumor cell line.

Protective effect of enzymatic hydrolysates from highbush blueberry (Vaccinium corymbosum L.) against hydrogen peroxide-induced oxidative damage in Chinese hamster lung fibroblast cell line

Blueberry was enzymatically hydrolyzed using selected commercial food grade carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to obtain water soluble compounds, and their protective effect was investigated against H₂O₂-induced damage in Chinese hamster lung fibroblast cell line (V79-4) via various published methods. Both AMG and Alcalase hydrolysates showed higher total phenolic content as well as higher cell viability and ROS scavenging activities, and hence, selected for further antioxidant assays. Both AMG and Alcalase hydrolysates also showed higher protective effects against lipid peroxidation, DNA damage and apoptotic body formation in a dose-dependent fashion. Thus, the results indicated that water soluble compounds obtained by enzymatic hydrolysis of blueberry possess good antioxidant activity against H₂O₂-induced cell damage in vitro.

Comparison of antioxidant capacity and phenolic compounds of berries, chokecherry and seabuckthorn

Antioxidant capacity and phenolic compounds (phenolic acids and anthocyanins) of four berry fruits (strawberry, Saskatoon berry, raspberry and wild blueberry), chokecherry and seabuckthorn were compared in the present study. Total phenolic content and total anthocyanin content ranged from 22.83 to 131.88 g/kg and 3.51 to 13.13 g/kg, respectively. 2,2-Diphenyl-1-picryhydrazyl free radical scavenging activity ranged from 29.97 to 78.86%. Chokecherry had the highest antioxidant capacity when compared with berry fruits and seabuckthorn. The highest caffeic acid, gallic acid and trans-cinnamic acid levels were found in chokecherry (6455 mg/kg), raspberry (1129 mg/kg) and strawberry (566 mg/kg), respectively. Caffeic acid was also the major phenolic acid in Saskatoon berry (2088 mg/kg) and wild blueberry (1473 mg/kg). The findings that chokecherry has very high antioxidant capacity and caffeic acid levels, are useful for developing novel value-added antioxidant products and also provide evidence essential for breeding novel cultivars of fruit plants with strong natural antioxidants.

Antiobesity and antidiabetic effects of biotransformed blueberry juice in KKA(y) mice

AIM

Biotransformation of blueberry juice by the Serratia vaccinii bacterium gave rise to adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and glucose uptake in muscle cells and adipocytes, but inhibited adipogenesis. This study investigated the antiobesity and antidiabetic potential of biotransformed blueberry juice (BJ) in KKA(y) mice, rodent model of leptin resistance.

METHODS

BJ was incorporated in drinking water of KKA(y) mice. Parameters of body weight, food intake, plasma glucose, insulin, leptin, and adiponectin were measured. Before and after therapy, animals were subjected to an oral glucose tolerance test. At the end of treatment, liver, muscle, kidney, epididymal fat pad, abdominal fat pad, and dorsal fat pad were collected and weighed.

RESULTS

Incorporating BJ in drinking water protected young KKA(y) mice from hyperphagia and significantly reduced their weight gain. Moreover, BJ protected young KKA(y) mice against the development of glucose intolerance and diabetes mellitus. Chronic BJ administration in obese and diabetic KKA(y) mice reduced food intake and body weight. This effect could not fully explain the associated antidiabetic effect because BJ-treated mice still showed lower blood glucose level when compared with pair-fed controls. The adipokines pathway also seems to be involved because BJ significantly increased adiponectin levels in obese mice.

CONCLUSIONS

This study shows that BJ decreases hyperglycemia in diabetic mice, at least in part by reversing adiponectin levels. BJ also protects young pre-diabetic mice from developing obesity and diabetes. Thus, BJ may represent a novel complementary therapy and a source of novel therapeutic agents against diabetes mellitus.

Fermented Canadian lowbush blueberry juice stimulates glucose uptake and AMP-activated protein kinase in insulin-sensitive cultured muscle cells and adipocytesThis article is one of a selection of papers published in this special issue (part 1 of 2) on the Safety and Efficacy of Natural Health Products

Extracts of the Canadian lowbush blueberry ( Vaccinium angustifolium Ait.) have recently been demonstrated to possess significant antidiabetic potential, in accordance with the traditional use of this plant as an antidiabetic natural health product. Fermentation of blueberry juice with the Serratia vaccinii bacterium is known to modify the phenolic content and increase antioxidant activity. The present study evaluated the effects of fermented blueberry juice on glucose uptake, adipogenesis, and the signaling pathways that regulate glucose transport in muscle cells and adipocytes. A 6-hour treatment with fermented juice potentiated glucose uptake by 48% in C2C12 myotubes and by 142% in 3T3-L1 adipocytes, in the presence or absence of insulin, whereas nonfermented juice had no effect on transport. Fermented juice dramatically inhibited triglyceride content during adipogenesis of 3T3-L1 cells. Chlorogenic acid and gallic acid, both major phenolic components of fermented juice, had no effect on glucose uptake. Western blot analysis of the insulin-independent AMP-activated protein kinase revealed increased phosphorylation resulting from a 6-hour treatment. This activation or the increase in glucose uptake could not be explained by increased cytosolic calcium. Fermentation with S. vaccinii is concluded to confer antidiabetic activities to blueberry juice. Although the active principles and their mechanisms of action remain to be identified, transformed blueberry juice may nevertheless represent a novel complementary therapy and a source of novel therapeutic agents against diabetes mellitus.

The bioavailability and absorption of anthocyanins: Towards a better understanding

Evidence that anthocyanin compounds have beneficial effects for health are increasingly being reported in the scientific literature and these compounds are now widely recognised as potential therapeutic compounds. Berry fruit are rich sources of anthocyanins and berry fruit products or derived beverages can provide 10s to 100s of milligrams of anthocyanins in a single serve. Anthocyanins exhibit complex chemical behaviours in vitro and this will result in complex behaviour in vivo. This review attempts to summarize some aspects of anthocyanin biochemistry and discusses these in the context of what is currently known about bioavailability and absorption. Compared with other flavonoid groups, such as flavonols, relatively little is known about details and mechanisms of anthocyanin absorption and transport and much remains to be discovered.