Polyphenol-enriched Fraction Research Articles

Phenolic Acid Profiling, Antioxidant, and Anti-Inflammatory Activities, and miRNA Regulation in the Polyphenols of 16 Blueberry Samples from China.

To investigate the anti-atherosclerosis related mechanism of blueberries, the phenolic acids (PAs) content, antioxidant and anti-inflammatory activities, as well as the microRNA (miRNA) regulation of polyphenol fractions in blueberry samples from China were studied. Sixteen batches of blueberries including 14 commercialized cultivars (Reka, Patriot, Brigitta, Bluecrop, Berkeley, Duke, Darrow, Northland, Northblue, Northcountry, Bluesource, Southgood, O’Neal, and Misty) were used in this study. Seven PAs in the polyphenol fractions from 16 blueberry samples in China were quantified by high performance liquid chromatography/tandem mass spectrometry (HPLC/MS2). The antioxidant activities of blueberry polyphenols were tested by (1,1-diphenyl-2-picrylhydrazyl [DPPH]) assay. The anti-inflammatory (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]) activities of the polyphenol fractions of the blueberries were investigated by using lipopolysaccharide (LPS) induced RAW 264.7 macrophages. The correlation analysis showed that the antioxidant (1,1-diphenyl-2-picrylhydrazyl [DPPH]) and anti-inflammatory (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]) activities of the polyphenol fractions of the blueberries were in accordance with their PA contents. Although the polyphenol-enriched fractions of blueberries could inhibit the microRNAs (miRNAs) (miR-21, miR-146a, and miR-125b) to different extents, no significant contribution from the PAs was observed. The inhibition of these miRNAs could mostly be attributed to the other compounds present in the polyphenol-enriched fraction of the blueberries. This is the first study to evaluate the PAs content, antioxidant and anti-inflammatory activities, and miRNA regulation of Chinese blueberries.

An approach to turn olive mill wastewater into a valuable food by-product based on spray drying in dehumidified air using drying aids

Several methods have been investigated for olive mill wastewater (OMW) management. However, there has been little success in finding an environmentally friendly and economically viable solution to be generally adopted. The main objective of this work was to develop a new method for OMW management, which simultaneously will lead to the recovery of high-added value substances, based on screening and spray drying. The polyphenol enriched solid fraction derived from screening (OMWS) is spray dried to make an olive powder product rich in antioxidants for dietary uses. A new technique for spray drying OMWS using dehumidified air as drying medium and maltodextrin as drying agent was developed. Different drying experiments were conducted varying the inlet air temperature, the drying air flow rate, the compressed air flow rate, the type of drying agent, and the ratio (OMWS solids)/(drying aid solids). Data for the product collected in the receiving vessel were gathered and the OMWS powders were analyzed for moisture content, bulk density, and solubility. The achieved values of product recovery (87–94%) were much higher than those obtained in a typical spray drying system (<3%). Thus, the combination of maltodextrin addition and use of dehumidified air as drying medium seems to be an effective way of producing a free-flowing olive mill wastewater powder to be included in food formulations.

Hepatoprotective Effect of Polyphenol-Enriched Fraction from Folium Microcos on Oxidative Stress and Apoptosis in Acetaminophen-Induced Liver Injury in Mice.

Folium Microcos (FM), the leaves of Microcos paniculata L., shows various biological functions including antioxidant activity and α-glucosidase inhibitory effect. However, its therapeutic potential in acute liver injury is still unknown. This study investigated the hepatoprotective effect and underlying mechanisms of the polyphenol-enriched fraction (FMF) from Folium Microcos. FMF exhibited strong free radical scavenging activities and prevented HepG2/Hepa1–6 cells from hydrogen peroxide- (H2O2-) induced ROS production and apoptosis in vitro. Antioxidant activity and cytoprotective effects were further verified by alleviating APAP-induced hepatotoxicity in mice. Western blot analysis revealed that FMF pretreatment significantly abrogated APAP-mediated phosphorylation of MAPKs, activation of proapoptotic protein caspase-3/9 and Bax, and restored expression of antiapoptotic protein Bcl2. APAP-intoxicated mice pretreated with FMF showed increased nuclear accumulation of nuclear factor erythroid 2-related factor (Nrf2) and elevated hepatic expression of its target genes, NAD(P)H:quinine oxidoreductase 1 (NQO1) and hemeoxygenase-1(HO-1). HPLC analysis revealed the four predominantly phenolic compounds present in FMF: narcissin, isorhamnetin-3-O-β-D-glucoside, isovitexin, and vitexin. Consequently, these findings indicate that FMF possesses a hepatoprotective effect against APAP-induced hepatotoxicity mainly through dual modification of ROS/MAPKs/apoptosis axis and Nrf2-mediated antioxidant response, which may be attributed to the strong antioxidant activity of phenolic components.

A polyphenol-enriched fraction of Cyclopia intermedia decreases lipid content in 3T3-L1 adipocytes and reduces body weight gain of obese db/db mice

Extracts of Cyclopia species, indigenous South African fynbos plants used for the production of honeybush tea, have potential as anti-obesity nutraceutical ingredients. Previously, we demonstrated that aqueous extracts of C. maculata and C. subternata exhibited anti-obesity effects in 3T3-L1 adipocytes. In this study, we further explored these anti-obesity effects of C. maculata and C. subternata as well as C. intermedia for the first time. Extracts were prepared using a 40% methanol–water mixture (40% MeOH) in order to enhance the polyphenolic content of the extracts. Moreover, these extracts were separated into aqueous and organic fractions using liquid–liquid partitioning with n-butanol and water to further enrich the polyphenol content of the organic fractions. Extracts of all three Cyclopia species decreased the lipid content in 3T3-L1 adipocytes, although differences in bioactivity of their aqueous and organic fractions were observed. The organic fraction of C. intermedia was further investigated. This fraction dose-dependently decreased the lipid content in 3T3-L1 adipocytes without affecting cell viability, while increasing mRNA expression of HSL (1.57-fold, P<0.05), SIRT1 (1.5-fold, P=0.07), UCP3 (1.5-fold, P<0.05) and PPARγ (1.29-fold, P<0.05). Daily treatment of obese db/db mice with 351.5mg/kg bodyweight of the organic C. intermedia fraction for 28days decreased bodyweight gain by 21% (P<0.05) without any effect on food or water consumption. The organic fraction was enriched in phenolic content relative to the extract with neoponcirin, a flavanone not previously identified in Cyclopia species, mangiferin, isomangiferin and hesperidin comprising 17.37% of the organic fraction of C. intermedia compared to 4.96% of its “large scale” prepared 40% MeOH extract. Their specific roles as anti-obesity agents in these models needs to be studied to guide product development.

In vitro modulation of inflammatory target gene expression by a polyphenol-enriched fraction of rose oil distillation waste water

Classical production of rose oil is based on water steam distillation from the flowers of Rosa damascena. During this process, large quantities of waste water accrue which are discharged to the environment, causing severe pollution of both, groundwater and surface water due to a high content of polyphenols. We recently developed a strategy to purify the waste water into a polyphenol-depleted and a polyphenol-enriched fraction RF20-(SP-207). RF20-(SP-207) and sub-fraction F(IV) significantly inhibited cell proliferation and migration of HaCaT cells. Since there is a close interplay between these actions and inflammatory processes, here we focused on the fractions' influence on pro-inflammatory biomarkers. HaCaT keratinocytes were treated with RF20-(SP-207), F(IV) (both at 50μg/mL) and ellagic acid (10μM) for 24h under TNF-α (20ng/mL) stimulated and non-stimulated conditions. Gene expression of IL-1β, IL-6, IL-8, RANTES and MCP-1 was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and cellular protein secretion of IL-8, RANTES and MCP-1 was determined by ELISA based assays. RF20-(SP-207) and F(IV) significantly decreased the expression and cellular protein secretion of IL-1β, IL-6, IL-8, RANTES and MCP-1. The diminishing effects on inflammatory target gene expression were slightly less pronounced under TNF-α stimulated conditions. In conclusion, the recovered polyphenol fraction RF20-(SP-207) from rose oil distillation waste water markedly modified inflammatory target gene expression in vitro, and, therefore, could be further developed as alternative treatment of acute and chronic inflammation.

The beneficial potential of polyphenol-enriched fraction from Erigerontis Herba on metabolic syndrome

Ethnopharmacological relevanceErigerontis Herba is a Chinese herb that is traditionally used to treat cardiovascular disease. Recent literatures suggested that it could exert beneficial effects on various cardiovascular metabolic risk factors including hypertension and hyperlipidemia in order to exert its cardio-protective effects. AimErigerontis Herba contains a variety of flavonoids and polyphenols that are bioactive. The aim of the present study was to investigate the cardio-protective effects of the total polyphenols of Erigerontis Herba (EHP), particularly on the metabolic parameters which could contribute to metabolic syndrome including obesity, hepatic steatosis, hyperlipidemia and hypertension. Materials and methodsC57Bl/6 metabolic syndrome mice model was used to determine the effects of EHP on metabolic syndrome. High-fat diet-induced metabolic syndrome in C57Bl/6 mice is an animal model which mimics human metabolic syndrome. The model is achieved by high-fat diet feeding to C57Bl/6 mice for 8 weeks. In our study, the mice were divided into 3 groups and fed for 8 weeks with: 1) normal chow (N); 2) high-fat diet (HF); or 3) high-fat diet supplemented with 2% EHP (HF+EHP). Various parameters such as body weight, adipose tissue weight and liver weight were measured. Liver and plasma lipid levels were also determined. In addition, the effect of EHP on vasodilation in Sprague Dawley rats was also determined using ex vivo aortic ring model. ResultsVarious types of adipose tissues weights were significantly lowered in HF+EHP vs HF mice. Hepatic lipid levels were also significantly decreased by EHP vs HF. For plasma lipid (including TC and TG), EHP exerted no significant effects on plasma lipid levels. To understand the mechanisms as to how EHP regulated lipid metabolism via liver, various hepatic gene expressions were also measured using real-time PCR. The results showed that EHP regulated the expressions of Cyp7α1, CD36 and PPAR-γ. EHP showed significant vasodilative effects in both intact aortas and endothelium-removed aortas. Further mechanistic studies indicated that EHP dilated aorta endothelium-dependently through nitric oxide synthase (NOS) pathway, and endothelium-independently through BKca, Kv and Kir channels. In addition to the vasodilative effects, EHP could also inhibit aorta contraction through Ca2+ channel. ConclusionsEHP exerted promising effects on diet-induced obesity and hepatic steatosis in C57Bl/6 mice model. It also exerted significant vasodilative effect ex vivo, suggesting the potential of EHP to be developed as a dietary supplement for metabolic syndrome.

A Polyphenol-Enriched Fraction of Rose Oil Distillation Wastewater Inhibits Cell Proliferation, Migration and TNF-α-Induced VEGF Secretion in Human Immortalized Keratinocytes.

Water steam distillation of rose flowers separates the essential oil from the polyphenol-containing rose oil distillation wastewater. Recently, a strategy was developed to separate rose oil distillation wastewater into a polyphenol depleted water fraction and a polyphenol-enriched fraction [RF20-(SP-207)]. The objective of the present study was to investigate RF20-(SP-207) and fraction F(IV), augmented in quercetin and ellagic acid, for possible antiproliferative effects in immortalized human keratinocytes (HaCaT) since rose petals are known to contain compounds with potential antiproliferative activity.RF20-(SP-207) revealed dose-dependent antiproliferative activity (IC50 of 9.78 µg/mL). In a nontoxic concentration of 10 µg/mL, this effect was stronger than that of the two positive controls LY294002 (10 µM, PI3 K-inhibitor, 30 % inhibition) and NVP-BEZ235 (100 nM, dual PI3 K/mTOR inhibitor, 30 % inhibition) and clearly exceeded the antiproliferative action of quercetin (50 µM, 25 % inhibition) and ellagic acid (1 µM, 15 % inhibition). Time-lapse microscopy detected a significant impairment of cell migration of RF20-(SP-207) and F(IV). At concentrations of 10 µg/mL of both, extract and fraction, cell migration was strongly suppressed (51 % and 28 % gap closure, respectively, compared to 95 % gap closure 24 hours after control treatment). The suppression of cell migration was comparable to the positive controls LY294002, NVP-BEZ235, and quercetin. Furthermore, basal and TNF-α-stimulated VEGF-secretion was significantly reduced by RF20-(SP-207) and F(IV) at 10 µg/mL (44 % vs. untreated control).In conclusion, RF20-(SP-207) showed promising antiproliferative and antimigratory effects and could be developed as a supportive, therapy against hyperproliferation-involved skin diseases.

Evaluation of the In Vivo Therapeutic Effects of Radix Paeoniae Rubra Ethanol Extract with the Hypoglycemic Activities Measured from Multiple Cell-Based Assays.

Background. Radix Paeoniae Rubra (Chi Shao) contains several phytochemicals with hypoglycemic actions. Current research aims to explore potential insulinotropic effects and long-term therapeutic efficacy of such herb against type 2 diabetes. Methods. Composition analysis for the ethanol extract (PRExt) was executed by high performance liquid chromatography. Polyphenol-enriched fraction was characterized by high pressure size exclusion chromatography. Multiple cell platforms were employed to evaluate hypoglycemic bioactivities. In animal experiments, blood glucose, the homeostasis model assessment (HOMA)-index assessment, glucose tolerance test, and in vivo glucose uptake were all measured. Additional effects of PRExt on obesity and hepatic steatosis were evaluated by serum and histological analysis. Results. PRExt provides multiple hypoglycemic effects including the enhancement of glucose-mediated insulin secretion. Pentagalloylglucose and polyphenol-enriched fraction are two insulinotropic constituents. Moreover, PRExt intraperitoneal injection causes acute hypoglycemic effects on fasted db/db mice. Oral administration of PRExt (200 mg/kg b.w.) gradually reduces blood glucose in db/db mice to the level similar to that in C57J/B6 mice after 30 days. The improvement of glucose intolerance, HOMA-index, and in vivo glucose uptake is evident in addition to the weight loss effect and attenuation of hepatic steatosis. Conclusion. PRExt is an effective antidiabetic herbal extract with multiple hypoglycemic bioactivities.

A polyphenol enriched fraction of rose oil distillation water inhibits proliferation in HaCaT cells and induces apoptosis

Water steam distillation of rose flowers (Rosa damascena) separates the essential oil from the polyphenol containing rose oil distillation waste water (RODW). While the essential oil represents the desired liquid for the cosmetic industry, the polyphenol containing RODW is in the center of our interest. Recently, a strategy was developed to separate RODW into a polyphenol depleted water fraction and a polyphenol enriched fraction [RF20-(SP-207)]. Polyphenols are known to have a wide spectrum of biochemical and pharmacological effects. In the present study, it was of interest to investigate possible antiproliferative effects of RF20-(SP-207) and fractions thereof F(I)-(IV) in immortalized human keratinocytes (HaCaT). The BrdU cell proliferation assay was used to measure cell proliferation. Cell migration was elucidated by time lapse microscopy. The data demonstrated that from all tested fractions only F(IV) revealed a dose dependent antiproliferative effect which is comparable to RF20-(SP-207) (IC50 of approx. 10 µg/mL). This effect is similar to both positive controls LY294002 (PI3K-inhibitor, 30% inhibition) and NVP-BEZ235 (dual PI3K/mTOR-inhibitor, 30% inhibition) and clearly exceeds the anti-proliferative action of quercetin (approx. 20% inhibition). Time lapse microscopy revealed that cell migration was dramatically decreased under influence of RF20-(SP-207) and F(IV). This effect was comparable to LY294002 and NVP-BEZ235. Fluorescence microscopy images confirm the qualitative increase of apoptosis under influence of RF20-(SP-207) and (IV).

A polyphenol enriched fraction of rose oil distillation water inhibits proliferation in HaCaT cells and induces apoptosis

A polyphenol enriched fraction of rose oil distillation water inhibits proliferation in HaCaT cells and induces apoptosis

Tyrosinase inhibitory constituents from a polyphenol enriched fraction of rose oil distillation wastewater

During the water steam distillation process of rose flowers, the non-volatile phenolic compounds remain in the waste. We recently developed a strategy to separate rose oil distillation water (RODW) into a polyphenol depleted water fraction and a polyphenol enriched fraction (RF20-SP207). Bioassay-guided investigation of RF20-SP207 led to the isolation of quercetin, kaempferol and ellagic acid. Their structures were elucidated by spectroscopic analysis as well as by comparison with literature data. Tyrosinase inhibition studies were performed with RF20-SP207, fractions I–IV, and the isolated compounds of the most active fraction. RF20-SP207 strongly inhibited the enzyme with an IC50 of 0.41μg/mL. From the tested fractions only fraction IV (IC50=5.81μg/mL) exhibited strong anti-tyrosinase activities. Quercetin, kaempferol and ellagic acid were identified in fraction IV and inhibited mushroom tyrosinase with IC50 values of 4.2μM, 5.5μM and 5.2μM, respectively, which is approximately 10 times more potent than that of the positive control kojic acid (56.1μM). The inhibition kinetics, analyzed by Lineweaver–Burk plots, indicated that RF20-SP207 and fraction IV are uncompetitive inhibitors of tyrosinase when l-tyrosine is used as a substrate. A mixed inhibition was determined for ellagic acid, and a competitive inhibition for quercetin and kaempferol. In conclusion, the recovered polyphenol fraction RF20-SP207 from RODW was found to be a potent tyrosinase inhibitor. This value-added product could be used as an active ingredient in cosmetic products related to hyperpigmentation.

복분자주 주박의 항균, 항산화 및 항혈전 활성

복분자는 당도가 낮고 신맛이 강해 과실주로 주로 제조되고 있으며, 복분자주 제조 후 부생되는 주박은 대부분 폐기되고 있다. 본 연구에서는 현재까지 생리활성이 보고된 바 없는 복분자주 주박을 대상으로 열수 추출물, ethanol 추출물 및 이들의 다양한 분획물을 조제하여 항균, 항산화 및 항혈전 활성을 평가하였다. 그 결과, 복분자주 주박의 ethylacetate (EA) 분획은 413~459 mg/g의 높은 polyphenol을 함유하고 있으며, 그람양성세균에 대한 강력한 성장억제 활성과, DPPH 음이온, ABTS 양이온에 대한 우수한 radical 소거능, nitrite 소거능 및 환원력을 나타내었다. 또한 혈액내의 thrombin, prothrombin, coagulation factor 에 대한 저해를 통한 혈액응고저해 활성이 우수하였다. 복분자주 주박의 butanol 분획은 우수한 항산화력과 함께 내인성 혈전 생성에 관련된 aPTT 연장활성을 나타내었으며, aspirin에 필적하는 강력한 혈소판 응집저해 활성을 나타내었다. 한편 복분자주 주박의 열수 추출물의 순차적 유기용매 분획 후의 물 잔류물은 aspirin보다 강력한 혈소판 응집저해를 나타내어 새로운 항혈소판제 개발 소재로 이용 가능함을 확인하였다. 본 연구결과는 폐기되고 있는 복분자주 주박을 이용한 고부가가치 식품 및 향장소재 개발이 가능함을 제시하고 있다. The immature fruit of Rubus coreanus Miquel (bokbunja in Korean) is mainly consumed as a fruit wine due to its sour taste and low sugar content. The lees (LBW) remaining after the production of bokbunja wine are discarded as they have no specific usage. The aim of this study was to develop high-value-added biomaterials for functional foods and beauty/health products by investigating the anti-microbial, anti-oxidant, and anti-thrombosis activities of LBW using ethanol and hot water extracts and their subsequent organic solvent fractions. The ethyl acetate (EA) fraction of LBW extracts has a high polyphenol content (413&#x2013;459 mg/g), and showed strong anti-microbial activity against gram-positive bacteria. The EA fraction also showed excellent radical-scavenging activity against DPPH anion, ABTS cation, and nitrite, with strong reducing power. The polyphenol-enriched EA fraction strongly inhibited thrombin, prothrombin, and blood coagulation factors. The butanol fraction showed a specific inhibition of coagulation factors, as measured in activated partial thromboplastin time assay, which is linked to intrinsic blood coagulation. The butanol fraction also showed strong inhibition of platelet aggregation, at levels comparable to aspirin. The residue of the hot-water extract, which is produced by sequential solvent fractionation of the LBW extract, showed superior inhibition against platelet aggregation when compared to aspirin. Our results suggest that the LBW, which are currently discarded, are a promising source of novel functional foods and beauty/health products.

A polyphenol enriched fraction of rose oil distillation water inhibits proliferation in hacat cells and induces apoptosis

A polyphenol enriched fraction of rose oil distillation water inhibits proliferation in hacat cells and induces apoptosis

Grape marc as a source of carbohydrates for bioethanol: Chemical composition, pre-treatment and saccharification

Global grape production could generate up to 13Mt/yr of wasted biomass. The compositions of Cabernet Sauvignon (red marc) and Sauvignon Blanc (white marc) were analyzed with a view to using marc as raw material for biofuel production. On a dry weight basis, 31–54% w/w of the grape marc consisted of carbohydrate, of which 47–80% was soluble in aqueous media. Ethanol insoluble residues consisted mainly of polyphenols, pectic polysaccharides, heteroxylans and cellulose. Acid and thermal pre-treatments were investigated for their effects on subsequent cellulose saccharification. A 0.5M sulfuric acid pre-treatment yielded a 10% increase in the amount of liberated glucose after enzymatic saccharification. The theoretical amount of bioethanol that could be produced by fermentation of grape marc was up to 400L/t. However, bioethanol from only soluble carbohydrates could yield 270L/t, leaving a polyphenol enriched fraction that may be used in animal feed or as fertilizer.

Recovery of polyphenols from rose oil distillation wastewater using adsorption resins--a pilot study.

The production of rose oil from rose flowers by water steam distillation leaves a water fraction of the distillate as main part of the waste. Therefore, the rose oil distillation wastewater represents a serious environmental problem due to the high content of polyphenols which are difficult to decompose and have to be considered as biopollutants when discarded into the drainage system and rivers. On the other hand, natural polyphenols are valuable compounds with useful properties as bioactive substances. Until now there is no established practice for processing of rose oil distillation wastewater and utilization of contained substances. Thus, it was the aim of this study to develop a strategy to separate this wastewater into a polyphenol depleted water fraction and a polyphenol enriched fraction which could be developed into innovative value-added products. In a first step, the phytochemical profile of rose oil distillation wastewater was determined. Its HPLC-PDA-MS analysis revealed the presence of flavan-3-ols, flavanones, flavonols and flavones. In a second step, the development of a stepwise concentration of rose oil distillation wastewater was performed. The concentration process includes a filtration process to eliminate suspended solids in the wastewater, followed by adsorption of the contained phenolic compounds onto adsorption resins (XAD and SP). Finally, desorption of the polyphenol fraction from the resin matrix was achieved using ethanol and/or aqueous ethanol. The result of the process was a wastewater low in soluble organic compounds and an enriched polyphenol fraction (RF20 SP-207). The profile of this fraction was similar to that of rose oil distillation wastewater and showed the presence of flavonols such as quercetin and kaempferol glycosides as major metabolites. These compounds were isolated from the enriched polyphenol fraction and their structures confirmed by NMR. In summary, a pilot medium scale system was developed using adsorption resins for the recovery of polyphenols from rose oil distillation wastewater suggesting an industrial scalability of the process.

Valuing the Endangered Species Antirrhinum lopesianum: Neuroprotective Activities and Strategies for in vitro Plant Propagation.

Plant phytochemicals are described as possessing considerable neuroprotective properties, due to radical scavenging capacity and acetylcholinesterase inhibitory activity, important bioactivities in neurodegeneration. Antirrhinum lopesianum is a rare endemism from the Iberian Peninsula, occurring at the northeastern border between Portugal and Spain. It is classified as Endangered, due to its highly fragmented geographical occupation, facing a high risk of extinction in the Portuguese territory, within 20 years. Here, we describe for the first time the chemical characterization of extracts of the species concerning total phenol content, flavonoid content and antioxidant properties. The profile of high performance liquid chromatography with diode array detector (HPLC-DAD) of the polyphenol-enriched fraction of plant extracts was also performed, showing the great potential of the species as a source of bioactive phytochemical compounds. A. lopesianum’s potential for neuroprotection was revealed by a significant acetylcholinesterase inhibitory activity and also by a neuroprotective effect on a human cell model of neurodegeneration. Moreover, this is the first report describing a successful procedure for the in vitro propagation of this endangered species. The comparison of phenolic content and the HPLC-DAD profile of wild and in vitro propagated plants revealed that in vitro plants maintain the ability to produce secondary metabolites, but the profiles are differentially affected by the growth regulators. The results presented here greatly contribute to the value for this species regarding its potential as a source of phytochemicals with prospective neuroprotective health benefits.

Grape stems from Sicilian Vitis vinifera cultivars as a source of polyphenol-enriched fractions with enhanced antioxidant activity

From a screening of six different samples of grape stems from Vitis vinifera Sicilian cultivars, ‘Nerello Mascalese’ as well as ‘Nero d'Avola’ ethanol extracts showed promising radical scavenging activity and phenol content (DPPH and GAE assays). Aliquots of these three extracts were subjected to two different fractionation protocols on polyamide (PF) and Amberlite XAD-16 (XF). The fractions were examined by DPPH and GAE assays, and subjected to HPLC-DAD analysis for the quantitative determination of the main phenolic compounds. Fractionation of the crude extract NM1E (SC50 = 28.2, GAE = 221.0) through the XF protocol, afforded a polyphenol-enriched fraction (XF1C, GAE = 392.5) with highly enhanced antioxidant activity (SC50 = 7.0), and accounting for only 6.5% in weight of the NM1E extract. Fraction XF1C shows high concentrations of a procyanidin B1 (Pcd) and catechin (Cat). Some considerations on the relationship between antioxidant activity and phenolic HPLC-DAD profiles are also reported.

Polar biophenolics in sweet potato greens extract synergize to inhibit prostate cancer cell proliferation and in vivo tumor growth

Polyphenolic phytochemicals present in fruits and vegetables indisputably confer anticancer benefits upon regular consumption. Recently, we demonstrated the growth-inhibitory and apoptosis-inducing properties of polyphenol-rich sweet potato greens extract (SPGE) in cell culture and in vivo prostate cancer xenograft models. However, the bioactive constituents remain elusive. Here, we report a bioactivity-guided fractionation of SPGE based upon differential solvent polarity using chromatographic techniques that led to the identification of a remarkably active polyphenol-enriched fraction, F5, which was ~100-fold more potent than the parent extract as shown by IC50 measurements in human prostate cancer cells. High-performance liquid chromatography-ultraviolet and mass spectrometric analyses of the seven SPGE fractions suggested varying abundance of the major phenols, quinic acid (QA), caffeic acid, its ester chlorogenic acid, and isochlorogenic acids, 4,5-di-CQA, 3,5-di-CQA and 3,4-di-CQA, with a distinct composition of the most active fraction, F5. Subfractionation of F5 resulted in loss of bioactivity, suggesting synergistic interactions among the constituent phytochemicals. Quantitative analyses revealed a ~2.6- and ~3.6-fold enrichment of QA and chlorogenic acid, respectively, in F5 and a definitive ratiometric relationship between the isochlorogenic acids. Daily oral administration of 400mg/kg body wt of F5 inhibited growth and progression of prostate tumor xenografts by ~75% in nude mice, as evidenced by tumor volume measurements and non-invasive real-time bioluminescence imaging. These data generate compelling grounds to further examine the chemopreventive efficacy of the most active fraction of SPGE and suggest its potential usefulness as a dietary supplement for prostate cancer management.

Experimental study on effect of hydroalcoholic extract of Emblica officinalis fruits on glucose homeostasis and metabolic parameters

Polyphenols from natural source are potential therapeutics that act alone or supplement anti-diabetic drugs in the prevention and treatment of diabetes. The present investigation was undertaken to study the effect of hydroalcoholic extract (HE) of fruits of Emblica officinalis on type 1 diabetic rats. Diabetes was induced by streptozotocin (STZ) (45 mg/kg i.v.). HE (100 mg/kg, p.o.) was administered for 4 weeks and at the end of treatment, blood samples were collected and analyzed for various biochemical parameters. STZ produced a diabetic state exhibiting all the cardinal symptoms such as loss of body weight, polydipsia, polyuria, glucosuria, polyphagia, hypoinsulinemia, and hyperglycemia associated with hypercholesterolemia and hypertriglyceridemia. Treatment with HE prevented cardinal symptoms and caused significant decrease in fasting serum glucose, AUCglucose, cholesterol, triglyceride, low-density lipoprotein (LDL) and very LDL in diabetic rats. However, insulin, AUCinsulin, and serum high-density lipoprotein level were not significantly altered by treatment. Treatment also reduced lipid peroxidation and increased anti-oxidant parameters in the liver homogenates of diabetic rats. Polyphenol enriched fraction of HE significantly improved disarranged carbohydrate and lipid metabolism of chemically induced diabetes in rats. The mechanism of its anti-diabetic activity appears to be either improvement in peripheral glucose utilization, increased insulin sensitivity, or anti-oxidant property.

Antioxidant activity of polyphenol-enriched fractions from Agrimonia Eupatoria L. infusion

Agrimony (Agrimonia eupatoria L.) is used in traditional medicine as infusion, decoction and tincture for oxidative stress-related diseases. In our previous works, we found that agrimony infusion has significant scavenging capacity against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, eventually related to their phenolic compounds, namely tannins and flavonoids, such as flavan-3-ols, flavonols and flavones derivatives1. The aim of this work was to evaluate the contribution of the phenolic compounds for the antioxidant activity, by using two different radical scavenging assays: DPPH and superoxide anion. A polyphenol-enriched fraction (AePEF) and two sub-fractions (FI, containing phenolic acids and tannins, and FII, containing flavonoids) were obtained from the infusion fractioning. Both AePEF and FII exhibited a marked activity against the DPPH and superoxide radicals. In conclusion, our results point that the agrimony flavonoids significantly contribute for antioxidant activity, which could be good candidates for the treatment of inflammation and cancer.