Important Flavonoids and Their Role as a Therapeutic Agent.

Flavonoids are phytochemical compounds present in many plants, fruits, vegetables, and leaves, with potential applications in medicinal chemistry. Flavonoids possess a number of medicinal benefits, including anticancer, antioxidant, anti-inflammatory, and antiviral properties. They also have neuroprotective and cardio-protective effects. These biological activities depend upon the type of flavonoid, its (possible) mode of action, and its bioavailability. These cost-effective medicinal components have significant biological activities, and their effectiveness has been proved for a variety of diseases. The most recent work is focused on their isolation, synthesis of their analogs, and their effects on human health using a variety of techniques and animal models. Thousands of flavonoids have been successfully isolated, and this number increases steadily. We have therefore made an effort to summarize the isolated flavonoids with useful activities in order to gain a better understanding of their effects on human health.

Xanthohumol from hop cones (Humulus lupulus L.) prevents ADP-induced platelet reactivity.

Hop cones (Humulus lupulus L.), very rich source of phenolic compounds, possessing anticancer, antioxidant and anti-inflammatory activities, are considered as beneficial diet ingredients improving human health. In this study, the antiplatelet action of xanthohumol (XN), the principal flavonoid in hop cones, was investigated. XN significantly attenuated ADP-induced blood platelet aggregation (97.2 ± 35.7 AU for 6 µg/ml of XN vs. 120.4 ± 30.1 AU for 0.17% dimethyl sulfoxide (DMSO), p < 0.001) and significantly reduced the expression of fibrinogen receptor (activated form of GPIIbIIIa) on platelets' surface (47.6 ± 15.8 for 1.5 µg/ml XN, 44.6 ± 17.3% for 3 µg/ml XN vs. 54.5 ± 19.2% for control or 43.3 ± 18.4% for 6 µg/ml XN vs. 49.7 ± 19.4% for 0.17% DMSO, p < 0.05 or less). These findings suggest that the phenolic compounds originating from hops (XN) have a novel role as antiplatelet agents and can likely be used as dietary supplements in prophylactic approaches.

Influence of berry ripeness on accumulation, composition and extractability of skin and seed flavonoids in cv. Sangiovese (Vitis vinifera L.).

BACKGROUND: The anthocyanin and tannin concentration and composition of Vitis vinifera L. cv. Sangiovese berries were investigated from post-veraison to harvest. Exhaustive extraction with methanol and acetone was performed to determine the total flavonoid concentration, while a model hydroalcoholic solution was used to prepare extracts representing the winemaking process. The aim of this study was to improve the knowledge of the phenolic maturity of Sangiovese grape. RESULTS: The total anthocyanin concentration increased during ripening, but the quantity of extractable anthocyanins increased more rapidly than the total. The total skin tannin concentration declined from post-veraison to harvest, whereas the extractable portion increased, with little difference in the composition of the fractions. Both the total and extractable seed tannin concentration diminished rapidly just after veraison, and only small fluctuations were detected until harvest. CONCLUSION: These results indicate that the extractability of anthocyanins and skin tannins increases during ripening, whereas there is no clear trend for seed tannins during the same period. This is the first survey to study the behavior of phenolic compounds during different steps of ripening of Sangiovese grape. © 2016 Society of Chemical Industry.

Chemical components from the haulm of Artemisia selengensis and the inhibitory effect on glycation of ß-lactoglobulin.

Artemisia selengensis (AS) has been traditionally used as both food and medicine for thousands of years in China. In our studies, l-tryptophan was first isolated from the haulm of AS together with luteolin, rutin, and kaempferol-3-O-glucuronide. Their structures were elucidated by spectroscopic methods including HRMS, 1D and 2D NMR. Three flavonoid compounds showed satisfactory suppression effects on the formation of advanced glycation end products (AGEs) in ß-lactoglobulin-lactose/MGO/GO model systems, and their anti-glycation activities exhibited a dose-dependent manner. Among these compounds, kaempferol-3-O-glucuronide was demonstrated to be the strongest inhibitor against the formation of AGEs.

Antibacterial, antiviral, and antifungal properties of wines and winery byproducts in relation to their flavonoid content.

Grapes produce organic compounds that may be involved in the defense of the plants against invading phytopathogens. These metabolites include numerous phenolic compounds that are also active against human pathogens. Grapes are used to produce a variety of wines, grape juices, and raisins. Grape pomace, seeds, and skins, the remains of the grapes that are a byproduct of winemaking, also contain numerous bioactive compounds that differ from those found in grapes and wines. This overview surveys and interprets our present knowledge of the activities of wines and winery byproducts and some of their bioactive components against foodborne (Bacillus cereus, Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, Salmonella enterica, Staphylococcus aureus, Yersinia enterocolitica, Vibrio cholerae, Vibrio vulnificus), medical (Helicobacter pylori, Klebsiella pneumoniae), and oral pathogenic bacteria, viruses (adeno, cytomegalo, hepatitis, noro, rota), fungi (Candida albicans, Botrytis cinerea), parasites (Eimeria tenella, Trichomonas vaginalis), and microbial toxins (ochratoxin A, Shiga toxin) in culture, in vivo, and in/on food (beef, chicken, frankfurters, hot dogs, lettuce, oysters, peppers, pork, sausages, soup, spinach) in relation to composition and sensory properties. Also covered are antimicrobial wine marinades, antioxidative and immunostimulating aspects, and adverse effects associated with wine consumption. The collated information and suggested research needs might facilitate and guide further studies needed to optimize the use of wines and byproducts to help improve microbial food safety and prevent or treat animal and human infections.

[Breviscapine listed on progress of new varieties and dosage form research].

Breviscapine, a flavone glucuronide, is a cardiovascular medicine extracted from a Chinese herb Erigeron breviscapinus. Modern pharmacological research shows breviscapine has a therapeutic effect on cardiovascular diseases such as cerebral thrombus,cerebral ischemia hemiparesis and platelet aggregation et al. However, its poor water solubility and low bioavailability in vivo severely restrict the clinical application. In this article, we reviewed the marketing preparations of breviscapine and its research progress on the new dosage forms.

Organic and conventional fertilisation procedures on the nitrate, antioxidants and pesticide content in parts of vegetables.

Different parts of plant foods are generally discarded by consumers such as peel, stalk and leaves, which could however possess a nutritional value. However, few studies have analysed the composition of these marginal foods. The phenolic compound, flavonoid, polyamine, nitrate and pesticide contents of parts of vegetables that are usually discarded--but which were cultivated according to conventional and non-conventional procedures--were analysed to provide suggestions on how to improve the consumption of these parts and to reduce the production of urban solid waste. Few, but significant, differences between the two manuring procedures were observed. Higher nitrate content and the presence of organochlorine pesticides were found in conventional cultivated papaya peel, lemon balm leaves, jack fruit pulp, and beet stalk and peel. Discarded parts of plant foods such as stalk, leaves and peels can be used as a source of antioxidant compounds, such as phenolic compounds.

Reutilization of mango byproducts: study of the effect of extraction solvent and temperature on their antioxidant properties.

UNLABELLED: Mango biowastes, obtained after processing, contain large amounts of compounds with antioxidant activity that can be reused to reduce their environmental impact. The present study evaluates the effect of solvent (methanol, ethanol, acetone, water, methanol:water [1:1], ethanol:water [1:1], and acetone:water [1:1]), and temperature (25, 50, and 75 °C) on the efficiency of the extraction of antioxidants from mango peel and seed. Among the factors optimized, extraction solvent was the most important. The solvents that best obtained extracts with high antioxidant capacity were methanol, methanol:water, ethanol:water, and acetone:water (ß-carotene test, antioxidant activity coefficient 173 to 926; thiobarbituric acid reactive substances test, inhibition ratio 15% to 89%; 2,2'-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid ABTS(·+); and 2,2-diphenyl-1-picrylhydrazyl DPPH· scavenging, 7 to 22 and 8 to 28 g trolox equivalent antioxidant capacity [TE] per 100 g mango biowaste on a dry matter basis [DW]). Similarly, the flavonoid (0.21 to 1.4 g (+)-catechin equivalents per 100 g DW), tannin (3.8 to 14 g tannic acid equivalents per 100 g DW), and proanthocyanidin (0.23 to 7.8 g leucoanthocyanidin equivalents per 100 g DW) content was highest in the peel extracts obtained with methanol, ethanol:water, or acetone:water and in the seed extracts obtained with methanol or acetone:water. From the perspective of food security, it is advisable to choose ethanol (which also has a notable antioxidant content), ethanol:water, or acetone:water, as they are all solvents that can be used in compliance with good manufacturing practice. In general, increasing temperature improves the capacity of the extracts obtained from mango peel and seed to inhibit lipid peroxidation; however, its effect on the extraction of phytochemical compounds or on the capacity of the extracts to scavenge free radicals was negligible in comparison to that of the solvent. PRACTICAL APPLICATION: There are many antioxidant compounds in mango peel and seed, and they could be used as a natural and very inexpensive alternative to synthetic food additives. However, the conditions in which the antioxidants are extracted must be optimized. This work proves that conditions such as extraction solvent or temperature have a crucial impact on obtaining extracts rich in antioxidants from mango biowastes.

Phytochemicals and antioxidant capacities in rice brans of different color.

Rice bran, a byproduct of the rice milling process, contains most of the phytochemicals. This study aimed at determining the concentrations of lipophilic, solvent-extractable (free), and cell wall-bound (bound) phytochemicals and their antioxidant capacities from brans of white, light brown, brown, purple, and red colors, and broccoli and blueberry for comparison. The concentrations of lipophilic antioxidants of vitamin E (tocopherol and tocotrienols) and γ-oryzanols were 319.67 to 443.73 and 3861.93 to 5911.12 µg/g bran dry weight (DW), respectively, and were not associated with bran color. The total phenolic, total flavonoid, and antioxidant capacities of ORAC (oxygen radical absorbance capacity), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, and iron-chelating in the free fraction were correlated with the intensity of bran color, while variations of these in the bound fraction were less than those in the free fraction among brans. Compounds in the bound fraction had higher antioxidant capacity of ORAC than DPPH, relative to those in the free fraction. The bound fraction of light-color brans contributed as much to its total ORAC as the free fraction. Total proanthocyanidin concentration was the highest in red rice bran, while total anthocyanin was highest in purple brans. The predominant anthocyanin was cyanidin-3-glucoside. Red and purple brans had several fold higher total phenolics and flavonoids as well as ORAC and DPPH, from both free and bound fractions, than freeze-dried blueberry and broccoli. These results indicate that rice brans are natural sources of hydrophilic and lipophilic phytochemicals for use in quality control of various food systems as well as for nutraceutical and functional food application.

Ginkgo biloba and ginkgotoxin.

Products prepared from Ginkgo biloba are top-selling phytopharmaceuticals especially in Europe and major botanical dietary supplements in the United States. In European medicine, G. biloba medications are used to improve memory, to treat neuronal disorders such as tinnitus or intermittent claudication, and to improve brain metabolism and peripheral blood flow. The whole array of indications is reflected by a number of defined natural product constituents in G. biloba. The most well-known ones are flavonoids and terpene lactones, but they also include allergenic and toxic compounds such as ginkgotoxin (1). Consequently, there are reports attributing beneficial as well as adverse effects to G. biloba products. The present paper summarizes recent experiences with G. biloba and its derived products and explains why their restricted use is recommended.

Pycnogenol treatment of acute hemorrhoidal episodes.

We investigated the efficacy of orally and topically applied Pycnogenol for the management of acute hemorrhoidal attacks in a controlled, randomized study with 84 subjects. Within less than 48 h of onset of an acute attack, patients were enrolled and signs and symptoms were scored. This evaluation was repeated after seven days' treatment and again seven days following treatment cessation. The decrease in scores was significantly more pronounced in the Pycnogenol-treated groups than in the control group given placebo (p < 0.05), showing the efficacy of Pycnogenol for relieving signs and symptoms of acute external hemorrhoids. In a group of patients given topical (0.5%) Pycnogenol in addition to oral Pycnogenol the improvement in symptoms set in significantly faster and was more pronounced. The most prominent symptom, hemorrhoidal bleeding, was completely absent in all patients treated with Pycnogenol for seven days and also at the 14 days follow-up. In contrast, bleedings were still observed in the control group during the two weeks follow-up. This study indicates that Pycnogenol, both in oral and in topical form, is effective for controlling this common, disabling health problem. The application of Pycnogenol eases the management of acute hemorrhoidal attacks and help avoid bleedings.

Ampelopsin, a small molecule inhibitor of HIV-1 infection targeting HIV entry.

OBJECTIVE: To investigate the anti-HIV effects of ampelopsin and its interaction with HIV-1 coreceptor CXCR4. METHODS: Through anti-virus experiments in vitro, the inhibitory effect of ampelopsin on HIV-1 infection was verified. Chemotaxis assay was performed to show the ability to induce PBMCs migration by ampelopsin, RANTES and SDF-1alpha. Fluorescence labelling monoclonal antibody was utilized to observe the interaction of ampelopsin and CXCR4. Mice immunosuppressant model was also established to detail the role ampelopsin played in regulating cellular immunological functions. RESULTS: Ampelopsin could protect sensitive cells against HIV-1 infection and dramatically reduce HIV-1 antigen P24 expression. HIV-1SF33 attaching to MT-4 cells was interfered by ampelopsin, and the EC50 was 0.175 mg/mL for cellular protection and 0.024 mg/mL for P24 inhibition. At co-cultivating phase, EC50 was 0.229 mg/mL and 0.197 mg/mL respectively. Furthermore, the EC50 was 0.179 mg/mL and 0.348 mg/mL in acute infection. Human PBMCs migration was induced after being challenged with ampelopsin or chemokines, and synergistic action was observed during co-treatment. Ampelopsin alone resulted in maximal chemotaxis at 1 mg/mL. HIV-1 co-receptor CXCR4 on the surface of PBMCs was decreased by internalization, which indicated the effect of ampelopsin on CXCR4. About 70% CXCR4 was reduced by ampelopsin at 1 mg/mL. Ampelopsin also augmented cellular immunological functions in immunosuppressive mice. CONCLUSION: Ampelopsin displays a strong inhibitive role during HIV-1 absorption, incubation and acute infection. These results are coincident with its immune enhancement.