apigenin-7-O-glucoside Research Articles

Optimisation of the extraction and processing conditions of chamomile ( Matricaria chamomilla L.) for incorporation into a beverage

The total phenols, apigenin 7-glucoside, turbidity and colour of extracts from dried chamomile flowers were studied with a view to develop chamomile extracts with potential anti-inflammatory properties for incorporation into beverages. The extraction of all constituents followed pseudo first-order kinetics. In general, the rate constant ( k) increased as the temperature increased from 57 to 100 °C. The turbidity only increased significantly between 90 and 100 °C. Therefore, aqueous chamomile extracts had maximum total phenol concentration and minimum turbidity when extracted at 90 °C for 20 min. The effect of drying conditions on chamomile extracted using these conditions was determined. A significant reduction in phenol concentration, from 19.7 ± 0.5 mg/g GAE in fresh chamomile to 13 ± 1 mg/g GAE, was found only in the plant material oven-dried at 80 °C ( p ⩽ 0.05). The biggest colour change was between fresh chamomile and that oven-dried at 80 °C, followed by samples air-dried. There was no significant difference in colour of material freeze-dried and oven-dried at 40 °C.

Anti-aromatase activity of the constituents from damiana ( Turnera diffusa)

Ethnopharmacological relevance Damiana ( Turnera diffusa Willd. Ex Schult) has traditionally been used as an herbal aphrodisiac. Aim of the study The study was aimed to investigate the anti-aromatse activity and the estrogenic activity of the constituents isolated from Turnera diffusa. Materials and methods The methanolic extract and 24 compounds isolated from the leaves of Turnera diffusa were evaluated for aromatase activity by using a tritiated-water release assay and for estrogenic activity by using yeast estrogen screen (YES) assay. Results The methanolic extract demonstrated a dose-dependent inhibitory activity of the aromatase enzyme with the IC 50 value of 63.1 μg/ml. Among the 24 tested compounds, pinocembrin and acacetin showed the most potent inhibition with IC 50 values of 10.8 and 18.7 μM, respectively. Estrogenic activity was also observed in the extract and three compounds including apigenin 7-glucoside, Z-echinacin and pinocembrin with EC 50 values of 10, 20 and 67 μM, respectively. Conclusions The extract of Turnera diffusa and two isolated compounds pinocembrin and acacetin could significantly suppress aromatase activity. Moreover, apigenin 7-glucoside, Z-echinacin and pinocembrin showed estrogenic activity.

A new cytotoxic acylated apigenin glucoside from Phyllanthus emblica L.

A new acylated apigenin glucoside (apigenin-7-O-(6′′-butyryl-β-glucopyranoside) (1) was isolated from the methanolic extract of the leaves of Phyllanthus emblica L. (Euphorbiaceae) together with the known compounds; gallic acid (2), methyl gallate (3), 1,2,3,4,6-penta-O-galloylglucose (4) and luteolin-4′-O-neohesperiodoside (5). Their chemical structures were elucidated on the basis of spectroscopic studies (1H NMR, 13C NMR, DEPT, HSQC, HMBC).

Effects of flavonoids on sphingolipid turnover in the toxin-damaged liver and liver cells.

BackgroundThe ceramide generation is an early event in the apoptotic response to numerous stimuli including the oxidative stress and ceramide analogs mimic the stress effect and induce apoptosis. Flavonoids of German chamomile are reported to exhibit the hepatoprotective effect. Flavonoids affect sphingolipid metabolism and reduce the elevated ceramide level in the aged liver. In the present paper, the ceramide content and production in the CCl4- and ethanol-treated liver and hepatocytes as well as the correction of sphingolipid metabolism in the damaged liver using the mixture of German chamomile flavonoids (chamiloflan) or apigenin-7-glucoside (AP7Glu) have been investigated.ResultsThe experiments were performed in either the rat liver or hepatocytes of normal, CCl4- and ethanol-treated or flavonoid- and toxin plus flavonoid-treated animals. [14C]palmitic acid and [methyl-14C-phosphorylcholine]sphingomyelin were used to investigate the sphingolipid turnover. Addition of the CCl4 or ethanol to isolated hepatocyte suspensions caused loss of cell viability and increased the lactate dehydrogenase release from the cells into supernatant and ceramide level in the cells. CCl4 administration to the rats enlarged ceramide mass as well as neutral sphingomyelinase (SMase) activity and reduced ceramide degradation by the neutral ceramidase. Pretreatment of isolated hepatocytes with flavonoids abrogated the CCl4 effects on the cell membrane integrity and normalized the ceramide content. Flavonoid administration to the rats normalized the elevated ceramide content in the damaged liver via neutral SMase inhibition and ceramidase activation.ConclusionThe data obtained have demonstrated that flavonoids affect sphingolipid metabolism in the CCl4- and ethanol-damaged liver and liver cells. Flavonoids normalized activities of key enzymes of sphingolipid turnover (neutral SMase and ceramidase) and ceramide contents in the damaged liver and liver cells, and stabilized the hepatocyte membranes.

Antiproliferative and Apoptotic Effects of Chamomile Extract in Various Human Cancer Cells

Chamomile (Matricaria chamomilla), a popular herb valued for centuries as a traditional medicine, has been used to treat various human ailments; however, its anticancer activity is unknown. We evaluated the anticancer properties of aqueous and methanolic extracts of chamomile against various human cancer cell lines. Exposure of chamomile extracts caused minimal growth inhibitory responses in normal cells, whereas a significant decrease in cell viability was observed in various human cancer cell lines. Chamomile exposure resulted in differential apoptosis in cancer cells but not in normal cells at similar doses. HPLC analysis of chamomile extract confirmed apigenin 7-O-glucoside as the major constituent of chamomile; some minor glycoside components were also observed. Apigenin glucosides inhibited cancer cell growth but to a lesser extent than the parent aglycone, apigenin. Ex vivo experiments suggest that deconjugation of glycosides occurs in vivo to produce aglycone, especially in the small intestine. This study represents the first reported demonstration of the anticancer effects of chamomile. Further investigations of the mechanism of action of chamomile are warranted in evaluating the potential usefulness of this herbal remedy in the management of cancer patients.

Induction of Growth Inhibition and Differentiation of Human Leukemia HL-60 Cells by a Tunisian Gerboui Olive Leaf Extract

Cancer protection associated with the consumption of olive products is well established, but not for leukemia. The protective effects of olive (Olea europaea L.) leaves were investigated by incubating human promyelocytic leukemia HL-60 cells with olive leaf extracts (OLEs) from seven principal Tunisian olive varieties, namely, Chemchali, Chemlali, Chétoui, Gerboui, Sayali, Zalmati and Zarrazi. The results showed significant growth inhibition of HL-60 cells incubated for 48 h with a 100-fold dilution of each OLE which had been obtained by incubating 10 g of dried leaves in 100 ml of 70% ethanol for one week with subsequent ultrafiltration. DNA fragmentation was observed in the cells incubated for 19 h with a 100-fold dilution of the Chemchali, Chemlali and Zalmati extracts. The results of a nitroblue tetrazolium (NBT) assay revealed NBT reduction, a differentiation marker, by the OLE-treated cells after an overnight incubation. The Gerboui extract showed the highest NBT reduction ability at more than 90%. An HPLC analysis revealed the presence of apigenin 7-glucoside in the extract, which was found in subsequent experiments to be responsible for the Gerboui extract-mediated cell differentiation.

Antianaphylactic and Antipruritic Effects of the Flowers of Impatiens textori MIQ.

The anti-anaphylactic and anti-pruritic activities of a 35% EtOH extract (IT) of the flowers of Impatiens textori MIQ. were investigated by in vivo assay. IT and apigenin (1), apigenin 7-glucoside (2) and luteolin (3), principal compounds from IT, inhibited compound 48/80 (COM)-induced by blood pressure (BP) decrease, which was an immunoglobulin (Ig)E-independent anaphylaxis-like response. Compounds 1-3 all inhibited BP decrease induced by IgE-dependent anaphylaxis. Furthermore, IT also inhibited the blood flow (BF) decrease induced by antigen-induced anaphylaxis in actively sensitized mice. IT showed a significant inhibitory effect on scratching behavior induced by COM without a central depressant. IT also significantly inhibited platelet activating factor (PAF)- and serotonin (5-HT)-induced scratching behavior and mitigated protease (PA)-induced scratching behavior. These findings showed that the flowers of I. textori can be utilized as an anti-anaphylactic and anti-pruritic agent in addition to the traditional applications of this plant.

Combined Effects of Elevated Co2and Herbivore Damage on Alfalfa and Cotton

We examined herbivore-induced responses of alfalfa (Medicago sativa) and cotton (Gossypium hirsutum) under different CO2 conditions. Plants were grown under ambient (350 ppm) or elevated (700 ppm) CO2 levels, and were either damaged or undamaged by Spodoptera littoralis larvae. At harvest, growth of undamaged (control) plants was determined, and foliar chemical composition of both undamaged and damaged plants was analyzed. Cotton grew faster overall and showed a greater increase in growth in response to CO2 enrichment than did alfalfa. Elevated CO2 levels increased starch and decreased nitrogen levels in damaged alfalfa and undamaged cotton plants. Alfalfa saponin levels were significantly increased by elevated CO2 and damage. Regarding specific saponins, medicagenic acid bidesmoside (3GlcA,28AraRhaXyl medicagenate) concentrations were reduced by high CO2, whereas zanhic acid tridesmoside (3GlcGlcGlc,23Ara,28AraRhaXylApi Za) levels were unaffected by the treatments. Soyasaponin I (3GlcAGalRha soyasapogenol B) was only detected in minute amounts. Alfalfa flavonoid analyses showed that total flavonoid levels were similar between treatments, although free apigenin increased and apigenin glucoside (7-O-[2-O-feruloyl-beta-D-glucuronopyranozyl (1-->2)-O-8-D-glucuronopyranozyl]-4'-O-beta-D-glucuronopyranozide apigenin) decreased in CO2-enriched plants. In cotton, herbivore damage increased levels of total terpenoid aldehydes, gossypol, hemigossypolone, the heliocides H1 and H4, but not H2 and H3, whereas CO2 enrichment had no effect. These results demonstrate that combined effects of CO2 and herbivore damage vary between plant species, which has implications for the competitive balance within plant communities.

Isolation, identification and stability of acylated derivatives of apigenin 7- O-glucoside from chamomile ( Chamomilla recutita [L.] Rauschert)

The major flavonoids in the white florets of chamomile ( Chamomilla recutita [L.] Rauschert) were rapidly purified using a combination of polyamide solid-phase extraction and preparative HPLC. From the combined LC/MS, LC/MS/MS, and NMR data the apigenin glucosides were identified as apigenin 7- O-glucoside (Ap-7-Glc), Ap-7-(6″-malonyl-Glc), Ap-7-(6″-acetyl-Glc), Ap-7-(6″-caffeoyl-Glc), Ap-7-(4″-acetyl-Glc), Ap-7-(4″-acetyl,6″-malonyl-Glc), and a partially characterised apigenin-7-(mono-acetyl/mono-malonylglucoside) isomer. Malonyl and caffeoyl derivatives of Ap-7-Glc have not previously been identified in chamomile. The two mono-acetyl/mono-malonyl flavonoids have not previously been reported in any plant species. These acylated glucosides are unstable and degrade to form acetylated compounds or Ap-7-Glc. The degradation products formed are dependent on the extraction and storage conditions, i.e. temperature, pH and solvent.

Effects on blood pressure decrease in response to PAF of Impatiens textori MIQ.

A 35% EtOH extract of flowers of Impatiens textori MIQ. showed an inhibitory effect on blood pressure decrease in response to platelet activating factor (PAF) measured with a blood pressure monitoring system. Bioassay-guided fractionation of the 35% EtOH extract (IT) led to isolation of the flavones apigenin (1) and luteolin (3), which significantly inhibited blood pressure decrease in response to PAF. Their compounds and apigenin 7-glucoside (2), chrysoeriol (4), quercetin (5), quercetin 3-glucoside (6), kaempferol (7), kaempferol 3-glucoside (8) and kaempferol 3-rhamnosyldiglucoside (9) were also isolated from the flowers of I. textori for the first time. This study revealed that the flowers of I. textori might be a possible anti-allergy agent.

Effect of six flavonoid compounds from Ixeris sonchifolia on stimulus-induced superoxide generation and tyrosyl phosphorylation in human neutrophils

Background: Ixeris sonchifolia (Bge.) Hance is an herbal medication used in China as an analgesic. Methods: The effect of six flavonoid compounds isolated from Ixeris sonchifolia (Bge.) Hance on stimulus-induced superoxide generation and phosphorylation of tyrosine residues of protein in human neutrophils was investigated. The six compounds examined were luteolin 7-glucuronide methylester (LGME), luteolin 7-glucuronide ethylester (LGEE), luteolin 7-glucoside (LG), luteolin 7-glucopyranosyl-(1→6)-glucoside (LGG6), luteolin 7-glucopyranosyl-(1→2)-glucoside (LGG2) and apigenin 7-glucoside (AG). Results: When the cells were preincubated with these six flavonoids, the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was significantly suppressed in a concentration-dependent manner. These flavonoids also suppressed the superoxide generation induced by arachidonic acid (AA). The rate of suppression by these flavonoids was AG>LG, LGG6, LGEE, LGG2>LGME. In case of the superoxide generation induced by phorbol 12-myristate 13-acetate (PMA), LG, LGG6 and AG suppressed the superoxide generation but LGME, LGEE and LGG2 gave no effect. When the cells were incubated with fMLP in the presence of LGME, LGEE and AG, fMLP-induced tyrosyl phosphorylation of 45-kDa proteins of the cells was dose-dependently suppressed in parallel to the suppression of fMLP-induced superoxide generation. Conclusion: Flavonoids suppress tyrosine phosphorylase in a dose-dependent manner, and may have pharmacoceutical applications.

The role of lipophilic and polar flavonoids in the classification of temperate members of the Anthemideae.

Lipophilic and vacuolar flavonoids were separately identified in representative temperate species of the genera Anthemis, Chrysanthemum, Cotula, Ismelia, Leucanthemum and Tripleurospermum. The four Anthemis species investigated variously produced four main surface constituents, in leaf and flower: santin, quercetagetin 3,6,3'-trimethyl ether, scutellarein 6,4'-dimethyl ether and 6-hydroxyluteolin 6,3'-dimethyl ether. By contrast, surface extracts of disc and ray florets of the species of Chrysanthemum, Cotula, Ismelia, Leucanthemum and Tripleurospermum surveyed yielded five common flavones in the free state: apigenin, luteolin, acacetin, apigenin 7-methyl ether and chrysoeriol. Polar flavonoids were isolated and identified in leaf, ray floret and disc floret of all the above plants. Anthemis species were distinctive in having flavonol glycosides in the leaves, whereas the leaf flavonoids of the other taxa were generally flavone O-glycosides. The 3-glucoside and 3-rutinoside of patuletin were characterised for the first time from Anthemis tinctoria ssp. subtinctoria. Two new flavonol glycosides, the 5-glucuronides of quercetin and kaempferol, were obtained from the leaf of Leucanthemum vulgare, where they co-occur with the related 5-glucosides and with several flavone glycosides. The ray florets of these Anthemideae generally contain apigenin and/or luteolin 7-glucoside and 7-glucuronide, whereas disc florets have additional flavonol glycosides, notably the 7-glucosides of quercetin and patuletin and the 7-glucuronide of quercetin. A comparison of the flavonoid pattern encountered here with those previously recorded for Tanacetum indicate some chemical affinity between Anthemis and Tanacetum. Flavonoid patterns of the other five genera are more distinct from those of Tanacetum and suggest that those genera form a related group. All 14 species surveyed for their flavonoid profiles have distinctive constituents and the chemical data are in harmony with modern taxonomic treatments of the "Chrysanthemum complex" as a series of separate genera.

The variability of (Z)‐ and (E)‐2‐β‐D‐glucopyranosyloxy‐4‐methoxycinnamic acids and apigenin glucosides in diploid and tetraploid Chamomilla recutita

Abstract(Z)‐ and (E)‐2‐β‐D‐glucopyranosyloxy‐4‐methoxycinnamic acids (GM‐CA) belong to the main compounds of water‐alcoholic extracts of Chamomilla recutita. The quantities of GMCA and apigenin in anthodia (flower heads) of diploid and tetraploid C. recutita cultivars were studied. The ploidy of a plant does not significantly influence the percentage of GMCA, in contrast to the total GMCA content in anthodia of diploid and tetraploid cultivars. Progenies of selected tetraploid plants with significantly high (9.95 mg/g) and low (5.47 mg/g) contents of GMCA were also evaluated. The higher and lower values of GMCA were conserved in the progeny generation, with significant differences in GMCA content found between the two groups of progenies.

LC coupled to ion-trap MS for the rapid screening and detection of polyphenol antioxidants from Helichrysum stoechas.

Liquid Chromatography-Ion Trap Mass Spectrometry with an atmospheric pressure chemical ionization (APCI) interface in the negative and positive-ion modes in parallel to UV-diode-array detection (DAD), was applied for the rapid detection/characterization in crude extracts of the water-soluble antioxidant phenolics from Helichrysum stoechas. APCI-MS provides unequivocal molecular weight data of these compounds and useful information about their structures (diagnostic fragments ions), which were confirmed by the UV-DAD fingerprints. This combined approach allows the identification of ten constituents, including the three naturally occurring isomers of caffeoylquinic acid (CGAs), namely neo-chlorogenic acid, chlorogenic acid and crypto-chlorogenic acid, 2 isomeric dicaffeoyl quinic acids, 2 isomeric naringenin glucosides, quercetin, kaempferol and apigenin glucosides and a tetrahydroxychalcone-glucoside. The water-soluble extract from H. stoechas, standardized in both total polyphenol and kaempferol-3-glucoside content, exhibits strong antioxidant activity in vitro when tested in both artificial membrane systems (phosphatidylcholine liposomes) and in a cell model (rat erythrocytes).

Purification of cytosolic β-glucosidase from pig liver and its reactivity towards flavonoid glycosides

Flavonoid glycosides are common dietary components which may have health-promoting activities. The metabolism of these compounds is thought to influence their bioactivity and uptake from the small intestine. It has been suggested that the enzyme cytosolic β-glucosidase could deglycosylate certain flavonoid glycosides. To test this hypothesis, the enzyme was purified to homogeneity from pig liver for the first time. It was found to have a molecular weight (55 kDa) and specific activity (with p-nitrophenol glucoside) consistent with other mammalian cytosolic β-glucosidases. The pure enzyme was indeed found to deglycosylate various flavonoid glycosides. Genistein 7-glucoside, daidzein 7-glucoside, apigenin 7-glucoside and naringenin 7-glucoside all acted as substrates, but we were unable to detect activity with naringenin 7-rhamnoglucoside. Quercetin 4′-glucoside was a substrate, but neither quercetin 3,4′-diglucoside, quercetin 3-glucoside nor quercetin 3-rhamnoglucoside were deglycosylated. Estimates of K m ranged from 25 to 90 μM while those for V max were about 10% of that found with the standard artificial substrate p-nitrophenol glucoside. The non-substrate quercetin 3-glucoside was found to partially inhibit deglycosylation of quercetin 4′-glucoside, but it had no effect upon activity with p-nitrophenol glucoside. This study confirms that mammalian cytosolic β-glucosidase can deglycosylate some, but not all, common dietary flavonoid glycosides. This enzyme may, therefore, be important in the metabolism of these compounds.

Flavonoids from flowers of two Crocus chrysanthus-biflorus cultivars: “Eye-catcher” and “Spring Pearl” (Iridaceae)

Eight flavonoids, of which five are new flavonols, were isolated from perianth segments of two Crocus chrysanthus-biflorus cultivars. The new flavonols were identified as 3- O -α- l -(2- O -β- d -glucopyranosyl)rhamnopyranoside-7- O -β- d -glucopyranosides of kaempferol, quercetin and myricetin, and two were the corresponding modified kaempferol triglycosides acylated at OH-6 of the 7-glucoside with malonic acid or acetic acid. The flavonols coexist with the known 7- O -β- d -glucosides of dihydrokaempferol and apigenin and with isorhamnetin 3,4′-di- O -β- d -glucoside. Complete structural determination of all compounds was achieved using 1-D and 2-D NMR techniques and other spectral evidence.

The flavonoid chemosystematics of two Teucrium species from Southern Sinai, Egypt

The flavonoids of Teucrium leucocladum and T. polium were studied. Apigenin 7-glucoside, vicenin-2, luteolin 7-glucoside and apigenin 5-galloylglucoside (newly reported) as well as one methylated aglycone (cirsimaritin) were identified and chemosystematic relationships discussed.

Grape Juice but Not Orange or Grapefruit Juice Inhibits Platelet Activity in Dogs and Monkeys (Macaca fasciularis)

Platelet aggregation (PA) contributes to both the development of atherosclerosis and acute platelet thrombus formation (APTF) followed by embolization producing cyclic flow reductions (CFR) in stenosed and damaged dog and human coronary arteries. In seven anesthetized dogs with coronary stenosis and medial damage, CFR occurred at 7 ± 3/30 min and were abolished 127 ± 18 min after gastric administration of 10 mL of purple grape juice/kg. Collagen-induced ex vivo whole blood PA decreased by 49 ± 9% after the abolishment of CFR with grape juice. Ten mL of orange juice/kg (n = 5) and 10 mLof grapefruit juice/kg (n = 5) had no significant effect on the frequency of the CFR or on ex vivo PA. In vitro studies have suggested that flavonoids bind to platelet cell membranes and thus may have an accumulative or tissue-loading effect over time. To test this we fed 5 mLof grape juice/kg to 5 cynomologous monkeys for 7 d. Collagen-induced ex vivo PA decreased by 41 ± 17% compared to control (pre-reatment) after 7 d of feeding. In the same 5 monkeys, neither 5 mL of orange juice/kg nor 5 mLof grapefruit juice/kg given orally for 7 d produced any significant change in PA. Grape juice contains the flavonoids quercetin, kaempferol and myricetin, which are known inhibitors of PA in vitro. Orange juice and grapefruit juice, while containing less quercetin than grape juice, primarily contain the flavonoids naringin, luteolin and apigenin glucoside. The flavonoids in grapes were shown in vitro to be good inhibitors of PA, whereas the flavonoids in oranges and grapefruit to be poor inhibitors of PA. The consumption of grape juice, containing these inhibitors of PA, may have some of the protection offered by red wine against the development of coronary artery disease (CAD) and acute occlusive thrombosis, whereas orange juice or grapefruit juice may be ineffective. Thus, grape juice may be a useful alternative dietary supplement to red wine without the concomitant alcohol intake.

Deglycosylation of flavonoid and isoflavonoid glycosides by human small intestine and liver β-glucosidase activity

Flavonoid and isoflavonoid glycosides are common dietary phenolics which may be absorbed from the small intestine of humans. The ability of cell-free extracts from human small intestine and liver to deglycosylate various (iso)flavonoid glycosides was investigated. Quercetin 4′-glucoside, naringenin 7-glucoside, apigenin 7-glucoside, genistein 7-glucoside and daidzein 7-glucoside were rapidly deglycosylated by both tissue extracts, whereas quercetin 3,4′-diglucoside, quercetin 3-glucoside, kaempferol 3-glucoside, quercetin 3-rhamnoglucoside and naringenin 7-rhamnoglucoside remained unchanged. The K m for hydrolysis of quercetin 4′-glucoside and genistein 7-glucoside was ∼32±12 and ∼14±3 μM in both tissues respectively. The enzymatic activity of the cell-free extracts exhibits similar properties to the cytosolic broad-specificity β-glucosidase previously described in mammals.

The influence of soil cadmium eliminating sorbents on Chamomilla recutita

Cadmium (Cd) influence on Chamomilla recutita (L.) Rauschert growth and efficiency of eliminating substrates (Zeolite and Ekofert) was studied in a pot experiment. The influence of extreme dose (25 mg Cd.kg‐1 of soil) caused very high accumulation in anthodia. Inhibition effect of cadmium was observed in the number and yield of anthodia per plant; height of plants and weight of anthodia were not influenced. Soil application of eliminating sorbents decreased concentration of Cd in chamomile anthodia by 27% or 19%, respectively. It also increased the number and yield of anthodia. No influence of cadmium on apigenin glucosides percentage in ligulate flowers of anthodia was found.