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PubMed1962

A study of possible mediators of inflammatory reactions in the mouse foot.

A number of compounds have been studied for their ability to antagonize the inflammatory reaction produced by injections of formaldehyde and 5-hydroxytryptamine in the mouse foot. An attempt has been made to elucidate the ways in which certain hydroxybenzoates, pyrazolones, sympathomimetic amines, flavone and flavanone glycosides, local anaesthetics, antihistamines and anti-5-hydroxytryptamine substances produce their anti-inflammatory effect.

Anesthetics, Local↗
PubMed2003

Homotropic versus heterotopic cooperativity of cytochrome P450eryF: a substrate oxidation and spectral titration study.

P450eryF is the only bacterial P450 to show cooperativity of substrate binding and oxidation. However, the studies reported so far have provided evidence only for homotropic cooperativity of P450eryF but not for heterotropic cooperativity. Therefore, oxidation of 7-benzyloxyquinoline (7-BQ) and 1-pyrenebutanol (1-PB) by P450eryF A245T and spectral binding of 9-aminophenanthrene (9-AP) to wild-type P450eryF were investigated in the presence of various effectors. The addition of steroids and flavones caused no stimulation but rather moderate inhibition of 7-BQ or 1-PB oxidation by P450eryF A245T. However, the binding affinity of 9-AP was significantly increased in the presence of androstenedione or alpha-naphthoflavone (ANF). A comparative study with CYP3A4 revealed a similar increase in the binding affinity of 9-AP for the enzyme at low ANF concentrations but some competition at higher ANF concentrations. These studies, to our knowledge, provide the first report of heterotropic cooperativity in P450eryF as well as spectroscopic evidence for simultaneous presence of two ligand molecules in the CYP3A4 active site.

Alanine↗
PubMed2004

Biotransformation of sinesetin by the larvae of the common cutworm (Spodoptera litura).

Biotransformation of sinesetin (1) by larvae of Spodoptera litura was investigated. Compound 1 was converted to a new flavonoid, (+)-5,7,3',4'-tetramethoxyflavone-6-O-beta-D-glucoside (4), and two known flavones, 4'-hydroxy-5,6,7,3'-tetramethoxyflavone (2) and 6-hydroxy-5,7,3',4'-tetramethoxyflavone (3). These structures were established by IR, HR-EI-MS, HR-FAB-MS, 1D NMR, and 2D NMR spectral studies. The results indicate that the metabolic reaction of compound 1 by larvae of S. litura proceeded along two pathways; the main pathway is demethylation at the C-6 position followed by glucosylation, and the minor pathway is demethylation at the C-4' position.

Animals↗
PubMed1999

Protective effect of flavonoids on endothelial cells against linoleic acid hydroperoxide-induced toxicity.

The protective effect of flavonoids against linoleic acid hydroperoxide (LOOH)-induced cytotoxicity was examined by using cultured endothelial cells. When the cells were incubated with both LOOH and flavonoids, most flavonols protected the cells from injury by LOOH. Flavones bearing an ortho-dihydroxy structure also showed a protective effect against the cytotoxicity of LOOH. However, flavanones had no effect. The structure-activity relationship revealed the presence of either the ortho-di-hydroxy structure in the B ring of the flavonoids or 3-hydroxyl and 4-oxo groups in the C ring to be important for the protective activities. The interaction between flavonoids and a-tocopherol was also examined in this system. Flavonoids that were protective against LOOH-induced cytotoxicity had at least an additive effect on the action of alpha-tocopherol against LOOH-induced damage.

Antioxidants↗
PubMedDate not supplied

Genista tinctoria hairy root cultures for selective production of isoliquiritigenin.

Hairy root cultures were established after inoculation of Genista tinctoria in vitro shoots with Agrobacterium rhizogenes, strain ATCC 15834. In transformed roots of G. tinctoria grown in Schenk-Hildebrandt medium without growth regulators the biosynthesis of isoflavones, derivatives of genistein and daidzein, and flavones, derivatives of luteolin and apigenin, characteristic for the intact plant, was completely inhibited. The only compound synthesized in G. tinctoria hairy roots was isoliquiritigenin (2.3 g/100 g DW), a daidzein precursor absent in the intact plant. This compound was stored entirely within cells and it was not until abscisic acid was added (37.8 microM supplement on day 42) that approx. 80% of it was released into the experimental medium. The paper discusses the effect of abscisic acid on the growth of G. tinctoria hairy root cultures, the biosynthesis of isoliquiritigenin and the way it is stored. A prototype basket-bubble bioreactor was designed and built to upgrade the scale of the G. tinctoria hairy root cultures. With immobilized roots and a new aeration system, large amounts of biomass were obtained (FWmax 914.5 g l(-1)) which produced high contents of isoliquiritigenin (2.9 g/100 g DW). The abscisic acid-induced release of the metabolite from the tissue into the growth medium greatly facilitated subsequent extraction and purification of isoliquiritigenin.

Bioreactors↗
PubMed2004

Trypanocidal activity of Meliaceae and Rutaceae plant extracts.

The in vitro trypanocidal activity of 22 extracts and 43 fractions of plants belonging to the families Meliaceae and Rutaceae was evaluated. The extracts from leaves of Conchocarphus heterophyllus and branches of Trichilia ramalhoi were the most active. The trypanocidal activity seems to be increased by fractionation of the extracts. Fractions from C. heterophyllus and Galipea carinata were the most active and a 100% lysis of the parasites was observed for five fractions. From one of them were isolated two flavonoids: flavone and 7-methoxyflavone, which showed weak trypanocidal activity. The results obtained from the extracts and fractions revealed that the order Rutales is a promising source for the search of new drugs for Chagas disease. Phytochemical studies with the other active fractions are underway in order to isolate compounds, which could be associated with observed activities.

Animals↗
PubMed2003

Gonadal differentiation in frogs exposed to estrogenic and antiestrogenic compounds.

Exposure of amphibians to endocrine disrupting compounds (EDCs) may alter differentiation of gonads, especially when exposures begin during early life stages. Gonadal differentiation was observed in leopard frogs (Rana pipiens) and wood frogs (Rana sylvatica) exposed as tadpoles to estrogenic (estradiol, ethinylestradiol, nonylphenol) and antiestrogenic compounds (an aromatase inhibitor, flavone, and an antiestrogen, ICI 182780). Exposure to all compounds at micrograms/L concentrations altered gonadal differentiation in some animals by inducing either complete feminization or an intersex condition, and altered testicular tubule morphology, increased germ cell maturation (vitellogenesis), and oocyte atresia. Comparisons between the two species indicate that R. pipiens are more susceptible to sex reversal and development of intersex gonads. However, R. sylvatica also showed alterations to testicular morphology, germ cell maturation, and ooctye atresia. These laboratory results indicate that amphibians could be susceptible to altered gonadal differentiation and development when exposed to estrogenic and antiestrogenic compounds in aquatic environments, such as those impacted by agricultural, industrial, and municipal runoff.

Animals↗
PubMed1995

Effects of bioflavonoids on hepatic P450 activities.

1. The effects of tangeretin, green tea flavonoids, and other flavonoids on 7-ethoxyresorufin-O-deethylase (EROD; 450 1A), 7-pentoxyresorufin-O-dealkylase (PROD; P450 2B), p-nitrophenol hydroxylase (PNPH, P450 2E1), and erythromycin-N-demethylase (ERDM; P450 3A) were examined in induced rat liver microsomes. EROD, PNPH, ERDM, and nifedipine oxidase (NIFO; P450 3A4) were examined in human liver microsomes. 2. All flavonoids tested inhibited EROD activity at higher concentrations in liver microsomes. Flavone and tangeretin were potent inhibitors of EROD, with IC50's of 0.7 and 0.8 microM respectively in rat liver microsomes and 0.15 and 16 microM respectively in human liver microsomes. The green tea flavonoid (-)-epicatechin-3-gallate (ECG) was the most potent inhibitor of EROD in human liver microsomes (IC50 = 75 microM). The effect of the green tea flavonoids on EROD was complex; in addition to inhibition at high concentrations of flavonoid, moderate activation was seen at lower concentrations. 3. 450 2B-, 2E1- and 3A-dependent activities in rat and human liver microsomes were only moderately inhibited by any of the flavonoids tested, and, in general, ECG was the most potent inhibitor for these activities with IC50's ranging from 75 to 300 microM. 4. Tangeretin inhibited EROD activity (P450 1A2) in human liver microsomes in a competitive manner with a Ki = 68 nM. Tangeretin inhibited NIFO activity (P450 3A4) in human liver microsomes in an uncompetitive manner with Ki = 72 microM.

Animals↗
PubMed2003

[Effect of phenolic compounds of virgin olive oil on LDL oxidation resistance].

BACKGROUND AND OBJECTIVE: Several epidemiological and experimental studies have associated the intake of antioxidants, which are abundant in the Mediterranean diet, with a low incidence of cardiovascular disease. One possible mechanism of this action is the oxidative protection in low density lipoproteins (LDL). The aim of our study was to compare the antioxidative activity of diverse phenolic compounds present in virgin olive oil on these lipoproteins. SUBJECTS AND METHOD: LDL was isolated from blood plasma of healthy volunteers by sequential ultracentrifugation. This was followed by oxidation with CuC12 in the presence of different concentrations of phenolic compounds and virgin olive oil extract. Production of conjugated dienes was determined by the continuous monitoring of increased absorbency at 234 nm as an indicator of LDL oxidation. RESULTS: Virgin olive oil extract prolonged the latency phase and significantly lowered the progression rate (p < 0.05) at low concentrations (2 g/ml). This antioxidative effect was also observed with low concentrations (2 M) of caffeic acid and oleuropein (p < 0.05). However, it was necessary to increase the concentration of flavone up to 50 times to observe a similar effect (p < 0.05). CONCLUSION: Both virgin olive oil extract enriched in phenolic compounds and phenolic compounds present in olive oil (caffeic acid and oleuropein) are potent antioxidants at very low concentrations. Thus, the beneficial effects of a Mediterranean diet may be partly due to the protective action of these compounds.

Antioxidants↗
PubMed2002

[Studies on chemical constituents in buds of Artemisia scoparia].

OBJECTIVE: To investigate the chemical constituents in flower buds of Artemisia scoparia. METHOD: The constituents were separated and purified by means of various chromatographic techniques, and their structures were determined on the basis of physical and chemical properties and spectral data. RESULT: Four flavones were isolated and their structures were identified as cirsilineol (I), cirsimaritin(II), arcapillin(III) and cirsiliol(IV) respectively. CONCLUSION: Compounds I, III and IV were isolated from this plant for the first time.

Artemisia↗
PubMed2004

Activation of protein kinase C betaII/epsilon-c-Jun NH2-terminal kinase pathway and inhibition of mitogen-activated protein/extracellular signal-regulated kinase 1/2 phosphorylation in antitumor invasive activity induced by the polymethoxy flavonoid, nobiletin.

Flavonoids from medicinal plants have been therapeutically administered for cancer therapy. We recently reported that nobiletin (5,6,7,8,3',4'-hexamethoxy flavone) exhibits novel antitumor invasive activities by suppressing the production of pro-matrix metalloproteinases (proMMPs) and augmenting the expression of tissue inhibitor of metalloproteinases-1 (TIMP-1) in vivo and in vitro. In the present study, intracellular target molecules associated with the actions of nobiletin against tumor invasion were identified. Nobiletin inhibited the phosphorylation of mitogen-activated protein/extracellular signal-regulated kinase (MEK) 1/2, but not the activity of Ras or the phosphorylation of Raf. Moreover, a MEK1/2 inhibitor, U0126, mimicked nobiletin's ability to decrease the production of proMMPs-1 and 9 in human fibrosarcoma HT-1080 cells stimulated by 12-O-tetradecanoyl phorbol-13-acetate (TPA). In addition, neither the activity of phosphatidylinositol 3-kinase (PI3K) nor the phosphorylation of Akt was influenced by nobiletin. However, nobiletin was found to augment the phosphorylation of c-Jun NH2-terminal kinase (JNK), a downstream signal factor of the PI3K-Akt pathway, in TPA-treated HT-1080 cells. A similar augmentation of JNK phosphorylation was observed on treatment with a PI3K inhibitor, LY-294002. Furthermore, nobiletin enhancement of TIMP-1 production in TPA-stimulated HT-1080 cells was found to be diminished by adding a JNK inhibitor, SP600125. Moreover, protein kinase C (PKC) inhibitor experiments showed that PKCbetaII/epsilon were associated with the nobiletin-mediated augmentation of JNK phosphorylation. Therefore, these results introduce novel evidence that the antitumor effects of nobiletin are finely regulated by the following intracellular mechanisms: (1) the inhibition of MEK1/2 activity is involved in the suppression of MMP expression and (2) the activation of the novel PKCbetaII/epsilon-JNK pathway is associated with the augmentation of TIMP-1 expression.

Anthracenes↗
PubMed2004

[Studies on chemical constituents in bud of Artemisia scoparia (II)].

OBJECTIVE: To investigate the chemical constituents in flower bud of Artemisia scoparia. METHOD: The constituents were isolated and purified by means of various chromatographic methods, and spectroscopic methods were used to identify their structures. RESULT: Four flavones were isolated and their structures were identified as hyperin (V), eupafolin (VI), pedalitin (VII), 5,7,2',4'-tetrahydroxy-6,5'-dimethoxyflavone (VIII). CONCLUSION: Compounds V, VI, VII, VIII were obtained from this plant for the first time.

Artemisia↗
PubMed2004

[Studies on the quality standard of "Lü Kang Yin Xing Ye Pian"].

OBJECTIVE: The quality control method of "Lü Kang Yin Xing Ye Pian" (LKYXYP) was studied and established. METHOD: The ginkgolides in LKYXYP were identified by TLC. The compounds of fatty acids in Perillae oil were determined by CC/MS. Flavones, ginkgolides and ginkgolic acids were determined by HPLC. RESULT: There were good linears relationship between the peak area and concentration, r = 0.999, RSD = 1.2% - 2.5% (n = 5), and recoveries of each composition was above 95%, the contation was stable in 24h. CONCLUSION: This method is proved to be accurate and able to be applied for the quality control of this preparation.

Bilobalides↗
PubMed2005

Antineoplastic agents 540. The Indian Gynandropsis gynandra (Capparidaceae).

The CH3OH-CH2Cl2 extract of an Indian collection (entire plant) of Gynandropsis gynandra (L.) Briq. was separated based on bioassay results employing cancer cell lines. Six cancer cell growth inhibitors were isolated and found to be known flavone apegenin (4) and flavonols 1-3, 5, and 6. The structure of flavonol 2 was confirmed by X-ray crystal structure determination. All of the five flavonols (1-3, 5, 6) inhibited the murine P388 lymphocytic leukemia cell line with ED50 values of 3.0, 9.2, 4.0, 0.37, and 3.9 microg/ml, respectively. All six of the flavonoids (1-6) also exhibited activity against a panel of six human cancer cell lines. Penduletin (3) inhibited growth of the Gram-negative pathogen Neisseria gonorrhoeae and apegenin (4) inhibited growth of the Gram-positive opportunist Enterococcus faecalis.

Animals↗
PubMed2005

[Studies on chemical components and pharmacological activities of geobiontic type medicinal plants in Orchidaceae family].

Geobiontic type medicinal plants subjected to Orchidaceae family are used as important traditional Chinese medicine. Scientists are paying more attentions to their chemical components and pharmacology recently. This paper reviewed their chemical components involved in phenanthrene, bibenzene, flavone, sterol, terpenes, alkoloids and pharmacology such as antibacterium, cytotoxic activity, antihyperliposis effects. All these information are beneficial to reveal the relative among these medicinal plants in Orchidaceae family and are helpful to develop new drugs.

Alkaloids↗
PubMed2005

[Study on chemical constituents from Incarvillea arguta and their accelerating PC-12 cell differentiation].

OBJECTIVE: To study chemical constituents of Incarvillea arguta and their accelerating PC-12 cell differentiation. METHOD: The constituents were isolated and repeatedly purified on silica gel column chromatography, and were identified on the basis of physicochemical and spectroscopic analysis. The neurotrophic activity of different portion and all purified compounds from I. arguta was determined on the model of PC-12 cell. RESULT: Five compounds were isolated from BuOH portion of alcohol extraction of I. arguta. Their structures were identified as plantarenaloside (I), 5-hydroxy-4', 6 7-trimethoxy-flavone (II), 4', 5-dihydroxy-6, 7-dimethoxyflavone (III), 4', 5-dihydroxy-7-methoxyflavone (IV), 5-dydroxy-4', 7-dimethoxyflavone (V). CONCLUSION: Compound I is isolated from the plant for the first time and it has neurotrophic activity for PC-12 cell. Compounds II approximately V are isolated from the genus Incarvillea for the first time.

Animals↗
PubMed2005

Flavonoid analysis and antimicrobial activity of commercially available propolis products.

Propolis ethanolic solutions are the most used propolis products on the market for the treatment of minor ulcers in the mouth, angina, thrush or skin infections. Since it is still an unofficial drug in pharmacy, we analyzed the contents of flavonoids in ten commercially available ethanolic solutions of propolis from the Croatian market using two complementary colorimetric methods. Antimicrobial activities, determined with the diffusion method, against six bacterial species (Bacillus subtilis NCTC 8236, Staphylococcus aureus ATCC 25923, Streptococcus pyogenes ATCC 12204, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 10536, Pseudomonas aeruginosa ATCC 27853, and one yeast-like fungus Candida albicans ATCC 10231 were compared. Results of flavonoids analysis suggested that the contents of flavones and flavonols in the products were uniform and ranged from 0.14 to 0.41%, but the content of flavanones varied greatly from 0.43 to 18.78%. Total flavonoid content, as the sum of two colorimetric methods, in propolis products was between 0.78 and 18.92%, and most products had the flavonoids content below 9%. All products with the total flavonoids content above 1% showed antimicrobial activity against the four Gram-positive bacterial species tested, and against P. aeruginosa and the yeast-like fungus C. albicans. Total flavonoids contents, expressed as the sum of two colorimetric methods, could be useful methods for estimating the flavonoid contents of propolis products. Our results indicate that the quality of commercially available propolis products requires verification.

Anti-Infective Agents↗