Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FLAVONES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
PubMed1994

Induction of tumor necrosis factor-alpha messenger RNA in human and murine cells by the flavone acetic acid analogue 5,6-dimethylxanthenone-4-acetic acid (NSC 640488).

The investigational antitumor agent, 5,6-dimethylxanthenone-4-acetic acid (5,6-MeXAA; NSC 640488) induced greater expression of tumor necrosis factor-alpha (TNF-alpha) mRNA in murine spleen cells in vivo at its optimal dose of 27.5 mg/kg than flavone acetic acid (FAA; NSC 347512) at its optimal dose of 220 mg/kg. Up-regulation of TNF-alpha mRNA was obtained using 5,6-MeXAA in vitro in cultures of murine splenocytes, the murine J774 macrophage cell line, and the human HL-60 myelomonocytic leukemia cell line. Maximal induction occurred at a 5,6-MeXAA concentration of 200 micrograms/ml for both murine J774 and human HL-60 cells. A direct comparison of FAA and 5,6-MeXAA (100-600 micrograms/ml) to stimulate TNF-alpha mRNA in HL-60 cells showed activity by 5,6-MeXAA at all doses but minimal activity with FAA. The results demonstrate that 5,6-MeXAA is equally potent in up-regulating TNF-alpha mRNA in human and murine cells of the monocyte/macrophage lineage, whereas FAA has demonstrable activity in murine cells only. The results suggest that 5,6-MeXAA would be a more active clinical agent than FAA because TNF-alpha induction appears to be a critical factor in the antitumor effects of this class of compounds.

Animals↗
PubMedDate not supplied

Inhibition of antitumor effects of flavone acetic acid by cortisone.

The effect of cortisone (2 mg/mouse) on the effect of the antitumour agent flavone acetic acid (NSC 347512) was measured in four different murine tumours, growing subcutaneously. Response was measured by histological assessment of haemorrhagic necrosis after 24 h, and by assessment of tumour growth delay. In C57B1/6 x DBA/2)F1 hosts, cortisone pre-treatment prevented FAA-induced haemorrhagic necrosis in Lewis lung (sub-line LLTC) tumours but did not inhibit necrosis induction in Colon 38 tumours. Similarly in C3H/HeN mice, cortisone pre-treatment prevented FAA-induced necrosis of Spon-2 and partially prevented necrosis induction in mammary M-16/C tumours. Since corticosteroids are often administered, or generated internally, in the course of clinical treatment, this result has implications for the clinical use of FAA and other compounds, which act on tumour vasculature as part of their antitumour action.

Adenocarcinoma↗
PubMed1993

[Potentiation of cytotoxicity of anticancer drugs by flavone acetic acid].

We used B 16 melanoma cells both in vitro and in vivo to determine whether Flavone acetic acid (FAA) can increase the cytotoxicity of mitomycin C (MMC) under normothermic and hyperthermic (HT) conditions. The significantly increased cytotoxicity of MMC combined with FAA and HT seems to be mainly related to activation of alkylating species under FAA mediated hypoxic condition.

Animals↗
PubMedDate not supplied

Effect of flavone acetic acid on endothelial cell proliferation: evidence for antiangiogenic properties.

Flavone acetic acid (FAA) causes regression of a range of slow growing solid tumors implanted subcutaneously in mice. Although its precise mechanism of action is unknown, vascular collapse has been shown to precede tumor growth delay and regression. The aim of this study was to determine whether or not endothelial cell function was directly affected by clinically relevant concentrations of FAA. FAA at 100-250 micrograms/ml inhibited endothelial cell proliferation in vitro, but did not compromise cellular function or viability. FAA abolished tubule formation in an in vitro angiogenesis assay and reduced vascular development of the chick embryo chorioallantoic membrane. In addition to targeting established tumor vasculature, FAA may also affect proliferating endothelium which may be involved in mediating the reduced tumor growth rate or stasis often often observed after drug exposure. The chorioallantoic membrane of the chick embryo may represent an important model to elucidate more clearly the effect of FAA on a growing vascular network.

Allantois↗
PubMed1996

Synthesis and antitumor activity of some analogues of flavone acetic acid.

Some coumarin-, flavonol- and flavanon-acetic acids are described. The cytotoxicity of the synthesized compounds was determined on a human colon carcinoma cell line (LoVo) through evaluation of neutral red uptake, performed by the Riddel method. All tested derivatives were able to induce a statistically significant reduction of lysosomal neutral red uptake at 5 x 10(-5) M concentration. Some compounds were more active than the reference compound flavon-8-acetic acid.

Acetates↗
PubMed1996

Direct detection of the antioxidant activity of a new flavonic derivative using the chemiluminescence method.

The antioxidant potential of a new water soluble flavonic derivative, namely theophylline rutoside (TR-1722) has been tested using the chemiluminescence method. The method is based on the oxidative degradation of luminol by the hydrogen peroxide in Tris-HCl-buffer, when reactive species of oxygen are being obtained: O2-., HO., 1O2, and allows for the capability of substances to inhibit the free radical processes in this test system to be quantified and hence for their antioxidant properties in respect to a standard substance (in our case quercetin) to be compared. The results obtained reveal that TR-1722 has antioxidant action comparable to that of quercetin, the highest efficacity being registered at the concentration of 2 mumol/l, the conditions being: H2O2 16,2 mmol/l; luminol 2 mumol/l, in Tris-HCl buffer 20 mmol/l, pH 8.3. The antioxidant potential of TR-1722 is also maintained when the conditions of the system are modified, that is, the concentration of the hydrogen peroxide, the intensity of the action being dependent on the hydrogen peroxide concentration, but no direct proportionality is registered.

Antioxidants↗
PubMedDate not supplied

Healing process induced by a flavonic fraction of Bidens aurea on chronic gastric lesion in rat. Role of angiogenesis and neutrophil inhibition.

The aim of this study was to elucidate the mechanism of the healing process mediated by the flavonic fraction of Bidens aurea on chronic gastric ulceration induced by 5% acetic acid in rats. The diethyl ether extract (125 and 62.5 mg kg-1 body weight) was administered in a single doses, 7 and 14 days after provocation of lesions. Our results demonstrated that both doses significantly decreased the macro and microscopic ulcer index. Usually after 14-days treatment the lesions were found completely covered with regenerative epithelium and also an important proliferation of blood vessels was observed. Myeloperoxidase (MPO) activity was assayed and used as an index of leucocyte infiltration. Application of acetic acid produced a significant increase of this activity 7 days after induction of chronic injury. Administration of 125 mg kg-1 of the ether extract provoked a sharp reduction on the enzymatic activity at the same period. After 14 days, this decrease was higher with both doses (p < 0.001). In addition, the macroscopic examination showed a drastic reduction of leucocyte infiltration in treated groups. These results suggest that the recovery of vascularization of the ulcerated area and the decrease of neutrophil infiltration are involved in the antiulcerogenic effect of the flavonoid fraction of Bidens aurea.

Acetic Acid↗
PubMed1997

Increased plasma serotonin following treatment with flavone-8-acetic acid, 5,6-dimethylxanthenone-4-acetic acid, vinblastine, and colchicine: relation to vascular effects.

A number of antitumor agents are known to cause selective reduction in tumor blood flow, leading in some cases to tumor necrosis and growth delay. These agents include flavone acetic acid (FAA), an antitumor agent with high experimental but no clinical antitumor activity, 5,6-dimethylxanthenone-4-acetic acid (DMXAA), a highly active analogue of FAA, endotoxin, vinblastine, and colchicine. We find here that plasma concentrations of serotonin (5-hydroxytryptamine) and its metabolite 5-hydroxyindole acetic acid (5-HIAA) are increased following administration of these agents. Mice were injected with each at the maximum tolerated dose and, at various times later, blood samples were taken, cells and platelets removed by centrifugation, and serotonin and 5-HIAA concentrations were measured by high performance liquid chromatography. FAA and DMXAA induced six- and sevenfold increases in serotonin and 5-HIAA, respectively, with maximal levels 4 h after drug administration. 8-Methylxanthenone-4-acetic acid, an inactive analogue of DMXAA, failed to increase serotonin and caused only a small increase in 5-HIAA. Endotoxin, vinblastine, and colchicine each caused increases in serotonin and 5-HIAA between 2 and 6 h after drug administration. The mitotic poison paclitaxel, despite inducing growth delays of Colon 38 tumors, did not induce tumor necrosis and caused no increase in serotonin or 5-HIAA up to 6 h. The effect of the presence of subcutaneous Colon 38 tumors was tested and found not to affect the induction of increases in serotonin and 5-HIAA by DMXAA and colchicine. We suggest that the increases in plasma serotonin and its metabolite are a result of drug-induced vascular effects in host tissues, and that measurement of these compounds provides a potential means of monitoring drugs exerting vascular effects.

Animals↗
PubMed1996

[Flavone constituents in the seeds of Sophora vicii folia Hance].

Four flavone compounds have been separated from the mature seeds of Sophora vicii folia. By means of physico-chemical and spectroscopic analysis, their structures have been identified as 5,7,3'-trihydroxy-4'-methoxyflavone (I); 7,3'-dihydroxy-1'-methoxyflavone (II); 7,4'-dihydroxyflavone (III) and 7,3',4'-trihydroxyflavone (IV). All of them are found in S. viciifolia for the first time, and I and II are found Sophora genus for the first time.

Drugs, Chinese Herbal↗
PubMed1997

Glucose-conjugation of the flavones of Psiadia arabica by Cunninghamella elegans.

Microbial transformation of psiadiarabin and its 6-desmethoxy analogue 5,3' dihydroxy-7,2',4'5'-tetramethoxyflavone by Cunninghamella elegans NRRL 1392 gave the 3'-glucoside conjugates of the two flavones. Structural elucidation of these two new metabolites was achieved using 1D and 2D NMR spectroscopy and CIMS.

Biotransformation↗