Disease relevance of TNP00099

• In the Ames assay, galangin showed an antimutagenic effect towards MNU-induced mutagenicity of Salmonella typhimurium TA 100 [1].
• Anticlastogenic effects of galangin against bleomycin-induced chromosomal aberrations in mouse spleen lymphocytes [2].
• Here we show that a combination of galangin or 3,7-dihydroxyflavone with vancomycin may be used to sensitize resistant strains of Enterococcus faecalis and Enterococcus faecium to the level of vancomycin-sensitive strains [3].
• Galangin expresses bactericidal activity against multiple-resistant bacteria: MRSA, Enterococcus spp. and Pseudomonas aeruginosa [4].
• Introduction into the E. coli cells of the flavanone 3beta-hydroxylase and flavonol synthase genes from the plant Citrus species led to production of flavonols: kaempferol (15.1 mg/l) from tyrosine and galangin (1.1 mg/l) from phenylalanine [5].

High impact information on TNP00099

• In our attempt to find naturally occurring dietary compounds which may stimulate the P-gp-mediated efflux of carcinogens, we found that certain flavonols, kaempferol, quercetin, and galangin, are potent stimulators of the P-gp-mediated efflux of 7,12-dimethylbenz(a)-anthracene [6].
• Of seven bioflavonoids screened, galangin (3,5,7-trihydroxyflavone) blocked PAH-induced but not C(2)-ceramide- or H(2)O(2)-induced pre-B cell apoptosis [7].
• The bioflavonoid galangin blocks aryl hydrocarbon receptor activation and polycyclic aromatic hydrocarbon-induced pre-B cell apoptosis [7].
• Methylation but not acetylation of the hydroxyl groups of galangin enhanced A3 affinity [8].
• Especially galangin was able to inhibit almost all cellular GSTP1-1 activity upon exposure of the cells to a concentration of 25microM [9].

Chemical compound and disease context of TNP00099

• Connections between the ability of quercetin (Qu)and galangin (Ga) to differentially modulate cis-Pt-induced apoptosis and their effects on glutathione system of murine L1210 leukemia cells were studied [10].
• OBJECTIVES: To test the capability of the flavonoid galangin to protect pig urinary bladder from damage due to a period of repetitive field stimulation as well as a period of anoxia/glucopenia and reperfusion [11].
• Flavones (chrysin, baicalein, and galangin), flavanones (naringenin) and isoflavones (genistein, biochanin A) inhibit the activity of aromatase (CYP19), thus decreasing estrogen biosynthesis and producing antiestrogenic effects, important in breast and prostate cancers [12].
• Activity of the flavonoids apigenin, baicalin and galangin against sensitive and antibiotic resistant strains of Staphylococculs aureus, Enterococcus faecalis, E. faecium, Escherichia coli and Pseudomonas aeruginosa was investigated [13].

Biological context of TNP00099

• Galangin also inhibited the formation of DMBA-DNA adducts, and prevented DMBA-induced inhibition of cell growth [14].
• Analysis of the inhibition kinetics by double-reciprocal plot demonstrated that galangin inhibited CYP1A1 activity in a noncompetitive manner [14].
• A number of other flavonoids, such as fisetin, galangin, myricetin, kaempferol, chrysin, and apigenin, were also potent inhibitors of P-form PST-mediated sulfation, with IC50 values < 1 microM [15].
• Using the crystal structure of the enzyme, a molecular modelling study predicts a possible orientation of galangin at the active site of the enzyme [16].
• The effect of galangin, a flavonol component of India root spice and the 'herbal' medicine propolis, on HL-60 human leukaemia cell survival is characterised [17].

Anatomical context of TNP00099

• Galangin caused a potent, dose-dependent inhibition of CYP1A1 activity, as measured by ethoxyresorufin-O-deethylase activity, in intact cells and in microsomes isolated from DMBA-treated cells [14].
• CONCLUSIONS: Galangin, at high concentrations, exerts an inhibitory effect on pig bladder smooth muscle contractility through the inhibition of calcium influx and the modulation of intracellular calcium movement [18].
• We investigated the suppressive effect of galangin on the induction of micronucleated reticulocytes (MNRETs) by mitomycin C (MMC) in mouse peripheral blood [19].
• When galangin metabolism was examined in fresh plated hepatocytes from six donors, glucuronidation clearly predominated followed by sulfation [20].
• Galangin, in contrast, did significantly increase the micronucleus frequency in bone marrow and blood erythrocytes under certain conditions, but the largest increases were only between 2 and 3 times control values and these were observed at highly toxic doses [21].

Associations of TNP00099 with other chemical compounds

• The effect of the dietary flavonoid galangin on the metabolism of 7,12-dimethylbenz[a]anthracene (DMBA), the activity of cytochrome P450 1A1 (CYP1A1), and the expression of CYP1A1 in MCF-7 human breast carcinoma cells was investigated [14].
• Organotin-flavone complexes of 3-hydroxyflavone 3,5,7-trihydroxyflavone (galangin) and 2',3,4',5,7-pentahydroxyflavone (morin) are potent inhibitors of the vacuolar H(+)-translocating ATPase from bovine adrenal chromaffin granules, with K, values around 0.3 microM [22].
• A survey of more than 40 structurally related compounds revealed one more isoflavone (prunetin) and four flavones (7-hydroxyflavone, apigenin, galangin, and kaempferol) that inhibit ADH [23].
• For an in vitro assay, galangin (0, 2 x 10(-8), 2 x 10(-7), and 2 x 10(-6) M) was added to mouse spleen lymphocyte cultures together with bleomycin (3 microgram/ml) at 24 h after Con A initiation of cultures [2].
• In this study we investigated the effect of ten flavonoids (quercetin, kaempferol, morin, galangin, rutin, apigenin, flavone, naringenin, hesperitin and silybin) on the contractile response elicited by electrical field stimulation in the rat isolated vas deferens [24].

Gene context of TNP00099

• Sulfation of galangin by the human liver cytosol, mediated mainly but not exclusively by sulfotransferase (SULT) 1A1, also appeared to be efficient [20].
• The inhibition by galangin of the methoxyresorufin O-demethylase activity of CYP1A2 was mixed-type, with a Ki value of 0.008 microM [25].
• Thus, galangin is a potent inhibitor of DMBA metabolism and an agonist/antagonist of the AhR, and may prove to be an effective chemopreventive agent [14].
• This study for the first time establishes that glucuronidation and sulfation of galangin, and maybe other flavonoids, are more efficient than P450-mediated oxidation, clearly being the metabolic pathways of choice in intact cells and therefore likely also in vivo [20].
• The tested phenolic compounds significantly decreased the IL-1beta mRNA level and IL-1beta protein concentration (P<0.05) (excluding galangin), iNOS mRNA level and NO production (P<0.001) [26].

Analytical, diagnostic and therapeutic context of TNP00099

• Galangin inhibited the catabolic breakdown of DMBA, as measured by thin-layer chromatography, in a dose-dependent manner [14].
• Based on our review, galangin may be a promising candidate for cancer chemoprevention [27].
• When galangin was given to mice 24 h before the intraperitoneal injection of MMC (1 mg/kg), a more marked decrease in the frequency of MNRETs was observed than in mice with simultaneous and post-treatment of galangin [19].
• One of the two propolis samples was more active and this extract was shown to be richer in the flavonoids pinocembrin and galangin using HPLC [28].
• Antimicrobial-guided separation of flavonoid aglycones (bioassay in situ on thin-layer chromatogram) showed that galangin (3,5,7-trihydroxyflavone) is one compound in EEP with bactericidal activity [4].

References