Luteolin-3',7-di-O-glucoside

Antiulcer activity of the ethanolic extract and ethyl acetate fraction of the leaves of Markhamia tomentosa in rats.[Pubmed:25240588]

J Ethnopharmacol. 2014 Nov 18;157:1-6.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Markhamia tomentosa (Benth.) K. Schum. Ex Engl. (Bignoniaceae) are used traditionally in the treatment of skin afflictions, sores, ulcers and inflammation. The aim of the study was to investigate the antiulcer activity of the crude ethanolic extract from the leaves of Markhamia tomentosa, determine the active fraction(s) of the extract and identify the chemical constituents in the active fraction by LC-MS. MATERIALS AND METHODS: The antiulcer activity of the crude extract (50, 100 and 150mg/kg, p.o.) was evaluated in ethanol and indomethacin-induced models while the solvent fractions (150mg/kg) were screened using ethanol-induced gastric lesions in rats. Furthermore, anti-ulcer activity of the active fraction (50, 100 and 150mg/kg, p.o.) was performed using indomethacin and pylorus ligation models. Parameters such as gastric volume, pH and acidity were determined in the pylorus ligation model. LC-ESI-MS analysis was used to identify the components in the active fraction. RESULTS: The extract at the dose of 50, 100 and 150mg/kg caused a significant (p<0.05) dose-dependent inhibition of ulcer in the ethanol and indomethacin-induced ulcer models, respectively. The ethyl acetate (EtOAc) fraction showed the most potent antiulcer activity from all the fractions tested. This fraction produced 72% and 92% inhibition of indomethacin and pylorus-induced ulcer at a dose of 150mg/kg respectively. Acteoside, luteolin, luteolin-7-rutinoside, Luteolin-3',7-di-O-glucoside, carnosol, dilapachone, tormentic acid, oxo-pomolic acid and ajugol were detected in the EtOAc fraction. CONCLUSION: Our data provide a rational base for the folkloric use of Markhamia tormentosa in the treatment of ulcers.

Simultaneous determination of glucuronic acid and sulfuric acid conjugated metabolites of daidzein and genistein in human plasma by high-performance liquid chromatography.[Pubmed:20149762]

J Chromatogr B Analyt Technol Biomed Life Sci. 2010 Mar 1;878(7-8):628-36.

Isoflavone aglycones daidzein (Dein) and genistein (Gein) are mainly present as glucuronides and sulfates in human plasma, and small amounts of the intact aglycones are also detected. In the present study, we have developed a high-performance liquid chromatography (HPLC)-UV-diode-array detector (DAD) method for the determination of intact 16 metabolites of Dein and Gein in plasma, especially focusing on highly polar conjugated metabolites at both 4' and 7 positions on the isoflavone ring with glucuronic acid and/or sulfuric acid (7-glucuronide-4'-sulfates and 4',7-diglucuronides). Luteolin-3',7-di-O-glucoside was used as an internal standard. Solid-phase extraction was performed on an Oasis HLB cartridge (60 mg, 3 cm(3)) with a recovery of >ca. 80%. The HPLC assay was performed on a Hydrosphere C18 column (100 mm x 4.6 mm I.D., particle size 3 microm). The mobile phase consisted of a mixture of 10 mM ammonium acetate solution and acetonitrile run under gradient mode at a flow rate of 1.5 ml/min. The UV detection wavelength was set at 250 nm. For UV spectral analysis, the diode-array detection wavelength was set at 220-360 nm. All HPLC analyses were performed at 45 degrees C. Each calibration for the determination of 16 metabolites gave a linear signal (r>0.997) over a concentration range of 5-5000 ng/ml. The lower limits of quantification of these metabolites were 21.1-23.4 ng/ml and the lower limits of detection were 7.9-9.4 ng/ml. This method was used in a preliminary experiment to determine the plasma concentration of intact 16 metabolites after oral administration of kinako (baked soybean powder) to a healthy volunteer. The present HPLC-UV-DAD method should be useful for the metabolic and pharmacokinetic investigations of isoflavones in humans.