Characterisation of metabolites of the putative cancer chemopreventive agent quercetin and their effect on cyclo-oxygenase activity

Quercetin (3,5,7,3′,4′-pentahydroxyflavone) is a flavone with putative ability to prevent cancer and cardiovascular diseases. Its metabolism was evaluated in rats and human. Rats received quercetin via the intravenous (i.v.) route and metabolites were isolated from the plasma, urine and bile. Analysis was by high-performance liquid chromatography and confirmation of species identity was achieved by mass spectrometry. Quercetin and isorhamnetin, the 3′-O-methyl analogue, were found in both the plasma and urine. In addition, several polar peaks were characterised as sulphated and glucuronidated conjugates of quercetin and isorhamnetin. Extension of the metabolism studies to a cancer patient who had received quercetin as an i.v. bolus showed that (Quercetin removed) isorhamnetin and quercetin 3′-O-sulphate were major plasma metabolites. As a catechol, quercetin can potentially be converted to a quinone and subsequently conjugated with glutathione (GSH). Oxidation of quercetin with mushroom tyrosinase in the presence of GSH furnished GSH conjugates of quercetin, two mono- and one bis-substituted conjugates. However, these species were not found in biomatrices in rats treated with quercetin. As cyclo-oxygenase-2 (COX-2) expression is mechanistically linked to carcinogenesis, we examined whether quercetin and its metabolites can inhibit COX-2 in a human colorectal cancer cell line (HCA-7). Isorhamnetin and its 4′-isomer tamarixetin were potent inhibitors, reflected in a 90% decrease in prostaglandin E-2 (PGE-2) levels, a marker of COX-2 activity. Quercetin was less effective, with a 50% decline. Quercetin 3- and 7-O-sulphate had no effect on PGE-2. The results indicate that quercetin may exert its pharmacological effects, at least in part, via its metabolites

Health Effects of Bioactive Components in Plant Foods; Results and Opinion of the EU-COST926 Action

This paper reviews the main results of EU-action: “COST 926: Impact of new technologies on the health benefits and safety of bioactive plant compounds”. The bioavailability and the effects on gene expression of various bioactive components in plant foods are described in relation with their implication for human health

Health Effects of Bioactive Components in Plant Foods; Results and Opinion of the EU-COST926 Action

This paper reviews the main results of EU-action: “COST 926: Impact of new technologies on the health benefits and safety of bioactive plant compounds”. The bioavailability and the effects on gene expression of various bioactive components in plant foods are described in relation with their implication for human health

Czasowa i przestrzenna zmienność biochemicznego składu materii organicznej i liczby bakterii w osadach wybranych plaż południowego Morza Bałtyckiego

Sandy sediments coming from three beaches of the southern Baltic Sea were collected and analyzed. Investigated beaches were divided according to strength of anthropogenic impact and degree of sheltering. The first beach was situated in Ustka on the eastern side of the mouth of the Słupia River, second in Czołpino and the last one in Puck. Core sediment samples were collected seasonally, depending on the influence of the sea water on the examined sediments. At each station, surface sediments (0-5 cm) were collected as well as sediments at the depth of 10-15 cm. The general content of organic matter, proteins, lipids, carbohydrates, organic carbon and total bacterial number were determined. The results of the conducted tests reveal, that anthropopressure, degree of sheltering, the depth where the collected sediments were taken and the direct influence of the sea water on the sediments have impact on the chemical composition of organic matter and bacterial number in beach sediments.Pobierano i analizowano piaszczyste osady pochodzące z trzech plaż południowego Bałtyku, które zostały podzielone na podstawie wpływu antropopresji i stopnia osłonięcia plaży. Pierwsza plaża położona była w Ustce we wschodniej części ujścia rzeki Słupi, druga w Czołpinie, a ostatnia w Pucku. Próbki osadów plażowych zbierano sezonowo, w zależności od wpływu wody morskiej na badane osady. Na każdym stanowisku pobierano osady powierzchniowe (0-5 cm), a także osady na głębokości 10-15 cm. Określono zawartość materii organicznej, białek, lipidów, węglowodanów, węgla organicznego i całkowitej liczby bakterii. Wyniki przeprowadzonych badań wykazały, że antropopresja, stopień osłonięcia plaży, głębokość pobieranych osadów i bezpośredni wpływ wody morskiej na osady oddziałują na skład chemiczny materii organicznej i liczbę bakterii w osadach plażowych

Glukozinolany w roznych odmianach kapusty uprawianych w Polsce

Tue content of particular glucosinolates in 4 kinds of cruciferous vegetables, i.e. white, red and savoy cabbage and Brussels sprouts was determined applying HPLC method. Twelve out of thirteen GLS identified were present in all the vegetables analysed except Brussels sprouts which contained also smaJI amounts of glucoerucin. Among aliphatic compounds sinigrin and glucoiberin dominated in all the vegetables and progoitrin in Brussels sprouts and red cabbage. Indole compounds made 30% to 40% oftotal GLS. Out of 4 indole GLS identified glucobrassicin occurred in greatest amounts in all the vegetables. Tue highest GLS concentration was found for Brussels sprouts (126.61 mg/g) and the lowest for red cabbage (26.50 mg/g)

Phytoestrogens and thyroid hormone levels in the cerebrospinal fluid of ewes fed red clover silage

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Ekstrakcja zwiazkow fenolowych z nasion soczewicy [Lens culinaris] roznymi rozpuszczalnikami

Phenolic compounds were extracted from lentil seeds (Lens culinaris) using acetone-water, methanol-water and ethanol-water system (8:2 v/v) at 80°C. The content of sugars and phenolic compounds in the extracts was determined colorimetrically. U V spectra were measured and TLC analysis was performed on silica gel to compare phenolic compounds extracted with particular solvent systems. Prevailing amount of sugars and phenolic compounds was extracted by all three solvent systems during the first 15 min of extraction. Acetone-water system extracted markedly greater amounts of phenolic compounds compared with methanol-water or ethanol-water systems. UV spectra of the extracts were similar. In acetone extract, TLC analysis revealed the presence of tannins of higher molecular weight which were not found in ethanol and methanol extracts.Z nasion soczewicy (Lens culinaris) ekstrahowano (80°C) związki fenolowe stosując układy aceton-woda, metanol-woda i etanol-woda (8 : 2, v/v). W uzyskanych ekstraktach oznaczono metodami kolorymetrycznymi zawartość cukrów i związków fenolowych, wyznaczono ich widma w UV oraz wykonano analizę TLC na żelu krzemionkowym celem jakościowego porównania związków fenolowych ekstrahowanych przez poszczególne układy rozpuszczalników. Przeważająca ilość cukrów i związków fenolowych ekstrahowana była przez wszystkie trzy układy rozpuszczalników w czasie pierwszych 15 minut ekstrakcji (tab. 1, rys. 1.) Układ aceton-woda ekstrahował znacznie większe ilości związków fenolowych w porównaniu z układami metanol-woda i etanol-woda (tab. 2). Widma UV uzyskanych ekstraktów były podobne (rys. 2). Analiza TLC wykazała obecność w ekstrakcie acetonowym tanin o większej masie cząsteczkowej, które były nieobecne w ekstrakcie metanolowym i etanolowym (rys. 3)