Chemical composition and biological activities of Indigofera hirsuta aerial parts' methanol fractions.

Methanol extract of Indigofera hirsuta, was evaluated for its antiradical potential and capacity in inhibiting lipoxygenase and aldose/aldehyde reductase enzymes. The ethyl acetate fraction derived from the methanol extract partition, showed the greatest antioxidant capacity, while the butanol was the strongest inhibitor of lipoxygenase enzyme. All fractions (diethyl ether, ethyl acetate, butanol and the aqueous residue) exhibited strong inhibition capacity of both aldose/aldehyde reductase enzymes, which comes in agreement with the ethnomedicinal plant utilization as an antidiabetic agent. LC-DAD-MS(ESI+) fraction analysis verified the findings above, leading to a conclusion regarding the biological activities attributed to the main compounds. Phytochemical analysis led to the identification of an indolic dimer, cinnamic acids, phenolics, flavonoid glycosides, a cyclic polyol, the rare sugar 1-methyl-ß-D-glucopyranoside and glycerol. Many of these compounds were isolated for the first time in Indigofera species while the indolic dimer was isolated for the first time in the Fabaceae family.

The phytochemical analysis and antioxidant activity assessment of orange peel (Citrus sinensis) cultivated in Greece-Crete indicates a new commercial source of hesperidin.

The flavonoid content of several methanolic extract fractions of Navel orange peel (flavedo and albedo of Citrus sinensis) cultivated in Crete (Greece) was first analysed phytochemically and then assessed for its antioxidant activity in vitro. The chemical structures of the constituents fractionated were originally determined by comparing their retention times and the obtained UV spectral data with the available bibliographic data and further verified by detailed LC-DAD-MS (ESI+) analysis. The main flavonoid groups found within the fractions examined were polymethoxylated flavones, O-glycosylated flavones, C-glycosylated flavones, O-glycosylated flavonols, O-glycosylated flavanones and phenolic acids along with their ester derivatives. In addition, the quantitative HPLC analysis confirmed that hesperidin is the major flavonoid glycoside found in the orange peel. Interestingly enough, its quantity at 48 mg/g of dry peel permits the commercial use of orange peel as a source for the production of hesperidin. The antioxidant activity of the orange peel methanolic extract fractions was evaluated by applying two complementary methodologies, DPPH(*) assay and the Co(II)/EDTA-induced luminol chemiluminescence approach. Overall, the results have shown that orange peel methanolic extracts possess moderate antioxidant activity as compared with the activity seen in tests where the corresponding aglycones, diosmetin and hesperetin were assessed in different ratios.

Development and validation of a high performance liquid chromatographic method for the determination of oxcarbazepine and its main metabolites in human plasma and cerebrospinal fluid and its application to pharmacokinetic study.

An isocratic reversed-phase HPLC-UV procedure for the determination of oxcarbazepine and its main metabolites 10-hydroxy-10,11-dihydrocarbamazepine and 10,11-dihydroxy-trans-10,11-dihydrocarbamazepine in human plasma and cerebrospinal fluid has been developed and validated. After addition of bromazepam as internal standard, the analytes were isolated from plasma and cerebrospinal fluid by liquid-liquid extraction. Separation was achieved on a X-TERRA C18 column using a mobile phase composed of 20 mM KH(2)PO(4), acetonitrile, and n-octylamine (76:24:0.05, v/v/v) at 40 degrees C and detected at 237 nm. The described assay was validated in terms of linearity, accuracy, precision, recovery and lower limit of quantification according to the FDA validation guidelines. Calibration curves were linear with a coefficient of variation (r) greater than 0.998. Accuracy ranged from 92.3% to 106.0% and precision was between 2.3% and 8.2%. The method has been applied to plasma and cerebrospinal fluid samples obtained from patients treated with oxcarbazepine, both in monotherapy and adjunctive therapy.

Phytochemical analysis with the antioxidant and aldose reductase inhibitory capacities of Tephrosia humilis aerial parts' extracts.

The aerial parts of Tephrosia humilis were tested about their antioxidant potential, their ability to inhibit the aldose/aldehyde reductase enzymes and their phenolic content. The plant material was exhaustively extracted with petroleum ether, dichloromethane and methanol, consecutively. The concentrated methanol extract was re-extracted, successively, with diethyl ether, ethyl acetate and n-butanol. All extracts showed significant antioxidant capacity, but the most effective was the ethyl acetate extract. As about the aldose reductase inhibition, all fractions, except the aqueous, were strong inhibitors of the enzyme, with the n-butanolic and ethyl acetate fractions to inhibit the enzyme above 75%. These findings provide support to the ethnopharmacological usage of the plant as antioxidant and validate its potential to act against the long-term diabetic complications. The phytochemical analysis showed the presence of 1,4-dihydroxy-3,4-(epoxyethano)-5-cyclohexene(1), cleroindicin E(2), lupeol(3), methyl p-coumarate(4), methyl 4-hydroxybenzoate(5), prunin(6), 5,7,2',5'-tetrahydroxyflavanone 7-rutinoside(7), protocatechuic acid(8), luteolin 7-glucoside(9), apigenin(10), naringin(11), rhoifolin(12) and luteolin 7-glucuronate(13).

No increased levels of the nicotine metabolite cotinine in smokers with schizophrenia.

The prevalence of smoking cigarettes has repeatedly been found to be greater in schizophrenia as compared with other psychiatric patients and the general population. Patients with schizophrenia have been found to engage in heavy smoking and consumption of higher doses of nicotine, probably by deeper inhalation of cigarettes. The aim of the current study was to assess nicotine exposure through smoking by measuring urinary cotinine, the major nicotine metabolite, in a group of smokers from Greece of smokers with schizophrenia and smokers from the general population. Participants were current smokers and belonged to one of two groups: 35 patients with schizophrenia and 48 healthy controls matched in age, education, and gender. The quantitative analysis of cotinine, the major metabolite of nicotine, in urine samples was performed by a modified high performance liquid chromatography (HPLC). Patients with schizophrenia who smoke presented a significantly larger time interval between last cigarette smoked and urine sample collection, as well as a significantly higher average number of cigarettes consumed daily than normal smokers. Urinary cotinine levels of patients with schizophrenia who smoke did not significantly differ from that of normal smokers when adjusted for average number of cigarettes per day and time interval between last cigarette smoked and urine collection. These results suggest that patients with schizophrenia did not present higher nicotine exposure through smoking compared with smokers from the community. The pharmacokinetic or pharmacodynamic properties of nicotine, as well as patient medications of the patients may explain our findings.

Simultaneous reversed-phase high-performance liquid chromatographic method for the determination of diosmin, hesperidin and naringin in different citrus fruit juices and pharmaceutical formulations.

Diosmin, hesperidin and naringin are flavonoid glycosides that occur naturally in citrus fruits. They exert a variety of pharmacological properties such as anti-inflammatory, antioxidant and free radical scavenging and antiulcer effects and also inhibit selected cytochrome P-450 enzymes resulting in drug interactions. A reversed-phase high-performance liquid chromatographic method has been developed for the simultaneous determination of diosmin, hesperidin and naringin in different citrus fruit juices and pharmaceutical preparations. Diosmin, hesperidin, naringin and the internal standard rhoifolin were separated using tetrahydrofuran/water/acetic acid (21:77:2, v/v/v) as the mobile phase at 34 degrees C, using a C8 reversed-phase column. The method was linear in the 0.25-20.0 microg/ml concentration range for all three flavonoid glycosides (r>0.999). The method has been successfully applied to the determination of all three flavonoid glycosides in several samples of different citrus fruit juices sold in Greece and for the determination of diosmin and hesperidin in pharmaceutical preparations.