This study examined whether ethyl pyruvate (EP) promotes the survival of nigrostriatal dopaminergic (DA) neurons in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson’s disease. MPTP induced degeneration of nigrostriatal DA neurons and glial activation as visualized by tyrosine hydroxylase, macrophage Ag complex-1, and/or glial fibrillary acidic protein immunoreactivity. Western blotting and immunohistochemistry showed activation of microglial NADPH oxidase and astroglial myeloperoxidase (MPO) and subsequent reactive oxygen species/reactive nitrogen species production and oxidative DNA damage in the MPTP-treated substantia nigra. Treatment with EP prevented degeneration of nigrostriatal DA neurons, increased striatal dopamine levels, and improved motor function. This neuroprotection afforded by EP was associated with the suppression of astroglial MPO expression, NADPH oxidase-, and/or inducible NO synthase-derived reactive oxygen species/reactive nitrogen species production by activated microglia. Interestingly, EP was found to protect DA neurons from 1-methyl-4-phenyl-pyridinium neurotoxicity in cocultures of mesencephalic neurons and microglia but not in neuron-enriched mesencephalic cultures devoid of microglia. The present findings show that EP may inhibit glial-mediated oxidative stress, suggesting that EP may have therapeutic value in the treatment of aspects of Parkinson’s disease related to glia-derived oxidative damage.
It is suspected that all the natural estrogens occurring in the human body, as well as dietary and synthetic estrogens, diversely affect the endocrine system depending on their exposure patterns. More rapid, reliable and accurate measurements of these compounds in various biological matrices are thus becoming an important task. After solid-phase extraction using an Oasis HLB extraction cartridge, the estrogen concentrates were derivatized with a mixture of N-methyl-N-trifluorotrimethylsilylacetamide/ammonium iodide/dithioerythritol (1000:4:5, v/w/w) for analysis by gas chromatography/mass spectrometry in the selected ion-monitoring (SIM) mode. The qualitative identification of estrogens detected in SIM mode was further confirmed by tandem mass spectrometry using low-energy collision-induced dissociation (CID) mode. The method for the assay of the 20 estrogens was linear over the ranges of 1-1000 micro g/L for biological fluids and 1-200 micro g/kg for hair with high correlation coefficient (>0.99). The limits of quantitation (LOQ) ranged from 1.0-10 micro g/L (or micro g/kg) and the limit of detection ranged from 0.2-3 micro g/L (or micro g/kg). The average precision (% CV) and accuracy (% bias) of the method determined at the LOQ, low, and medium concentrations were in the ranges 2.6-9.2 and -4.1-7.7, respectively. The average extraction recovery of the estrogens from plasma and hair at the three concentration levels varied in the ranges 77-103% (1.9-14.3% CV) and 73-104% (3.1-14%), respectively. The distribution patterns of the estrogens were characteristic of each biosample. Five estrogens in the range 1.5-44.9 micro g/Lwere measured in breast milk, 8 estrogens in the range 3.5-322 micro g/L in plasma, 12 estrogens at 1.2-442 micro g/L in urine, and biochanin-A at 13.2-39.1 micro g/kg in hair. Because of its high sensitivity, good precision and specificity, the present method was found suitable for the trace analysis of dietary and synthetic estrogens in complex biosamples such as breast milk, plasma, urine and hair.
The column chromatographic separation of the MeOH extract from the aerial parts of Prunella vulgaris var. lilacina Nakai led to the isolation of fifteen triterpenoic acids (2-6, 9-13, 16-20), four flavonoids (14, 21-23), four phenolics (7, 8, 15, 24), and a diterpene (1). Their structures were determined by spectroscopic methods to be trans-phytol (1), oleanic acid (2) ursolic acid (3), 2alpha,3alpha,19alpha-trihydroxyurs-12en-28oic acid (4), 2alpha,3alpha-dihydroxyurs-12en-28oic acid (5), maslinic acid (6), caffeic acid (7), phydroxy cinnamic acid (8), 2alpha,3alpha,19alpha,23-tetrahydroxyurs-12en-28oic acid (9), 2alpha,3alpha,23-trihydroxyurs-12en-28oic acid (10), 2alpha,3beta-dihydroxyurs-12en-28oic acid (11), 2alpha,3beta,24-trihydroxyolea-12en-28oic acid (12), (12R, 13S)-2alpha,3alpha,24,trihydroxy-12,13-cyclo-taraxer-14-en-28oic acid (13), quercertin 3-O-beta-D-glucopyranoside (14), rosmarinic acid (15), 2alpha,3alpha,24-trihydroxyurs-12,20(30)-dien-28oic acid (16), 2alpha,3alpha,24-trihydroxyolea-12en-28oic acid (17), 2alpha,3beta,19alpha,24-tetrahydroxyurs-12en-28oic acid 28-O-Dglucopyranoside (18), 2alpha,3alpha,19alpha,24-tetrahydroxyurs-12en-28oic acid 28-O-D-glucopyranoside (19), prunvuloside A (20), kaempferol 3-O-alpha-L-rhamnopyranosyl(1-->6)-beta-D-glucopranoside (21), kaempferol 3-O-beta-D-glucopyranoside (22), quercertin 3-O-alpha-L-rhamnopyranosyl(1-->6)-beta-D-glucopyranoside (23), and 2-hydroxy-3-(3',4'-dihydroxyphenly)propanoic acid (24). Compounds 1, 8-12, 17, 21, 23, and 24 were isolated from this plant source for the first time. The isolated compounds were evaluated for their cytotoxicity against A549, SK-OV-3, SK-MEL-2, and HCT15 cells in vitro using the sulforhodamin B bioassay (SRB) method. Compound 3 exhibited moderate cytotoxic activity against A549, SK-OV-3, SK-MEL-2, and HCT15 cells, with ED(50) values of 3.71, 3.65, 13.62, and 5.44 microM, respectively.
Newmelanin synthesis inhibitors (MR566Aand B ) and six related known isocyanocyclopentenes were isolated from the fermentation broth of Trichoderma harzianum, and their structures were elucidated by spectroscopic methods. The structures of novel isocyanides, MR566A(1) and B (2), were elucidated as 1-(3-chloro-1,2-dihydroxy-4-isocyano-4-cyclopenten-1-yl)ethanol, 1-(1,2,3-trihydroxy-3-isocyano-4-cyclopentenl -yl)ethanol, respectively. The structure of novel oxazole, MR93B (9), was elucidated as 4-MR566A (1) Table 1. The observation of characteristic absorption at 2121cm"1 in the IR spectrum of 1 indicatedthe presence of an isocyano group3). From the observation of CI-MS, the molecular weightof 1 could be assigned as 203. Themolecular formula of 1 was Fig. 1. Structures of MR566A (1), B (2), MR93B(9) and related compounds.
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