Electron spin resonance assessment of the antioxidant potential of medicinal plants. Part I. Contribution of anthocyanosides and flavonoids to the radical scavenging ability of fruit and herbal teas. (33/612)

Radical scavenging properties of the extracts of some fruits and flowers, as well as of their complex formulations used as fruit teas, were tested on DPPH radical using electron spin resonance spectroscopy. The contents of anthocyanosides and flavonoids in plant materials were determined with spectrophotometric method. The most effective DPPH radical scavengers were extracts from Fructus Aroniae, Fructus Myrtilli and Fructus Rosae and the fruit teas, including them as main ingredients. No simple correlation was found between the scavenging activity and the content of anthocyanosides and flavonoids. The results can be rationalised by taking into account the presence of catechins and ascorbic acid.  (+info)

Extractive-spectrophotometric determination of some 2- and 10-disubstituted phenothiazines with dipicrylamine. (34/612)

Dipicrylamine reacts in neutral medium with some 2,10-disubstituted phenothiazines (promazine, chlorpromazine and promethazine hydrochlorides, trifluoperazine dihydrochloride, thioproperazine dimethanosulphonate) forming orange or brown ion-association compounds. The compounds are insoluble in water but quantitatively extracted into chloroform. These properties have been exploited for the determination of phenothiazines in pure solutions and pharmaceuticals.  (+info)

IL-1 alpha, but not IL-1 beta, is required for contact-allergen-specific T cell activation during the sensitization phase in contact hypersensitivity. (35/612)

Contact hypersensitivity (CHS) is a T cell-mediated cellular immune response caused by epicutaneous exposure to contact allergens. In this reaction, after the first epicutaneous allergen sensitization, Langerhans cells (LC) catch allergens and migrate from the skin to draining lymph nodes (LN) and activate naive T cells. Although IL-1 is suggested to be involved in these processes, the mechanisms have not been elucidated completely. In this report, to elucidate roles of IL-1alpha and IL-1beta in CHS, we analyzed ear swelling in 2,4,6-trinitrochlorobenzene (TNCB)-induced CHS using gene-targeted mice. We found that ear swelling was suppressed in IL-1alpha-deficient (IL-1alpha(-/-)) mice but not in IL-1beta(-/-) mice. LC migration from the skin into LN was delayed in both IL-1alpha(-/-) and IL-1beta(-/-) mice, suggesting that this defect was not the direct cause for the reduced CHS in these mice. However, we found that the proliferative response of trinitrophenyl (TNP)-specific T cells after sensitization with TNCB was specifically reduced in IL-1alpha(-/-) mice. Furthermore, adoptive transfer of TNP-conjugated IL-1-deficient epidermal cells (EC) into wild-type mice indicated that only IL-1alpha, but not IL-1beta, produced by antigen-presenting cells in EC could prime allergen-specific T cells. These observations indicate that IL-1alpha, but not IL-1beta, plays a crucial role in TNCB-induced CHS by sensitizing TNP-specific T cells.  (+info)

Superoxide- and 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activities of soyasaponin beta g related to gallic acid. (36/612)

Soyasaponin beta p g at 1 mm had 8% scavenging activity for O2-, and 25 microM beta g scavenged 20.9% for the DPPH radical (IC50: 63.8 microM). In the soyasaponin beta g-gallic acid system, synerigistic effects were observed at a low level of gallic acid concentration. The spin density distribution calculated by the MNDO/AM1 method showed unpaired electron localization on the carbons at C-4 and C-6, and on the ketone group at C-4 of the DDMP moiety. Furthermore, for soyasaponin beta g, the MNDO/AM1 method gave an ionization potential of 8.38 eV, electron affinity of 1.16 eV and Mulliken electronegativity of 4.77 eV. Based on this evidence, the synergistic antiradical effects of the soyasaponin beta g-gallic acid system are assumed to involve two-electron reduction from gallic acid.  (+info)

Sorbicillinol, a key intermediate of bisorbicillinoid biosynthesis in Trichoderma sp. USF-2690. (37/612)

In the course of our screening program for free radical scavengers from Trichoderma sp. USF-2690, we found an unidentified metabolite (1) that appeared by the method used for HPLC analysis. Metabolite 1 gradually decreased with the production of bisorbicillinoids and was easily missed during the general isolation procedure. The LC-ESI-MS (negative) analysis for 1 gave m/z 247 as the (M-1)- ion peak. The hydrolysis of synthetic 6-O-acetylsorbicillinol (+/- -2) by 0.05 M KOH and acetylation of product 1 in an aqueous solution indicated that the structure of 1 was (6S)-4-(2,4-hexadienoyl)-3,6-dihydroxy-2,6-dimethyl-2,4-cyclohexadien-1-one, designated sorbicillinol, a quinol that has been postulated to be important in bisorbicillinoid biosynthesis.  (+info)

The interrelated roles of TGF-beta and IL-10 in the regulation of experimental colitis. (38/612)

In the present study, we define the relation between TGF-beta and IL-10 in the regulation of the Th1-mediated inflammation occurring in trinitrobenzene sulfonic acid (TNBS)-colitis. In initial studies, we showed that the feeding of trinitrophenol-haptenated colonic protein to SJL/J mice induces CD4(+) regulatory T cells that transfer protection from induction of TNBS-colitis, and that such protection correlates with cells producing TGF-beta, not IL-10. Further studies in which SJL/J mice were fed haptenated colonic protein, and then administered either anti-TGF-beta or anti-IL-10 at the time of subsequent TNBS administration per rectum, showed that while both Abs abolished protection, anti-TGF-beta administration prevented TGF-beta secretion, but left IL-10 secretion intact; whereas anti-IL-10 administration prevented both TGF-beta secretion and IL-10 secretion. Thus, it appeared that the protective effect of IL-10 was an indirect consequence of its effect on TGF-beta secretion. To establish this point further, we conducted adoptive transfer studies and showed that anti-IL-10 administration had no effect on induction of TGF-beta producing T cells in donor mice. However, it did inhibit their subsequent expansion in recipient mice, probably by regulating the magnitude of the Th1 T cell response which would otherwise inhibit the TGF-beta response. Therefore, these studies suggest that TGF-beta production is a primary mechanism of counter-regulation of Th1 T cell-mediated mucosal inflammation, and that IL-10 is necessary as a secondary factor that facilitates TGF-beta production.  (+info)

Hepatoprotective and antioxidative properties of Salacia reticulata: preventive effects of phenolic constituents on CCl4-induced liver injury in mice. (39/612)

The hepatoprotective effects of the hot water (SRHW) and methanolic (SRM) extracts from the roots and stems of Salacia reticulata were examined using an oxidative stress-induced liver injury model. Both SRHW and SRM extracts (400 mg/kg, p.o.) significantly suppressed the increase in glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) activities in carbon tetrachloride (CCl4)-treated mice. These extracts also inhibited CCl4-induced thiobarbituric acid-reactive substance (TBA-RS) formation, which indicates increased lipid peroxidation in the liver. A good correlation (r=0.945, p<0.01) was observed between the amount of phenolic compounds in the extracts and their inhibitions of TBA-RS formation. The IC50 values of the extracts on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging were less than 10 microg/ml and the antioxidative activities of six phenolic compounds from the roots of S. reticulata were examined. Mangiferin, (-)-4'-O-methylepigallocatechin, and (-)-epicatechin-(4beta-->8)-(-)-4'-O-methylepigallocatechin, which a principal phenolic compounds, showed potent scavenging activity on DPPH radicals and their concentrations required for 50% reduction of 40 microM DPPH radicals were 5.9, 10, and 3.2 microM, respectively. On the other hand, against the CCl4-induced serum GOT and GPT elevations and TBA-RS formation in mice, mangiferin and (-)-4'-O-methylepigallocatechin showed potent activity at a dose of 100 mg/kg, but (-)-epicatechin-(4beta-->8)-(-)-4'-O-methylepigallocatechin did not. These results suggest that the antioxidative activity of the principal phenolic compounds is involved in the hepatoprotective activity of S. reticulata.  (+info)

Constituents of the underground parts of Glehnia littoralis. (40/612)

From the underground parts of Glehnia littoralis FR. Schmidt ex Miquel (Umbelliferae), 26 compounds, including two new lignan glycosides [giehlinosides A (1) and B (2)], a new neolignan glycoside [glehlinoside C (3)], and a new phenylpropanoid glycoside 14-[beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranosyloxyl-3-methoxypropiophenone (4)1, were obtained and their structures were determined by analysis of their spectral data. The 1,1-diphenyl-2-picrylhydrazyl radical-scavenging assay disclosed quercetin (8), isoquercetin (9), rutin (10), chlorogenic acid (11), and caffeic acid (24) as the major antioxidative constituents in this crude drug.  (+info)