Effects of phenolic acids on human phenolsulfotransferases in relation to their antioxidant activity

Sulfate conjugation by phenolsulfotransferase (PST) enzyme is an important process in the detoxification of xenobiotics and endogenous compounds. There are two forms of PST that are specific for the sulfation of small phenols (PST-P) and monoamines (PST-M). Phenoilc acids have been reported to have important biological and pharmacological properties and may have benefits to human health. In the present study, human platelets were used as a model to investigate the influence of 13 phenolic acids on human PST activity and to evaluate the relationship to their antioxidant activity. The results showed that chlorogenic acid, syringic acid, protocatechuic acid, vanillic acid, sinapic acid, and caffeic acid significantly (p < 0.05) inhibited the activities of both forms of PST by 21-30% at a concentration of 6.7 microM. The activity of PST-P was enhanced (p < 0.05) by p-hydroxybenzoic acid, gallic acid, gentisic acid, o-coumaric acid, p-coumaric acid, and m-coumaric acid at a concentration of 6.7 microM, whereas the activity of PST-M was enhanced by gentisic acid, gallic acid, p-hydroxybenzoic acid, and ferulic acid. The phenolic acids exhibited antioxidant activity as determined by the oxygen radical absorbance capacity (ORAC) assay and Trolox equivalent antioxidant capacity (TEAC) assay, especially gallic acid, p-hydroxybenzoic acid, gentisic acid, and coumaric acid, which had strong activity. The overall effect of phenolic acids tested on the activity of PST-P and PST-M was well correlated to their antioxidant activity of ORAC value (r = 0.71, p < 0.01; and r = 0.66, p < 0.01). These observations suggest that antioxidant phenolic acids might alter sulfate conjugation.     

The roles of water vapor and carbon monoxide in the photooxidation of propylene

The effects of water vapor and CO on the photooxidation of propylene in the presence of NO _x , were investigated. The presence of up to 11 000 ppm of water vapor had no significant effect on either the consumption of hydrocarbon and NO, or the formation of N0₂ and 0₃. A simplified mechanism for the phooxidation of propylene accounts for the observation by showing that the concentration of the major reactive radical-the OH radical-is not affected by the presence of HN0₂ formed initially as a result of the presence of water. Carbon monoxide at up to 200 ppm accentuated all symptoms of smog in the propylene-nitrogen oxide system. However, the effect caused by CO is much less than that caused by small changes in initial N0₂ concentrations. The magnitude of the accentuation does not justify control of CO solely to alleviate the symptoms of photochemical smog.     

Antioxidant effects of extracts from Cassia tora L. prepared under different degrees of roasting on the oxidative damage to biomolecules

The effects of water extracts from Cassia tora L. (WECT) treated with different degrees of roasting (unroasted and roasted at 150, 200, and 250 degrees C) on the oxidative damage to deoxyribose, DNA, and DNA base in vitro were investigated. It was found that WECT alone induced a slight strand breaking of DNA. In the presence of Fe(3+)/H(2)O(2), WECT accelerated the strand breaking of DNA at a concentration of 2 microg/mL; however, it decreased with increasing concentrations (>5 microg/mL) of WECT. WECT also accelerated the oxidation of deoxyribose induced by Fe(3+)-EDTA/H(2)O(2) at a concentration of 0.2 mg/mL but inhibited the oxidation of deoxyribose induced by Fe(3+)-EDTA/H(2)O(2)/ascorbic acid. Furthermore, WECT accelerated the oxidation of 2'-deoxyguanosine (2'-dG) to form 8-OH-2'-dG induced by Fe(3+)-EDTA/H(2)O(2). The prooxidant action of WECT on the oxidation of 2'-dG was in the order of unroasted > roasted at 150 degrees C > roasted at 200 degrees C > roasted at 250 degrees C. The decrease in the prooxidant activity of the roasted sample might be due to the reduction in its anthraquinone glycoside content or the formation of antioxidant Maillard reaction products after roasting. Thus, WECT exhibited either a prooxidant or an antioxidant property in the model system that was dependent on the activities of the reducing metal ions, scavenging hydroxyl radical, and chelating ferrous ion.     

Water repellency and warmth retention finishes for polyester fabrics based on hybrid materials comprising zirconia,silica, and thiazole dyes prepared via sol-gel synthesis

A series of hybrid materials composed of zirconia, silica, and thiazole dyes were synthesized from zirconium npropoxide (ZNP) and tetraethoxysilane (TEOS) using heteroaryl 2-amino-thiazole azo dyes, and prepared via the sol-gel process. The heterocyclic 2-amino-thiazole azo dyes underwent a hydrolysis-condensation reaction with an appropriate proportion of ZNP under a catalyst, using a constant ratio of vinyltriethoxysilane (VTES) and TEOS. The structures of these hybrid materials composed of zirconia/silica/thiazole dyes were characterized using Fourier transform infrared (FT-IR) analysis. The surface morphologies of the polyethylene terephthalate (PET) fabrics were evaluated using scanning electron microscopy (SEM). The SEM images demonstrated the uniform dyeing of the PET fabrics, which confirmed the reaction of the hybrid materials with the PET fabrics. The water contact angle, washing fastness, color uniformity, and warmth retention of the PET fabrics dyed with the hybrid materials composed of the zirconia/silica/thiazole dyes were evaluated. The evaluation results indicated that these fabrics offered enhanced warmth retention properties and good water repellency.     

Investigations into the toxicity of Echium plantagineum in sheep: 1. Field grazing experiments

A field grazing trial was undertaken to monitor the health and production of crossbred sheep grazing pasture where Echium plantagineum constituted a considerable proportion of the available forage. The trial, conducted for 19 months over successive grazing seasons, demonstrated a significant difference in production, with sheep on the E. plantagineum pasture being lighter and growing less wool compared with sheep on Echium-free pasture. No mortalities involving pyrrolizidine alkaloid poisoning were recorded in sheep grazing E. plantagineum, although there was histological evidence of moderately severe liver damage associated with high liver copper concentrations in at least one sheep following the grazing of large quantities of the plant.     

COMPARISON OF TRANSCOLONIC 123I-IODOAMPHETAMINE AND PORTAL VEIN INJECTION OF 99mTc-MACROAGGREGATED ALBUMIN SHUNT FRACTION CALCU-LATIONS IN EXPERIMENTAL DOGS WITH ACQUIRED POR-TOSYSTEMIC SHUNTS

Shunt fraction was determined using transcolonic ¹²³I-iodoamphetamine (IMP) and portal vein injection of ^99mTc-macroaggregated albumin (MAA) in a group of eight dogs with chronic cirrhosis and acquired portosystemic shunts subsequent to total common bile duct ligation. Hepatic parenchymal damage was confirmed by alterations in liver function tests and liver histology. Seven of the eight dogs developed portal hypertension and had angiographic evidence of hepatofugal portal blood flow with multiple peripheral portosystemic anastomoses. Shunt fractions determined in the seven dogs with shunts varied from 39 to 100 using IMP and 45 to 93 using MAA. The remaining dog had normal portal pressure, a normal portal angiogram, and normal IMP and MAA scintigraphic studies. There was an excellent correlation between the two methods of shunt fraction calculation (R²= 0.98) and the line of regression was not significantly different from unity (IMP = 1.09 × MAA - 0.03).     

Responses to cimaterol in genetically obese and lean pigs

Twenty-four genetically obese and 24 lean barrows were allotted within genotype to either a 16% CP corn-soybean meal basal diet, the basal + .69 ppm cimaterol or the basal + 1.38 ppm cimaterol. Pigs had ad libitum access to their diets from 59.3 kg to 104.5 kg body weight. No genotype x cimaterol interactions were detected (P greater than .05). Neither genotype nor cimaterol supplementation had any effect (P greater than .05) on average daily weight gain or gain-to-feed ratio. Compared with lean pigs, obese pigs had higher fasting plasma urea nitrogen (BUN), a smaller gastrointestinal tract and a greater dressing percentage with a shorter and fatter carcass (P less than .05). Cimaterol produced a higher fasting plasma BUN, a greater dressing percentage with a leaner carcass and a higher shear force value for loin chops (P less than .05). Cimaterol also tended (P less than .10) to increase heart weight. However, no difference was observed in these measurements between pigs fed .69 or 1.38 ppm cimaterol. In lean pigs fed the basal or .69 ppm cimaterol diet, there was no difference (P greater than .05) in the 8 to 24 h postprandial whole-animal heat production. Cimaterol effectively decreased fat deposition and increased lean accretion both in genetically obese and in lean pigs; there were no differential responses to cimaterol in pigs with different propensities to deposit body fat.