Chlorogenic acid, an antioxidant principle from the aerial parts ofArtemisia iwayomogi that acts on 1,1-diphenyl-2-picrylhydrazyl radical

The antioxidant activity ofArtemisia iwayomogi was determined by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical The methanol extract ofA. iwayomogi showed strong antioxidant activity, and thus fractionated with several solvents. The antioxidant activity potential of the individual fraction was in the order of ethyl acetate>n-butanol>water>chloroform>n-hexane fraction. The ethyl acetate andn-butanol soluble fractions exhibiting strong antioxidant activity were further purified by repeated silica gel and Sephadex LH-20 column chromatography. Antioxidant chlorogenic acid was isolated as one of the active principles from then-butanol fraction, together with the inactive components, 1-octacosanol, scopoletin, scopolin, apigenin 7,4′-di-O-methylether luteolin 6,3′-di-O-methylether (jaceosidin), apigenin 7-methylether (genkwanin), 2,4-dihydroxy-6-methoxyacetophenone 4-O-β-D-glucopyranoside and quebrachitol. The antioxidant activity of chlorogenic acid was comparable to that of L-ascorbic acid, which is a well known antioxidant.     

Metabolism and excretion study of DW116, a new fluoroquinolone, in rats

Metabolite identification and urinary and biliary excretion of the new fluoroquinolone antibacterial agent DW116 [1-(5-fluoro-2-pyridyl)-6-fluoro-7-(4-methyl-1-piperazinyl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid, hydrochloride] after oral administration have been studied in Sprague-Dawley rats. The excretion kinetics were monoexponential. Most of the drug was eliminated via the hepatic and renal routes. Mean renal clearance of DW116 was 73.4 ml/hr/kg and mean biliary clearance was 83.8 ml/hr/kg. The major metabolite excreted in the bile was identified as the glucuronide ester of the parent drug using base-hydrolysis of the conjugate metabolite followed by co-HPLC with standard compound,¹⁹F-NMR and LC-MS methods. The glucuronide conjugate was also found in urine. The mean urinary recoveries of free and total (free plus glucuronide ester) DW116 were 28.6±2.7% and 36.4±1.8% of the administered dose and the corresponding biliary recoveries were 14.4±5.5% and 37.0±7.6%, respectively.     

Induction of apoptosis in HepG2 human hepatocellular carcinoma cells by a novel derivative of ursodeoxycholic acid (UDCA)

The effects of ursodeoxycholic acid (UDCA) and its novel derivative, named as HS-1030, on the proliferation of HepG2, human hepatocellular carcinoma cells were investigated. Whereas UDCA had no significant effect in a concentration range we have tested, HS-1030 inhibited the proliferation of HepG2 cells in a concentration dependent manner. Surprisingly, HS-1030 had no effect on the proliferation of Human Chang liver cell which is a normal liver cell line. We also found that proliferation-inhibitory effect of HS-1030 was due to the induction of apoptosis of HepG2 cells, which was confirmed by observing the internucleosomal DNA fragmentation and morphological changes (i.e. cell shrinkage, nuclear condensation and the formation of apoptotic bodies). These results suggest that HS-1030 may be a good candidate as a drug for the treatment of liver cancer.     

Evaluation of a microplate assay specific for heavy metal toxicity

A rapid, quantitative microbial assay, which is specific for heavy metal toxicity, has been developed. The assay (MetPLATE) is in a 96-well microtitration plate format and is suitable for determining toxicity characteristics such as median inhibitory concentrations. The sensitivity of MetPLATE to heavy metals [Cu, Zn, Cd, Pb, Hg, Cr(III)] was generally higher than Microtox and was of the same order as or better than Daphnia and fish bioassay. MetPLATE was insensitive to organic compounds at concentrations higher than those found in the environment. Six out of 10 industrial wastewaters or process waters surveyed were toxic. Heavy metal analysis of these waters confirmed the presence of heavy metals in the toxic samples. MetPLATE can be run concurrently with other assays for general toxicity to help determine the nature of chemicals causing toxicity.     

Effects of local muscle fatigue on three-dimensional scapulohumeral rhythm

The relationship of scapulothoracic motion to glenohumeral motion, commonly referred to as the scapulohumeral rhythm, has been the subject of numerous investigations. The purpose of this study was to assess the effects of localized muscular fatigue on three-dimensional scapulothoracic motion and the resulting scapulohumeral rhythm during elevation of the humerus in the plane of the scapula. A six-degree-of-freedom digitizing system (Metrecom(TM)) was used to define scapular and trunk reference frames, and three-dimensional Eulerian angles were determined for scapular motion for 0-135 degrees of humeral elevation before and after fatigue of the upper and lower trapezius muscles. Local muscle fatigue was determined using spectral analysis of electromyographic signals for the upper and lower trapezius muscles. The results demonstrated an average of 22% decrease in the median frequencies of the muscles sampled following resistive exercise, suggesting a state of local muscle fatigue. Concomitant with the fatigue was a selective decrease in scapulothoracic motion about two of the three scapular axes. RELEVANCE: Occupational and recreational conditions often require repetitive overhead elevations of the arms, resulting in muscular fatigue and various pathologies. During repetitive arm elevations the scapulohumeral rhythm or synchronization between the humerus and the scapula is balanced to allow the most efficient elevation of the arm. A better understanding of this much-discussed scapulohumeral rhythm and the changes induced by muscular fatigue may provide insight into the pathomechanics associated with shoulder dysfunction.     

Beta-amyloid precursor protein is detectable on monocytes and is increased in Alzheimer's disease

Using the anti-beta-amyloid precursor protein (betaAPP) monoclonal antibodies 4G8, 6E10 and 22C11 and flow cytometry, we report that human circulating peripheral blood monocytes display surface immunoreactivity for betaAPP. In contrast, circulating lymphocytes do not possess cell surface betaAPP immunoreactivity, despite similar levels of betaAPP expression. Immunoblotting analysis showed that monocytes, but not lymphocytes, possess an 82 kDa C-terminal betaAPP fragment consistent with a processed transmembrane species. Monocyte surface betaAPP was upregulated approximately threefold by activation with lipopolysaccharide and interferon-gamma, activation did not produce detectable betaAPP on the cell surface of lymphocytes. Surface betaAPP immunoreactivity was reduced in a normal aged population compared to normal young controls (Young = 81.07 +/- 13.67 mean fluorescence units, Aged = 36.74 +/- 3.81, p < 0.01), but was significantly increased in AD subjects compared to age-matched healthy controls (AD = 60.31 +/- 7.42, p < 0.05). Our data suggest that a proportion of peripheral A beta may be derived from monocyte/macrophages, and that defects in brain cell processing of betaAPP in AD may be shared by this readily accessible peripheral cell.     

Processing of the beta-amyloid precursor protein in ex vivo human brain cells

We studied distribution and processing of the Alzheimer's beta-amyloid precursor protein (betaAPP) in immediately ex vivo human brain cells obtained during neurosurgical procedures. Immunoblotting and flow cytometry studies revealed that brain cells supported betaAPP as a transmembrane holoprotein. Brain cells in short-term suspension culture were competent to process betaAPP into Abeta as shown by [35S]methionine pulse-chase studies. Brain cell Abeta was immunoprecipitated as SDS-stable dimers and higher-order multimers. Cleavage of cell surface betaAPP with trypsin prior to metabolic labeling reduced cellular Abeta by approximately 50%. We conclude that plasmalemmal betaAPP in human brain cells is a source of cellular Abeta, presumably via endosomal-lysosomal processing.     

cAMP potentiates beta-amyloid-induced nitric oxide release from microglia

The beta-amyloid peptide (Abeta) has been known to activate microglia and to induce release of nitric oxide (NO). In this study, we examined the effect of cAMP on Abeta-induced microglial activation using cultured rat brain microglia. Dibutyryl-cAMP (dbcAMP) and 3-isobutyl-1-methylxanthine (IBMX) significantly potentiated Abeta(25-35)- or Abeta(1-42)-induced NO release in a dose-dependent manner. The increase in NO release was due to the increased expression of inducible nitric oxide synthase (iNOS). However, forskolin, an adenylate cyclase activator, weakly increased NO release at 10-50 microM but caused a decrease at 100 microM. These results suggest that increase in intracellular cAMP could potentiate microglial activation induced by Abeta.     

Effect of intravesical nitric oxide therapy on cyclophosphamide-induced cystitis

PURPOSE: This study was conducted to examine effects of nitric oxide (NO) donors on bladder hyperactivity induced by cyclophosphamide (CYP)-induced cystitis. MATERIALS AND METHODS: Female Sprague-Dawley rats received a single intraperitoneal injection of CYP (100 mg./kg.), and then their micturition pattern including mean micturition volume and the number of micturitions during 24 hours was recorded in a metabolic cage before and after CYP treatment. Forty-eight hours after CYP injection, bladder function under urethane anesthesia was evaluated by cystometry with continuous saline infusion (0.04 ml. per minute) or under isovolumetric conditions (0.8 ml. bladder volume). NO donors, S-nitroso-N-acetyl-penicillamine (SNAP, 2 mM) or sodium nitroprusside (SNP, 1 mM), and an NO synthase (NOS) inhibitor, N-nitro-L-arginine methyl ester (L-NAME, 20 mM) were administered intravesically. Direct action of SNAP on bladder afferent neurons was also tested in a patch-clamp recording study. RESULTS: The number of micturitions significantly increased during the first 24 hours after CYP injection (19.0 +/- 0.88 versus 92.1 +/- 16.3 micturitions/24 hours, mean +/- SE, n = 25) (p <0.001). There was no significant difference in total micturition volume before (12.3 +/- 1.0 ml./24 hours) and after CYP treatment (15.6 +/- 1.5 ml./24 hours). During continuous infusion cystometry, intercontraction interval (ICI) was smaller in CYP-injected rats than in control rats. In CYP-injected animals, NO donors increased the ICI, but did not change the amplitude of bladder contractions. Continuous intravesical infusion of the NOS inhibitor did not alter the cystometric parameters. During cystometry under isovolumetric conditions, contraction frequency was decreased after NO donor administration. NO donors did not influence bladder activity in control rats. In patch clamp recordings, when SNAP (500 microM) was directly applied to dissociated afferent neurons innervating the urinary bladder, high-voltage-activated Ca2+ channel currents were suppressed by approximately 30%. CONCLUSIONS: Intravesical NO donors can suppress CYP-induced bladder hyperactivity. We hypothesize that the effect of NO donors is not due to smooth muscle relaxation, but rather due to an inhibitory effect on bladder afferent pathways that was manifested by an increase in intercontraction interval without changes in contraction amplitude. NO donors may be considered as a possible treatment of CYP-induced and other types of bladder inflammation.