The relationship between the cardiac glycoside contents in Corchorus olitorius seeds and the seed color was examined. The seed color was assigned a shade (color value)(L value in UCS system). The dark grayish green seeds, showing lower L value, contained more cardiac glycosides than dark grayish yellow seeds showing higher L value. When the total cardiac glycoside contents were plotted against the L values, a positive correlation (r = -0.913) was observed. Also, there was a higher content ratio of strophanthidin glycosides (erysimoside and olitoriside) in the seeds showing lower L value, while there was a lower content ratio of digitoxigenin glycosides (coroloside and glucoevatromonoside) in the seeds showing lower L value.
Rice bran effectively removed pesticides from an aqueous solution. The removal by rice bran was examined using 22 different pesticides. The removal efficiencies varied from 22.2% to 98.8%. The variation in the removal efficiency of different pesticides was studied, and the pesticidese with high lipophilicity were found to be easily removed by rice bran. The amount of captan adsorbed was plotted against the equilibrium concentration of substances in solution on a logarithmic scale, and a linear relationship was obtained, indicating that the adsorption reaction was a Freundlich-type. The mechanism of pesticides removal by rice bran was attributed to the uptake into intracellular particles called spherosomes.
The effects of tea catechins, including (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechingallate (ECg) or (-)-epigallocatechingallate (EGCg) on the lipid peroxidation induced by either ferrous (Fe), copper (Cu) or vanadium (V) ions were examined in normal and α-linolenic acid-loaded (LNA-loaded) cultured rat hepatocytes. The order of antioxidative activity was almost similar and ranked as follows: EGCg>ECg>EGC>EC against the three metal-induced lipid peroxidations in both groups of cultured hepatocytes. However, each catechin displayed a marked variation in its antioxidative potency depending on the added metal ion species, whereas dibutyl hydroxy toluene (BHT), a typical lipid radical scavenger, exhibited a similar antioxidative potency with all metal ions. The half inhibition concentration (IC50) values of the catechins for Fe ion-induced lipid peroxidation were 2 to 3 times and 5 to 14 times higher than those for V ion and Cu ion, respectively in normal hepatocytes. Only in LNA-loaded hepatocytes, was EC antioxidative at 20 μM Fe concentration but it became prooxidative above 50 μM Fe concentration. Catechins such as (+)-catechin, (+)-epicatechin and (±)-catechin also acted as prooxidants at high Fe concentrations in LNA-loaded hepatocytes. The antioxidative efficiency of EGC, ECg or EGCg decreased with the increase in Fe ion concentrations from 20 μM up to 500 μM in LNA-loaded hepatocytes. These findings suggest that the metal-chelating property of catechins may play a major role in determining antioxidative activity in cultured hepatocytes.
Green tea polyphenol (Polyphenon) or tannic acid was administered orally to rats at a dose of 0.01-1.0 or 0.1-1.0 g/kg for 23 days, and changes both in serum and hepatic lipid concentrations and in fecal steroid excretion were examined. The administration of 0.2-1.0 g/kg of Polyphenon caused a significant decrease in levels of serum HDL-cholesterol, whereas tannic acid had no significant effect on serum lipid concentrations. The hepatic triglyceride concentration was significantly higher than controls in rats given more than 0.5 g/kg of Polyphenon, whereas both hepatic triglyceride and phospholipid concentrations were significantly higher after tannic acid administration. Serum thiobarbituric acid reactive substances were significantly low in rats given either 1.0 g/kg of Polyphenon or more than 0.1 g/kg of tannic acid. Fecal neutral steroid excretion increased significantly in rats given a dose of 1.0 g/kg of either Polyphenon or tannic acid. The excretion of fecal bile acids increased significantly in rats given 0.2 g/kg of tannic acid, but then tended to decrease at higher doses; however, excretion of fecal bile acids did not change after Polyphenon administration. We found that alterations in the compositions of fecal neutral steroids and bile acids were independent of the tannic acid or Polyphenon dose: the ratio of coprostanol to cholesterol decreased significantly in rats given 0.05-0.2 g/kg of Polyphenon or 0.5 g/kg of tannic acid; and the ratio of cholic-acid-derived bile acids to chenodeoxycholic-acid-derived bile acids decreased significantly after administration of 0.05, 0.2 and 0.5 g/kg of Polyphenon or 0.1 and 0.5 g/kg of tannic acid. Primary bile acid excretion increased significantly only in rats given a dose of 0.1 g/kg of Polyphenon. This is the first report that documents the changes occurring in fecal steroid excretion induced by oral administration of green tea polyphenol or tannic acid.
The extent of pollution in the rivers flowing into Tokyo Bay was studied comparatively using river sediment extracts in an assay system based on the arylhydrocarbon receptor (AhR)-dependent induction of 7-ethoxycoumarin O-deethylase (ECOD) activity in HepG2 cells. The sampling points of river sediment were as follows: Namamugi on the Tsurumi River, Rokugo on the Tama River, Hirai, Senjyu and Funado on the Ara River, Baraki on the Edo River, and Makuhari on the Hanami River (Fig. 1). The Tsurumi River (Namamugi) located in the middle of Keihin Industrial District was considered most polluted, followed by the Ara River (Hirai). The river sediment collected at Baraki on the Edo River was least polluted. The extracts of highly polluted river sediments sampled at Namamugi and Hirai exhibited a reverse U-shaped dose-response curve, for which polycyclic aromatic hydrocarbons (PAHs) might be mainly responsible, in a range of non-toxic concentrations. The pollution of river sediment collected at Namamugi was roughly estimated to be 2 to 20 μg as PAHs/g sediment by consulting the data of Nakama et al. and 0.2 to 2 μg as PAHs/g was assigned to the river sediment of Hirai.
Dose-response profiles for both induction and elicitation phases were evaluated with seven chemical allergens using the guinea pig maximization test. Considering the risk assessment of contact sensitization in its practical sense, the profile of elicitation would be more critical than that of induction, and it should be evaluated in a maximally induced human population or experimental animals. When mean skin reaction scores in a group of maximally sensitized animals with each allergen were plotted against log challenge concentrations, linear regression lines with good fitness were adapted to all allergens. An elicitation threshold calculated from the linear regression line of each allergen could be used as an index of the relative elicitation potency of a chemical. However, unlike other cases of risk assessment, maximum acceptable concentrations for allergens in consumer products cannot be obtained simply by dividing an elicitation threshold by a fixed safety factor. The value of a safety factor for each allergen should be set on a case by case basis. As a practical matter, consumers are at a risk of exposure to allergens at concentrations greater than elicitation thresholds. Thus a dose-response profile for elicitation in maximally sensitized animals should be included in the evaluation of the risk. We propose to use the area under the linear regression line between the threshold and 1% of the elicitation concentration as a relative elicitation potency index of each allergen, because it reflects the integrated degree of skin reaction that would emerge among a maximally sensitized population exposed to an allergen.
To assess the photodegradation extent of the organophosphorus pesticides, fenthion and disulfoton in the environment, degradation rates of their chemicals under irradiation by visible light and each region of the ultraviolet (UV) sources, UVA (320-400 nm radiation), UVB (280-320 nm radiation) and UVC (250-260 nm radiation) in liquid- and solid-phases were determined and their photolysis products identified. Although visible light did not cause photodegradation of either fenthion or disulfoton even after the maximal irradiation of 8 hr in both phases, all the ranges of UV sources resulted in the photolysis of both pesticides, despite the solid-phase. The photolysis rates of fenthion under UVB and UVC irradiation in both phases were higher than that under UVA irradiation and also exceeded all of the degradation rates of disulfoton. This confirms that fenthion is more readily degraded than disulfoton in the UVB range. Fenthion sulfoxide and disulfoton sulfoxide were identified as oxidative photolysis products whose photolysis rates were considerably slower than parent compounds, and the oxidation reaction of both pesticides in the liquid-phase was superior to those on the solid-phase, indicating that dissolved oxygen in water is an important factor affecting the photolysis. These results suggest that fanthion in the environment is more rapidly degraded by UVB irradiation in natural sunlight than disulfoton, and sulfoxides of both pesticides remain stable as a photolysis product in the environment.
We treated testicular cell lines Leydig TM3 and Sertoli TM4 with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and used two-dimensional electrophoresis to investigate the resulting protein alterations. Cells were cultured in a medium containing 10-5 to 10 nM TCDD for 4 hr, under which condition viability was not affected. Protein expression was compared semi-quantitatively by silver staining, by autoradiography of [35S] methionine-labeled proteins, and by anti-phosphotyrosine antibody. In TM3, 34 protein spots were altered by TCDD, 26 of which were increased and 8 of which were decreased; in TM4, the amount of total protein appeared to be reduced and 19 protein spots were altered by TCDD, 12 of which were increased and 7 of which were decreased. Four of these altered proteins were identified by N-terminal protein microsequencing and by a homology search against protein databases. Whereas a pyruvate dehydrogenase E1 beta subunit was decreased by TCDD exposure, ATP synthase beta chain, mitochondrial matrix protein P1 and 78 kDa glucose-regulated protein were relatively increased. The precise role of these proteins in TCDD toxicity remains to be determined, but the observed alterations suggest the proteins to be important in the effects of TCDD on testicular cells.
Daily intake from meals, and excretion from feces and sebum of 20 congeners of polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF) and coplanar polychlorinated biphenyl (Co-PCB) were analyzed in healthy Japanese men who are considered to be a standard for the Japanese. Daily intake of these congeners was 84.2 ± 12.5 pg toxic equivalent (TEQ) and daily excretion from feces and sebum were 18.3 ± 5.9 and 23.8 ± 5.6 pg TEQ, respectively, indicating 22% the daily intake of dioxins from meals is excreted from feces and 29% from sebum. 1,2,3,7,8-Pentachlorodibenzo-p-dioxin (1,2,3,7,8-PeCDD), 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PeCDF) and 3,3',4,4',5-pentachlorobiphenyl (3,3',4,4',5-PeCB) were most abundant in TEQ, in meals, feces, sebum and blood. Co-PCBs were most efficiently excreted among three congener groups in TEQ, especially from sebum. Octachlorodibenzo-p-dioxin (OCDD), 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF) and 3,3',4,4'-tetrachlorobiphenyl (3,3',4,4'-TCB) were well absorbed from intestine and excreted at more than 100% of intake, mainly from the sebum. In contrast, 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (1,2,3,4,7,8-HxCDD) and 1,2,3,7,8,9-hexachlorodibenzofuran (1,2,3,7,8,9-HxCDF) were excreted at relatively low levels from sebum, although well absorbed from the intestine, and the excretion ratios were lowest among the 20 congeners. It was suggested that 80.5-85.2% TEQ of each congener-group might be absorbed from the intestine, after taking bile excretion into consideration.
The material balance of phosphorus in a semi-closed bay (Omura bay) has been calculated by actuality measurements and data from an observation satellite (LANDSAT 5) over the last eleven years. It appeared that the phosphorus inflows to the bay from the 696 places of business and the twelve rivers were 293 tons/year and 20 tons/year, respectively. About 90% of the phosphorus from the places of business was released into the bay from only six sewage treatment plants. The phosphorus outflows from the bay, which occurred with the tide changes and with the catching of fish, were 219 tons/year and 7 tons/year, respectively. The urban areas inside the watershed that were calculated from the LANDSAT data using the normalized difference vegetation index (NDVI) value showed an increase each year with a wide range of variation. This slope was closer to the one showing the increasing amount of phosphorus in the bay than to the slope of the increase in population inside the watershed.
Methylmercury (MeHg)-induced neurotoxicity includes skeletal muscle symptoms (muscle weakness and wasting, muscle cramp). In this study the effects of long-term low dose exposure to MeHg on skeletal muscle were investigated using rats which had received food containing MeHg (5 ppm Hg; the average intake: 200 μg Hg/kg/day). From six months after the first MeHg administration, total mercury levels in the skeletal muscle remained almost stable at 3.5-5.5 μg/g, about one tenth of the levels achieved in the acute MeHg-intoxicated model receiving 5 mg MeHgCl/kg/day for 12 days. However low-dose, long-term administration of MeHg induces histochemical changes similar to those in the acute model with decreases in mitochondrial electron transport system enzyme activities. The results indicate that even low dose MeHg administration causes disturbances in mitochondrial enzyme activities if the administration continues long term. In rats treated with MeHg for 21 months, mild myopathic changes appeared: variations in fiber size, increases in central nuclei and an increase of acid phosphatase activity. The declining function of the redox system in skeletal muscle during aging may accentuate the effects of chronic MeHg intoxication on skeletal muscle.
The effects of perfluorooctanoic acid (PFOA) on the synthesis of phospholipids were studied in combination with feeding of various dietary oils (soybean oil (SO), perilla oil (PO) or fish oil (FO)). Hepatic contents of phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn) and phosphatidylinositol (PtdIns) did not differ between the three dietary groups except for a high level of PtdEtn in FO-fed mice. PFOA treatment increased the hepatic content of PtdCho and PtdEtn by 1.5 fold but did not affect that of PtdIns. Fatty acid compositions of phospholipids were different between the three groups reflecting the fatty acid composition in their diet. The rate of incorporation of [3H]glycerol into PtdEtn in the FO-fed group was significantly higher and that into TG was lower, compared to other dietary groups in PFOA-untreated mice. PFOA treatment significantly increased the incorporation of [3H]glycerol into PtdEtn and PtdSer and decreased that into TG, whereas those into other lipid classes were not altered by PFOA treatment. These results suggest that acceleration of PtdEtn synthesis de novo is responsible for a marked increase in the hepatic content of PtdEtn in PFOA-treated mice, whereas an increase in hepatic content of PtdCho is thought not to be due to increased synthesis de novo.
Effects of styrene exposure on middle latency auditory-evoked potentials (MAEPs), which reflect the central auditory function, were investigated. As significant delay in latencies of No, Po, Na, and Pa components and increases in the peak to peak intervals of MAEPs, but not amplitudes, were observed in a dose-dependent manner, The present and our previous studies demonstrate that electrophysiological alterations occur before neuronal cell damage induced by styrene exposure. The present results suggested that styrene has a marked effect on the processing of auditory information related to MAEPs.
The isolation of differentially expressed genes in the nucleus accumbens (NA) from chronically ethanol-administered rats may help in understanding the underlying molecular mechanisms for the development and reinforcement of ethanol addiction. The differential display indicated that around 0.1-0.2% of mRNA could be considered to be affected by chronic ethanol-administration in the NA, regardless of whether ethanol directly affected gene expression in the NA or the gene alteration was secondary to changes in neuronal activity caused by ethanol. Forty-six clones were successfully reamplified, and screening by reverse Northern blot analysis resulted in the isolation of five up-regulated and three down-regulated genes. One of the up-regulated cDNAs was homologous to human TGFβ1 and its preferential expression was also observed in the cerebellum and locus coeruleus (LC). Since clone c10 displayed an extremely strong preferential expression in the ethanol-administred NA, its upstream sequence was analyzed by 5' rapid amplification of DNA ends (5'RACE) but the coding sequence has not yet been isolated. c118 showed enrichment in the ethanol-administred NA and displayed strong homology to the mouse KH domain RNA binding protein QKI-5A. The 5'RACE analysis confirmed that this clone encoded rat QKI-5A. Since QKI proteins are considered to be regulators of myelination and their absence causes dysmyelination, its up-regulation may offer protection against ethanol-induced dysmyelination. Another 12 cDNAs were registered as expression sequence tags (ESTs) or novel with their functions unknown. It is considered important, however, that to their upsteam sequences including coding regions and promoter sequences are identified not only to estimate the roles of these differentially expressed genes in ethanol addiction but also to clarify whether ethanol-dependent gene-regulation can occur or not.
Up to the mid-1990s benign prostatic hyperplasia (BPH) was commonly treated surgically. However, surgery is associated with numerous instances of failure, high patient morbidity rates, and substantial annual costs. Tamsulosin, an α1-adrenergic receptor antagonist, was originally developed as an alternative to surgery for BPH. It significantly improves urinary obstruction by relaxing smooth muscle in the bladder neck and prostate via specific inhibition of the α1A-adrenergic receptor subtype, the predominant subtype in these tissues. However, since α1-adrenergic receptors also mediate constriction of smooth muscle in the vascular wall, extensive tests were carried out during phase III clinical trials to investigate whether tamsulosin has any effect on mediation of the cardiovascular system. Since BPH is a condition that affects men from middle age and many patients are also hypertensive, a subanalysis was carried out during these phase III clinical trials to investigate whether tamsulosin has any effect on blood pressure control or vasodilation in men who are also being treated for hypertension. During 13-week double-blind administration of once-daily tamsulosin or placebo, no statistically significant differences were observed in blood pressure or heart rate among normotensive, controlled hypertensive, and uncontrolled hyprtensive patients. The results of this study demonstrate that tamsulosin can be used in BPH patients who are hypertensive without any restrictions on blood pressure control medication.
Inactivation of free phage carrying slt2 from enterohemorrhagic Escherichia coli (E. coli) O157:H7 by four kinds of common disinfectants in Japan was examined under conditions with (dirty) and without (clean) interfering substance. Ethanol (EtOH) inactivated the phage within one minute under both conditions. The effect of sodium hypochlorite (NaOCl) on this phage decreased under the dirty condition, but was potentiated by increasing the concentration and contact time to the degree that could be sufficient for practical use. Use of benzalkonium chloride (BAC) at a high concentration: 0.2%, would be effective. Alkyldiaminoethylglycine hydrochloride (DAG) was not effective on this phage.
Cacao liquor crude polyphenols (CLP) contained potent anti-oxidants, such as catechin, and their oligomers. An investigation was conducted on the effects of CLP on experimental arteriosclerosis with calcification in rats, induced by giving vitamin D2 (2.5 × 105 I.U./kg) for the first 4 consecutive days with an atherogenic diet (2% cholesterol, 1.5% cholic acid, 0.1% methylthiouracil). The diet was prepared using a vitamin E deficient diet. CLP inhibited the increase of serum lipid peroxides, the increase of calcium (Ca) in the aorta, the increase of Ca and inorganic phosphorus (P) in the aortic elastin fraction, or in the renal Ca and P of the arteriosclerotic rats. Previously, vitamin E and vitamin K2 showed anti-calcification and radical scavenging activities under the above experimental conditions without vitamin E deficiency. Moreover, CLP reduced lipid peroxides in plasma and in tissue induced by vitamin E deficiency, without maintaining vitamin E levels. It is suggested that the inhibitory effects of CLP on the accumulation of Ca and P in the aorta or kidney were partially due to an anti-oxidant activity.
Vitellogenin (VTG) is believed to be an effective and sensitive biomarker to detect the effects of endocrine-disrupting chemicals (EDCs) on fish. An enzymelinked immunosorbent assay (ELISA) was developed in this study for the quantification of VTG in goldfish (Carassius auratus) blood plasma using a monoclonal antibody against carp lipovitellin which is known to cross-react with goldfish VTG, and a working range of 7.8 to 500 ng VTG/ml was established. A laboratory study involving the dosing of male goldfish for 28 days with a range of bisphenol-A (BPA) concentrations was conducted, and the established ELISA was used. There was no significant induction of VTG at the concentrations of 1 and 10 μg/l. Exposure to 100 μg/l and 1000 μg/l BPA for 28 days significantly elevated plasma VTG concentrations to 201 ± 90 μg/ml and 104552 ± 24920 μg/ml, respectively. To confirm the effect of temperature on VTG induction, male goldfish were exposed to the nominal concentration of 17β-es-tradiol (E2) 100 μg/l at 10° and 30°C for 10 days. Plasma VTG concentration in male goldfish increased more quickly in the fish exposed at 30°C than in those at 10°C. In addition, the plasma VTG concentration in the 30°C group (10463 ± 3268 μg/ml) was higher than that of the 10°C group (1.42 ± 1.6 μg/ml) after 1 day of exposure. Thus goldfish are useful for the investigation of EDCs under various conditions since they are relatively small in size, and the ELISA established in the present study will contribute to various types of research.