Common small fruit produced naturally in Japan is attracted as healthy food. We studied on inhibitory activity of several small fruit extracts on growth of cancer cells to look for a candidate of healthy food or low toxic anti-cancer drugs. Among the fruit extracts examined, Actinidia polygama (Matatabi) extract had dose-dependent potent inhibitory activity against the growth of a promyelocytic leukemia cell line, HL-60, but was less effective on a colon cancer cell line, LS-174T, or normal human dermal fibroblast cells. We examined a part of the responsible mechanism of growth inhibition of HL-60 cells. Active agents in A. polygama fruit were heat-stable and small molecular weight of less than 1000. HL-60 cells incubated with an extract of A. polygama fruit induced apoptosis, which was detected by electrophoretic DNA fragmentation, morphological chromatin condensation and the TUNEL method with flow cytometry.
The tumorigenic action of environmental chemical substances has been variously examined, although the effect on malignancies after tumor occurrence has not been studied well. In this study, we established a bioassay system based on tumor cell invasion as a possible index of tumor malignancy, and evaluated the effect of various environmental chemicals on tumor cell invasiveness. We previously established a simple invasion assay system using fluorescent cells and a culture insert with fluorescence blocking micropore membrane (FBM). In this study, the effect of various environmental chemicals on the migration of green fluorescent protein (GFP) gene-transfected HT1080 fibrosarcoma cells through a Matrigel-coated filter was examined. The invasive ability of GFP-HT1080 cells was enhanced in the presence of phenol, 2,5-dichlorophenol, 2,4,5-trichlorophenol, and lindane, and was inhibited with bisphenol A, benthiocarb and others among 31 environmental chemicals tested. Enhancement of the migration of GFP-HT1080 cells with phenol and halogenated phenol derivatives depended on the number of linked chloride moieties. The morphological change of HT1080 cells in the presence of phenol and polychlorophenols was determined by confocal laser fluorescence microscopy, and we observed that it was partly correlated with the invasive characteristics. Finally, we assessed the invasion assay with combinations of chemical substances. As a result, none of the combinations increased the invasion ability of HT1080 cells. Although the effect of environmental chemicals on tumor cell invasiveness may not directly relate to the malignancy of tumor cell itself, it is possible that it relates the tumor progression and metastases.
We investigated the effect of exposure of pregnant mice to diesel exhaust on male gonad development at the level of mRNA expression. Expression of mRNAs for steroidogenic factor-1 (Ad4BP/SF-1) and Müllerian inhibitory substance (MIS), which are essential for male gonadal differentiation, decreased significantly in male fetuses when maternal mice were exposed to diesel exhaust at levels of 0.1 mg and 3.0 mg diesel exhaust particles (DEP)/m3 for 8 hr per day between days 2 and 13 post coitum. Expression levels of mRNAs for steroidogenic cytochrome P450 genes regulated by Ad4BP/SF-1, especially 3β-hydroxysteroid dehydrogenase (3β-HSD) and aromatase, were also decreased by exposure to diesel exhaust. There were no significant differences in levels of estrogen receptor (ER) or androgen receptor (AR) mRNAs between control and exposed mice. The data indicate that exposure of pregnant mice to diesel exhaust affects the expression of genes essential in the early stages of embryonic development.
The effect of Sargassum horneri on bone components in the femoral-diaphyseal and -metaphyseal tissues of young and aged rats was investigated. Rats were orally administered a water-solubilized extract (2.5, 5, and 10 mg/100 g body weight) of S. horneri once a day for 7 or 14 days. Calcium content, alkaline phosphatase activity and deoxyribonucleic acid (DNA) content in the femoral-diaphyseal and -metaphyseal tissues of young male (4 weeks old) rats was significantly increased by the administration of S. horneri extract (2.5, 5, and 10 mg/100 g) for 7 days. Moreover, these bone components in the femoral-diaphyseal and -metaphyseal tissues of aged female (50 weeks old) rats were significantly increased by the administration of S. horneri extract (10 mg/100 g) for 14 days. Meanwhile, body weight and serum calcium, zinc and inorganic phosphorus concentrations of female aged rats were not significantly altered by the administration of S. horneri extract (10 mg/ 100 g) for 14 days. The present study demonstrates that the oral intake of the water-solubilized extract of S. horneri can exhibit an anabolic effect on bone components of young rats in vivo, and that this effect is also seen in aged rats. The intake of S. horneri extract may have a preventive effect on bone loss with increasing age.
Nine different food cans, packed with water, were heat-treated for 30 min at 80 or 100°C in order to elucidate the trends associated with the leaching of bisphenol A (BPA) from internal coatings. Low levels of BPA were detected in water from all unheated cans, rising to 0.06 to 32 ng/cm2 after heating at 100°C. Reducing the heat-treatment temperature to 80°C was found to reduce the BPA concentration in the contained water by up to two-thirds. The cans that recorded the highest BPA concentrations in water after heating were found to have components (lid, bottom or body) with high available BPA contents.
A method was developed for the simultaneous determination of 3 sulfonylurea herbicides, azimsulfuron, flazasulfuron and halosulfuron-methyl in agricultural products. The herbicides were extracted with acetone, re-extracted with ethyl acetate, and then transferred to 2% dipotassium hydrogenphosphate solution. The herbicides were extracted again into ethyl acetate and cleaned up using Sep-Pak® Plus Alumina N and Bond Elut® SAX cartridge columns. The 3 sulfonylurea herbicides were determined by HPLC. The fortified peaks were confirmed by LC/MS with electrospray ionization (ESI), and the peaks of azimsulfuron, flazasulfuron and halosulfuron-methyl were determined. The recoveries of the 3 sulfonylurea herbicides from brown rice, corn, cotton seed, ginkgonut, chestnut, almond, walnut, cucumber, pumpkin, orange, grapefruit, mandarin, lemon and grape ranged from 77.0 to 112.3% following fortification at 0.05-0.5 μg/g. The detection limits were 0.01 μg/g for azimsulfuron and halosulfuron-methyl, and 0.02 μg/ml for flazasulfuron(S/N > 3).
The protective effects on neonatal (3.5 weeks old) and young mice (7 weeks old) of eight pertussis vaccines prepared from various components at various concentrations were investigated in a murine model of respiratory infection (aerosol challenge model). Neonatal mice were more sensitive than young mice to infection by Bordetella pertussis after aerosol challenge. In young mice with all vaccines, there were significant differences between immunized mice and control mice. The efficacy of vaccines was increased by the inclusion of additional filamentous hemagglutinin (FHA), pertussis toxin (PT), or pertactin (PRN) in the basic vaccine (FHA : PT : PRN, 7 : 2 : 1, w/w). An elevated level of FHA strongly increased the efficacy of the vaccine in young mice. It was, however, more difficult to induce protection against B. pertussis in neonatal mice than in young mice, irrespective of the levels of the various components in the vaccines. Our data suggest that pertussis vaccines are less effective in neonatal mice than in young mice, as assessed by the aerosol challenge model.
Composition and inducibility of cytochrome P450 (CYP) in ocular tissues were investigated using reverse transcription-polymerase chain reaction (RT-PCR) and immunoblot techniques. Composition of ocular CYPs is more restricted than that of hepatic forms. High levels of CYP2B1/2 and reduced levels of CYP2C11 expression were detected in rat ocular tissues. Phenobarbital induced CYP2B1/2 expression in the lens but not in the rest of the eye, whereas CYP2C11 induction was observed in both regions. In addition, CYP2B1/2 proteins were found to be prominent in the retina. Our data indicate eye-specific regulation of CYP expression.
Beta-cryptoxanthin (β-CRX) is a carotenoid pigment found in peach, papaya, and citrus fruits such as orange and tangerine. It is also found, especially, in Satsuma mandarin (Citrus unshiu Marc.), which is heavily produced in Japan and is mainly harvested from October to February. In this study, we investigated the relationship of serum concentration of β-CRX to the frequency of Satsuma mandarin consumption using 94 healthy nonsmoking female volunteers. In September, when Satsuma mandarin is not in season, even though the volunteers had not eaten citrus fruits or processed food including citrus for a two-month period, the serum concentration of β-CRX in the participants who ate more than four Satsuma mandarins daily was high enough to be statistically significant compared with the participants who rarely ate any (p < 0.05). Furthermore, when the Satsuma mandarin was in season in January, the serum concentration of β-CRX increased remarkably depending on the frequency of Satsuma mandarin consumption. These results suggest that β-CRX is stored in some tissues for several months and that it is a useful biomarker for estimating the frequency of Satsuma mandarin consumption.
To address the question of whether or not tumor necrosis factor-α (TNF-α) regulates the functions of vascular smooth muscle cells (SMCs), dense or sparse cultures of the cells derived from human aorta were treated with TNF-α or TNF-αneutralizing antibody (TNF-α Ab). The incorporation of [3H]thymidine into the acid-insoluble fraction of SMCs was significantly inhibited by TNF-α, but stimulated by TNF-α Ab only when the cells had a high cell density. TNF-αsignificantly increased the accumulation of matrix metalloproteinase-1 and -3 (MMT-1 and -3, respectively) in the conditioned medium of dense SMCs, but does not affect that of tissue inhibitors of metalloproteinases-1 (TIMP-1); MMP-9 and TIMP-2 were undetectable. The invasive migration of SMCs determined by a Transwell system was stimulated by neither TNF-α nor TNF-α Ab. Taking these results together, it is suggested that TNF-α regulates DNA and MMP synthesis in dense SMCs but does not affect their invasive migration.
We investigated the subacute toxicity of 2 wood preservatives, DDAC (principal component: 37.5% didecyldimethyl ammonium chloride) and BAAC (principal components: 40% DDAC, 13.4% boric acid), in a number of aquatic invertebrates: a green alga (Selenastrum capricornutum), 2 cladocerans (Ceriodaphnia dubia and Daphnia magna), 2 fishes (Danio rerio and Oryzias latipes), and photobacteria (Microtox®). DDAC and BAAC inhibited biological functions in all of the organisms tested; the order of sensitivity was green alga > cladocerans > fish. Growth of S. capricornutum was inhibited by both preservatives at very similar levels of exposure. DDAC inhibited reproduction in C. dubia at lower levels of exposure than for D. magna, and the reverse was true for BAAC. Both DDAC and BAAC reduced the survival rate of D. rerio at lower exposure levels than for O. latipes. However, phylogenetic class differences in sensitivity to the preservatives were much greater than species differences.
Recently, the consumption of fruit has decreased or remained at the same level in Japan. It is possible that this may be due to a general mistaken connection between fruit consumption and the risks for diabetes, hyperlipemia, and obesity. This study is an evaluation of the hypothesis that a high-volume consumption of fruit might contribute to the same diseases. A cross-sectional analysis was used to investigate the relationship between the frequency of Satsuma mandarin (Citrus unshiu Marc.) consumption and health status based on data from 6049 participants aged 20-79 years old on a self-administered questionnaire. After adjustments for age, sex, and body mass index, the odds ratios of risk for diabetes for participants consuming one to three pieces daily (middle consumption group) or more than four pieces daily (high consumption group) compared with those consuming fewer than three pieces a week (low consumption group) were 0.70 [95% confidence interval (CI), 0.59-0.83] and 0.48 (95% CI, 0.41-0.58), respectively. On the other hand, the odds ratios of risk for hyperlipemia and obesity in the middle and high consumption groups compared with the low consumption group were not statistically significant. These results indicate the possibility that the consumption of Satsuma mandarin may act as a deterrent to diabetes and not be a risk factor for diabetes, hyperlipemia, and obesity.
Airborne particulates were collected at a site near a group of factories in Kitakyushu, one of the most industrialized cities in Japan, and at downtown sites in Sapporo and Tokyo, typical large commercial cities. We determined the levels of polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs), which are known to be carcinogenic and/or mutagenic. The atmospheric concentrations of most PAHs with 4-, 5-, and 6-rings were higher in Kitakyushu and Tokyo than in Sapporo. On the other hand, atmospheric concentrations of the strongly mutagenic NPAHs were the highest in Sapporo, intermediate in Tokyo, and lowest in Kitakyushu. The atmospheric concentrations of 1-nitropyrene (1-NP) in Kitakyushu were one order of magnitude lower than those in the two commercial cities. Therefore the concentration ratios of NPAHs to their nucleus PAHs were significantly smaller in Kitakyushu than in the two commercial cities. This result suggested that the atmospheric levels of NPAHs in Kitakyushu were comparatively low, although the air in Kitakyushu was as heavily polluted with PAHs as the air in Tokyo. The concentration ratio of dinitropyrenes (DNPs) to 1-NP in Kitakyushu was much higher than that in the other two cities. A possible reason for the above two differences between the two types of cities is the contribution of chimney exhaust of steel manufacturing plants in Kitakyushu, which contains high concentrations of PAHs.
The effects of dietary polyamines have been investigated on 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP)- induced carcinogenesis of the breast in rats by feeding spermidine (Spd) at three different concentrations. The cumulative incidence of mammary tumor in the group treated with PhIP plus Spd was 92% (low spermidine diet) and 68% (high spermidine diet), compared to 50% in the PhIP group with a control diet. These results suggest that dietary polyamines may enhance the promotion of PhIP- induced mammary carcinogenesis. In addition, however, a low spermidine diet can promote the development of tumor in rats, but on the other hand a high spermidine diet may suppress the mammary carcinogenesis.
Methylmercury (MeHg) is a well-known environmental pollutant that causes severe neurological damage, especially in the developing nervous system. When human neuroblastoma NB-1 cells were treated with MeHg at sublethal concentrations, down-regulation of two apoptosis-associated genes, mtHSP70 (GRP75/PBP74/ mtHSP75 /HSPA9B/mortalin) and phospholipase A2 (PLA2), was identified using the cDNA macroarray technique. These observations were further confirmed by RT-PCR and Northern blotting experiments. Northern blotting data also demonstrated that only groups III and VI B of PLA2 were down-regulated, while group IIE remained unchanged. These results suggest that the mtHSP70 and PLA2 may be involved in the MeHg-mediated degeneration of neuronal cells.