Prostate cancer is the most common tumor in men in Western countries and mortality in Asian counties from the disease has been constantly increasing and a recent steep increase in the incidence is of a great concern. Six characteristics of prostate cancer include (1) frequent discovery of latent carcinoma in counties with low incidences of clinical cancer; (2) very long latent period to clinically manifested cancer; (3) primarily a disease of elderly men; (4) strong influences of environmental factors such as foods; (5) temporal effectiveness of androgen deprival therapy; (6) no effective therapeutic approaches to hormone-refractory types. Clinical malignancy clearly appears from growth and progression of latent type by tumor promotional factor(s). Therefore, prostate cancer is particularly important subject for prevention, i,e., chemoprevention. A variety of food components have been investigated to find prevention potentials by epidemiological approaches as well as preclinical experimental researches and some are found to be risk factors and others to be potent preventers. However, no concrete chemopreventor or risk factors have been identified. In this review, each food component will be discussed regarding cancer prevention potentials.

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To propose effective preparation methods for natural antioxidants as food additives, we estimated and reported variability analysis of marker constituents and antioxidative potencies of extracts depending on different extraction methods described in the list of existing food additives. Several extracts were prepared using different solvents from ten samples [aerial parts of Houttuynia cordata (Dokudami), leaves of Salvia officinalis (Sage), fruits of Foeniculum vulgare (Fennel), fruits of Pimenta dioica (Pimenta), buds of Syzygium aromaticum (Clove), seeds of Helianthus annuus (Sunflower seeds), the leaves of Camellia sinensis (Tea), leaves of Rosmarinus officinalis (Rosemary), beans of Coffea arabica (Green coffee beans), bark of Myrica rubra (Bayberry)], which are the raw materials of natural food additives. Their antioxidant potencies and marker constituents were estimated based on the oxygen radical absorbance capacity (ORAC) and HPLC analysis, respectively. This review outlines and describes the data obtained in their studies, and discusses ways of improvement for the preparation of these natural food additives, and characterization of their antioxidant marker substances.

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It is considered that both phytoestrogens and organochlorine pesticides found in pet animal diets are possible sources of interference with bioassays that assess estrogenic activity. In the present study, we investigated the levels of dietary phytoestrogens, organochlorine pesticides, and estrogenic activities in various commercial pet animal diets and discussed the potential contributions of these substances to the estrogenic activity in comparison to those tested in previous studies. Following hydrolysis by β-glucuronidase, genistein and daidzein were detected in all of the tested diets, and these results were comparable to the data from previous investigations. In addition, organochlorine pesticides, such as α-HCH, β-HCH, HCB, p,p'-DDE and dieldrin, were detected in 2 of 15 tested diets. All of these diets exhibited higher levels of activation of the estrogen receptor β(ERβ) than the estrogen receptor α(ERα) in an in vitro yeast-based bioassay. These results indicated that phytoestrogens, such as genistein and daidzein, were the main substances contributing to the estrogenic activity of the diets. Moreover, the levels of phytoestrogen found in 5 of 15 tested diets may have sufficient amounts to produce a significant estrogenic activity in pet animals.

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Cinnamon Bark is the bark of the trunk of Cinnamomum cassia Blume (Lauraceae), or such bark from which a part of the periderm has been removed, which is designated in the Japanese Pharmacopoeia Sixteenth Edition. It is used in many stomachics of Kampo formulas, and also used as a spice which flavor is unique and favoured around the world. Origin plant species of Cinnamon Bark has some relative species, and they are used for medicinal and food purposes in many countries. It is difficult to distinguish C.cassia from other species only by appearance and taste when they are in a form of powder which is one of the most common styles for use. In order to develop methods for identification of origin plant of Cinnamon Bark, we tried some procedures using DNA sequences. Fresh leaves whose origin plant species were known were used to search for suitable DNA regions to distinguish C.cassia, and rbcL region was found. A combination of PCR amplification with restriction enzyme digestion of DNAs from either fresh leaves or powder could distinguish C.cassia from others. The method we developed in this research could be one of the solutions for the difficulties of DNA extraction and PCR amplification of some crude drugs because of their viscous liquid. It worked well for the samples whose DNA was fragmented by heat and dry. So this method may support the identification of other origin plants which were difficult to be distinguished by conventional simple DNA sequencing method.

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Daily intake of glyphosate in 2010 and 2011 at Chiba prefecture was estimated using total diet samples prepared according to the market basket method. One hundred eighty six and 175 kinds of foods were purchased from supermarket at Chiba in December 2010 and December 2011, respectively. The purchased foods were divided into 14 food groups as total diet samples, and contents of glyphosate in those groups was analysed by high-performance liquid chromatography with fluorescence (HPLC-FL). Glyphosate was detected from second food group (Cereals and potatoes) and 13th food group (Seasonings and spices, other foods) among 14 food groups. Estimated daily intake of glyphosate in all food groups were 24.2μg/day in 2010, and 17.6μg/day in 2011. These estimated daily intake were accounted for 0.064% in 2010, and 0.047% in 2011 of the ADI assuming a body weight of 50 kg. The foods contribute to glyphosate detected from second food group were breads, fu, boiled noodle, macaroni, and that in 13th food group was soy sauce. Glyphosate detected by HPLC-FL method from above two food groups and those foods was identified by liquid chromatography with tandem mass spectrometry. Above these foods were all contained flour. Therefore, it seems to be high possibility that detected glyphosate is originated from flour.

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Various types of compounds are used as additives in packaging materials, and their number is increasing each year. In this study, we developed a GC/MS database containing information, such as retention times and calibration curves, for 125 additives. The extracts of several processed foods obtained by the stir-bar sportive extraction (SBSE) method were analyzed for additives, such as plasticizers and lubricants, using the database. It was found that the database was useful for the rapid and easy screening analysis of these additives.

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A subchronic toxicity study of garden balsam (Impatiens balsamina L.) extract (GBE) was performed in male and female F344 rats with oral administration in their drinking water at concentrations of 0%, 1.25%, 2.5%, and 5.0% for 13 weeks. No chemical-related clinical signs and changes of body weights, food intake, and water consumption were observed in any groups during the experiment. Regarding serum biochemistry, in males, significant increase of Na was observed in 2.5% and 5.0% group and that of Cl was seen in all treated groups. In females, significant increase of Cl and decrease of inorganic phosphorus (IP) were detected at 2.5% and 5.0%. However, no related histopathological lesions were observed in the kidney, intestine and bone tissue. Therefore, it is considered that the changes in serum electrolyte levels were not associated with any meaningful toxicological effects. There were no significant differences in hematological data, organ weights and histopathological findings among the groups. Based on the results, the no-observed-adverse-effect level (NOAEL) for GBE in male and female F344 rats was estimated to be more than 5.0% (3997 and 4577 mg/kg bw/day, respectively).

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The superoxide anion scavenging capacity of 11 antioxidants (AH) was observed, and the results were compared with the antioxidant capacity as measured by DPPH and galvinoxyl methods. The superoxide anion was generated by the xanthine/xanthine oxidase system. 4-[3-(4-iodophenyl)-2-(4- nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate sodium salt (WST-1) was used as a probe of the superoxide anion. The color development rates of WST-1 were measured under various [AH]/[WST-1] ratios, and the data obtained were analyzed according to the following formula. R=ΔA₀/ΔA=1+(k_A/k_W)*([AH]/[WST-1]), where ΔA₀ and ΔA are the color development rates of WST-1 in the absence and presence of antioxidants, respectively, and k_A and k_W are the rate constants of the reaction of superoxide anion with the antioxidants and WST-1. The slope k_A/k_W calculated from the linear regression of the plot of [AH]/[WST-1] vs. V₀/V, indicated the relative superoxide anion scavenging capacity of each antioxidant. The superoxide anion scavenging capacity decreased in the order of caffeic acid, n-propyl gallate, 7,8-dihydroxyflavone, gallic acid, catechin, pyrogallol, quercetin, L-ascorbic acid, BHA, 4-hydroxycoumarin and ferulic acid. Correlation coefficients between the superoxide anion scavenging capacity and the antioxidant capacity as measured by the galvinoxyl or DPPH method were as low as 0.448 (galvinoxyl method) and 0.368 (DPPH method), and it was shown that the antioxidant capacity measured by DPPH method or galvinoxyl method does not necessarily reflect the scavenging capacity of superoxide anion.

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Methyl iodide is a fumigant for which the maximum residue level (MRL) was set in September 2009. Because the usage of methyl iodide as an agrichemical resembles that of methyl bromide, it is widely used as a substitute, and the amount of residue in agricultural products is strictly controlled by the Japanese Food Sanitation Law. The residual level of bromine derived from methyl bromide is also regulated in Japan, and bromine analysis is performed for its surveillance. Therefore, if residual methyl iodide could be evaluated concomitantly with bromine analysis, the efficiency of this analysis could be improved. However, the volatility and reactivity are markedly different between bromine and methyl iodide, and simultaneous analysis is not possible. When methyl iodide is used as a soil fumigant in the United States and Australia, no MRL is set because it does not remain in agricultural products. Although residual testing of crops carried out in Japan also gives results less than the limit of quantification (LOQ) (0.01 ppm), the decomposition product iodine is detected. Furthermore, methyl iodide can be detected in chestnuts that are fumigated directly, and more iodine is detected than methyl iodide. Therefore, we investigated a method to easily screening for the presence or absence of residual methyl iodide by means of its decomposition product, iodine. We attempted to adapt the method of analyzing bromine using a wavelength dispersive X-ray fluorescence (WDXRF) spectrometer for simultaneous analysis of iodine. Iodine and bromine compounds were extracted from samples using distilled water, and extracts from sugar-rich samples were further purified using a PSA mini-column. A portion of the test solution was dried on to filter paper, and iodine and bromine were measured using a WDXRF spectrometer. When potassium iodide was added to agricultural products as iodine at 5.0 μg/g, the recovery and coefficient of variation were 70-98% and 2.0-6.9%, respectively, and the limit of detection (LOD) and LOQ were 0.7 and 2.2 μg/g, respectively. Because the iodine content of agricultural products is generally 0.5 μg/g or lower, detection of iodine at a level higher than the LOD suggests that the parent compound methyl iodide was used and iodine was retained. When methyl bromide was added to agricultural products as bromine at 5.0 μg/g, the recovery and coefficients of variation were 76-102% and 0.6-8.6%, respectively, and the LOD and LOQ were 0.4 and 1.3 μg/g, respectively. Although it was clear that an adequate recovery rate could be obtained in recovery tests by adding 5.0 μg/g of iodine and bromine to various agricultural products, if the MRL for methyl iodide is not set and a uniform standard (0.01 ppm) is applied, it is difficult to check for residual methyl iodide from the analysis results for iodine using this method. This method is, therefore, thought to be usable for screening methyl iodide in tomato, melon, ginger, ha-shoga, Japanese ginger (myoga), and chestnuts where the form of the residue has been clarified by crop residue testing in the past and the current reference value is set to 0.05 to 0.5 ppm.

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