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Background: In the field of breast screening using mammography, announcing to the examinees whether they are dense or not has not been deprecated in Japan. One of the reasons is a shortage of objectivity estimating their dense breast. Our aim is to build a system with deep learning algorithm to calculate and quantify objective breast density automatically., Material and Method: Mammography images taken in our institute that were diagnosed as category 1 were collected. Each processed image was transformed into eight-bit grayscale, with the size of 2294 pixels by 1914 pixels. The "base pixel value" was calculated from the fatty area within the breast for each image. The "relative density" was calculated by dividing each pixel value by the base pixel value. Semantic segmentation algorithm was used to automatically segment the area of breast tissue within the mammography image, which was resized to 144 pixels by 120 pixels. By aggregating the relative density within the breast tissue area, the "breast density" was obtained automatically., Result: From each but one mammography image, the breast density was successfully calculated automatically. By defining a dense breast as the breast density being greater than or equal to 30%, the evaluation of the dense breast was consistent with that by a computer and human (76.6%)., Conclusion: Deep learning provides an excellent estimation of quantification of breast density. This system could contribute to improve the efficiency of mammography screening system.

Estradiol (E2) with the strongest bioactivity of the estrogens, is synthesized by the cytochrome p450 aromatase enzyme and plays a key role in sex differentiation of the vertebrate's gonads. In Xenopus, aromatase mRNA is highly expressed in the brain rather than in the gonad during sex differentiation. In this study, we analyzed the stage change, tissue specificity, and localization of the aromatase expression in the Xenopus brain. Regardless of the sex difference, expression level of aromatase was remarkably higher in the brain than in other tissues during the early stages of brain morphogenesis and was observed in the formation regions of the choroid plexus of cerebral ventricle and the paleocortex and olfactory bulb of the prosencephalon. However, E2 concentrations in each tissue indicated a different localization of aromatase and were seen in the heart at almost double the level as seen in the brain. In addition, while aromatase expression level in the brain was increasing, E2 in the whole body began to increase at the same stage. Since the expression level of estrogen receptor α also corresponded to localization of E2, these results may imply that the E2 synthesized by the high aromatase expression in the choroid plexus, which generates cerebrospinal fluid, circulates to the heart and acts through ERα., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objectives: We have previously reported that an antioxidant, auraptene (AUR), isolated from citrus fruit effectively inhibits chemically induced carcinogenesis in digestive tracts, such as the oral cavity, esophagus and large bowel. In this study, we investigated the modifying effects of dietary supplementation with AUR on N,N-diethylnitrosamine (DEN)-initiated hepatocarcinogenesis in male F344 rats in two different experiments to determine whether the compound exerts a cancer-chemopreventive action in other organs., Methods: In the first experiment, animals were fed diets containing AUR at dose levels of 100 and 500 ppm for 7 weeks 1 week before, during, and 1 week after the start of liver carcinogenesis induced by DEN (40 ppm in drinking water for 5 weeks) to predict the modulatory effect on hepatocarcinogenesis. After 7 weeks, the numbers of hepatocellular enzyme-altered foci (EAF; cm(2)) which stained positive for the placental form of glutathione S-transferase (GST-P) and transforming growth factor (TGF)-alpha were determined on immunohistochemically stained sections. In the second experiment conducted to confirm the findings, animals subjected to DEN treatment were fed AUR-containing diets (100 and 500 ppm) during either the initiation stage ('initiation' feeding for 7 weeks) or post-initiation phase ('post-initiation' feeding for 25 weeks) of DEN-induced hepatocarcinogenesis., Results: In the first experiment, feeding with AUR at both doses during DEN exposure decreased the mean numbers of GST-P-positive and TGF-alpha-positive EAF/cm(2), and the reduction in the number of TGF-alpha-positive EAF by feeding 500 ppm AUR was statistically significant (p < 0.005). In the second experiment, the 'initiation' feeding with 500 ppm AUR significantly inhibited the incidence (33 vs. 83%, p = 0.000511) and multiplicity (0.67 +/- 1.09 vs. 1.96 +/- 1.85, p < 0.005) of liver cell carcinoma. Also, the 'post-initiation' feeding with AUR at both doses significantly reduced the development of hepatocellular carcinoma (100 ppm: incidence, 15%, p = 0.000006; multiplicity: 0.25 +/- 0.64, p < 0.001; 500 ppm: incidence, 11%, p = 0.000002; multiplicity, 0.26 +/- 0.81, p < 0.001). In addition, AUR feeding reduced cell proliferation and the apoptotic index in liver cell neoplasms., Conclusions: The results suggest that the citrus antioxidant AUR is a potential chemopreventive agent against DEN-induced hepatocarcinogenesis in rats., (Copyright 2004 S. Karger AG, Basel)

The inhibitory effects of dietary feeding of citrus nobiletin on azoxymethane (AOM)-induced rat colon carcinogenesis using a long-term bioassay were investigated. Five-week old male F344 rats were initiated with two weekly subcutaneous injections of AOM (20 mg/kg bw) to induce colonic tumors. They were also given the diets containing 0.01% or 0.05% nobiletin for 34 weeks, starting one week after the last dosing of AOM. At the end of the study, the incidence of colonic adenocarcinoma were 67% in the AOM alone group, 55% in the AOM-->0.01% nobiletin group, 35% (p<0.05) in the AOM-->0.05% nobiletin group. Also, nobiletin feeding reduced the cell-proliferation activity, increased the apoptotic index, and decreased the prostaglandin E2 content in colonic adenocarcinoma and/or colonic mucosa. These findings might suggest that citrus nobiletin has chemopreventive ability against AOM-induced rat colon carcinogenesis.

Degradation of IkappaB (IkappaB) is a key step for nuclear factor-kappaB (NF-kappaB)-induced transcription of certain proinflammatory genes, including inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2. We selected seven chemopreventive agents and examined their effects on combined lipopolysaccharide- and interferon-gamma-induced IkappaB degradation in RAW264.7 murine macrophages. IkappaB degradation was notably suppressed by 1'-acetoxychavicol acetate (ACA), zerumbone (ZER), and benzylisothiocyanate (BITC), however, not by auraptene (AUR), while the suppressive potencies of nobiletin (NOB), genistein (GEN), and resveratrol (RES) were low, but significant. These results suggest that ACA, ZER, and BITC suppress iNOS/COX-2 gene expression mainly by attenuating IkappaB degradation, while other chemopreventive agents use alternative pathway(s) to suppress the expression of proinflammatory genes.

Combinatorial chemopreventive strategies, in contrast to those with individual agents, show potential in terms of potentially lower toxicity and higher efficacy. In this study, we combined several agents and examined their suppressive effects on the combined lipopolysaccharide (LPS)- and interferon(IFN)-gamma-induced formation of proinflammatory mediators, including prostaglandin (PG) E2 and tumor necrosis factor (TNF)-alpha, in RAW264.7 murine macrophages. The combinatorial effects of indomethacin/genistein (GEN) and aspirin/GEN were found to be synergistic for PGE2 suppression, while the nimesulide/GEN combination was antagonistic. Further, while (-)-epigallocatechin gallate (EGCG) alone increased LPS/IFM-gamma-induced production of PGE2 and TNF-alpha as well as cyclooxygenase-2 expression, the EGCG/GEN combination markedly suppressed these parameters. Our results suggest that certain chemopreventive agents act complexly and that, when used in combination, they affect the intracellular signaling pathways of the paired agents to exert additive, synergistic, or antagonistic effects.

In contrast to chemopreventive strategies using individual agents, a combination of specified compounds may be effectual to achieve desirable results with higher efficacy and lower toxicity. In the present in vitro study, we examined combinations of agents and assessed which concentrations were appropriate to yield notable synergism. L-N(G)-Monomethyl-L-arginine (L-NMMA), a synthetic inducible nitric oxide synthase (iNOS) inhibitor, and zerumbone, a natural sesquiterpene that suppresses iNOS de novo synthesis, were combined at various concentrations, with the aim to diminish combined lipopolysaccharide- and interferon-gamma-induced nitric oxide generation in a murine macrophage line, RAW264.7. Although the combinatorial effects (CEs) were antagonistic or additive at higher concentrations, significant synergism was obtained at lower concentrations where each agent alone did not cause significant inhibition. Similarly, the CEs were synergistic when (-)-epigallocatechin gallate (EGCG) and genistein were combined at lower concentrations, whereas those of two iNOS inhibitors, L-NMMA and L-N(G)-aminoethyl-L-ornithine, were either additive or antagonistic at all concentrations tested, suggesting that a combination of given agents with different action mechanisms is a prerequisite for synergistic effects. For suppression of phorbol ester-induced superoxide anion radical (O(2)*(-)) generation in differentiated HL-60 cells, the CEs of 1'-acetoxycahvicol acetate (ACA), a phenyl propanoid that suppresses O(2)*(-) generation, and O(2)*(-) dismutase were also synergistic, though only at lower concentrations. The CEs of ACA/EGCG were antagonistic or additive, even at low concentrations, suggesting that the signal transduction pathways triggered by these agents are antagonistic. The present findings suggest that individual food phytochemicals have complex interactions that can be antagonistic, additive, and/or synergistic in biological systems, depending upon certain environmental factors including concentrations. Further, these results support and emphasize the concept that combinations of different types of chemicals at low concentrations are one of the essential areas of study for chemopreventive strategies., (Copyright 2002 Elsevier Science B.V.)

Purpose: Recent preclinical assays using animal models have shown that naturally-occurring and synthetic chemicals such as auraptene (AUR), nobiletin (NOB), hesperidin (HE), diosmin (DIO), indole-3-carbinol (I3C), 1'-acetoxychavicol acetate (ACA), 2,5-di-O-acetyl-D-1,4-glucaro-6,3-dilactone (ACE), D-glucuronic acid gamma-lactone (GL), chlorogenic acid (CGA), protocatechuic acid (PA), and sinigrin (SIN) are possible preventive agents against the development of cancer. However, the mode of action of such preventive agents remains to be elucidated. The current study, therefore, was conducted to analyze whether these agents induce apoptosis and/or inhibit DNA synthesis in human colorectal cancer cell lines., Methods: We performed an 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay to evaluate the modifying effects of the chemicals on cell viability as the first screening. Then, induction of apoptosis was detected by means of a DNA fragmentation assay, a quantitative enzyme immunoassay, and morphological analysis using 4-diamidino-2-phenylindole staining. In addition, the modulating effects of the compounds on DNA synthesis of the cells with fixed doses of the compounds were analyzed by scoring the 5-bromo-2'-deoxyuridine labeling index., Results: AUR, NOB, I3C, ACA, and ACE had apoptosis-inducing effects in a concentration- and time-dependent manner, some of which were followed by a reduction in replicating DNA synthesis. CGA, PA, SIN, GL, DIO, and HE had little modulating effect on cell viability, apoptosis, and DNA synthesis in this cell system., Conclusions: Our results suggest that AUR, I3C, ACA, NOB, and ACE might exert tumor-preventive action through apoptosis- and/or cell proliferation-dependent mechanisms and, on the other hand, CGA, PA, SIN, HE, DIO, and GL might be apoptosis- and cell proliferation-independent. These assays provided an initial tool for further mechanical studies of tumor-preventive agents and future applications to mechanism-based chemopreventive studies.

In our previous study, FA15 (2-methyl-1-butyl ferulic acid) was chemically synthesized as a novel ferulic acid (FA) analog, and found to notably suppress phorbol ester-induced Epstein-Barr virus activation and superoxide anion generation in vitro. In this report, we demonstrated that FA15, in contrast to FA, markedly suppressed the combined lipopolysaccharide and interferon-gamma-induced protein expressions of inducible nitric oxide synthase and cyclooxygenase-2, and also inhibited the release of tumor necrosis factor-alpha accompanied by suppression of I-kappa B degradation in RAW264.7, a murine macrophage cell line. In ICR mouse skin, topical application of FA15 significantly attenuated phorbol ester-triggered hydrogen peroxide production and edema formation as well as papilloma development while that of FA did not. Our results suggest that FA15, derived from natural sources, is a novel chemopreventive agent, both structurally and functionally.

We prepared 14 feruloyl-myo-inositol derivatives, and evaluated the relationships between their stereostructure and inhibitory activity toward the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced superoxide (O(2)(-)) generation. And further, their suppressive effect on the TPA-induced Epstein-Barr virus (EBV) activation was examined in order to estimate their anti-carcinogenic potentials. Among the derivatives tested, 1,6-O-bis[3-(4'-hydroxy-3'-methoxyphenyl)-2-propenoyl]-myo-inositol (6b) showed an excellent suppressive activity on the O(2)(-) generation at a concentration of 20 microM. For the suppressive effects on the EBV activation, 2,4,6-O-tris[3-(4'-hydroxy-3'-methoxyphenyl)-2-propenoyl]-myo-inositol 1,3,5-orthoformate (9b) showed the highest activity at a concentration of 100 microM among the derivatives tested. These results suggest that the inhibitory potencies of feruloyl-myo-inositol derivatives depend on the stereostructure of molecules rather than the hydrophobicity of molecules.

Zerumbone (ZER), a sesquiterpene from the edible plant Zingiber zerumbet Smith, has recently been found to suppress tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein-Barr virus activation in a potent manner. In the present study, we evaluated the anti-inflammatory and chemopreventive potentials of ZER in a variety of cell culture experiments. ZER effectively suppressed TPA-induced superoxide anion generation from both NADPH oxidase in dimethylsulfoxide-differentiated HL-60 human acute promyelocytic leukemia cells and xanthine oxidase in AS52 Chinese hamster ovary cells. The combined lipopolysaccharide- and interferon-gamma-stimulated protein expressions of inducible nitric oxide synthase and cyclooxygenase (COX)-2, together with the release of tumor necrosis factor-alpha, in RAW 264.7 mouse macrophages were also markedly diminished. These suppressive events were accompanied with a combined decrease in the medium concentrations of nitrite and prostaglandin E(2), while the expression level of COX-1 was unchanged. ZER inhibited the proliferation of human colonic adenocarcinoma cell lines (LS174T, LS180, COLO205, and COLO320DM) in a dose-dependent manner, while the growth of normal human dermal (2F0-C25) and colon (CCD-18 Co) fibroblasts was less affected. It also induced apoptosis in COLO205 cells, as detected by dysfunction of the mitochondria transmembrane, Annexin V-detected translocation of phosphatidylserine, and chromatin condensation. Intriguingly, alpha-humulene, a structural analog lacking only the carbonyl group in ZER, was virtually inactive in all experiments conducted, indicating that the alpha,beta-unsaturated carbonyl group in ZER may play some pivotal roles in interactions with unidentified target molecule(s). Taken together, our results indicate that ZER is a food phytochemical that has distinct potentials for use in anti-inflammation, chemoprevention, and chemotherapy strategies.

We prepared novel polyphenols which were esters composed of two naturally occurring products, ferulic and gallic acids, and investigated their inhibitory effects on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein-Barr virus (EBV) activation and superoxide (O2-) generation. Most of these compounds exhibited significant EBV activation suppression at a concentration of 20 microM and in particular, the ester 5f having 2-methyl-1-butyl group showed high activity. The suppressive effects on O2- generation were also observed in most of the esters.

Elucidation of the mechanisms underlying potential anticancer drugs continues and unraveling these mechanisms would not only provide a conceptual framework for drug design but also promote use of natural products for chemotherapy. To further evaluate the efficacy of the anticancer activity of 1'-acetoxychavicol acetate (ACA), this study investigates the underlying mechanisms by which ACA induces death of Ehrlich ascites tumor cells. ACA treatment induced loss of cell viability, and Western blotting analysis revealed that the compound stimulated tyrosine phosphorylation of several proteins with 27 and 70 kDa proteins being regulated in both dose- and time-dependent manner prior to loss of viability. Protein tyrosine kinase inhibitor herbimycin A moderately protected cells from ACA-induced toxicity. In addition, cellular glutathione and protein sulfydryl groups were also significantly reduced both dose- and time-dependently during evidence of cell death. Replenishing thiol levels by antioxidant, N-acetylcysteine (NAC), an excellent supplier of glutathione and precursor of glutathione, substantially recovered the viability loss, but the recovery being time-dependent, as late addition of NAC (at least 30 min after ACA addition to cultures) was, however, ineffective. Addition of NAC to ACA treated cultures also abolished tyrosine phosphorylation of the 27 kDa protein. These results, at least partly, identify cellular sulfhydryl groups and protein tyrosine phosphorylation as targets of ACA cytotoxicity in tumor cells.

Nobiletin (NOB), a polymethoxyflavonoid, is an effective anti-inflammatory and chemopreventive phytochemical found in citrus fruits. We compared the absorption and metabolism characteristics of NOB with those of luteolin (LT) in male SD rats. Each flavonoid (67.1 micromol/kg of body weight) was given separately by gastric intubation, and then concentrations were measured at 1, 4, and 24 hours after administration. In the digestive organs, NOB showed a notable tendency for localizing into the mucous membrane and muscularis from 1 to 4 hours, in contrast to LT, though both NOB and LT were completely excreted within 24 hours. Further, significant amounts of NOB were detected in the whole liver and kidney specimens, whereas LT accumulation was slight. Although serum concentrations of NOB from 1 to 4 hours were comparable to those of LT, urinary concentrations of LT were significantly higher from 4 to 24 hours. Following glucuronidase/sulfatase treatments of urinary materials, we detected 3 types of mono-demethylated NOB, including 3'-demethyl-NOB, and two di-demethylated types, as well as 3'-demethyl-NOB alone in serum samples using liquid chromatography-mass spectral analysis. Our results suggest that the metabolic properties of polymethoxyflavonoids are distinct from those of other general flavonoids, because of their wide distribution and accumulation in tissue.

Five bufadienolides (1-5) isolated from the leaves of Kalanchoe pinnata and K. daigremontiana x tubiflora (Crassulaceae) were examined for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation in Raji cells induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate. All bufadienolides showed inhibitory activity, and bryophyllin A (1) exhibited the most marked inhibition (IC50 = 0.4 microM) among the tested compounds. Bryophyllin C (2), a reduction analogue of 1, and bersaldegenin-3-acetate (3) lacking the orthoacetate moiety were less active. These results strongly suggest that bufadienolides are potential cancer chemopreventive agents.

The polymethoxyflavonoid (PMF), nobiletin (NOB), specifically occurs in citrus fruits, and is currently believed to be a promising anti-inflammatory and antitumor promoting agent. In the present study, we investigated the in vitro absorption and metabolism of NOB and compared them with those of the polyhydroxyflavonoid (PHF), luteolin (LT). NOB preferentially accumulated in a differentiated Caco-2 cell monolayer, which is a model for small intestinal epithelial cells, while LT did not. Treatment of NOB with a rat liver S-9 mixture led to the formation of 3'-demethyl-NOB, while that of LT did not. We thus suggest that PMFs including NOB have properties distinct from those of general flavonoids for absorption and metabolism in vitro.

Expression of inducible nitric oxide synthase (iNOS) has been reported to be involved in certain organs of potential tumorigenesis, including the stomach and colon. The mechanisms for iNOS expression in epithelial cells, however, are not fully understood. In the present study, we investigated the role of macrophages in epithelial iNOS expression by coculturing a stimulated murine macrophage-like cell line, RAW 264.7, with either tumor promoter-sensitive (P+) or promoter-resistant (P-) JB6 murine epidermal cells. After monoculture, treatment of RAW 264.7 cells with IFN-gamma for 24 h generated a large amount of nitrite (NO2-), as reported previously, whereas no increase in NO2- concentration was observed in the IFN-gamma-treated P+ or P-subclones. Interestingly, when IFN-gamma-treated RAW 264.7 cells were cocultured with P+ but not P- cells, we observed a marked increase in NO2- concentration (30.8+/-3.6 microM), which significantly exceeded (P < 0.01) the sum of the concentrations (20.0+/-2.3 microM) added from each cell line monoculture. Western blotting analysis revealed that, after coculture, iNOS protein was up-regulated 55-fold more than the control in JB6 P+ but not in P- cells. IFN-gamma-treated RAW 264.7 cells secreted proinflammatory cytokines, including tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta. The addition of IFN-gamma-treated RAW 264.7 cell-conditioned media to P+ subclones led to a significant enhancement of NO2- formation that was diminished by the TNF-alpha-specific but not IL-1beta-specific antibody. When combined with IFN-gamma, the recombinant TNF-alpha (1-100 ng/ml) enhanced NO2- formation in JB6 P+ cells, whereas IL-1beta (1-100 ng/ml) did not. These results led us to conclude that IFN-gamma-treated RAW 264.7 cells release TNF-alpha to induce iNOS expression in promoter-sensitive JB6 cells. Thus, we propose the hypothesis that macrophages stimulate neoplastic cells with TNF-alpha via a paracrine loop to induce epithelial iNOS protein expression.

The intake of citrus fruits has been suggested as a way to prevent the development of some types of human cancer. Nitric oxide (NO) is closely associated with the processes of epithelial carcinogenesis. We attempted a search for NO generation inhibitors in Citrus unshiu. The active constituent was traced by an activity-guiding separation. NO and superoxide (O2-) generation was induced by a combination of lipopolysaccharide and IFN-gamma in mouse macrophage RAW 264.7 cells, and by 12-O-tetradecanoylphorbol-13-acetate (TPA) in differentiated human promyelocyte HL-60, respectively. Expression of inducible NO synthase and cyclooxygenase 2 proteins were detected by Western blotting. The in vivo anti-inflammatory and antitumor promoting activities were evaluated by topical TPA application to ICR mouse skin with measurement of edema formation, epidermal thickness, leukocyte infiltration, hydrogen peroxide production, and the rate of proliferating cell nuclear antigen-stained cells. As a result, nobiletin, a polymethoxyflavonoid, was identified as an inhibitor of both NO and O2- generation. Nobiletin significantly inhibited two distinct stages of skin inflammation induced by double TPA application [first stage priming (leukocyte infiltration) and second stage activation (oxidative insult by leukocytes)] by decreasing the inflammatory parameters. It also suppressed the expression of cyclooxygenase-2 and inducible NO synthase proteins and prostaglandin E2 release. Nobiletin inhibited dimethylbenz[a]anthracene (0.19 micromol)/TPA (1.6 nmol)-induced skin tumor formation at doses of 160 and 320 nmol by reducing the number of tumors per mouse by 61.2% (P < 0.001) and 75.7% (P < 0.001), respectively. The present study suggests that nobiletin is a functionally novel and possible chemopreventive agent in inflammation-associated tumorigenesis.

The structure-activity relationships of (1'S)-1'-acetoxychavicol acetate (ACA), a cancer chemopreventive agent of food origin, were investigated in an inhibitory test of tumor promoter teleocidin B-4-induced Epstein-Barr virus (EBV) activation in Raji cells. Through a test of 16 derivatives, the structural factors regulating activity were found to be as follows: (1) the absolute configuration at the 1'-position does not affect activity; (2) hydrogenation of the terminal methylene group abolishes activity; (3) both the phenolic and alcoholic hydroxyl groups are compulsorily acetylated, and it is necessary that the former is oriented only at the position para to the side chain; (4) an additional acetoxyl group is allowed to locate at the ortho or meta position; and (5) substitution of the hydrogen atom at the 1'-position by a methyl group reduces activity. Upon esterase blockade in Raji cells, (1'R,S)-ACA suppressed EBV activation, the extent of which was the same as tested in the control, suggesting that ACA bearing two acetoxyl groups is an intracellular structure prerequisite for activity exhibition. The present study suggests that nucleophilic attack to the 3'-position is important and involved in the interaction of ACA with an unidentified target molecule(s) participating in the process of EBV activation.

The influence of 1'-acetoxychavicol acetate (ACA) during the initiation stage was investigated in the N-nitrosobis(2-oxopropyl)amine (BOP)-initiated hamster tumorigenesis model. Ninety male 5-week-old hamsters were divided into three groups, each consisting of 30 animals, and s.c. injected with 20 mg / kg of BOP twice with a one-week interval. Groups 1 through 3 were fed diet supplemented with ACA at concentrations of 500, 100 and 0 ppm, respectively, for 3 weeks starting one week before the first carcinogen application. At the termination of experimental week 54, the total incidence and multiplicity of cholangiocellular adenomas and carcinomas in group 1 (17.9% and 0.3 < 0.9) were significantly (P < 0.05 and P < 0.01) decreased as compared to the group 3 values (50.0% and 0.7 < 0.8). The ACA treatments also showed a tendency to reduce the development of preneoplastic lesions in the pancreas, a main target organ of BOP, although this was not statistically significant. Our results thus indicate that ACA exerts an inhibitory effect on BOP-induced cholangiocarcinogenesis in hamsters. Taken together with previous findings of inhibited colon, oral and skin carcinogenesis in rats and mice, they suggest that ACA is a candidate chemopreventive agent with a wide spectrum of activity.

The modifying effects of auraptene on N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumorigenesis were investigated in male F344 rats. At 5 weeks of age, all animals, except those with the test chemical alone and control rats, received s.c. injections of NMBA (0.5 mg/kg body weight/injection, three times per week) for 5 weeks. At the end of the study (20 weeks), 75% of the rats treated with NMBA alone had esophageal neoplasms (papillomas). However, the groups who received a dose of 500 ppm auraptene during the initiation phase developed significantly reduced incidence of tumors (39%; P<0.05). Exposure to auraptene (500 ppm) during the post-initiation phase also decreased the frequency of the tumors (29%; P<0.01). The reduction of the incidence of severe dysplasia was obtained when auraptene was administered in the post-initiation phase (P<0.05). Cell proliferation in the esophageal epithelium determined by proliferating cell nuclear antigen (PCNA) was lowered by auraptene (P<0.01). Blood polyamine contents in rats who received NMBA and the test compound were also smaller than those of rats that received the carcinogen (P<0.05). These findings suggest that dietary auraptene is effective in inhibiting the development of esophageal tumors by NMBA when given during the initiation as well as post-initiation phases, and such inhibition is related to suppression of cell proliferation in the esophageal epithelium.

The modifying effects of 1'-acetoxychavicol acetate (ACA) on N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumorigenesis were investigated in male F344 rats. At 5 weeks of age, all test animals, except those given the test chemical alone, and the control rats received s.c. injections of NMBA (0.5 mg/kg body weight/injection, three times per week) for 5 weeks. At the termination of the study (20 weeks), 75% of rats treated with NMBA alone had esophageal neoplasms (papillomas). However, the groups given a dose of 500 ppm ACA during the initiation phase developed a significantly reduced incidence of tumors (29%; P<0.01). Exposure to ACA (500 ppm) during the post-initiation phase also decreased the frequency of the tumors (38%; P<0.05). A reduction of the incidence of preneoplastic lesions (hyperplasia or dysplasia) was obtained when ACA was administered in the initiation phase (P<0.01). Cell proliferation in the esophageal epithelium, determined by assay of proliferating cell nuclear antigen (PCNA), was lowered by ACA (P<0.05). Blood polyamine contents in rats given NMBA and the test compound were also smaller than those of rats given the carcinogen (P<0.05). These findings suggest that dietary ACA is effective in inhibiting the development of esophageal tumors by NMBA when given during the initiation or post-initiation phase, and such inhibition is related to suppression of cell proliferation in the esophageal epithelium.

We investigated the suppressive effects of 16 coumarin-related compounds on both lipopolysaccharide (LPS)- and interferon (IFN)-gamma-induced nitric oxide (NO) generation in a mouse macrophage cell line, RAW 264.7. Notably, coumarins possessing prenyl unit(s) were found to be highly active, a tendency consistent with our previous study. Among the coumarins tested, 1,1-dimethylallylcoumarins showed the highest inhibitory activity. Western blotting analysis revealed that they inhibited NO generation by suppressing inducible NO synthase (iNOS) protein expression. Our ongoing studies suggest that coumarins are prominent natural compounds that attenuate excessive and prolonged NO generation at inflammatory sites.

We previously reported that auraptene (7-geranyloxycoumarin, AUR), widely occurring in citrus fruit, is a structurally novel type of effective cancer-preventive agent, as manifested in several rodent models. However, its bio-availability and metabolism in biological systems have yet to be investigated. In the present study, we examined the chemical stability of AUR at pH 1.57 and 37 degrees C (as a stomach digestion model) and observed its stoichiometric conversion to umbelliferone [7-hydroxycoumarin, UMB; half-life (t1/2) = 15 h; 7-ethoxycoumarin (ETC) was stable for 24 h]. Differentiated Caco-2 cells, a human colorectal adenocarcinoma cell line, were used as a small intestine model. ETC permeated the basolateral (portal vein) side of Caco-2 cells in a time-dependent manner; AUR slightly permeated the cells, but with an intracellular accumulation. Epoxyauraptene and UMB were detected when AUR was treated with the rat liver S-9 mixture. ETC was also converted to UMB, but its t1/2 of two hours was much shorter than that of AUR (> 24 h). This suggests that AUR, bearing a geranyloxyl side chain, is a relatively metabolism-resistant substrate for cytochrome P-450 enzymes and, thus, is stable in the liver compared with ETC. Oral administration of AUR by gavage at 50-200 mg/kg body wt dose dependently induced glutathione S-transferase (GST) activity in mouse livers without affecting cytochrome P-450 activity. Using 10 coumarin-related compounds, we found that only those coumarins having a 7-alkyloxyl group induced GST, but not cytochrome P-450, activity. The present study presumes that AUR accumulates in the epithelial cells of the small intestine and then gradually permeates into the portal vein. Stable localizability of AUR in the colon and liver may be associated with the induction of GST activity, which is important as the action mechanism for suppression of rodent chemical carcinogenesis.

Citrus fruit intake is known to be associated with a reduction of cancer incidence. Free radicals, including superoxide (O2-) and nitric oxide (NO), are involved in some epithelial carcinogenesis processes. In the present study, we screened thirty-one citrus fruits for their suppressive activities toward three lines of free radical generating systems: 1) O2- generation by the xanthine (XA)-xanthine oxidase (XOD) system; 2) O2- generation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in differentiated human promyelocytic HL-60 cells; and 3) NO generation in murine macrophage RAW264.7 cells stimulated with lipopolysaccharide (LPS) and interferon (IFN)-gamma. As a result, the inhibitory activities of peel parts were largely found to be higher than those of the corresponding juice sac parts. In particular, the peel portion of Dancy tangerine (Citrus tangerinia) showed marked anti-oxidative activities in these systems. In addition, nobiletin, a polymethoxyflavonoid isolated from C. nobilis, showed a higher anti-inflammatory activity than indomethacin in a TPA-induced edema formation test in mouse ears. These results indicate that citrus fruits could be notable sources of anti-oxidative, anti-inflammatory, and cancer preventive compounds.

A total of 114 methanol extracts from 42 plant families of edible Malaysian plants were screened for their inhibitory activities toward tumor promoter 12-O-hexadecanoylphorbol-13-acetate (HPA)-induced Epstein-Barr virus (EBV) activation in Raji cells. By testing at a concentration of 200 micrograms/ml, 74% of the 114 extracts inhibited EBV activation by 30% or more. This rate is comparable to those observed in the previous tests on edible Thai (60%) and Indonesian (71%) plants, and, importantly, much higher than that (26%) observed for Japanese edible plants. Approximately half of the Malaysian plants did not taxonomically overlap those from the other three countries, suggesting that Malaysian plants, as well as Thai and Indonesian plants, are an exclusive source of effective chemopreventive agents. Further dilution experiments indicated an extract from the leaves of Piper betle L. (Piperaceae) to be one of the most promising species. The high potential of edible Southeast Asian plants for cancer chemoprevention is collectively discussed.

Zerumbone was isolated from the rhizomes of Zingiber zerumbet Smith as a potent inhibitor of tumor promoter 12-O-tetradecanoylphorbol-13-acetate-induced Epstein-Barr virus activation. The IC50 value of zerumbone (0.14 microM) is noticeably lower than those of the anti-tumor promoters we have hitherto obtained. Interestingly, alpha-humulene lacking the carbonyl group at the 8-position in zerumbone was inactive (IC50 > 100 microM), while 8-hydroxy-alpha-humulune was markedly active (IC50 = 0.95 microM).

Three coumarins were isolated as siginificant inhibitors of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein-Barr virus (EBV) activation in Raji cells from the peel of lemon fruit. They were identified as 8-geranyloxypsolaren (LE-1), 5-geranyloxypsolaren (bergamottin, LE-2), and 5-geranyloxy-7-methoxycoumarin (LE-3), respectively, by spectroscopic analysis. Three isolates had no potential O(2)-scavenging and markedly suppressed TPA-induced superoxide (O(2)(-)) generation in differentiated human promyelocytic HL-60 cells. Furthermore, LE-1 and LE-3 reduced both lypopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-induced nitric oxide (NO) generation in mouse macrophage RAW 264.7 cells. Similarly, they were found to be NO generation inhibitors rather than scavengers by measuring the extracellular L-citrulline levels. The occurrence of these coumarins in a lemon fruit was abundant in the flavedo of the peel based on quantitative analysis using high-performance liquid chromatography (HPLC). The present study suggests that the coumarins in lemon fruit are promising chemopreventive agents by inhibiting radical generation.

Three known coumarins have been isolated from Citrus hystrix DC as inhibitors of both lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-induced nitric oxide (NO) generation in RAW 264.7 cells. The inhibitory activity of bergamottin (IC(50) = 14 microM) was comparable to that of N-(iminoethyl)-L-ornithine (L-NIO) (IC(50) = 7. 9 microM), whereas oxypeucedanin and 5-[(6',7'-dihydroxy-3', 7'-dimethyl-2-octenyl)oxy]psoralen, structurally different from bergamottin only in their side-chain moieties, were notably less active. Using 21 coumarins, we structurally classified various types of coumarins into groups A-C: (A) bearing an isoprenyl (IP) or a geranyl (GR) group, highly active; (B) bearing an IP group cyclized to a coumarin ring, moderately active; (C) bearing an IP group modified with hydroxyl group(s) and/or having other functional groups except for the IP, completely inactive. Cellular uptake studies suggested that coumarins in group C are inactive because of poor permeability to the cell membrane.

In our previous short-term experiment, Citrus auraptene inhibited the development of azoxymethane (AOM)-induced aberrant crypt foci, which are precursor lesions for colorectal carcinoma. In the present study, the possible inhibitory effect of dietary administration of auraptene was investigated using an animal colon carcinogenesis model with a colon carcinogen AOM. Male F344 rats were given s.c. injections of AOM (15 mg/kg body weight) once a week for 3 weeks to induce colon neoplasms. They also received diets containing 100 or 500 ppm auraptene for 4 weeks in groups of "initiation" feeding, starting 1 week before the first dosing of AOM. The diets containing auraptene were also given to rats for 38 weeks in groups of "postinitiation" feeding. At the termination of the study (38 weeks), dietary administration of auraptene caused dose-dependent inhibition in AOM-induced large bowel carcinogenesis. Auraptene feeding during the initiation phase reduced the incidence of colon adenocarcinoma by 49% at 100 ppm (P = 0.099) and 65% at 500 ppm (P = 0.0075). Auraptene administration during the postinitiation phase inhibited the incidence of colon adenocarcinoma by 58% at 100 ppm (P = 0.021) and 65% at 500 ppm (P = 0.0075). Also, the multiplicity of colon carcinoma was significantly reduced by initiation feeding at a dose level of 500 ppm (P < 0.01) and postinitiation feeding at a level of 100 and 500 ppm (P < 0.05 and P < 0.01, respectively). Feeding of auraptene suppressed the expression of cell proliferation biomarkers (ornithine decarboxylase activity and polyamine content) in the colonic mucosa and reduced the production of aldehydic lipid peroxidation [malondialdehyde and 4-hydroxy-2(E)-nonenal]. In addition, auraptene increased the activities of Phase II drug-metabolizing enzymes (glutathione S-transferase and quinone reductase) in the liver and colon. These findings suggest that the inhibitory effects of auraptene on AOM-induced colon tumorigenesis at the initiation level might be associated, in part, with increased activity of Phase II enzymes, and those at the postinitiation stage might be related to suppression of cell proliferation and lipid peroxidation in the colonic mucosa.

Three known thiocarbamate (TC)- and isothiocyanate (ITC)-related compounds have been isolated from the leaves of Moringa oleifera, a traditional herb in southeast Asia, as inhibitors of tumor promoter teleocidin B-4-induced Epstein-Barr virus (EBV) activation in Raji cells. Interestingly, only niaziminin among 10 TCs including 8 synthetic ones showed considerable inhibition against EBV activation. The structure-activity relationships indicated that the presence of an acetoxy group at the 4'-position of niaziminin is important and indispensable for inhibition. On the other hand, among the ITC-related compounds, naturally occurring 4-[(4'-O-acetyl-alpha-L-rhamnosyloxy)benzyl]ITC and commercially available allyl- and benzyl-ITC significantly inhibited activation, suggesting that the isothiocyano group is a critical structural factor for activity.

A total of 135 methanol extracts from 48 plant families (107 species) of edible Indonesian plants were screened for their in vitro anti-tumor-promoting activities using the tumor promoter 12-O-hexadecanoylphorbol-13-acetate (HPA)induced Epstein-Barr virus (EBV) activation test in Raji cells. Examined at a concentration of 200 mg/ml, 71% of the extracts inhibited EBV activation by 30% or more. The rate is comparable to the rate observed in our previous tests of edible Thai (60%) plants and much higher than the rate (26%) observed with Japanese plants. In particular, the plant families Zingiberaceae (13/13 active) and Umbelliferae (7/8 active) are suggested to be desirable sources of effective cancer-preventive agents because of the strikingly high frequency of inhibitory activity. Thus, a high potential of edible Southeast Asian plants for cancer chemoprevention is indicated.

In our studies to find natural compounds with chemopreventive efficacy in foods, using azoxymethane (AOM)-induced colonic aberrant crypt foci and colonic mucosal cell proliferation as biomarkers, a xanthine oxidase inhibitor, 1'-acetoxychavicol acetate (ACA), present in the edible plant Languas galanga from Thailand was found to be effective. This study was conducted to test the ability of ACA to inhibit AOM-induced colon tumorigenesis when it was fed to rats during the initiation or post-initiation phase. Male F344 rats were given three weekly s.c. injections of AOM (15 mg/kg body weight) to induce colonic neoplasms. They were fed diet containing 100 or 500 ppm ACA for 4 weeks, starting one week before the first dosing of AOM (the initiation feeding). The other groups were fed the ACA diet for 34 weeks, starting one week after the last AOM injection (the post-initiation feeding). At the termination of the study (week 38), AOM had induced 71% incidence of colonic adenocarcinoma (12/17 rats). The initiation feeding with ACA caused significant reduction in the incidence of colon carcinoma (54% inhibition by 100 ppm ACA feeding and 77% inhibition by 500 ppm ACA feeding, P = 0.03 and P = 0.001, respectively). The post-initiation feeding with ACA also suppressed the incidence of colonic carcinoma (45% inhibition by 100 ppm ACA feeding and 93% inhibition by 500 ppm ACA feeding, P = 0.06 and P = 0.00003, respectively). Such inhibition was dose-dependent and was associated with suppression of proliferation biomarkers, such as ornithine decarboxylase activity in the colonic mucosa, and blood and colonic mucosal polyamine contents. ACA also elevated the activities of phase II enzymes, glutathione S-transferase (GST) and quinone reductase (QR), in the liver and colon. These results indicate that ACA could inhibit the development of AOM-induced colon tumorigenesis through its suppression of cell proliferation in the colonic mucosa and its induction of GST and QR. The results confirm our previous finding that ACA feeding effectively suppressed the development of colonic aberrant crypt foci. These findings suggest possible chemopreventive ability of ACA against colon tumorigenesis.

Coumarin-related compounds, auraptene and umbelliferone, have been isolated from the cold-pressed oil of natsumikan (Citrus natsudaidai HAYATA), and tested as inhibitors of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein-Barr virus activation in Raji cells. The 50% inhibitory concentration (IC50) of auraptene (18 microM) was almost equal to that of genistein. Umbelliferone, which lacks a geranyloxyl group present in auraptene, was less active (IC50 = 450 microM). In a two-stage carcinogenesis experiment with 7,12-dimethylbenz[a] anthracene (topical application at 0.19 mumol) and TPA (topical application at 1.6 nmol) in ICR mouse skin, topical application of auraptene (at 160 nmol) significantly reduced tumor incidence and the numbers of tumors per mouse by 27% (P < 0.01) and 23% (P < 0.05), respectively. Auraptene at a concentration of 50 microM markedly suppressed superoxide (O2-) generation induced by 100 microM TPA in differentiated human promyelocytic HL-60 cells. Having no O2(-)-scavenging potential, auraptene may inhibit the multicomponent NADPH oxidase system. Inhibition of intracellular hydroperoxide formation in differentiated HL-60 cells by auraptene was also confirmed by flow-cytometric analysis using 2',7'-dichlorofluorescein diacetate as a fluorescence probe. Quantitative analyses using high-performance liquid chromatography showed the occurrence of auraptene not only in both the peels and sarcocarps of natsumikan, but also in those of hassaku orange (C. hassaku) and grapefruit (C. paradisi), and even in their bottled fresh juice form. These results indicate that auraptene is a chemopreventer of skin tumorigenesis, and implies that suppression of leukocyte activation might be the mechanism through which it inhibits tumor promotion.

The aim of this study is to evaluate the accuracy of three-step diagnosis in discriminating subtypes of acute ischemic stroke. A total of 120 consecutive patients with first-ever ischemic stroke, admitted to one general hospital, were prospectively studied. In the first step (within 24 hours of clinical onset), the first diagnosis was made according to clinical symptoms and signs, and patients were subdivided into four groups according to the classification of Oxfordshire Community Stroke Project: lacunar infarcts (LACI), total anterior circulation infarcts (TACI), partial anterior circulation infarcts (PACI), and posterior circulation infarcts (POCI). In the second step (24 hours to 72 hours from the onset), neuroimaging diagnosis was performed by CT and/or MRI. Four lesion sites were classified: 1) small subcortical infarction < or = 1.5 cm in diameter in the perforating artery territory (SSI), 2) supratentorial cortical or striatocapsular infarction (CI), 3) low-flow infarction (LFI) which includes centrum semiovale infarct and internal junctional infarct, and 4) posterior circulation infarction other than SSI (PI). In the third step, etiological diagnosis was made by examination including trans-thoracic echocardiography and MRA (3-D, PC). In accordance with the TOAST Study, the presumed stroke mechanism was categorized as either small-vessel occlusion (lacune), cardioembolism (CE), large-artery atherosclerosis (LAA), or others. The majority of patients with TACI, PACI or POCI showed the corresponding lesions on CT or MRI, while only 69% of LACI patients demonstrated SSI. Seventy-five percent of patients with TACI were categorized as CE in the third diagnosis, while the etiology of the patients with PACI was either CE or LAA in equal numbers. Only 60% of LACI patients were classified as lacune and 21% of them as LAA. Patients with LACI but classified as LAA usually had atypical clinical symptoms (e.g. monoparesis) and lesions other than SSI. The positive predictive value (PPV) of lacune in the combination of LACI and SSI was 0.75. Eighty-two percent of patients with CE had atrial fibrillation (af), which was the most frequent cardioembolic source. When patients with TACI or PACI had af, the PPV of CE was 0.93, but when they did not, the PPV of LAA was only 0.68. The etiology of POCI was variable. In conclusion, the agreement of the three-step diagnosis is considerable, but more rigorous clinical examination is needed for some clinical groups (POCI and LACI) and the etiological diagnosis of LAA.

The anti-tumor-promoting activity of 1'-acetoxychavicol acetate (ACA) was examined in a two-stage carcinogenesis experiment in ICR mouse skin using 7,12-dimethylbenz[a]anthracene (0.19 mumol) and 12-O-tetradecanoylphorbol-13-acetate (TPA; 1.6 nmol). Topical application of ACA (160 nmol) markedly reduced the average number of tumors per mouse and the ratio of tumor-bearing mice: inhibition ratios 90% (p < 0.001) and 42% (p < 0.005), respectively. ACA even at a dose equimolar to TPA (1.6 nmol) significantly reduced the average number of tumors per mouse: inhibitory ratio 44% (p < 0.05). ACA potently inhibited TPA-induced superoxide (O2-) generation in differentiated HL-60 cells (IC50 = 4.3 microM) and suppressed the lipid hydroperoxide formation by 42% (p < 0.001) in the ethyl linoleate autoxidation test.

Six chlorophyll-related compounds isolated from leaves of Neptunia oleracea (Leguminosae) inhibited the activation of tumor promoter-induced Epstein-Barr virus (EBV). Photo-irradiation of pheophorbide a, the major active constituent, did not enhance this inhibitory activity, and thus ruled out any photosensitizing effect playing the major role.

The effect of a xanthine oxidase inhibitor, 1'-acetoxychavicol acetate (ACA), on 4-nitroquinoline 1-oxide (4-NQO)-induced oral carcinogenesis was investigated in male F344 rats. All rats except those in the ACA-alone and untreated groups were given 4-NQO (20 ppm) In the drinking water for 8 weeks to induce oral cancer. Starting 1 week before the 4-NQO exposure, animals were fed diet containing 100 ppm or 500 ppm ACA for 10 weeks, followed by the basal diet without ACA for 22 weeks. Other groups were fed the diet containing ACA at 100 ppm or 500 ppm for 22 weeks, starting 1 week after the cessation of 4-NQO exposure. The remaining groups consisted of rats given 500 ppm ACA alone or untreated rats. At the termination of the experiment (32 weeks), the incidences of tongue neoplasms and preneoplastic lesions, polyamine levels in the tongue tissue, and cell proliferation activity estimated in terms of 5-bromodeoxyuridine (BrdU)-labeling index and by morphometric analysis of silver-stained nucleolar organizer regions' protein (AgNORs) were compared among the groups. Feeding of ACA at the two doses during initiation or postinitiation significantly decreased the development of tongue carcinoma (93-100% reduction, P < 0.001) and preneoplasia (43-50% reduction for hyperplasia and 34-48% reduction for dysplasia, P < 0.05). There were no such lesions in rats fed ACA alone or those in the untreated control group. The number of AgNORs per cell nucleus was significantly decreased by feeding of ACA at a high dose (500 ppm) (29% inhibition, P < 0.05). The BrdU-labeling index was also reduced by dietary administration of ACA (23-32% inhibition, P < 0.01). In addition, ACA feeding reduced tongue polyamine levels (35-40% inhibition, P < 0.05). These results indicate that ACA inhibited rat oral carcinogenesis, and such inhibition might be related to suppression of cell proliferation in the oral mucosa by the xanthine oxidase inhibitor.

Cancer chemoprevention is currently regarded as a promising avenue for cancer control. In particular, the inhibition of tumor promotion (anti-tumor promotion) in multistage carcinogenesis is expected to be an efficient strategy, because tumor promotion is experimentally accomplished through the long-term, repetitive exposures of rodents to a tumor promoter, and premalignant lesions caused by a tumor promoter regress, at least in their earlier stages. In this review, we first describe the background of cancer chemoprevention studies as well as recent results of clinical trials. Subsequently, some hypothetical biological and cellular pathways in tumor promotion are explored. In addition, the anti-tumor promoting properties of vegetables, fruits, and edible marine algae, together with their active constituents and action mechanisms thus far known, are also described. Anti-tumor promotion with food phytochemicals may be characterized as an efficient and reliable strategy for cancer chemoprevention.

Inhibition of tumor promoter-induced Epstein-Barr virus (EBV) activation was screened using tissue culture and thallus extracts of lichens. Usnea longissima ACH. thallus and Cetraria ornata MULL. ARG. tissue culture showed strong inhibitory activity. We identified (+)-usnic acid (1), barbatic acid (2), diffractaic acid (3), 4-O-demethylbarbatic acid (4), and evernic acid (5) as inhibitors of EBV activation from the U. longissima thallus. Of these compounds, (+)-usnic acid exhibited the highest inhibitory activity (IC50 = 1.0 microM).

A case of astrocytoma whose first clinical presentation was diagnostic dyspraxia was reported. A 38-year-old right-handed male experienced funny motion of his left hand triggered by voluntary movement of his right hand. One day, he tried to insert a coin into the vending machine with his right hand, then the left hand was against the other. One month after that event, he experienced headache and vertigo. On admission, there were no abnormal findings on neurological examination. On neuropsychological examination, he was cooperative, well orientated and attentive, and there were no callosal disconnection symptoms. Frontal lobe function tests were slightly impaired. T1-weighted MRI demonstrated irregular mixed signal intensity mass lesion extending from the genu to the body of the corpus callosum and the cingulate gyrus. This lesion was slightly enhanced with Gd-DTPA. Biopsy was performed and histological diagnosis was fibrillary astrocytoma. After irradiation and chemotherapy, he was discharged from the hospital without evident neurological deficit. About 20 cases of diagnostic dyspraxia have been reported and almost all of them were caused by cerebro-vascular disease. This is the first case of brain tumor who presented diagnostic dyspraxia.

From a viewpoint of cancer chemoprevention, possible anti-tumour promoting properties of daily food items and some of their active constituents have been investigated by a convenient in-vitro assay, the Epstein-Barr virus (EBV) activation test. In a screening test for the inhibitory activity toward EBV activation by 40 methanol extracts from Thai edible plants used for flavours, condiments or folk medicines, more than three-quarters of the total were found to possess inhibitory activities. Significantly, the ratio of activity-exhibiting plants was about three times higher than that of Japanese common vegetables and fruits previously studied. The two plant families of Zingiberaceae and Rutaceae, in particular, were suggested to be promising sources for highly effective anti-tumour promoters. Hitherto, geranial (Cymbopogon citratus, Gramineae), cardamonin (Boesenbergia pandurata, Zingiberaceae). curcumin (Zingiber cassumunar, Zingiberaceae) and 1-acetoxychavicol acetate (Languas galanga, Zingiberaceae) have been idenflfied as the acfive constituents of strongly active plants in the tumour promoter-induced EBV activation test. They showed more potent inhibitory activities than the representative anti-tumour promoters such as β-carotene or quercetin. The high potential of the traditional food items of Thailand in the search for potent anti-tumour promoters is described in this article.

Endemicity of Burkitt's lymphoma (BL) coincides with profusion of a plant Euphorbia tirucalli in tropical Africa. E. tirucalli contains 4-deoxyphorbol ester that enhances Epstein-Barr virus (EBV) infection of B lymphocytes. In this study, we found that 4-deoxyphorbol ester reduced EBV-specific cytotoxic T-cell function. Furthermore, the B lymphocytes dually exposed to EBV and 4-deoxyphorbol ester were resistant to EBV-specific T cell cytotoxicity, through down-regulation of latent membrane protein 1 (LMP1), the major target to EBV-specific cytotoxic T-cells. These immunologic findings strengthen the notion that E. tirucalli may be an important environmental risk factor for the genesis of African BL.

Two new teleocidin-related metabolites, (-)-7-geranylindolactam-V [2] and blastmycetin F [3], were isolated from fermentation broths of the actinomycete Streptoverticillium blastmyceticum NA34-17, and their structures were determined by spectroscopic methods. Compound 2 bound strongly to phorbol ester receptors in a mouse epidermal particulate fraction, suggesting that it is a potent in vivo tumor promoter comparable to teleocidins A-1 [4] and B-4 [5].

The bitter and related constituents have been isolated fromVernonia amygdalina (Compositae), a plant ingested by wild chimpanzees possibly suffering from parasite-related diseases in the Mahale Mountains National Park, Tanzania. Isolated from the plant were four known sesquiterpene lactones, seven new steroid glucosides, and two aglycones of the glucosides. The sesquiterpene lactones showed significant in vitro antischistosomal, plasmodicidal, and leishmanicidal activities. Antischistosomal activity was also found for the major steroid glucoside, vernonioside B1. A trend in the glucosides to show significant antischistosomal, plasmodicidal, and amebicidal activities when the sugar moiety was removed, was observed. Vernodalin, judged as the most significant constituent for antiparasitic activities in vitro, was tested for in vivo antischistosomal effect. It was, however, highly toxic to the cercaria-infected mouse. Chimpanzees have been only rarely observed to ingest anything but the pith of the young stem. The occurrence of vernonioside B1 and its aglycone vernoniol B1, the major constituents among the steroid-related constituents, were detected at significant levels in the pith. However, vernodalin was abundant only in the leaves and bark. Thus, chimpanzees at Mahale were hypothesized to control parasite-related diseases by ingesting the young pith of this tree containing steroid-related constituents.

A new water-soluble porphyrin derivative, 2,4-bis(1-decyloxyethyl)-deuteroporphyrinyl-6,7-bisaspart ic acid (C10-DP), and its metal complexes (Ga, I(n), Zn, Mn, Cu, Ni and Fe) were examined for their physicochemical properties (absorption, fluorescence, triplet lifetime and partition coefficient) and photocytotoxicity on HeLa cells. The five derivatives with longer (> 1 ms) triplet lifetimes (free base, Zn, Ga, I(n) and Sn complexes) exhibited remarkable photocytotoxicity, and the other derivatives (Mn, Cu, Ni and Fe), which had or were deduced to have fairly short (< 0.01 ms) triplet lifetimes, manifested no photocytotoxicity, indicating that the triplet lifetime of these derivatives played a significant role in their photocytotoxicity. Cellular fluorescence due to C10-DP and its gallium complex was observed mainly on the plasma membrane at the concentrations showing significant photocytotoxicity with low (< 32.6%) cytotoxicity in the dark (2-10 microM).