Comparative study of lifestyles of residents in high and low risk areas for gastric cancer in Jiangsu Province, China; with special reference to allium vegetables.
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There is a low risk area for gastric cancer in Jiangsu Province, China, where people frequently consume raw allium vegetables. As a first step epidemiological study to clarify the factors involved in the low incidence of gastric cancer, we conducted a comparative study of the ecological factors in a high risk area (HRA), Yangzhong, and a low risk area (LRA), Pizhou, using a questionnaire. Subjects were selected from the general population according to age and sex, and comprised 414 residents of the HRA and 425 residents of the LRA. Ecological factors were compared for the two areas by Cochran-Mantel-Haenszel method, age-adjusted. Smoking and drinking habits were found to be more common in the LRA. On the other hand, allium vegetables were consumed in the LRA much more frequently, with high consumption of raw vegetables fruit, tomatoes, kidney beans and soybean products. People who consumed garlic en masse 3 times or more per week were 82% of men and 75% of women in the LRA, and 1% of men and women in the HRA. The results of the survey suggest that frequent consumption of allium vegetables, in addition to other anticancer foods, may be a factor in low mortality for gastric cancer. (+info)
Import of lyso-phosphatidylcholine into chloroplasts likely at the origin of eukaryotic plastidial lipids.
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Plastids rely on the import of extraplastidial precursor for the synthesis of their own lipids. This key phenomenon in the formation of plastidial phosphatidylcholine (PC) and of the most abundant lipids on earth, namely galactolipids, is poorly understood. Various suggestions have been made on the nature of the precursor molecule(s) transferred to plastids, but despite general agreement that PC or a close metabolite plays a central role, there is no clear-cut answer to this question because of a lack of conclusive experimental data. We therefore designed experiments to discriminate between a transfer of PC, 1-acylglycero phosphorylcholine (lyso-PC), or glycerophosphorylcholine. After pulse-chase experiments with glycerol and acetate, plastids of leek (Allium porrum L.) seedlings were purified. The labels of the glycerol moiety and the sn-1- and sn-2-bound fatty acids of plastidial lipids were determined and compared with those associated with the extraplastidial PC. After import, plastid lipids contained the glycerol moiety and the fatty acids esterified to the sn-1 position originating from the extraplastidial PC; no import of sn-2-bound fatty acid was detected. These results rule out a transfer of PC or glycerophosphorylcholine, and are totally explained by an import of lyso-PC molecules used subsequently as precursor for the synthesis of eukaryotic plastid lipids. (+info)
Modulation of human glutathione S-transferases by botanically defined vegetable diets.
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Glutathione S-transferases (GSTs) conjugate activated xenobiotics with glutathione; thus, GST induction may improve detoxification and excretion of potentially harmful compounds. Using a randomized cross-over design, we tested the hypothesis that, in humans, serum GST-alpha concentration (GST-alpha) and GST activity increase with vegetable consumption and that this effect is GSTM1 genotype dependent. Twenty-one men (10 GSTM1-null and 11 GSTM1+) and 22 women (15 GSTM1-null and 7 GSTM1+), nonsmokers, 20-40 years of age and not on medications, ate four 6-day controlled diets: basal (vegetable-free), and basal supplemented with three botanically defined groups of vegetables (i.e., brassica, allium, and apiaceous). Fasting blood samples, collected on the last 2 days of each feeding period, were analyzed for GST-alpha, serum GST activity [against 1-chloro-2,4-dinitrobenzene (CDNB) and 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl)] and peripheral-lymphocyte GST-mu activity (against trans-stilbene oxide). The brassica, but not allium or apiaceous, vegetable diets (relative to the basal diet) increased GST-alpha by 26% (P = 0.005) and GST (NBD-Cl) activity by 7% (P = 0.02) in the GSTM1-null individuals, particularly the women. Apiaceous vegetable supplementation decreased GST-alpha in the GSTM1+ men (P = 0.03). Among the GSTM1+ women, both brassica and the allium diets increased GST-mu activity by 18% (P = 0.02) and 26% (P = 0.001), respectively. The vegetable diets had no effect on GST (CDNB) activity, irrespective of GSTM1 genotype or sex. These results demonstrate that GSTM1 genotype has a significant effect on GST responses to diet and that brassica vegetables are most effective at inducing GST-alpha, whereas both brassica and allium vegetables induce GST-mu. GST responses were more pronounced in women than men, but it is not clear from this study whether this is a dose-per-body-weight or a sex-specific effect. (+info)
How to distinguish garlic from the other Allium vegetables.
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The establishment of international monographs for herbs is in progress. Here, we propose both a marker compound and a method for its analysis for the identification of garlic bulbs and their products. The constituents in 26 kinds of fresh edible parts of Allium vegetables and three types of garlic preparations were analyzed. Sulfur compounds are the most characteristic constituents in garlic, but manufacturing processes of garlic products dramatically affect these constituents. Thus, no sulfur compound could be specified as a universal marker of identification applicable for any type of garlic. On the other hand, garlic contains other characteristic compounds, namely, saponins. After analyzing Allium vegetables and garlic preparations, we concluded that sapogenins, especially beta-chlorogenin, may be a viable candidate for identifying and distinguishing garlic from other Allium vegetables. (+info)
Antiproliferative effects of allium derivatives from garlic.
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There is increasing evidence that allium derivatives from garlic have significant antiproliferative actions on human cancers. Both hormone-responsive and hormone-unresponsive cells lines respond to these derivatives. The effects shown by allium derivatives include induction of apoptosis, regulation of cell cycle progression and modification of pathways of signal transduction. Allium derivatives appear to regulate nuclear factors involved in immune function and inflammation, as well as in cellular proliferation. Our own studies indicate that allium derivatives inhibit proliferation of the human prostate cancer cell line (LNCaP) and the human breast cancer cell line (MCF-7). Further research is required to clarify the mechanisms of inhibition of cellular proliferation by allium derivatives and to explore their potential application to cancer prevention and control. (+info)
Antibacterial activity of S-methyl methanethiosulfinate and S-methyl 2-propene-1-thiosulfinate from Chinese chive toward Escherichia coli O157:H7.
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S-Methyl methanethiosufinate (1) and S-methyl 2-propene-1-thiosulfinate (2) were easily seperated from Chinese chive (Allium tuberosum L.) using simple column chromatography. Both compounds showed significant antibacterial activities against E. coli O-157:H7 including spoilage microorganism in food. Structural assignment was based on Mass and NMR-spectroscopic methods. (+info)
Quantification of stomatal uptake of ionic solutes using a new model system.
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Evidence for stomatal uptake of solutes by leaves without the application of surfactants or pressure has recently been provided (Eichert et al., 1998). In the present study, experimental conditions were refined in that the water potential was held at <0 on the physiologically inner side of the epidermal strips (ES) by use of a ceramic plate or the proper mesophyll of the plant. The penetrated substances were immobilized on the inner side by ion exchange membranes. The influence of humidity, light, stomatal density, and re-wetting on the uptake of anions (fluorescein) and cations (Fe(3+)) was investigated, using leaves of Allium porrum, Commelina communis and Sedum telephium. Uptake increased with humidity, stomatal aperture and stomatal density. It was restricted to stomatal areas, and was especially high below the rims of drying droplets. Again, penetration of stomatal pores was observed. Uptake was strongly correlated with the number of penetrated stomata, although usually less than 10% of the stomata contributed to uptake. The number of stomata that had been penetrated was highly variable, increasing extremely significantly with the number of repeated drying/ wetting cycles. These results indicate that stomatal uptake can be a major pathway for the foliar uptake of ionic solutes. It is a dynamic process, depending on environmental conditions and history of the residues on the leaf, aspects that had been neglected in previous concepts. (+info)
Frequencies of plasmodesmata in Allium cepa L. roots: implications for solute transport pathways.
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Plasmodesmatal frequencies (PFs) were analysed in Allium cepa L. roots with a mature exodermis (100 mm from the tip). For all interfaces within the root, the numbers of plasmodesmata (PD) microm(-2) wall surface (Fw) were calculated from measurements of 60 walls on ultrathin sections. For tissues ranging from the epidermis up to the stelar parenchyma, the frequencies were also expressed as total PD numbers mm(-1) root length (Fn), which is most instructive for considering the radial transport of ions and photosynthates (because the tissues were arranged in concentric cylinders). The Fn values were constantly high at the interfaces of exodermis-central cortex, central cortex-endodermis and endodermis-pericycle (4.05x10(5), 5.13x10(5), and 5.64x10(5), respectively). If the plasmodesmata are functional, a considerable symplastic transport pathway exists between the exodermis and pericycle. Two interfaces had especially low PFs: epidermis-exodermis (Fn=8.96x10(4)) and pericycle-stelar parenchyma (Fn=6.44x10(4)). This suggests that there is significant membrane transport across the interface of epidermis-exodermis (through short cells) and direct transfer of ions from pericycle to protoxylem vessels. In the phloem, the highest PF was detected at the metaphloem sieve element-companion cell interface (Fw=0.42), and all other interfaces had much lower PFs (around 0.10). In the pericycle, the radial walls had a high PF (Fw=0.75), a feature that could permit lateral circulation of solutes, thus facilitating ion (inward) and photosynthate (outward) delivery. (+info)