Iron is essential for life and has numerous biochemical roles. Phytic acid (PA) has been recognized as a natural antioxidant by its chelating properties and reducing the catalytic activities of many divalent transition metals. We investigated the effect of PA on the formation of aberrant crypt foci (ACF) induced by azoxymethane (AOM) in dietary iron-deficient F344 rats. After acclimation for one week, six-week old F344 male rats were fed with the AIN-93G purified diet (normal diet) or an iron-deficient diet (3 ppm Fe, only 10% vs control diet) for 8 weeks. PA (0.5% or 2% PA in water) was given for drink throughout the experimental period. Animals were treated subcutaneously with AOM (15 ㎎/㎏) twice (1 st and 2 nd week of the experiment) to induce colonic ACF. After sacrifice, the colonic mucosa were examined for the total numbers of aberrant crypt (AC) and ACF after staining with methylene blue. The blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. Iron-deficient diet induced an anemic status of rats as indicated by significantly low values in RBC count, hemoglobin, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin, compared with the AOMtreated control (P＜0.01). However, treatments of PA increased these values. Treatment with 2% PA significantly increased the numbers of both ACF/colon and AC/colon in iron deficient rats, compared with the respective control (P＜0.05). The number of large ACF (≥4 AC/ACF), which had been suggested to possess a greater tumorogenic potential than small ACF (≤3 AC/ACF), was significantly enhanced by treatment with 2% PA (P＜0.05). These results suggest that PA may promote colon carcinogenesis in irondeficient status in rats.

The present study was conducted to elucidate the susceptibility of embryos and fetuses at different gestational stages to the maternal stress in mice. Groups of pregnant ICR mice were subjected to daily 12-h restraint stress, taped in the supine position on a plastic board, on gestational days (GD) 1-4, 5-8, 9-12 and 13-16, respectively. Caesarean sections were performed on gestational day 18, and the fetuses were weighed and examined for morphological defects. During the daily restraint for 4 days, the maternal body weights markedly decreased. Although the body weights recovered gradually after termination of the stress, the recovery was not full until the final stage of pregnancy. Interestingly, restraint stress caused growth retardation of the fetuses, leading to a significant decrease in their body weights, and increased early and late resorptions of embryos and fetuses according to the stress periods. Although the preceding (GD1-4) and concurrent (GD5-8) stresses did not affect embryonic implantation, restraint stress on GD9-12 caused cleft palate. Whereas vertebral abnormalities, mainly bipartite ossification, were observed only in animals stressed on GD5-8, abnormalities of sternebrae, exhibiting asymmetric or bipartite ossification, were enhanced by the stress at all of the gestational stages. On the other hand, the incidence of other malformations including renal malposition and costal abnormalities was not increased by stress at any of the 4 stages. Taken together, the results suggest that intensive restraint stress influences the maternal body weight resulting in growth retardation and increased mortality of embryos and fetuses, in addition to gestational stage-specific ventricular dilatation, cleft palate and sternal abnormalities.

Phytic acid(PA) (Inositol hexaphosphate, ) is a naturally occurring polyphosphorylated carbohydrate that is present in substantial amounts in almost all plants and mammalian cells. Recently PA has received much attention for its role in anticancer activity. In the present study, the preventive effects of PA on colon carcinogenesis were investigated. Six-week old Fisher 344 male rats were fed a AIN-93G purified diet and PA(0.5% or 2% PA in water) for 8 weeks. The animals received two ( week) injections of azoxymethane(AOM, 15 mg/kg b.w.) to induce colonic aberrant crypt foci(ACF). After sacrifice, the total numbers of aberrant crypts(AC) and ACF in colonic mucosa were examined after staining with methylene blue. Blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. AOM induced the total numbers of ACF/colon and AC/colon. PA at the doses of 0.5 and 2% decreased the numbers of ACF and AC/colon in a dose-dependent manner. The numbers of ACF/colon and AC/colon by PA at the dose of 0.5% were , respectively. PA at the dose of 2% significantly decreased the ACF and AC numbers to , respectively(p AC/ACF) from ACF/colon to ACF/colon(p

Conjugated linoleic acid (CLA) has been recently reported to have an anti-obesity effect in animals and humans. The objective of this study was to investigate effects of diglyceride (DG)-CLA on proliferation and differentiation of 3T3-L1 preadipocytes. Cell proliferation was determined using WST-8 analysis and cell differentiation was determined by glycerol-3-phosphate dehydrogenase (GPDH) activity. Lipid accumulation in differentiating 3T3-L1 cells was determined by Oil red 0 staining. There were four experimental groups including vehicle control (DMSO), CLA, triglyceride (TG)-CLA, and DG-CLA. Treatments of CLA, TG-CLA, and DG-CLA at the concentrations of 10 similar to 1000 pg/ml reduced proliferation of preconfluent 3T3-L1 cells in a dose-dependent manner. Among them CLA was the most effective in the proliferation inhibition of preconfluent 3T3-L1 cells with increasing concentrations. Treatments of CLA and DG-CLA at the concentration of 100 tg/ml significantly inhibited differentiation of postconfluent 3T3-L1 cells as measured by GPDH activity (p < 0.05). In addition, treatments of CLA, TG-CLA, and DG-CLA effectively inhibited lipid accumulation during differentiation of 3T3-L1 cells. DG-CLA had the most inhibitory effect on the differentiation and lipid accumulation. These results suggest that the compounds including CLA have a respectable anti-obesity effect and that consumption of DG-CLA as a dietary oil may give a benefit for controlling overweight in humans.

Zinc is an endogenous transition metal that can be synaptically released during neuronal activity. However, zinc may contribute to the neuropathology associated with a variety of conditions. Camosine expressed in glial cells can modulate the effects of zinc on neuronal excitability as a zinc chelator. We hypothesize that camosine may protect against neurotoxicity of zinc in cortical neuronal cells. The cortical neuronal cells from newborn rats were prepared and exposed to zinc chloride and/or camosine at various concentrations. Zinc at the doses of 0 to 500 mu M decreased neuronal cell viability in a dosedependent manner. Additionally, at the concentrations of 100 and 200 mu M, it significantly decreased cell viability in an exposed time-dependent manner (p < 0.05). Treatment with carnosine at the concentrations of 20 and 200 mu M significantly increased neuronal cell proliferation by approximately 14% and 20%, respectively, compared to the control (p < 0.05). At the concentrations of 100 and 200 mu M zinc, 20 mu M carnosine significantly increased the viability of neuronal cells by 18.3% and 12.1%, and 200 mu M camosine also increased it by 33.5% and 28.6%, respectively, compared to the normal control group (p < 0.01). These results suggest that carnosine at a physiologically relevant level may protect against zinc-mediated toxicity in neuronal cells as an endogenous neuroprotective agent.

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Although phosphates have never been classified as antimicrobial agents, a number of investigators have reported that phosphates have antimicrobial activities. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activities of sodium phytate(SPT), sodium pyrophosphate (SPP), sodium tripolyphosphate (STPP) on Escherichia coli O157:H7 on tryptic soy broth and in beef, pork and chicken. In tryptic soy broth, SPT, SPP and STPP at the concentrations of 0.05, 0.1, and 0.5% effectively inhibited the growth of Escherichia coli O157:H7 in a concentration-dependent manner. The bactericidal activity of SPT was the stronger than that of SPP or STPP at the same concentrations. In addition, the antibacterial effects of SPT, SPP and STPP at the concentrations of 0.05, 0.1, 0.3, and 0.5% on Escherichia coli O157:H7 were also investigated in raw or cooked meats including beef, pork and chicken. SPT, SPP and STPP significantly inhibited the bacterial growth in a dose-dependant manner (p

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we inves- tigated antibacterial activity of sodium phytate (SPT) against Salmonella typhimurium in tryptic soy broth with differ- ent pHs and in chicken, pork and beef. In tryptic soy broth, SPT at the concentrations of 0.1, 0.5, and 1.0% effectively inhibited the growth of Salmonella typhymurium in a concentration-dependent manner. At pH 5.5-7.0 similar to meat pHs, 1% SPT almost completely inhibited the bacterial growth. The inhibitory effect of SPT was stronger at pH 7.0 than pH 5.5. In chicken, pork, and beef, SPT at the concentrations of 0.1, 0.5, and 1% significantly inhibited the growth of Salmonella typhimurium in a dose-dependant manner (p<0.01). The addition of 1% SPT in the meats sig- nificantly increased the meat pHs. These results indicate that SPT is very effective for inhibition of bacterial growth as a muscle food additive for increasing food safety and functions.

Green tea, Crataegus oxycantha fruit, gingko leaves and tangleweed were known to increase blood circulation and improve brain function. The mixture containing green tea (50 g), Crataegus oxycantha fruit (50 g), gingko leaves (20 g), and tangleweed (20 g) was water-extracted and freeze-dried to powder. The pharmacological effect of the extract of herbal drugs on acetylcholinesterase (AChE) in an in vitro enzyme system and in rats was investigated. The extract of herbal drugs at the doses of 10, 25, 50 and 100 ㎍/㎖ decreased activity of AChE by 8.8, 22.1, 43.1 and 63.0%, respectively. The treatment of the extract of herbal drugs at the dose of 0.1 g/㎏ b.w. to rats for 5 and 10 consecutive days reduced AChE activity in the brain by 12.8 and 26.9 %, respectively, corresponding to increases by 26.4 and 59.7% in the concentration of acetylcholine (ACh) in the brain of rats, compared with the control rats. The levels of ATP in the brain also increased in treatment group in a time-dependent manner. The liver toxicity was not shown as determined by serum biochemistry. These results suggest that a composition of these herbal drugs may improve brain function by increasing the levels of acetylcholine and ATP.