Zinc oxide nanoparticles (nZnO) are used in a various range, including ceramic manufacture, photocatalysis, UV filters, and the food industry. However, little is known about the effects of micro- and nano-particles during mouse embryo organogenesis. To determine whether ZnO affects size-dependent anomalies during embryonic organogenesis, mouse embryos were cultured for two days with 300 ug/ml micro ZnO (mZnO;80±25 μm) and nZnO (< 100 nm) and the developmental changes were then investigated. Quantity of Zn by inductively coupled plasma mass spectrometry analysis, and expression patterns of various antioxidant enzymes in the embryos were investigated. Embryos exposed to mZnO or nZnO exhibited severe retardation of growth and development. In embryos exposed to mZnO and nZnO, yolk sac diameter, crown-rump length, and head length were significantly diminished. The morphological parameters, including yolk sac circulation, allantois, flexion, heart, hindbrain, midbrain, forebrain, otic system, optic system, branchial bars, maxillary process, mandibular process, olfactory system, caudal neural tube, forelimb, hindlimb, and somites in mZnO and nZnO-treated groups were significantly decreased. Zn absorption of the nZnO-treated group was significantly higher than that of the mZnO-treated group. Significantly decreased levels of CuZn-SOD, Mn-SOD, cGPx, and PHGPx mRNA were observed in the ZnO-treated group. In addition, antioxidant enzyme mRNA expressions of the nZnO group were significantly diminished, less than those of the mZnO treated group. These findings indicate that 300 ug/ml ZnO showed abnormality and nZnO may have a more severe effect than mZnO in developing embryos.

Selenium is an essential micronutrient which functions as an essential constituent of selenoproteins. The selenoproteins play an important role in the body’s defense from free radicals associated with chronic diseases such as cancer. The effect of selenium on colon carcinogenesis was investigated using an experimental animal model. Five-week old ICR mice were acclimated for one week, and fed on the Fe-overloaded diet (450 ppm) with different Se diets (0.02, 0.1 or 0.5 ppm) for 12 weeks. Animals were injected intraperitoneally with azoxymethane (AOM, 10 mg/㎏ B.W. weekly for 3 weeks), followed by 2% dextran sodium sulfate (DSS) in the drinking water for a week. There were three experimental groups including low Se group (Lse), medium (normal standard diet for mice) Se (MSe), and high Se (HSe). The numbers of aberrant crypt foci (ACF) and aberrant crypt (AC) were measured in the colonic mucosa. The iron and selenium concentrations in liver was measured using ICP-AES. Glutathione peroxidase (GPx) activity was determined in the liver and colon. TUNEL assay for cell apoptosis and proliferating cell nuclear antigen (PCNA) staining for cell proliferation were performed. Immunohistochemical staining of β-catenin was also performed in mucous tissue of colon. The dietary Se decreased the numbers of ACF/㎠ and AC/㎠ in a dose-dependent manner. HSe diet significantly decreased the numbers of AC/㎠, compared with LSe diet (p<0.05). The tumor incidence rate in low Se diet group was 5% higher than medium Se diet group and 20% higher than high Se diet group. The activities of GPx in the liver and colon were dependent on the content of dietary selenium. Apoptosis-positive cells were also increased by dietary Se in a dose-dependent manner. PCNA-positive staining was weak in high Se group. β-catenin stained area was increased in low Se group while it was decreased in high Se group. These findings indicate that dietary selenium exert a protecting effect on colon cancer by inhibiting the development of ACF/AC, increasing GPX and apoptosis, and decreasing cell proliferation and expression of β-catenin in mice.

To investigate the effect of carnosine on exhaustive exercise, swimming tests were conducted weekly with loads corresponding to 5% of body weight attached to the tails of mice, and the swimming time to exhaustion was measured. Eighty male ICR mice were divided into four groups, to which carnosine was administered at doses of 0 (control), 10, 50, and 250 mg/kg/day, respectively, for a period of four weeks. At the end of swimming exercise challenges, serum biochemistry, oxidative stress enzyme activity, and antioxidant enzyme activity in tissues were determined. Treatment with 250 mg/kg carnosine resulted in a significant increase in swimming times to exhaustion, compared to the control group in the first (P<0.01) and third week (P<0.05). Significantly lower serum lactate levels were observed after the swimming exercise in the carnosine-treated groups (10 and 250 mg/kg), compared with the control (P<0.01). Malondialdehyde levels in the liver (10 and 50 mg/kg carnosine treated groups) and skeletal muscle (250 mg/kg carnosine treated group) were significantly lower, compared with the control (P<0.05). Significantly lower protein carbonyl levels in skeletal muscle were observed in the 50 and 250 mg/kg carnosine treated groups, compared with the control (P<0.01). Superoxide dismutase and glutathione peroxidase activities in skeletal muscle did not differ significantly among the groups. These results indicate that carnosine may improve swimming exercise capacity by attenuating production of lactate and reducing oxidative stress in mice.

Neurotoxicity and oxidative injury induced by glutamate cause neuronal degeneration related to various central nervous system diseases. Resveratrol, a polyphenolic compound, is known to have antioxidative and anti-inflammatory effects. The aim of this study was to investigate the question of whether resveratrol has a neuroprotective effect against glutamate-induced toxicity in cultured cortical neurons. Following exposure to glutamate for 15 min, cortical neurons originating from ICR mouse fetuses on embryonic days 15-16 were then treated with resveratrol for 24 h in the post-treatment paradigm. Glutamate induced a significant reduction in cell viability; however, resveratrol induced a significant increase in cell viability. Glutamate induced generation of ROS and apoptotic neuronal death; however, these were decreased by exposure to resveratrol. mRNA expression in antioxidant enzymes, cytoplasmic glutathione peroxidase, copper/zinc superoxide dismutase (SOD), and manganese SOD, and anti-apoptotic regulator Bcl-xL were decreased by exposure to glutamate, however, exposure to resveratrol resulted in a significant increase in their mRNA levels. In addition, mRNA expression of pro-inflammatory cytokines, interleukin-1β and tumor necosis factor-α, was increased by glutamate insult, but significantly reduced by resveratrol. These findings indicate that resveratrol is neuroprotective against glutamate-induced toxicity, suggesting a useful therapeutic application in treatment of neurodegenerative disorders.

Selenium (Se) obtained from dietary sources is an essential micronutrient for normal body function and it functions as an essential constituent of selenoproteins. We investigated the influence of Se on the formation of colonic aberrant crpyt foci (ACF) and tumor formation induced by azoxymethane (AOM) and dextran sodium sulfate (DSS) in male ICR mice. Five-week old ICR mice were acclimated for one week and fed on the low iron diet (LFe, 4.5 ppm) and different Se diet [Lse (0.02 ppm), Normal Se (0.1 ppm), HSe (0.5 ppm)] for 12 weeks. Animals received intraperitoneal injections of AOM (10㎎/㎏ B.W. in saline weekly for 3 weeks), followed by 2% DSS (molecular weight 36,000～50,000) in the drinking water for a week. There were five experimental groups, including a normal control group, AOM/DSS, LFe+AOM/DSS, LFe+AOM/DSS+LSe, LFe+AOM/DSS+HSe. After sacrifice of animals, the total numbers of AC and ACF were measured in the colonic mucosa. The number of mice bearing tumors was expressed as tumor incidence rate. The iron and selenium liver concentration was measured using ICP-AES. Glutathione peroxidase (GPx) activity was determined using a GPx assay kit in the liver and colon. TUNEL and proliferating cell nuclear antigen (PCNA) staining were performed to examine the cell apoptosis and cell proliferation. In addition, immunohistochemistry of β-catenin was also performed on the mucous membrane tissue of colon. In AOM/DSS-induced colon carcinogenesis animal model, LFe diet decreased the number of 2.95±2.5 ACF/cm2 to 1.85±1.1 ACF/cm2 but it increased the total number of 5.06±4.2 AC/cm2 to 6.19±4.8 AC/cm2 compared with normal iron diet. In the iron-deficient mice, selenium did not affect the either the number of ACF or AC. The tumor incidence rate was higher in LFe diet groups than in normal iron diet group and high selenium diet weakly reduced the tumor incidence. Low selenium diet decreased the activity of GPx in the liver and colon. Apoptotic positive cells were decreased in the low selenium diet group. In addition, on the β-catenin staining, positive cells were increased in the low selenium diet group while they were decreased in the high selenium diet group. These findings indicate that the dietary levels of selenium was not highly enough to exhibit a significant protection against colon carcinogenesis in the iron-deficient mice. However, our results also indicate that dietary selenium might exert a protecting effect against colon cancer by increasing GPx activity and apoptosis and by inhibiting cell proliferation and β-catenin over-expression.

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is a unique antioxidant enzyme involved in reduction of peroxidized phospholipids within biomembranes. To investigate the expression pattern of the PHGPx gene during fetal development, in situ hybridization analyses were performed using mouse FITC-labeled PHGPx cRNA probes in fetal tissues on embryonic days (Ed) 13.5-18.5. During these periods, PHGPx mRNA appeared in the developing telencephalon, diencephalon, spinal cord, and spinal ganglion. In particular, PHGPx mRNA was strongly expressed in pyramidal cells of the cerebral cortex. On Eds 17.5-18.5, PHGPx mRNA was detected in various tissues including liver, intestinal villi and crypt, pancreas, lung, and olfactory epithelium of the nasal cavity. In addition, PHGPx mRNA was highly expressed in the inner ear on Eds 14.5-18.5, brown fat on Ed 17.5, and adrenal gland on Ed 18.5. It is conceivable that PHGPx may act as an important antioxidant against fetal oxidative stress during mouse organogenesis.

본 연구에서는 azoxymethane (AOM)과 dextran sodium sulfate (DSS)로 유도된 대장 발암과정에 대한 셀레늄의 방어 효과를 조사하였다. 셀레늄 결핍(0.02 ppm Se), 정상(0.1 ppm Se), 과다(0.5 ppm Se)사료를 12주간 식이로 급여하여 혈액검사와 대장암 발생의 초기단계인 aberrant crypt foci (ACF)수를 측정했으며, 암 발생율을 조사하였다. ICP-AES 를 사용하여 간의 셀레늄 농도를 측정하였으며, 또한 셀레늄포함 항산화효소인 glutathione peroxidase (GPx) 활성을 알아보았다. 또한 TUNEL assay와 PCNA, β-catenin에 대한 면역조직 염색을 수행하였다. ACF 수 및 종양 발생률에 있어서, 셀레늄과다사료를 급여한 군이 정상셀레늄사료를 급여한 군보다 낮았으며, 셀레늄결핍사료를 급여한 군은 오히려 ACF 수 및 종양 발생률이 높았다. GPx 활성은 셀레늄의 섭취가 과다한 군에서 높게 나타났으며, 이 때, TUNEL 에서 apoptotic positive cell이 증가하는 것을 확인했다. 또 한 셀레늄의 섭취가 과다한 군에서 PCNA와 β-catenin의 발현이 감소됨을 볼 수 있었다. 본 마우스 모델실험에서 셀레늄은 여러 기전에 의해 대장암 발생을 억제할 수 있을 것으로 사료된다.

Animal crude drugs (natural medicines derived from animal organs) have been widely used in various Chinese medicine for the therapeutic effects and for enhancement of immunologic functions. We found the specific identification methods using DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses for mitochondrial DNA (mt DNA) in order to discriminate between the animal species and organs as well as the placenta of humans. Species-specific PCR bands of D-loop mt DNA for equine, bovine, porcine, and human were 133 bp, 137 bp, 231 bp, and 240 bp, respectively. Porcine organs were identified using restriction enzyme, HphI cut into two subfragments, 36 bp and 195 bp bands in the heart, spleen, and liver, except for kidney. The heart and liver of porcine were identified using restriction enzyme, SpeI cut into two subfragments, 84 bp and 147 bp bands, except for kidney and spleen. Bovine organs were cut into 68 bp and 69 bp bands in the liver, kidney, and spleen using NalIV, except heart and placenta. Placentas of bovine and humans were easily identified using each primer. Our results suggest that sequencing of mt DNA and its PCR-RFLP methods are useful for identification and discrimination of inter- and intra-specific variations in equine, bovine, porcine, and human by routine analysis.

Wrinkles are an outward sign of cutaneous aging appearing preferentially on ultraviolet B (UVB)-exposed areas. The anti-wrinkle effects of herbal extracts were investigated in an animal model. Female albino hairless mice (HR/ICR) were randomly allocated to the control group (non-irradiated vehicle), positive control group (UVB irradiated-vehicle), and two herbal extract mixture groups (HE-1 and HE-2). HE-1 included Glycyrrhizae radix, Rhei Rhizoma, Cornus officinalis, and Sesami semeni, and HE-2 included Swertia pseudo-chinensis, Sophora flavescens, Scutellaria baicalensis, and Salvia miltiorrhiza. The herbal extract mixtures were pre-treated dorsally with 0.2 ml per individual five times per week for four weeks prior to the start of UVB irradiation. At the fifth week, the animals were exposed to UVB irradiation for a subsequent eight weeks, three times per week. The intensity of irradiation showed a gradual increase, from 30 mJ/cm 2 to 240 mJ/cm2 (1 MED: 60 mJ/cm2 ). Dorsal skin samples were stained with H&E in order to examine the epidermal thickness. In addition, Masson-Trichrome staining was performed for determination of the amount of collagen fiber. Treatments with HE-1&2 resulted in an increase in the amount of collagen fiber, a better appearance, and fewer wrinkles, compared with the positive control. As determined by hydroxyproline assay, treatments with HE-1&2 led to a significant increase in the amount of collagen, compared with the positive control group (p<0.05). Chronic UVB irradiation to skin of hairless mice resulted in an increase in expression of matrix metalloproteinase-1 (MMP-1), however, treatments with HE-1&2 tended to decrease the expression of MMP-1. These results indicate that the herbal extracts used in this study have a preventive effect on UVB-induced wrinkle formation in a hairless mouse model, due in part to inhibition of MMP-1 expression and increment of collagen amount.

Iron catalyzes the production of free radicals, which can be related to a variety of pathological events, such as cancer and aging. The effect of dietary iron was investigated on formation of colonic aberrant crypt foci (ACF) induced by azoxymethane in male F344 rats. Animals were fed three different diets, including iron-deficient (3 ppm Fe), iron-normal (35 ppm Fe), and iron-overloaded (350 ppm Fe) diets for eight weeks. During the first and second weeks of the experiment, animals received two subcutaneous injections of azoxymethane (AOM, 15 mg/kg body weight) to induce ACF. After staining with methylene blue, the total numbers of ACF and aberrant crypts (AC) were counted on the colonic mucosa. Analysis of blood and serum was performed using a blood cell differential counter and an automatic serum analyzer. Iron-deficient diets induced a significant decrease in red blood cell counts and the values of hemoglobin concentration, hematocrit, mean corpuscular hemoglobin, and mean corpuscular volume, while an iron-overloaded diet did not affect these values. The iron-overloaded diet induced an increase in deposits of iron in the liver of rats, as determined by the ICP method and Perl’s staining. The numbers of ACF per colon showed a slight increase in iron-overloaded or iron-deficient rats, without statistical significance, compared to iron-normal rats. The number of total AC per colon in iron-overloaded rats was significantly higher than that in iron-normal rats (p<0.05). The number of large ACF (≥ 4 AC per ACF) in iron-overloaded rats was also significantly higher than that in iron-normal rats (p<0.05). These results suggest that dietary iron intake may play an important role in colon carcinogenesis in humans and animals.

Although hair disorders are not life threatening, a lot of people who suffer hair loss and/or hair thinning is increasing in accordance with changes in lifestyle and nutritional balance. The aim of this study was to examine the effects of herbal extracts on hair regrowth in C3H/HeJ mice. There were 6 experimental groups including distilled water (D.W.), 50% ethanol (a vehicle control), 3% minoxidil (a positive control), and 3 kinds of herbal extracts mixtures (C, D & E). The test compounds included followings; C : Glycyrrhizae radix, Rhei Rhizoma, Cornus officinalis and Sesami semeni, D : Viticus fructus, Pulsatilla chinensis, Gardenia fructus and Artemisiae argyi herb, E : Swertia pseudo-chinensis, Sophora flavescens Scutellaria baicalensis and Salvia miltiorrhiza. The animals were shaved with an electric clipper. The test compounds were daily treated to dorsal skin with 0.2 ml per mouse for 3 weeks. The topical application of the E test solution accelerated hair regrowth after 10 days faster than that of the positive and vehicle controls. The activities of alkaline phosphatase (ALP) and γ-glutamyl transpeptidase significantly were increased in all the treatment groups after 3 weeks, compared with D.W. group. Especially, the E test solution notably increased ALP activity compared with positive or vehicle control group. Epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) were increased in all the treatment groups after 3 weeks compared with D.W. group. These results suggest that the herbal extracts have hair regrowth effect by increasing enzyme activities and growth factors and it can be useful for treatment for alopecia in humans.

Maternal hypoxia induced by a variety of exogenous oxidative stresses such as ethanol intake, diabetes, and cigarette during pregnancy provokes the impaired embryonic gene expression and developmental malformations. We investigated the gene expression patterns of the representative selenium containing antioxidant enzymes (selenoproteins) such as cytosolic GPx (cGPx), gestrointestinal GPx (GI-GPx), plasma GPx (pGPx), phospholipid hydroperoxide GPx (PHGPx), and selenoprotein P (SePP) in the cultured mouse embryos under normal or hypoxic (low oxygen state, 5% O₂) condition at embryonic day 8.5 for 2 days using real-time PCR analysis. cGPx, pGPx, and SePP mRNAs were significantly decreased, but GI-GPx and PHGPx mRNAs were remarkably increased in the hypoxic state compared to normal gassing state (p<0.05). These findings indicate that hypoxic condition leads to the unusual expressions of selenoproteins during mouse organogenesis.

A level of dietary iron may play a role in colon carcinogenesis. The effect of dietary iron on colon carcinogenesis was investigated in male ICR mice. Five-week old mice were acclimated for one week and fed on iron-normal diet (35 ppm Fe), iron-deficient diet (3 ppm), or iron-overloaded diet (350 ppm Fe) for 8 weeks. Animals received three (0-2^nd weeks after starting experiment) injections of azoxymethane (AOM; 10 mg/kg b.w.) to induce colonic aberrant crypt foci (ACF). There were five experimental groups including normal control without AOM, AOM+iron-normal diet (AOM+NFe), AOM+iron-deficient (AOM+LFe), AOM+ironoverloaded diet (AOM+HFe) groups. The total numbers of ACF and aberrant crypt (AC) were measured in the colonic mucosa after staining with methylene blue. The blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. The hepatic iron levels were significantly dependent on the presence of iron in the diets. Iron-deficient diet significantly decreased the several hematological values. The values of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) were also significantly decreased in iron-overloaded or iron-deficient diet groups, compared with normal iron diet group. Dietary iron-deficiency decreased the numbers of ACF (64.9) and AC (79.8) per colon by 20.6 and 21.8%, respectively, compared with AOM+NFe group (72.4 ACF/colon and 90.3 AC/colon). However, ironoverloaded diet increased ACF (82.9) and AC (96.0) induction by AOM, compared with normal iron diet. These results suggest that dietary iron can affect the colon carcinogenesis in the animal model of mice.

This study was carried out to investigate effect of herbal extracts mixtures on hair growth in an alopecia model of C57BL/6 mice. There were 4 experimental groups including distilled water (DW, negative control), 25% ethanol(EtOH, vehicle control) and two herbal extract mixtures (HE-1 and HE-2). HE-1 included Polygonum and Brassica campestris extracts and HE-2 included Mulberry root and Gardenia extracts. The 6 weeks-old C57BL/6 male mice were shaved with an electric clipper and the test compounds were topically treated with 0.2 ml per mouse daily for 3 weeks. The hair re-growth was photographically determined at days 0, 4, 7, 10, 14, 17, and 21. The number of mast cells which is an important modulator of hair growth was counted in 1 cm of dorsal skin section of mice. There were no clinical signs in all experimental groups. As the results of photometric analysis, the topical application of the herbal extracts (HE-1 & 2) for 2 weeks to dorsal skin accelerated hair re-growth remarkably faster than that of DW group (p＜0.05). Activity of alkaline phosphatase (ALP) was significantly increased in EtOH group compared to DW group (p＜0.05). Both herbal extract mixtures also increased the ALP activity, but it was not significantly different from DW. Treatment of mice with HE-2 significantly increased mast cell population compared to EtOH. Taken together, these results suggest that herbal extract mixtures used in this study may have hair-growth promoting activities and can be useful for treatment for male pattern baldness or alopecia in humans.

The aim of this study was to examine the promoting effect of herbal extracts on hair regrowth in C3H/HeJ mice. The herbal extracts were obtained from the Damo-cosmetics Inc. There were four experimental groups including distilled water (D. W., negative control), 20% ethanol (EtOH, vehicle control), 3% minoxidil (MXD, positive control), and herbal extract (Ext). The herbal extract included the mixture of water and alcohol extract from Pleuropterus multflorus, Lonicera japonica Thunberg, Phellinus linteus, and Phaseolus radiatus. Test compounds were applied to the shaved dorsal skin of mice mouse for 3 weeks. The photograph of hair regrowth was taken at day 0, 4, 7, 10, 14, 17, and 21. The herbal extract group showed faster hair regrowth than negative control group or 20% EtOH groups after 10 and 14 days of treatments. The elongation of hair follicles in MXD and the herbal extract groups were observed. The activities of alkaline phosphatase (ALP) and γ-glutamyl transpeptidase were sfanificantly (γ-GT) increased in MXD and herbal extract groups compared with negative control group (p＜0.05). The expression of epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) were also sfanificantly hfaher in MXD and herbal extract group than negative control group (p＜0.05), althouah there were no sfanificant differences amoularhe groups of 20% EtOH, MXD, and herbal extract. These results suagest that the herbal extract used in this study may have grpromoting effect on hair regrowth by increasing activities of ALP and γ-GT and expression of EGF and VEGF.

Anti-wrinkle effect of herbal extracts was investigated on the skin of in a model of animal irradiated by ultraviolet rey B (UVB). The female albino hairless mice (HR/ICR) were randomly allocated to the normal control group (NC-non irradiated-vechicle), positive control group (PC, UVB irradiated vehicle) and herbal extract (HE) group. The herbal extract included the mixture of water and alcohol extract from Pleuropterus multflorus, Lonicera japonica Thunbert, Phellinus linteus, and Phaseolus radiatus. The herbal extract was treated dorsally with 0.2 ml per mouse five times a week for 12 weeks. At fifth week of the treatment, the animals were exposed to UVB irradiation for subsequent eight weeks three times a week. The intensity of irradiation was gradually increased from 30 mJ/㎠ to 240 mJ/㎠ (1MED: 60 mJ/㎠). Dorsal skins were obtained and stained with H&E to examine histological changes and epidermal/dermal thckness. The collagen fiber was also observed in Masson-Trichrome staining. Hydroxyproline assay and western blot analysis were also carried out to detect the change of collagen amount and to investigate MMP-1 expression, respectively. The HE group showed a better appearance and weak wrinkling, compared to PC group, The treatment of herbal extract significantly increased the thickness of dermis and the amount of collagen fibers compared to PC group (p＜0.05). The treatment of HE significantly increased the hydroxyproline amount compared to PC group (p＜0.05). The chronic UVB irradiation to hairless mice skin increased expression of MMP-1 but the treatment of HE decreased the expression of MMP-1. These results indicate that the herbal extract used in this study have a preventive effect on the UVB-induced wrinkle in a hairless mice model, partly due to the reduction of MMP-1 expression and increment of collagen amount.

Phytic acid (PA) is a naturallu 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. We investigated the preventive effect of PA on the formation of colonic aberrant crypt foci (ACF), a preneoplastic lesion, induced by azoxymethane (AOM). After acclimation for one week, six-week old male ICR mice were fed on the AIN-93G purified diet and PA (0.5% or 2% PA in water) for 8 weeks. The animals were treated with azoxymethane (AOM, 10 mg/kg b.w.) three times (0, 1, and 2 weeks) to induce colonic aberrant crypt foci (ACF). After sacrifice, the total numbers of aberrant crypts (AC) and ACF in colonic mucosa were counted after staining with methylene blue. Blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. AOM treatment without PA induced the total numbers of 85.7 ± 12.9 and 115.2 ± 19.9, respectively. PA at the dose of 2% AC/colon by PA at the dose of 0.5% were 73.4 ± 12.9 and 115.2 ± 19.9, respectively. PA at the dose of 2% significantly decreased the ACF and AC numbers to 56.5 ± 14.6 and 95.4 ± 17.2, respectively (p＜0.01). PA at the doses of 0.5 and 2% decreased the numbers of ACF and AC/colon in a dose-dependent manner. Although some parameters in blood counts and serum chemistry were changed compared with the control, no specific toxicity was found. Theses findings suggest that phytic acid can be a chemopreventive agent for colon carcinogenesis resulting from inhibition of the development of ACF in ICR mice.