Erratum: Protective effects of cultured and fermented ginseng extracts against scopolamine-induced memory loss in a mouse model.

[This corrects the article on p. 37 in vol. 34, PMID: 29628975.].

The effect of near-infrared fluorescence conjugation on the anti-cancer potential of cetuximab.

This study investigated the anti-cancer potential of a near-infrared fluorescence (NIRF) molecule conjugated with Cetuximab (Cetuximab-NIRF) in six-week-old female BALB/c athymic (nu+/nu+) nude mice. A431 cells were cultured and injected into the animals to induce solid tumors. Paclitaxel (30 mg/kg body weight (BW)), Cetuximab (1 mg/kg BW), and Cetuximab-NIRF (0.25, 0.5 and 1.0 mg/kg BW) were intraperitoneally injected twice a week into the A431 cell xenografts of the nude mice. Changes in BW, tumor volume and weight, fat and lean mass, and diameter of the peri-tumoral blood vessel were determined after two weeks. Tumor volumes and weights were significantly decreased in the Cetuximab-NIRF (1 mg/kg BW) group compared with the control group (P<0.001). Lean mass and total body water content were also conspicuously reduced in the Cetuximab-NIRF (1 mg/kg BW) group compared with the vehicle control group. Peri-tumoral blood vessel diameters were very thin in the Cetuximab-NIRF groups compared with those of the paclitaxel group. These results indicate that the conjugation of Cetuximab with NIRF does not affect the anti-cancer potential of Cetuximab and NIRF can be used for molecular imaging in cancer treatments.

Protective effects of cultured and fermented ginseng extracts against scopolamine-induced memory loss in a mouse model.

This study was performed to investigate the effect of a concentrate of fermented wild ginseng root culture (HLJG0701) on memory improvement in the scopolamine (SPL)-induced memory-deficient mouse model. Eight-week-old male ICR mice were used to evaluate the protective effect of HLJG0701 against the SPL-induced memory loss animal model. The Morris water maze test, which measures hippocampus-dependent learning ability, and the Y-maze test, a short-term memory assessment test, were performed and related markers were analyzed. HLJG0701-treated groups displayed significantly reduced acetylcholinesterase activity and increased acetylcholine level compared with the SPL-administered group (SPL-G) (P<0.05). In the Y-maze test, the spontaneous alternation in al HLJG0711-treated groups was significantly increased compared with that in SPL-G (P<0.05). In the Morris water maze test, the escape latency and time spent in the target quadrant in all HLJG0701-treated groups were significantly decreased and increased, respectively, compared with those in SPL-G (P<0.05). In addition, the brain-derived neurotrophic factor level in groups treated with HLJG0701 300 and 600 mg/kg body weight was significantly increased compared with that in SPL-G (P<0.05). These results suggest that the HLJG0701 may protect against memory loss by inhibiting acetylcholinesterase activity and preventing acetylcholine deficiency.

Withdrawal: Protective effects of cultured and fermented ginseng extracts against scopolamine-induced memory loss in a mouse model.

[This retracts the article on p. 37 in vol. 34, PMID: 29628975.].

Enhanced Protective Effects of Combined Treatment with ß-Carotene and Curcumin against Hyperthermic Spermatogenic Disorders in Mice.

Scrotal hyperthermia leads to oxidative stress and apoptosis in spermatogenic cells, which subsequently causes male infertility. In this study, we examined the effects of ß-carotene and/or curcumin on heat-stress- (HS-) induced testicular injuries in mice. ICR male mice (8 weeks old) were consecutively treated with ß-carotene (10 mg/kg) and/or curcumin (20 mg/kg) orally once a day for 14 days and then subjected to single exposure with scrotal HS at 43°C for 15 min on day 7. HS induced a significant reduction in testicular weight, appearance of multinucleated giant cells, and desquamation of germ cells in destructive seminiferous tubules, as well as degenerative Leydig cells. Moreover, HS reduced the superoxide dismutase (SOD) activity and mRNA levels of mitochondrial SOD, phospholipid hydroperoxide glutathione peroxidase, B-cell lymphoma-extra-large, and 3ß-hydroxysteroid dehydrogenase, with increases in lipid peroxidation levels and mRNA levels of BCL2-associated X protein and caspase-3 relative to those of the control group. However, these changes were significantly recovered by combined treatment with ß-carotene and curcumin after HS. These findings indicate that the combined treatment with ß-carotene and curcumin might be a valuable protective agent to ameliorate hyperthermic spermatogenic disorders via its potent antioxidative, antiapoptotic, and androgen synthetic effects.

Phospholipid hydroperoxide glutathione peroxidase is involved in the maintenance of male fertility under cryptorchidism in mice.

Severe oxidative stress by cryptorchidism leads to infertility. To assess the functional significance of phospholipid hydroperoxidase glutathione peroxidase (PHGPx) under cryptorchidism, PHGPx expression was spatiotemporally analyzed in testes and epididymis excised at 1, 4, 7, 14, 21, and 28 days after experimental bilateral cryptorchidism in adult mice. In testes, while apoptosis-related caspase 3 and Bcl-xL mRNAs were significantly changed after 14 days, 3 beta-hydroxysteroid dehydrogenase mRNA was greatly reduced immediately after cryptorchidism. Under cryptorchidism, PHGPx was significantly decreased in both organs after 21 days, while its mRNA was greatly reduced in testes after 14 days and in epididymis after 4 days. However, PHGPx was upregulated in degenerative spermatids, multinucleated giant cells, and Leydig cells in testes and desquamous spermatids in epididymis until 21 days, but was weakly detected in the spermatids at 28 days. These findings suggest that PHGPx is necessary for maintenance of male fertility under cryptorchidism in testes.

4-O-methylhonokiol inhibits serious embryo anomalies caused by nicotine via modulations of oxidative stress, apoptosis, and inflammation.

BACKGROUND: Since the increasing smoking rate among women has resulted in higher rates of embryonic malformations, it is important to search for an efficient and inexpensive agent that can help reduce the rate of serious fetal anomalies caused by maternal cigarette smoking. In this study, the bioavailability of 4-O-methylhonokiol isolated from Magnolia officinalis was first demonstrated in the mouse embryos exposed to nicotine using a whole embryo culture system. METHODS: Mouse embryos on embryonic day 8.5 were cultured with 1 mM nicotine and/or 4-O-methylhonokiol (1 × 10(-4) or 1 × 10(-3) µM) for 48 hr and were analyzed on the viewpoints of embryo developmental changes, oxidative damages, and apoptotic and inflammatory changes. RESULTS: Embryos exposed to 1 mM nicotine developed not only severe morphological anomalies, increased expressions of tumor necrosis factor-α, interleukin-1ß, and caspase 3 mRNAs; and elevated levels of lipid peroxidation, but also decreased levels of cytoplasmic superoxide dismutase, cytosolic glutathione peroxidase, phospholipid hydroperoxide glutathione peroxidase, hypoxia inducible factor-1α, and B-cell lymphoma-extra large mRNAs, and reduced superoxide dismutase activity. However, these parameters were significantly improved when embryos exposed to the nicotine were concurrently treated with 4-O-methylhonokiol (1 × 10(-4) or 1 × 10(-3) µM). CONCLUSIONS: These findings indicate that 4-O-methylhonokiol reduces serious embryo anomalies caused by nicotine in mouse embryos via the modulations of oxidative stress, apoptosis, and inflammation, suggesting that 4-O-methylhonokiol may be a preventive and therapeutic agent against the dysmorphology induced by maternal smoking during pregnancy.

Distribution and accumulation of Cy5.5-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles in the tissues of ICR mice.

Free Cy5.5 dye and Cy5.5-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) have been routinely used for in vivo optical imaging. However, there is little information about the distribution and accumulation of free Cy5.5 dye and Cy5.5-labeled TCL-SPION in the tissues of mice. Free Cy5.5 dye (0.1 mg/kg body weight) and Cy5.5-labeled TCL-SPION (15 mg/kg body weight) were intravenously injected into the tail vein of ICR mice. The biodistribution and accumulation of the TCL-SPION and Cy5.5 were observed by ex vivo optical imaging and fluorescence signal generation at various time points over 28 days. Cy5.5 dye fluorescence in various organs was rapidly eliminated from 0.5 to 24 h post-injection. Fluorescence intensity of Cy5.5 dye in the liver, lung, kidney, and stomach was fairly strong at the early time points within 1 day post-injection. Cy5.5-labeled TCL-SPION had the highest fluorescence density in the lung at 0.5 h post-injection and decreased rapidly over time. Fluorescence density in liver and spleen was maintained over 28 days. These results suggest that TCL-SPION can be useful as a carrier of therapeutic reagents to treat diseases by persisting for long periods of time in the body.

Antiteratogenic Effects of ß-Carotene in Cultured Mouse Embryos Exposed to Nicotine.

After maternal intake, nicotine crosses the placental barrier and causes severe embryonic disorders and fetal death. In this study, we investigated whether ß -carotene has a beneficial effect against nicotine-induced teratogenesis in mouse embryos (embryonic day 8.5) cultured for 48 h in a whole embryo culture system. Embryos exposed to nicotine (1 mM) exhibited severe morphological anomalies and apoptotic cell death, as well as increased levels of TNF- α , IL-1 ß , and caspase 3 mRNAs, and lipid peroxidation. The levels of cytoplasmic superoxide dismutase (SOD), mitochondrial manganese-dependent SOD, cytosolic glutathione peroxidase (GPx), phospholipid hydroperoxide GPx, hypoxia inducible factor 1 α , and Bcl-x L mRNAs decreased, and SOD activity was reduced compared to the control group. However, when ß -carotene (1 × 10(-7) or 5 × 10(-7) µM) was present in cultures of embryos exposed to nicotine, these parameters improved significantly. These findings indicate that ß -carotene effectively protects against nicotine-induced teratogenesis in mouse embryos through its antioxidative, antiapoptotic, and anti-inflammatory activities.

Emodin prevents ethanol-induced developmental anomalies in cultured mouse fetus through multiple activities.

BACKGROUND: Maternal alcohol ingestion on pregnant period causes fetal alcohol syndrome including psychological and behavioral problems, and developmental abnormality. In this study, we investigated the effect of emodin, an active anthraquinone component found in the roots and bark of the genus Rhamnus (Buckthorn), on ethanol-induced teratogenesis during embryonic organogenesis. METHODS: We cultured mouse embryos on embryonic day 8.5 for 2 days with ethanol (5 µl/3 ml) and/or emodin (1×10(-5) and 1×10(-4) µg/ml) using a whole embryo culture system and then investigated the developmental evaluation, superoxide dismutase (SOD) activity, and expression patterns of cytoplasmic SOD (SOD1), mitochondrial SOD (SOD2), cytosolic glutathione peroxidase (cGPx), tumor necrosis factor-α (TNF-α), caspase 3, and hypoxia inducible factor 1α (HIF-1α). RESULTS: Morphological parameters, including growth in yolk sac and fetal head, body length, and development of the central nervous system, circulation system, sensory organs, skeletal system, and limbs in embryos exposed to ethanol were significantly decreased compared to those of the normal control group, but co-treatment with emodin (1 × 10(-5) and 1 × 10(-4) µg/ml) significantly improved these parameters. Furthermore, the reduced levels of SOD activity, and SOD1, SOD2, cGPx, and HIF-1α and the increased gene levels of TNF-α and caspase-3 due to ethanol exposure were significantly restored by cotreatment with emodin. Birth Defects Res (Part B) 98:268-275, 2013. © 2013 Wiley Periodicals, Inc. CONCLUSIONS: This study revealed that cotreatment with emodin significantly prevented teratogenesis induced by ethanol, not only by modulating hypoxia and antioxidant enzymes, but also by attenuating the enhanced levels of TNF-α and caspase 3 in cultured embryos. Therefore, emodin may be an effective preventive agent for ethanol-induced teratogenesis.

Decreased pain responses of C-C chemokine receptor 5 knockout mice to chemical or inflammatory stimuli.

Chemokines are small chemotactic cytokines that elicit many physiological and pathological effects through binding to their corresponding receptors. Recent studies have suggested that C-C chemokine receptor (CCR) 5 interacts with µ-opioid receptor and modifies a nociceptive reaction. We examined effects of CCR5 deficiency on pain responses by employing CCR5 knockout (KO) mice. We found that pain responses of CCR5 KO mice to chemical or inflammation stimuli were milder than those of CCR5 wild type (WT) mice. However, there was no remarkable change in thermal nociception. To prove the involvement of CCR5 deletion in lowered nociception, we examined pain reactions with CCR5 WT mice following treatment of a CCR5 antagonist (D-Ala(1)-peptide T-NH(2,) DAPTA). Chemical or inflammatory pain behavior was significantly relieved by intracerebroventricular infusion of the inhibitor. When we assessed expression level of µ-opioid receptor (MOR) in the periaqueductal gray where the receptors are critical for analgesic effects, immunoreactivity of MOR was significantly higher in CCR5 KO mice than WT mice without change in phosphorylation level of the receptor. Reduced nociceptive responses in CCR5 KO mice were moderated by administration of naloxone and d-Phe-Cys-Tyr-d-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP), MOR antagonists. Our data indicate that CCR5 deficiency is related to up-regulation of MOR without an increase in the receptor desensitization which might result in increased analgesic effects against chemical or inflammatory stimuli. Alternatively, higher amount of opioid ligands in CCR5 mice might be linked to these results. Therefore, CCR5 appears to be a therapeutic target for treatment of pain related diseases such as inflammatory hyperalgesia.

Resveratrol prevents nicotine-induced teratogenesis in cultured mouse embryos.

Nicotine, a major toxic component in tobacco smoke, leads to severe embryonic damage during organogenesis in embryos. We investigated whether resveratrol would positively influence nicotine-induced teratogenesis in mouse embryos (embryonic day 8.5) cultured for 48 h using a whole embryo culture system. Embryos exposed to nicotine (1mM) revealed significantly severe morphological anomalies, increased levels of caspase-3 mRNA and lipid peroxidation, and decreased levels of cytoplasmic superoxide dismutase (SOD), mitochondrial manganese SOD, cytosolic glutathione peroxidase, phospholipid hydroperoxide glutathione peroxidase, hypoxia-inducible factor 1α, Bcl-x(L), and sirtuin1 (SIRT1) mRNAs and SOD activity compared to those in the normal control group. However, when resveratrol (1×10(-8) µM or 1×10(-7) µM) was added concurrently to the embryos exposed to nicotine, all the parameters in above improved conspicuously. These findings indicate that resveratrol has a noted protective effect against nicotine-induced teratogenesis in mouse embryos through its antioxidative and anti-apoptotic effects.

Protective effect of [6]-gingerol on the ethanol-induced teratogenesis of cultured mouse embryos.

Excessive ethanol consumption during pregnancy causes fetal alcohol syndrome. We investigated the effect of [6]-gingerol on ethanol-induced embryotoxicity using a whole embryo culture system. The morphological changes of embryos and the gene expression patterns of the antioxidant enzymes cytosolic glutathione peroxidase (cGPx), cytoplasmic Cu/Zn superoxide dismutase (SOD1), and Mn-SOD (SOD2), and SOD activity were examined in the cultured mouse embryos exposed to ethanol (5 µL/3 mL) and/or [6]-gingerol (1×10(-8) or 1×10(-7) µg/mL) for 2 days. In ethanol-exposed embryos, the standard morphological score of embryos was significantly decreased compared with those of the control (vehicle) group. However, cotreatment of embryos with [6]-gingerol and ethanol significantly improved all of the developmental parameters except crownrump length and head length, compared with those of the ethanol alone group. The mRNA expression levels of cGPx and SOD2, not SOD1, were decreased consistently, SOD activity were significantly decreased compared with the control group. However, the decreases in mRNA levels of antioxidant enzymes and SOD activity were significantly restored to the control levels by [6]-gingerol supplement. These results indicate that [6]-gingerol has a protective effect against ethanol-induced teratogenicity during mouse embryogenesis.

4-O-methylhonokiol prevents memory impairment in the Tg2576 transgenic mice model of Alzheimer's disease via regulation of ß-secretase activity.

Alzheimer's disease (AD), the most common form of dementia, is characterized by memory deficits and deposition of amyloid-ß (Aß) in the brain. It has been known that neuroinflammation and oxidative stress are critical factors in the development of AD. 4-O-methylhonokiol, an extract from Magnolia officinalis, is known to have anti-inflammatory and anti-oxidative effects. Thus, we investigated the properties of 4-O-methylhonokiol against progression and development of AD in Tg2576 mice. Tg2576 mice models show memory impairment and AD-like pathological features including Aß deposition. Oral administration of 4-O-methylhonokiol through drinking water (1 mg/kg in 0.0002% Tween 80) for 12 weeks not only prevented memory impairment but also inhibited Aß deposition. In addition, 4-O-methylhonokiol decreased ß-secretase activity, oxidative lipid and protein damage levels, activation of astrocytes and microglia cells, and generation of IL-1ß and TNF-α with increase of glutathione level in the brain. Our results showed that 4-O-methylhonokiol effectively prevented memory impairment by down-regulating ß-secretase activity through inhibition of oxidative stress and neuroinflammatory responses in Tg2576 transgenic mice.

Inhibitory effect of 4-O-methylhonokiol on lipopolysaccharide-induced neuroinflammation, amyloidogenesis and memory impairment via inhibition of nuclear factor-kappaB in vitro and in vivo models.

BACKGROUND: Neuroinflammation is important in the pathogenesis and progression of Alzheimer disease (AD). Previously, we demonstrated that lipopolysaccharide (LPS)-induced neuroinflammation caused memory impairments. In the present study, we investigated the possible preventive effects of 4-O-methylhonokiol, a constituent of Magnolia officinalis, on memory deficiency caused by LPS, along with the underlying mechanisms. METHODS: We investigated whether 4-O-methylhonokiol (0.5 and 1 mg/kg in 0.05% ethanol) prevents memory dysfunction and amyloidogenesis on AD model mice by intraperitoneal LPS (250 µg/kg daily 7 times) injection. In addition, LPS-treated cultured astrocytes and microglial BV-2 cells were investigated for anti-neuroinflammatory and anti-amyloidogenic effect of 4-O-methylhonkiol (0.5, 1 and 2 µM). RESULTS: Oral administration of 4-O-methylhonokiol ameliorated LPS-induced memory impairment in a dose-dependent manner. In addition, 4-O-methylhonokiol prevented the LPS-induced expression of inflammatory proteins; inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as activation of astrocytes (expression of glial fibrillary acidic protein; GFAP) in the brain. In in vitro study, we also found that 4-O-methylhonokiol suppressed the expression of iNOS and COX-2 as well as the production of reactive oxygen species, nitric oxide, prostaglandin E2, tumor necrosis factor-α, and interleukin-1ß in the LPS-stimulated cultured astrocytes. 4-O-methylhonokiol also inhibited transcriptional and DNA binding activity of NF-κB via inhibition of IκB degradation as well as p50 and p65 translocation into nucleus of the brain and cultured astrocytes. Consistent with the inhibitory effect on neuroinflammation, 4-O-methylhonokiol inhibited LPS-induced Aß1-42 generation, ß- and γ-secretase activities, and expression of amyloid precursor protein (APP), BACE1 and C99 as well as activation of astrocytes and neuronal cell death in the brain, in cultured astrocytes and in microglial BV-2 cells. CONCLUSION: These results suggest that 4-O-methylhonokiol inhibits LPS-induced amyloidogenesis via anti-inflammatory mechanisms. Thus, 4-O-methylhonokiol can be a useful agent against neuroinflammation-associated development or the progression of AD.

Suppressive effect of zinc on the formation of colonic preneoplastic lesions in the mouse fed high levels of dietary iron.

We investigated the effect of zinc on the formation of colonic aberrant crypt foci induced by azoxymethane (AOM) followed by dextran sodium sulfate (DSS) in mice with high iron diet (HFe; 450 ppm iron). Sixweek old ICR mice were fed on high iron diets with combination of three different levels of zinc in diets, low-zinc (LZn; 0.01 ppm), medium-zinc (MZn; 0.1 ppm), and high-zinc (HZn; 1 ppm) for 12 weeks. Animals were received weekly intraperitoneal injections of AOM (10 mg/kg B.W. in saline) for 3 weeks followed by 2% DSS (molecular weight 36,000~50,000) in the drinking water for a week. To confirm the iron storage in the body, the hepatic iron concentration has been determine chemically and compared with histological assessment visualized by Prussian blue reaction. Aberrant crypt (AC) and aberrant crypt foci (ACF) were analyzed in the colonic mucosa of mouse fed high dietary iron. Superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) level were also investigated. Apoptosis in the preneoplastic lesion was determined by terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling (TUNEL). In addition, immunohistochemistry of ß-catenin was also performed on the mucous membrane of colon. The number of large ACF (≥ 4 AC/ACF), which possess greater tumorigenic potential, was significantly lower in MZn and HZn groups compared with LZn group. Cytosolic SOD activity in the liver was significantly higher in HZn group compared with LZn group. Hepatic MDA level was decreased significantly in HZn group compared with MZn and LZn groups. Apoptotic index was significantly higher in HZn group. Taken together, these findings indicate that dietary zinc might exert a protective effect against colonic preneoplastic lesion induced by AOM/DSS in ICR mice with high iron status, and suggest that dietary supplement of zinc might play a role in suppressing colon carcinogenesis in mice.

Developmental expression of plasma glutathione peroxidase during mouse organogenesis.

Plasma glutathione peroxidase (pGPx) is an extracellular antioxidative selenoenzyme which has been detected in various adult tissues, but little is known about the expression and distribution of pGPx during embryogenesis. To investigate the expression patterns of pGPx during embryogenesis, we performed quantitative real-time PCR, in situ hybridization, Western blot, and immunohistochemistry analyses in whole embryos or each developing organ of mice on embryonic days (E)7.5-18.5. In whole embryos of E7.5-8.5, pGPx mRNA was more typically expressed in extra-embryonic tissues including ectoplacental cone, trophectoderm, and decidual cells than in embryos. However, after E9.5, pGPx mRNA and protein levels were increased in the embryos with differentiation and growth, but trended to gradually decrease in the extra-embryonic tissues until E18.5. In sectioned embryonic tissues on E13.5-18.5, pGPx mRNA and protein were mainly expressed in the developing nervous tissues, the sensory organs, and the epithelia of lung, skin, and intestine, the heart and artery, and the kidney. In particular, pGPx immunoreactivity was very strong in the developing liver. These results indicate that pGPx is spatio-temporally expressed in various embryonic organs as well as extra-embryonic tissues, suggesting that pGPx may function to protect the embryos against endogenous and exogenous reactive oxygen species during organogenesis.

Effects of selenium on colon carcinogenesis induced by azoxymethane and dextran sodium sulfate in mouse model with high-iron diet.

Selenium (Se) is known to prevent several cancers while the relationship between high iron and the risk of colorectal cancer is controversial. To investigate the effects of Se in colon carcinogenesis, we subjected three different levels of Se and high-iron diet to a mouse model of colon cancer in which animals were treated with three azoxymethane (AOM) injections followed by dextran sodium sulfate (DSS) administration. There were five experimental groups including vehicle group [normal-Fe (NFe, 45 ppm)+medium-Se (MSe, 0.1 ppm)], positive control group (AOM/DSS+NFe+MSe), AOM/DSS+high-Fe (HFe, 450 ppm)+low-Se (LSe, 0.02 ppm), AOM/DSS+HFe+MSe, and AOM/DSS+HFe+high-Se (HSe, 0.5 ppm). The animals were fed on the three different Se diets for 24 weeks. The incidence of colon tumor in the high-Se diet group (AOM/DSS+HFe+HSe) showed 19.4% lower than positive control group, 5.9% lower than AOM/DSS+HFe+MSe diet group, and 11.1% lower than AOM/DSS+HFe+LSe group. The tumor multiplicity was significantly higher in the low-Se diet group (AOM/DSS+HFe+LSe) compare to all other AOM/DSS treated groups. In the high-Se diet group, the activity of hepatic GPx was comparable to that of positive control group, and significantly higher than those of low-Se or medium-Se diet groups. Expression level of hepatic GPx-1 showed similar results. Hepatic malondialdehyde (MDA) level (indicator of oxidative stress) in the low-Se diet group showed the highest compared to the other groups, and it was significantly higher than positive control group. In the high-Se diet group the level of MDA in the liver was significantly lower than all other AOM/DSS treated groups. High-Se diet group showed significantly lower proliferative index than low-Se and medium-Se groups. The apoptotic indices in low-Se group and medium-Se group were significantly lower than positive control group. However, apoptotic index of high-Se diet group was significantly higher than all other AOM/DSS treated groups. These findings suggest that dietary Se supplement may have protective effect against colon cancer by decreasing proliferation, increasing apoptosis of tumor cells, and reducing oxidative stress in mice with high iron diet.

Phospholipid hydroperoxide glutathione peroxidase gene is regulated via an estrogen and estrogen receptor signaling in cultured mouse fetuses.

Although it has been suggested that the transcription of phospholipid hydroperoxide glutathione peroxidase (PHGPx), an essential antioxidant selenoenzyme, may be affected by the estrogen state in mammals, the direct mechanism underlying the regulation of the PHGPx gene by estrogens in mammalian tissues remains to be clearly elucidated. In this study, we evaluated the expression of the PHGPx mRNA in cultured mouse fetuses (embryonic days 8.5-10.5) exposed to 17ß-estradiol (E(2); 0.1, 1, 10, 100, and 1,000 ng/ml); estrogen receptor (ER) agonists [propyl pyrazole triol (PPT, an ERα-selective ligand, 1 µl/ml) and diarylpropionitrile (DPN, an ERß-selective ligand, 1 µl/ml)]; and/or ER antagonist [ICI 182,780 (ICI, 1 µl/ml)] using a whole embryo culture system. E(2)-alone treatment significantly stimulated the expressions of both ERα and ERß mRNAs in all the cultured fetuses (p < 0.05), although the ERß mRNA levels were higher than ERα mRNA. PHGPx mRNA expression was significantly increased in all the fetuses treated with E(2) (1-1,000 ng/ml), PPT, and DPN (p < 0.05). Furthermore, pretreatment with ICI completely blocked the E(2)-induced PHGPx mRNA expression in the fetuses. In addition, the mRNA levels of cytosolic GPx, the other intracellular antioxidant selenoenzyme, did not differ significantly from the controls by an exposure to those agents. These results suggest that the PHGPx gene is regulated via an estrogen and ER signal pathway in the cultured mouse fetus.

Dynamic expression of manganese superoxide dismutase during mouse embryonic organogenesis.

The balance between reactive oxygen species production and antioxidant defense enzymes in embryos is necessary for normal embryogenesis. To determine the dynamic expression profile of manganese superoxide dismutase (MnSOD) in embryos, which is an essential antioxidant enzyme in embryonic organogenesis, the expression level and distribution of MnSOD mRNA and protein were investigated in mouse embryos, as well as extraembryonic tissues on embryonic days (EDs) 7.5-18.5. MnSOD mRNA levels were remarkably high in extraembryonic tissues rather than in embryos during these periods. MnSOD protein levels were also higher in extraembryonic tissues than in embryos until ED 16.5, but the opposite trend was found after ED 17.5. MnSOD mRNA was observed in the chorion, allantois, amnion, ectoderm, ectoplacental cone and neural fold at ED 7.5 and in the neural fold, gut, ectoplacental cone, outer extraembryonic membranes and primitive heart at ED 8.5. After removing the extraembryonic tissues, the prominent expression of MnSOD mRNA in embryos was seen in the sensory organs, central nervous system and limbs on EDs 9.5-12.5 and in the ganglia, spinal cord, sensory organ epithelia, lung, blood cells and vessels, intestinal and skin epithelia, hepatocytes and thymus on EDs 13.5-18.5. Strong MnSOD immunoreactivity was observed in the choroid plexus, ganglia, myocardium, blood vessels, heapatocytes, pancreatic acinus, osteogenic tissues, brown adipose tissue, thymus and skin. These findings suggest that MnSOD is mainly produced from extraembryonic tissues and then may be utilized to protect the embryos against endogenous or exogenous oxidative stress during embryogenesis.