• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.105-111
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• 2001

We performed this study to determine the effect of Jiegeng(Platycodon grandiflorum), Danggui(Angelica sinensis), Gancao(Glycyrrhiza glabla), Chaihu(Bupleurum falcatnosa), Shoudehuang(Rehmannia glutinosa), Huangqi(Satragalus membranaceus), Muxiang(Saussurea lappa), Yuanzhi(Polygala tenuifolia), Rensen(Panax ginseng) and Baishaoyao(Paeonia lactiflolia), as Oriental radices herbs, on jejunal crypt survival, endogenous spleen colony formation and apoptosis in jejunal crypt cells of mice irradiated with high and low dose of ${\gamma}-radiation$. Jiegeng(p<0.005), Danggui(p<0.0005), Gancao(p<0.005), Chaihu(p<0.05), Muxiang(p<0.05), Rensen(p<0.005) and Baishaoyao(p<0.005) were effective in intestinal crypt survival. Danggui(p<0.05), Chaihu(p<0.05), Shoudehuang(p<0.05), Huangqi(p<0.05), Rensan(p<0.005) and Baishaoyao(p<0.05) increased the formation of endogenous spleen colony. The frequency of radiation induced apoptosis was also reduced by pretreatment with Chaihu(p<0.05), Muxiang(p<0.005), Yuanzhi(p<0.05), Rensan(p<0.05) and Baishaoyao(p<0.05). Although the mechanisms of this effect remain to be elucidated, these results indicated that Danggui, Chaihu, Muxiang, Rensan and Baishaiyao might be a useful radioprotector, especially since it is a relatively nontoxic natural product.

• Korean Journal of Environmental Biology
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• v.23 no.1
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• pp.21-26
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• 2005

Cell response to genotoxic agents is complex and involves the participation of different classes of genes including cell cycle control, DNA repair and apoptosis. In this report, we presented a approach to characterize the cellular functions associated with the altered transcript profiles of MCF-7 exposed to low-dose in vitro gamma-irradiation. We used the method of human 2.4 k cDNA microarrays containing apoptosis, cell cycle, chromatin, repair, stress and chromosome genes to analyze the differential gene expression characterization that were displayed by radiation-exposed cell, human breast carcinoma MCF-7 cell line, such as 4 Gy 4 hr, 8 Gy 4 hr, and 8 Gy 12 hr. Among these genes, 66 were up-regulated and 49 were down-regulated. Specific genes were concomitantly induced in the results. Cyclin dependent kinase 4 (Cdk4) is induced for starting the cell cycle. This regulation is required for a DNA damage­induced G1 arrest. In addition to, an apoptotic pathways gene Bcl-w was concomitantly induced. Mismatch repair protein homologue-l (hMLH1), a necessary component of DNA mismatch protein repair (MMR), in G2-M cell cycle checkpoint arrest. The present study provides new information on the molecular mechanism underlying the cell response to genotoxic stress, with relevance to basic and clinical research.

• Journal of Radiation Protection and Research
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• v.24 no.2
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• pp.87-92
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• 1999

The present study was carried out to evaluate the morphological changes in the degenerating primordial follicles induced by $\gamma$-radiation. The prepubertal female mice of three weeks old ICR strain were whole-body irradiated with a dose of $LD_{80(30)}$ (8.3 Gy). The ovaries were collected at 0 h, 3 h, 6 h, and 12 h post-irradiation. The largest cross sections were prepared with histological semi-thin sections and then observed microscopically. The ratio of normal to atretic follicles was reduced significantly after 6th post-irradiation. At 6 h post-irradiation, the number of degenerated primordial follicles increased. Germinal vesicles disappeared, and lipid droplets increased. No more ooplasmic membranes were seen. Granulosa cells became round in shape, and apoptotic cells started to appear. The ratio of normal to atretic follicles in the control group was 62.50%. The ratio decreased with time after irradiation. The ratio decreased down to 51.61 %, 48.97 %, 11.11 %, and 7.14 % at 0 h, 3 h, 6 h, and 12 h, respectively. Taken together, ionizing radiation acutely induced the degeneration of primordial follicles. The patterns of degeneration are 1) apoptosis of one or more granulosa cells with relatively intact oocyte, 2) apoptosis of oocyte with intact follicle cells, or 3) apoptotic degenerations of both cells. The Present study can provide morphological clues for the identification of degenerating primordial follicles.

• Radiation Oncology Journal
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• v.14 no.4
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• pp.265-279
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• 1996

Damage produced by radiation elicits a complex response in mammalian cells, including growth rate changes and the induction of a variety of genes associated with growth control and apoptosis. At doses of 10,000 cGy or greater, the exposed individual was killed in a matter of minutes to a couple of days, with symptoms consistent with pathology of the central nervous system(CNS) including degenerative changes. The nature of the damage in irradiated cells underlies the unique hazards of ionizing radiation. Radiation injury to CNS is a rare event in clinical medicine, but it is catastrophic for the patient in whom it occurs. The incidence of cerebral necrosis has been reported as high as 16% for doses greater than 6,000 cGy. In this study, the effect of radiation on brain tissue was studied in vivo. Jun and p53 genes in the rat brain were induced by whole body irradiation of rat with 600Co in doses between 1 Gy and 100 Gy and analyzed for expression of jun and p53 genes at the postirradiation time up to 6 hours. Northern analyses were done using 1.8 Kb & 0.8 Kb-pGEM-2-JUN/Eco RI/Pst I fragments, 2.0 Kb-php53B/Bam HI fragment and ,1.1 Kb-pBluescript SK--ACTIN/Eco RI fragment as the digoxigenin or [${\alpha}^{32}P$] dCTPlabeled probes for Jun, p53 and ${\beta}$-actin genes, respectively. Jun gene seemed to be expressed near the threshold levels in 1 hour after irradiation of $^{60}$Co in dose less than 1 Gy and was expressed in maximum at 1 hour after irradiation of $^{60}$Co in dose of 30 Gy. Jun was expressed increasingly with time until 5 or 6 hours after irradiation of $^{60}$Co in doses of 1 Gy and 10 Gy. After irradiation of $^{60}$Co in dose between 20 Gr and 100 Gy, the expression of Jun was however increased to peak in 2 hours and decreased thereafter. p53 gene in this study also seemed to be expressed near the threshold levels in 1 hour after irradiation of $^{60}$Co in dose less than 1 Gy and was expressed in maximum at 6 hours after irradiation of $^{60}$Co in dose of 1 Gy, p53 was expressed increasingly with time until 5 or 6 hours after irradiation of $^{60}$Co in dose between 1 Gy and 40 Gy. After irradiation of $^{60}$Co in doses of 50 Gy and 100 Gy, the expression of p53 was however increased to peak in 2 hours and decreased thereafter. The expression of Jun and p53 genes was not correlative in the brain tissue from rats. It seemed to be very important for the establishment of the optimum conditions for the animal studies relevant to the responses of genes inducible on DNA damage to ionizing radiation in mammalian cells. But there are many limitations to the animal studies such as the ununiform patterns of gene expression from the tissue because of its complex compositions. It is necessary to overcome the limitations for development of in situ Northern analysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.93-98
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• 2000

We performed this study to determine the radioprotective effects of Shi-Quan-Dai-Bu-Tang, as a prescription of traditional Oriental medicine, and its major ingredients. The jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells were investigated in mice irradiated with high and low dose of ${\gamma}$-rays. The administration of danggui, baishaoyao, rensan, gancao or baifuling before irradiation protected the jejunal crypts (p<0.005). Shoudehuang, danggui, baishaoyao, rensan and huangqui increased the formation of endogenous spleen colony (p<0.05). Chuanxiong, baishaoyao, rensan and baifuling reduced the frequency of radiation-induced apotosis (p<0.05). The results indicated that the extracts of danggui, baishaoyao, rensan and baifuling may have radoprotective effects in mice irradiated with high and low dose of ${\gamma}$-rays. The radioprotective effect of the prescription, Shi-Qaun-Da-Bu-Tang, was not significant.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1871-1877
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• 2014

Enhancing of radioresponsiveness of tumors by using radiosensitizers is a promising approach to increase the efficacy of radiation therapy. Recently, the ethanolic extract of the medicinal plant, Derris scandens Benth has been identified as a potent radiosensitizer of human colon cancer HT29 cells. However, cell death mechanisms underlying radiosensitization activity of D scandens extract have not been identified. Here, we show that treatment of HT-29 cells with D scandens extract in combination with gamma irradiation synergistically sensitizes HT-29 cells to cell lethality by apoptosis and mitotic catastrophe. Furthermore, the extract was found to decrease Erk1/2 activation. These findings suggest that D scandens extract mediates radiosensitization via at least two distinct modes of cell death and silences pro-survival signaling in HT-29 cells.

• Korean Journal of Veterinary Research
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• v.41 no.2
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• pp.203-210
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• 2001

Here, we compared the effectiveness of 50 MeV($p{\to}RBe^+$) cyclotron fast neutrons versus $^{60}Co$ ${\gamma}$-rays by the apoptotic fragment frequency in both rat peripheral lymphocytes and crypt cells to check a radiobiological endpoint. The incidence of apoptotic cell death was increased in all irradiated groups, and radiation at all doses trigger rapid changes in both crypt cells and peripheral lymphocytes. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for these data of apoptotic fragments frequencies was $y=0.3+(6.512{\pm}0.279)D(r^2=0.975)$ after neutrons, while $y=0.3+(4.435{\pm}0.473)D+(-1.300{\pm}0.551)D^2(r^2=0.988)$ after ${\gamma}$-rays. In addition, $y=3.5+(118.410{\pm}10.325)D+(-33.548{\pm}12.023)D^2(r^2=0.992)$ after ${\gamma}$-rays in rat lymphocytes. A significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic cells with increasing dose. Dose-response curves for high and low linear energy transfer (LET) radiation modalities in these studies were different. The relative biological effectiveness (RBE) value for crypt cells was 1.919. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morphological findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis induction in both crypt cells and peripheral lymphocytes could be a useful endpoint of rat model for studying screening test and microdosimetic indicator to evaluate the biological effects of radiation-induced cell damage.

• Radiation Oncology Journal
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• v.28 no.3
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• pp.141-146
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• 2010

Purpose: We examined the radioprotective effects of 5-androstendiol (5-AED), a natural hormone produced in the reticularis of the adrenal cortex, as a result of intestinal damage in gamma-irradiated C3H/HeN mice. Materials and Methods: Thirty mice (C3H/HeN) were divided into three groups; 1) non-irradiated control group, 2) irradiated group, and 3) 5-AED-treated group prior to irradiation. Next, 5-AED (50 mg/kg per body weight) was subcutaneously injected 24 hours before irradiation. The mice were whole-body irradiated with 10 Gy for the histological examination of jejunal crypt survival and the determination of the villus morphology including crypt depth, crypt size, number of villi, villus height, and length of basal lamina, as well as 5 Gy for the detection of apoptosis. Results: The 5-AED pre-treated group significantly increased the survival of the jejunal crypt, compared to irradiation controls (p<0.05 vs. irradiation controls at 3.5 days after 10 Gy). The evaluation of morphological changes revealed that the administration of 5-AED reduced the radiation-induced intestinal damages such as villus shortening and increased length of the basal lamina of enterocytes (p<0.05 vs irradiation controls on 3.5 day after 10 Gy, respectively). The administration of 5-AED decreased the radiation-induced apoptosis in the intestinal crypt, with no significant difference between the vehicle and 5-AED at 12 hours after 5 Gy. Conclusion: The results of this study suggest that the administration of 5-AED has a protective effect on intestinal damage induced by $\gamma$-irradiation. In turn, these results suggest that 5-AED could be a useful candidate for radioprotection against intestinal mucosal injury following irradiation.

• Journal of Radiation Protection and Research
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• v.40 no.1
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• pp.25-35
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• 2015

We analyzed the differential effects of histopathology, apoptosis and expression of radiation response genes after chronic low dose rate (LDR) and acute high dose rate (HDR) radiation exposure in spleen, lung and liver of rats. Female 6-week-old Sprague-Dawley rats were used. For chronic low-dose whole body irradiation, rats were maintained for 14 days in a $^{60}Co$ gamma ray irradiated room and received a cumulative dose of 2 Gy or 5 Gy. Rats in the acute whole body exposure group were exposed to an equal dose of radiation delivered as a single pulse ($^{137}Cs$-gamma). At 24 hours after exposure, spleen, lung and liver tissues were extracted for histopathologic examination, western blotting and RT-PCR analysis. 1. The spleen showed the most dramatic differential response to acute and chronic exposure, with the induction of substantial tissue damage by HDR but not by LDR radiation. Effects of LDR radiation on the lung were only apparent at the higher dose (5 Gy), but not at lower dose (2 Gy). In the liver, HDR and LDR exposure induced a similar damage response at both doses. RT-PCR analysis identified cyclin G1 as a LDR-responsive gene in the spleen of rats exposed to 2 Gy and 5 Gy gamma radiation and in the lung of animals irradiated with 5 Gy. 2. The effects of LDR radiation differed among lung, liver, and spleen tissues. The spleen showed the greatest differential effect between HDR and LDR. The response to LDR radiation may involve expression of cyclin G1.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1108-1113
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• 2003

We performed this study to determine the effect of green tea on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with high and low dose of gammairradiation. The radioprotective effect of green tea was compared with the effect of diethyldithiocarbamate (DDC). Jejunal crypts were protected by pretreatment of green tea (p<0.01). Green tea administration before irradiation resulted in an increase of the formation of endogenous spleen colony (p<0.05). The frequency of radiation-induced apoptosis in intestinal crypt cells was also reduced by pretreatment of green tea (p<0.05). The radioprotective effect on jejunal crypts and apoptosis in the DDC treated group appeared similar to those in the green tea treated groups. Treatment with DDC showed no significant modifying effects on the formation of endogenous spleen colony. These results indicated that green tea might be a useful radioprotector, especially since it is a relatively nontoxic natural product. Further studies are needed to characterize better the promotion nature of green tea and its components.