• BMB Reports
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• v.41 no.10
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• pp.745-750
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• 2008

Selenium, an essential trace element possessing anti-carcinogenic properties, can induce apoptosis in cancer cells. We have previously shown that sodium selenite can induce apoptosis by activating the mitochondrial apoptosis pathway in NB4 cells. However, the detailed mechanism remains unclear. Presently, we demonstrate that p53 contributes to apoptosis by directing signaling at the mitochondria. Immunofluorescent and Western blot procedures revealed selenite-induced p53 translocation to mitochondria. Inhibition of p53 blocked accumulation of reactive oxygen species (ROS) and loss of mitochondrial membrane potential, suggesting that mitochondrial p53 acts as an upstream signal of ROS and activates the mitochondrial apoptosis pathway. Selenite also disrupted cellular calcium ion homeostasis in a ROS-dependent manner and increased mitochondrial calcium ion concentration. p38 kinase mediated phosphorylation and mitochondrial translocation of p53. Taken together, these results indicate that p53 involves selenite-induced NB4 cell apoptosis by translocation to mitochondria and activation mitochondrial apoptosis pathway in a transcription-independent manner.

• Journal of Plant Biotechnology
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• v.30 no.4
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• pp.387-397
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• 2003

During the first half of twentieth century, even though the importance of non-calorie essential micronutrients of 13 vitamins and 17 minerals has been known to alleviate nutritional disorder; the primary objective of agriculture and plant breeding programs has been to increase the productivity and seed yields, and macronutrients of proteins, fats, and carbohydrates made up the bulk of foodstuff which were used primarily as an energy source. In the last decade it has been found that non-essential micronutrients encompass a vast group of phytochemicals including antioxidants that are not strictly required in the diet but when present at sufficient levels work as health-promoting chemicals. Nowadays agricultural crops are grown for health rather than for food or fiber, and modifying the nutritional compositions of plant foods has become an urgent health issue. To ensure an adequate intake of essential vitamins and minerals, and to increase the consumption of health-promoting phytochemicals, the researches on plant secondary metabolism have been made. The attempt to improve nutritional quality of crops has been blocked by a lack of basic knowledge of plant metabolism. The advent of genomics era enabled new approaches to make crossing regardless of species, family, or phylum barriers, and the accumulation in our basic knowledge on plant secondary metabolism during the coming decade would be tremendous. As the major staple crops contain insufficient amount of many micronutrients, fortification strategy will be a necessary practice. Elevated intake of specific vitamins, C, E, and $\beta$-carotene, mineral selenium, antioxidants, and phytochemicals significantly reduces the risk of chronic disease such as cancer, cardiovascular disorder, diabetis, and other degenerative disease associated with aging. As the attempt to improve the nutritional quality of crops requires the basic knowledges on plant metabolism, plant biochemistry, human physiology, and food chemistry, strong interdisplinary collaboration among plant biotechnologists, human nutritionists, and food scientists will be needed. Inhibition of cancer, cardiovascular disease, and other degenerative disorder may be the biggest goal facing nutritional plant breeders. But the assumption that simply increasing dietary level of any compound will necessarily improve human health is a dangerous idea because many plant secondary products and dietary contaminants have paradoxical (hermetic) effects. Before biotechnical manipulation is undertaken to elevate or reduce any individual constituent of crops, the contribution of the micronutrient to human health must first be investigated.

• Journal of Nutrition and Health
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• v.9 no.4
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• pp.19-27
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• 1976

Perilla (frutescens) seed oil, which is widely used as a source of vegetable oil in Korea, contains a strikingly large amount (58.4% of total fatty acids) of polyunsaturated linolenic acid (18 : 3) which is one of the essential fatty acids. Our hypothesis was that vitamin E contained in this oil would not be enough to prevent peroxidation of this polyunsaturated oil. A comparative study was carried out using rats and chicks devided into seven groups with various diet combinations emphasizing fat sources for the period of four weeks. The level of fat in each diet was 15% and animals were fed ad libitum. Various diet combinations were as follows; perilla seed oil and sesame seed oil with and without vitamin E supplementation, tallow as a saturated fat source and perilla seed hull group (10% at the expense of carbohydrate). The fat constituents of control group were consisted of 50% vegetable oil and 50% animal fat. A few important findings are as follows: 1. Rats fed perilla seed oil lost their hair focally around the neck and suffered from a bad skin lesion at the same place. In chicks, yellow pigmentation both of feather and of skin was clearly observed only in groups fed perilla seed oil with or without vitamin E supplementation. The basis of biochemical mechanisms of this phenomena remains as an important research interest. 2. The mean value for hematocrit was significantly lower for the chicks fed perilla seed oil than for those fed control diet. This result seems to be attributable to the effect on the red cell membrane known as peroxidation-hemolysis of vitamin E deficiency. 3. The serum cholesterol level was higher for the rats fed perilla seed oil than for those fed control diet, whereas in chicks the group fed perilla seed oil showed lower value than the control group indicating that different animal species could vary in their responses to the same diet. 4. In pathological examinations, the sign of hepatic fibrosis was seen in the perilla seed hull group and it was noticeable that the level of hepatic RNA was significantly increased in the rat recovering from vitamin E deficiency. It is hoped that more detailed studies on perilla seed oil and hulls will soon be carried out in many aspects especially i) at various levels of fat in the diet, ii) in relation to dietary selenium level and iii) to find an optimum level of dietary essential fatty acids in terms of P/S ratio using various animal species. In the mean time, the public should be informed to preserve this particular oil with care to minimize fatty acid oxidation and should be discouraged from overconsuming this oil. This study was supported by UB (United Board) Research Grant (Graduate School, Yonsei University, Seoul, Korea)

• Journal of Embryo Transfer
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• v.21 no.1
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• pp.21-27
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• 2006

This study was conducted to determine the distribution of cat follicles among varying ages and produce oocytes from preantral follicles cultured in vitro. We used ovaries from 41 cats ranging in age from 0.3 to 5 years. Ovaries were obtained from cats undergoing routine ovariectomy at local veterinary clinics. As a prelude to in vitro culture of preantral follicles, the length and the width and the weight of ovaries among cats of varying ages were measured. Ovaries were fixed in 10% formalin, embedded in paraffin, cut into $3{\mu}m$-sections, mounted on slides and stained with hematoxylin and eosin. Follicles were evaluated at 200X and 400X magnification. Distribution of follicles among cats of varying ages were evaluated according to follicle classification: primordial, primary, transitional, preantral and antral follicles. Preantral follicles were isolated by the simple mechanical procedure. Each follicle was cultured in a well containing $100{\mu}l$ of medium 199 supplemented with 10% fetal bovine serum (FBS) or polyvinylalcohol (PVA) for 16 days. Follicle diameters were measured under inverted microscope every 4 days. The length, the width and the weight of ovaries were increased gradually according to ages but there was not significant difference among cats of varying ages. Majority of follicles were primordial follicles (84%) regardless of cat ages (p<0.05). Follicle diameter increased until 4 days of culture. However, period longer than 4 days of culture in vitro had a deleterious effect on follicle survival regardless of supplement (FBS or PVA). A few oocytes were collected from preantral follicles cultured in vitro. These basic reproductive techniques in domestic cats can be a useful tool to save endangered feline species.