Un-Jae Chang

Inhibitory Effects of Fucoidan in 3T3-L1 Adipocyte Differentiation

Fucoidan is a group of sulfated fucose-containing polysaccharides that derived from non-mammalian origin such as marine brown algae, the jelly coat from sea urchin eggs, and the sea cucumber body wall. However, potential biological activities against obesity from fucoidan were not reported in the literature. The objective of this study was to evaluate protective effect of fucoidan in 3T3-L1 adipocyte differentiation. Preadipocyte 3T3-L1 was treated with 100 and 200xa0μg/ml fucoidan during adipogenesis. Adipogenesis was determined through Oil Red O staining method and the expression of adipogenic genes aP2, ACC, and PPARγ. Adipogenesis of 3T3-L1 treated with 100 and 200xa0μg/ml fucoidan were significantly inhibited at 32.8% and 39.7% using Oil Red O staining method, respectively (Pu2009<u20090.05). Treating the 3T3-L1 cells with 100 and 200xa0μg/ml fucoidan significantly decreased the expression of aP2 gene by 6.2% and 27.2%, respectively, of ACC gene by 22.2% and 38.2%, respectively, and of PPARγ gene by 44.2% and 69.4%, respectively, compared to adipocyte controls (Pu2009<u20090.05). The results suggest that fucoidan could be used for inhibiting fat accumulation, which is mediated by decreasing aP2, ACC, and PPARγ gene expression.

Appetite suppressive effects of yeast hydrolysate on nitric oxide synthase (NOS) expression and vasoactive intestinal peptide (VIP) immunoreactivity in hypothalamus.

To investigate the effects of yeast hydrolysate on appetite regulation mechanisms in the central nervous system, nitric oxide synthase (NOS) expression and vasoactive intestinal peptide (VIP) immunoreactivity in the paraventricular nucleus (PVN) and ventromedial hypothalamic nucleus (VMH) of the hypothalamus were examined. Male Sprague‐Dawley (SD) rats were assigned to five groups: control (normal diet), BY‐1 and BY‐2 (normal diet with oral administration of 0.1 g and 1.0 g of yeast hydrolysate <10 kDa/kg body weight, respectively), AY‐1 and AY‐2 (normal diet with oral administration of 0.1 g and 1.0 g of yeast hydrolysate 10–30 kDa/kg body weight, respectively). The body weight gain in the BY groups was less than that in the control. In particular, the weight gain of the BY‐2 group (133.0 ± 5.1 g) was significantly lower (p < 0.05) than that of the control group (150.1 ± 3.7 g). Among the test groups, the BY‐2 group was shown to have significantly lower triacylglycerol (TG) levels (p < 0.05) than the other groups. The staining intensities and optical densities of NOS neurons in the PVN of the AY group were significantly higher (p < 0.05) than in the control and BY groups. The staining intensities and optical densities of VIP immunoreactivity in the PVN and VMH of the BY groups were higher than those of the AY groups and the control. In conclusion, these results indicated that yeast hydrolysate of <10 kDa reduced the body weight gain and body fat in normal diet‐fed rats and increased the lipid energy metabolism by altering the expression of NOS and VIP in neurons. Copyright

Effects of yeast hydrolysate on neuropeptide Y (NPY) and tryptophan hydroxylase (TPH) immunoreactivity in rats.

To investigate the appetite regulation mechanism of low and high molecular weight yeast hydrolysate, neuropeptide Y (NPY) and tryptophan hydroxylase (TPH) expressions were analyzed in the brains on rats using immunohistochemical method; normal diet (control), 0.1 g/kg (BY‐1) or 1.0 g/kg (BY‐2) of yeast hydrolysate below 10 kDa, 0.1 g/kg (AY‐1) or 1.0 g/kg (AY‐2) of yeast hydrolysate of 10–30 kDa. Body weight gain was lower in the BY‐2 (133.0 g) than in the control (150.1 g) (p < 0.05). Triacylglyceride, total cholesterol, and LDL‐cholesterol levels were lower in the BY‐2 as compared to control, BY‐1 and AY‐2 (p < 0.05). NPY staining intensities at paraventricular nucleus (PVN) were lower in the BY groups (BY‐1: 96.1, BY‐2: 88.6) as compared to the control (105.6) and AY groups (AY‐1: 110.5, AY‐2: 114.1) (p < 0.05). NPY expression at lateral hypothalamic area (LHA) was lower in the BY‐2 (92.3) than in the control (98.9) (p < 0.05). The BY groups (BY‐1: 143.9, BY‐2: 154.6) had higher TPH staining intensities at dorsal raphe (DR) than the AY‐2 (115.9) (p < 0.05). In conclusion, the results indicate that administering yeast hydrolysate of below 10 kDa to normal diet‐fed rats reduced body weight gain and serum lipids by altering NPY and TPH expressions. Copyright

Physiological effects of yeast hydrolysate SCP-20

When the yeast hydrolysate SCP-20 from Saccharomyces cerevisiae ingested to the rat to identify the effect on anti-stress, SCP-20 have an potent effect on the weight of adrenal, spleen, kidney and thyroid, and the glutamic pyruvic transaminase (GOT), glutamic oxaloacetic transaminse (GPT) and lactic dehydrogenase (LDH) activity recovered as much as the non-stress level. In addition, the swimming time was significantly increased in the group to administer SCP-20. It is assumed that anti-fatigue effect might relate to the resistance effect on the stress induced intensive exercise. SCP-20 stimulated not only the activation of macrophage (1.9-fold of saline control) but also IL-6 production (1.9-fold) at 2.0 g/kg/day. By the culture supernatant of Peyers patch cells from C3H/HeJ mice fed SCP-20 at 2.0 g/kg/day for 7 days, the bone marrow cells significantly proliferated as 2.1 fold to compare with those of mice received only saline (control). In addition, the contents of IL-6 in the culture supernatant of Peyers patch cells from mice fed SCP 20 at 2.0 g/kg per day were increased in the comparison with those from control (2.3-fold).

Vitamin C increases the fecal fat excretion by chitosan in guinea-pigs, thereby reducing body weight gain

The aims of this study were to investigate the antiobesity properties of chitosan on its own, as well as in the presence of vitamin C, in vivo. Hartley guinea‐pigs were divided into Control (normal diet), F‐control (high fat diet), Chitosan (high fat diet with 5.0% chitosan) and Chito‐vit C (high fat diet with 5.0% chitosan containing 0.5% vitamin C) groups, respectively. The effects of chitosan, both alone and in the presence of vitamin C, on body weight, total fecal weight, fecal composition and plasma lipid level were studied for 5 weeks. The results of this study indicated that the fat‐binding and water‐holding capacity of chitosan might decrease body weight by reducing the absorption of cholesterol and fat, subsequently increasing total fecal weight, fecal fat excretion and fecal water excretion. Vitamin C increased the fecal fat excretion by chitosan in guinea‐pigs, thereby reducing body weight gain. Copyright

Dissimilarity in Fos and Jun immunoreactivity in hypothalamic regions between obese and lean Zucker rats.

The obese Zucker rat, whose genotype is transmitted in an autosomal recessive fashion, is an animal model widely used in the field of obesity. The expression of the nuclear transcription factors c-Fos and c-Jun in the paraventricular nucleus (PVN) and arcuate nucleus (ARC) of the hypothalamus of obese Zucker rats was studied using immunohistochemical methods. PVN and ARC in the hypothalamus are known as centers for the control of food intake. It was observed that the numbers of c-Fos-positive and c-Jun-positive neurons in these regions decreased in obese rats compared to lean rats, and that difference was more evident in the ARC than in the PVN which has to do with the regulation of body weight. The reduction in expression in the ARC of obese rats was greater for c-Jun than for c-Fos. These results suggest a possible difference in Fos immunoreactivity in hypothalamic resistance to circulating satiety factors in genetically obese Zucker rats.

Tendency and Network Analysis of Diet Using Big Data

Limitation of a questionnaire survey which is widely used is time and money, limited numbers of participants, biased confidence interval and unreliable results. To overcome these, we performed tendency and network analysis of diet using big Data in Koreans. The keyword on diet were collected from the portal site Naver from January 1, 2015 until December 31, 2015 and collected data were analyzed by simple frequency analysis, N-gram analysis, keyword network analysis and seasonality analysis. The results showed that diet menu appeared most frequently by N-gram analysis, even though exercise had the highest frequency by simple frequency analysis. In addition, keyword network analysis were categorized into four groups: diet group, exercise group, commercial diet program company group and commercial diet food group. The analysis of seasonality showed that subjects’ interests in diet had increased steadily since February, 2015, although subjects were most interested indiet in July, these results suggest that the best strategies for weight loss are based on diet menu and starting diet before July. As people are especially sensitive to diet trends, researches are needed about annual analysis of big data.

Melatonin enhances NADPH-diaphorase activities in the hypothalamus of maternally-separated rats.

Maternal separation or social isolation is a risk factor in the development of mammalian species affecting both physical and mental growth, and food intake regulation. Melatonin has been known to regulate body weight on various species including rodents. We investigated the effect of melatonin treatment on the expression of nitric oxide synthase, which may involved in food intake regulation, in the brain of maternally separated-rats using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. Melatonin (10 mg/kg i.p.) was injected to 14-day-old maternally-separated rats for 7 days. Maternally-separated rats with melatonin administration showed significantly higher staining intensities of NADPH-d-positive neurons in the paraventricular nucleus (PVN) and in lateral hypothalamic area (LHA) than maternally-separated without melatonin administration (P < 0.05). Body weight of melatonin treated rats significantly increased at the 6th and 7th day compared to that of rats without melatonin treatment (P < 0.05). These results indicate that melatonin may be associated with increase body weight via NOS in the hypothalamic areas in maternally-separated or socially isolated rats.

The Analysis of a Diet for the Human Being and the Companion Animal using Big Data in 2016

The purpose of this study was to investigate the diet tendencies of human and companion animals using big data analysis. The keyword data of human diet and companion animals diet were collected from the portal site Naver from January 1, 2016 until December 31, 2016 and collected data were analyzed by simple frequency analysis, N-gram analysis, keyword network analysis and seasonality analysis. In terms of human, the word exercise had the highest frequency through simple frequency analysis, whereas diet menu most frequently appeared in the N-gram analysis. companion animals, the term dog had the highest frequency in simple frequency analysis, whereas diet method was most frequent through N-gram analysis. Keyword network analysis for human indicated 4 groups: diet group, exercise group, commercial diet food group, and commercial diet program group. However, the keyword network analysis for companion animals indicated 3 groups: diet group, exercise group, and professional medical help group. The analysis of seasonality showed that the interest in diet for both human and companion animals increased steadily since February of 2016 and reached its peak in July. In conclusion, diets of human and companion animals showed similar tendencies, particularly having higher preference for dietary control over other methods. The diets of companion animals are determined by the choice of their owners as effective diet method for owners are usually applied to the companion animals. Therefore, it is necessary to have empirical demonstration of whether correlation of obesity between human being and the companion animals exist.

Effects of Food Consumption Monitoring Using Modified Rice Bowls on Food Intake, Satiety Rate, and Eating Rate

ABSTRACT The study examined dietary intake, satiety rate, and eating rate using rice bowls with an elevated bottom (diet rice bowl) and rice bowls with an elevated bottom and monitoring line (monitoring rice bowl). The monitoring rice bowl was used to help subjects monitor amounts they had eaten as they ate. Eighteen normal weight college female students participated in this study once a week for 2 weeks. Three hundred grams of fried rice in a diet rice bowl (1st week), and 300 g of fried rice in a monitoring rice bowl were served to the participants over 2 consecutive weeks. After each lunch, dietary intake, satiety rate, and eating rate were measured. The consumption amount of fried rice was 261.6 g in the diet rice bowl group, and 264.8 g in the monitoring rice bowl group. There was no significant difference in fried rice intake between the two groups. The satiety rate of fried rice in the monitoring rice bowl group was significantly higher than that of the diet rice bowl group after 1 hour and 2 hours (P＜0.05). The eating rate of the diet rice bowl group (21.3 g/min) was significantly faster than that of the monitoring rice bowl group (18.7 g/min) (P＜0.05). This result shows that food consumption monitoring can affect not only eating rate but also the subjective feelings of satiety af-ter meal eating. Although more study is needed, these data suggest consumption monitoring in a rice bowl may help to control obesity and weight.