• BMB Reports
• /
• v.49 no.3
• /
• pp.173-178
• /
• 2016

Liver cells experience hypoxic stress when drug-metabolizing enzymes excessively consume O₂ for hydroxylation. Hypoxic stress changes the transcription of several genes by activating a heterodimeric transcription factor called hypoxia-inducible factor-1α/β (HIF-1α/β). We found that hypoxic stress (0.1% O₂) decreased the expression of cytochrome P450 7A1 (CYP7A1), a rate-limiting enzyme involved in bile acid biosynthesis. Chenodeoxycholic acid (CDCA), a major component of bile acids, represses CYP7A1 by activating a transcriptional repressor named small heterodimer partner (SHP). We observed that hypoxia decreased the levels of both CDCA and SHP, suggesting that hypoxia repressed CYP7A1 without inducing SHP. The finding that overexpression of HIF-1α increased the activity of the CYP7A1 promoter suggested that hypoxia decreased the expression of CYP7A1 in a HIF-1-independent manner. Thus, the results of this study suggested that hypoxia decreased the activity of CYP7A1 by limiting its substrate O₂, and by decreasing the transcription of CYP7A1.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.5
• /
• pp.872-877
• /
• 1997

Soybean curd whey(SCW) containing plenty of nutrients is the discarded by-product in soybean curd processing. To test the potential utilization of SCW as a medium for the cultivation of Lactobacilus acidophilus, the chemical composition of SCW, as well as the growth, acid production, acid-tolerance, and bile-tolerance of L. acidophilus in SCW-based media were investigated. Sucrose and stachyose, the main free sugars of SCW, were 0.42% and 0.41%, respectively. SCW contained 36.1mg/L of total free amino acids. L. acidophilus KFRI 150 showed lower cell growth and acid production in SCW than those in MRS broth. In optimized SCW-based medium supplemented with 1.0% glucose, 0.5% yeast extract, and 0.2% $K_{2}HPO_{4}$, the growth and acid production of L. acidophilus KFRI 150 increased by twice against those in SCW. In optimized SCW-based medium, the viable counts of four L. acidophilus strains were mostly at the level of $10^{9}$/ml, which is similar to those in MRS broth. Each acid-tolerance and biletolerance of four L. acidophilus strains cultured in optimized SCW-based medium and MRS broth showed no dist-inguishable difference.

• International Journal of Oral Biology
• /
• v.38 no.3
• /
• pp.93-100
• /
• 2013

Bile acids and synthetic bile acid derivatives induce apoptosis in various kinds of cancer cells and thus have anticancer properties. Recently, it has been suggested that autophagy may play an important role in cancer therapy. However, few data are available regarding the role of autophagy in oral cancers and there have been no reports of autophagic cell death in OSCCs (oral squamous cell carcinoma cells) induced by HS-1200, a synthetic bile acid derivative. We thus examine whether HS-1200 modulates autophagy in OSCCs. Our findings indicate that HS-1200 has anticancer effects in OSCCs, and we observed in these cells that autophagic vacuoles were visible by monodansylcadaverine (MDC)and acridine orange staining. When we analyzed HS-1200-treated OSCC cells for the presence of biochemical markers, we observed that this treatment directly affects the conversion of LC-3II, degradation of p62/SQSTM1 and full-length beclin-1, cleavage of ATG5-12 and the activation of caspase. An autophagy inhibitor suppressed HS-1200-induced cell death in OSCCs, confirming that autophagy acts as a pro-death signal in these cells. Furthermore, HS-1200 shows anticancer activity against OSCCs via both autophagy and apoptosis. Our current findings suggest that HS-1200 may potentially contribute to oral cancer treatment and thus provide useful information for the future development of a new therapeutic agent.

• Animal Bioscience
• /
• v.36 no.8
• /
• pp.1209-1220
• /
• 2023

Objective: The use of probiotics as an alternative to antibiotics in animal feed has received considerable attention in recent decades. Lactic acid bacteria (LAB) have remarkable functional properties promoting host health and are major microorganisms for probiotic purposes. The aim of this study was to characterize LAB strains of the chicken digestive tract and to determine their functional properties for further use as potential probiotics in poultry. Methods: A total of 2,000 colonies were isolated from the ileum and cecal contents of the chickens based on their phenotypic profiles and followed by a preliminary detection for acid and bile tolerance. The selected 200 LAB isolates with exhibited well-tolerance in acid and bile conditions were then identified by sequencing the 16S rDNA gene, followed by acid and bile tolerance, antimicrobial activity, adhesion to epithelial cells and additional characteristics on the removal of cholesterol. Then, the two probiotic strains (L. ingluviei and L. salivarious) which showed the greatest advantage in vitro testing were selected to assess their efficacy in broiler chickens. Results: It was found that 200 LAB isolates that complied with all measurement criteria belonged to five strains, including L. acidophilus (63 colonies), L. ingluviei (2 colonies), L. reuteri (58 colonies), L. salivarius (72 colonies), and L. saerimneri (5 colonies). We found that the L. ingluviei and L. salivarius can increase the population of LAB and Bifidobacterium spp. while reducing Enterobacteria spp. and Escherichia coli in the cecal content of chickens. Additionally, increased concentrations of valeric acid and short chain fatty acids were also observed. Conclusion: This study indicates that all five Lactobacillus strains isolated from gut contents of chickens are safe and possess probiotic properties, especially L. ingluviei and L. salivarius. Future studies should evaluate the potential for growth improvement in broilers.

• Journal of Nutrition and Health
• /
• v.21 no.2
• /
• pp.89-98
• /
• 1988

This study was done to determine the effects of coix on the content of cholesterol. lipids, phosphoilpids, total bile acids in liver, plasma, and feces of rats fed containing 1% cholesterol. Four groups of experimental diets, such as soybean oil-starch diet, soybean oil-coix diet, lard-starch diet, lard-coix diet were fed ad libitum to the 6 weeks old white male rat of Spargue-Dawley strain for 27 days. The results obtained are summarized as follows: 1) Plasma cholesterol level of the lard-starch group was significantly higher than the other groups (p<0.05), and that of the lard-coix group was the lowest. The content of plasma triglyceride, total bile acids was not different among the lard-starch group was significantly higher than the other groups(p<0.05). 2) The contents of the liver lipids, cholesterol, and triglycerides of the lard-coix group were significantly lower than the other groups(p<0.05). The contents of phospholipid of the liver of the lard-starch group was significantly lower than the other groups(p<0.05), and those of the soybean oil-coix group and the lard-coix group were high. 3) The contents of intestinal lipids, triglyceride, and phospholipid of the lard-coix group were significantly lower than the other groups(p<0.05). The contents of the intestinal tissue cholesterol of the lard-coix group was significantly lower than the other groups(p<0.05). 4) Cholesterol content of the feces was not different among the experimental groups. Triglyceride content of the feces of the soybean oil-starch group was significantly higher than the other groups, but total bile acid content of the feces was not different among the experimental groups. 5) Dry matter digestibility was not different among the experimental groups, but cholesterol retention was rather low when soybean oil-diet was fed. The results of this study reveales that coix has an effect to lower the plasma cholesterol level. Coix were decreased the content of liver cholesterol, increased the contend of liver phospholipid, and induced triglyceride excretion of the feces in the lard diet which lead to hypercholesterolemia. It could be suggested that the coix has influesced liped metabolsim in body.

• Journal of Animal Science and Technology
• /
• v.64 no.4
• /
• pp.671-695
• /
• 2022

The gastrointestinal tract is a complex ecosystem that contains a large number of microorganisms with different metabolic capacities. Modulation of the gut microbiome can improve the growth and promote health in pigs. Crosstalk between the host, diet, and the gut microbiome can influence the health of the host, potentially through the production of several metabolites with various functions. Short-chain and branched-chain fatty acids, secondary bile acids, polyamines, indoles, and phenolic compounds are metabolites produced by the gut microbiome. The gut microbiome can also produce neurotransmitters (such as γ-aminobutyric acid, catecholamines, and serotonin), their precursors, and vitamins. Several studies in pigs have demonstrated the importance of the gut microbiome and its metabolites in improving growth performance and feed efficiency, alleviating stress, and providing protection from pathogens. The use of probiotics is one of the strategies employed to target the gut microbiome of pigs. Promising results have been published on the use of probiotics in optimizing pig production. This review focuses on the role of gut microbiome-derived metabolites in the performance of pigs and the effects of probiotics on altering the levels of these metabolites.

• Biomolecules & Therapeutics
• /
• v.32 no.4
• /
• pp.403-423
• /
• 2024

The human gastrointestinal (GI) tract houses a diverse microbial community, known as the gut microbiome comprising bacteria, viruses, fungi, and protozoa. The gut microbiome plays a crucial role in maintaining the body's equilibrium and has recently been discovered to influence the functioning of the central nervous system (CNS). The communication between the nervous system and the GI tract occurs through a two-way network called the gut-brain axis. The nervous system and the GI tract can modulate each other through activated neuronal cells, the immune system, and metabolites produced by the gut microbiome. Extensive research both in preclinical and clinical realms, has highlighted the complex relationship between the gut and diseases associated with the CNS, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. This review aims to delineate receptor and target enzymes linked with gut microbiota metabolites and explore their specific roles within the brain, particularly their impact on CNS-related diseases.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.2
• /
• pp.314-318
• /
• 1997

This study was performed to examine the effects of Meju supplementation to high cholesterol diet on lipid metabolism in rats. Male Sprague-Dawley rats were divided into two groups(Steamed soybean, Meju) and were fed with 0.5% cholesterol diet. Serum and liver lipid profiles and fecal bile acids excretion were examined after four weeks of experimental diet. Food intake, weight gain and liver weight were not significantly different between the two groups. Total cholesterol concentrations in serum was significantly lower in Meju group compared to steamed soybean group(p＜0.05). HDL-cholesterol, triglyceride, phospholipids and nonestrified fatty acid concentrations in serum were not significantly different between the two groups. Cholesterol, triglyceride, and phospholipids concentrations in liver were not significantly different between the two groups. Fecal bile acid excretion were markedly higher in Meju groups than the group fed steamed soybean(p＜0.05). These results suggest that the cholesterol lowering effect by Meju supplementation might be resulted from the modulation of fecal bile acid excretion in rats.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.6
• /
• pp.906-912
• /
• 2003

The study was conducted to investigate the effect of Saengshik supplementation on lipid metabolism in rats fed high cholesterol diets. Male Spraque-Dawley rats were administrated 1% cholesterol to induce hypercholesterolemia and were fed on diet containing Saengshik (30%, w/w). Serum and liver lipid profiles and fecal bile acids excretion were examined after 7 weeks of experimental diet. The feeding of diet containing 30% Saengshik significantly decreased total cholesterol (TC) contents in liver and plasma. Since cholesterol was balanced by entero-hepatic circulation through bile acid synthesis and reabsorption, inhibition of bile acid re-uptake in intestine decreases total cholesterol in liver and blood. In this point, significant increament of fecal bile acid excretion in Shaengshik group decreased TC and improved hypercholesterolemia. Also plasma high density lipoprotein-cholesterol (HDL-C) decreasing risk for coronary heart disease in Saengshik supplemented group was significantly higher than control group, whereas low-density lipoprotein-cholesterol (LDL-C) accumulation in arterial vessel wall was significantly lower than control group. In this result, we supposed that supplementation of Saengshik, uncooked natural food, may improve hypercholesterolemia through increment of cholesterol excretion.

• Journal of Dairy Science and Biotechnology
• /
• v.30 no.1
• /
• pp.45-53
• /
• 2012

Lactobacillus acidophilus isolated from the feces of a 7-day-old breast-fed infant was characterized to examine the scope of its commercial use. Forty-three Lactobacillus strains, which could grow at pH 5.5, were isolated. From these Lactobacillus isolates, 14 Lactobacillus strains were selected, which demonstrated more than 80% viability and homofermentative lactic fermentation. Finally, 9 L. acidophilus strains (NB 201~NB 209) were identified as candidate strains based upon biochemical properties, carbohydrate utilization, and cellular fatty acid composition. L. acidophilus isolates demonstrated a survival rate of more than 80% when exposed to pH 2.5 for 2 h. In particular, L. acidophilus NB 204 showed a strong acid tolerance, with a 71% survival rate even at pH 2.0. L. acidophilus isolates also manifested high bile acid tolerance; more than 87% of the cells survived on agar containing 1% bile extract, except for L. acidophilus NB 206, which showed a 73% survival rate. All L. acidophilus isolates were confirmed to have proteolytic activity; L. acidophilus NB 204 and NB 209 yielded higher levels of TCA-soluble peptides and free amino acids. The ${\beta}$-galactosidase activity of the L. acidophilus isolates was in the range of 1.97~2.45 units/mL.