For the purpose of estimating the maximum absorption of riboflavin and thiamine from the intestine, large test doses of riboflavin and thiamine were administered orally to apparently normal male subjects, receiving normal Korean diets, and their maximum absorption were estimated by determining the excretion in urine. The maximum absorption of riboflavin and thiamine were estimated 10.700 and 3.800 mg. respectively.
Human ; Intestinal Absorption* ; Male ; Riboflavin/metabolism* ; Thiamine/metabolism*

Flavoproteins are proteins that contain a nucleic acid derivative of riboflavin: flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN). Flavoproteins are involved in a wide array of biological processes, such as photosynthesis, DNA repair and natural product biosynthesis. It should be noted that 5%-10% of flavoproteins have a covalently linked flavin prosthetic group. Such covalent linkages benefit the holoenzyme in several ways including improving the stability and catalytic potency. During the past decade, significant progress has been made in covalent flavoproteins, especially with respect to enzyme-dependent biogenesis and discovery of novel linkage types. The present review gives a condensed overview of investigations published from March 2009 to December 2021, with emphasis on the discovery, biogenesis and their catalytic role in natural product biosynthesis.
Flavoproteins/metabolism* ; Flavin-Adenine Dinucleotide/metabolism* ; Flavin Mononucleotide/metabolism* ; Riboflavin ; Biological Products

Riboflavin is a constituent of coenzyme, FMN, FAD and its content varies according to the physiological and nutritional status. However, the measurement of its content is so disputable that a new technique to determine its content has been developed, done by determination of glutathione reductase activity in red blood cell hemolysate. With this technique, the effect of various anesthetic agents (ether, halothane, tetracaine) upon riboflavin metabolism has been studied by the authors. In conclusion, the effects of anesthetics upon riboflavin metabolism are insignificant.
Anesthetics ; Erythrocytes* ; Flavin Mononucleotide ; Flavin-Adenine Dinucleotide ; Glutathione Reductase ; Glutathione* ; Halothane ; Metabolism ; Nutritional Status ; Riboflavin

OBJECTIVETo explore the improvement effect of vitamins B1, B2, PP supplementation to the metabolism changes of carbohydrates, lipids, protein and energy in mice exposed to acute hypoxia.

METHODSFifty male Kunming mice were randomly divided into normal, acute hypoxia, acute hypoxia plus 2 times, 4 times and 8 times vitamins B1, B2, PP supplemented groups. All mice were fed corresponding diets for two weeks and then except the normal group were exposed to a simulated altitude of 6 000 meters for 8 hours. The changes of glucose, pyruvate, lactate, urea nitrogen, free fatty acids and beta-hydroxybutyric acid from serum, liver glycogen and blood adenosine triphosphate (ATP) concentration were measured.

RESULTSAfter being exposed to acute hypoxia, the mice glucose, liver glycogen, pyruvate, lactate, free fatty acids, beta-hydroxybutyric acid and urea nitrogen level were increased significantly (P < 0.05), while blood ATP concentration was decreased. In the vitamins B1, B2 and PP supplemented groups, these changes were improved.

CONCLUSIONThe significant changes in carbohydrate, lipid and protein metabolism were observed in mice exposed to acute hypoxia, and the supplementation of vitamins B1, B2 and PP was proved to be beneficial in improving some metabolic pathways. It is suggested that the supplemented dose of four times was good.

Animals ; Carbohydrate Metabolism ; Hypoxia ; metabolism ; physiopathology ; Lipid Metabolism ; Male ; Mice ; Niacinamide ; administration & dosage ; Proteins ; metabolism ; Riboflavin ; administration & dosage ; Thiamine ; administration & dosage ; Vitamin B Complex ; administration & dosage

In Bacillus subtilis , raising the amount of carbon catabolite in vivo would lead to carbon catabolite repression (CCR) and restrain the absorption of glucose. By deleting CcpA the CCR effect could be relieved, but the absorption of glucose remains restrained. The phosphoenol-pyruvate-sugar phosphotransferase system (PTS) is the main glucose transportation system in B. subtilis. HPr protein together with HprK/P participate in the glucose transportation. The HPr protein is phosphorylated at His-15 forming HPr-His-15-P transferring phosphate group from HPr to E II . While HprK/P phosphorylate HPr at Ser-46 forming HPr-Ser-46-P. HPr-Ser-46-P cannot participate in the transportation of glucose. The Knockout of ccpA gene increases the amount of fructose 1,6-bisphosphate(FBP) in vivo. And FBP could activate HPr kinase. So when CcpA is deleted, most part of the HPr will be phosphorylated at Ser-46. Absorpton of glucose is blocked. In this study, by disruption of hprk gene, the obtained B. subtilisZHc/pMX45 reaches the peak riboflavin production of 4.374mg/mL at the optimum glucose concentration of 10%, 19.2% higher than that of B. subtilis24 A1/pMX45 at the optimum glucose concentration of 8%.
Bacillus subtilis ; metabolism ; Bacterial Proteins ; genetics ; physiology ; Fermentation ; Glucose ; metabolism ; Mutation ; Phosphoenolpyruvate Sugar Phosphotransferase System ; genetics ; physiology ; Riboflavin ; metabolism ; Sucrose ; metabolism

To delineate the relationship between the nutrient intake from diet and the serum biochemical markers of bone metabolism, 56 postmenopausal women of 50 to 77 years of age were recruited. The biochemical markers including osteocalcin, calcium, phosphorus, estradiol and free testosterone were measured in fasting blood. Bone mineral density(BMD) was measured also by dual energy X-ray absorptiometry, and the nutrient intake of earth individual subject was estimated by 24-hour recall of 3 days. The age of the subjects was 64.8 +/- 7.7 years, and the BMDs of the subject were 0.86 +/- 0.26g/cm2(Lumbar spine), 0.60 +/- 0.10g/cm2 (Femoral neck), 0.49 +/- 0.10g/cm2(Trochanter), and 0.41 +/- 0.14g/cm2(Ward's triangle). There were no significant differences among age and nutrient intake level groups due to the small sample size. The biochemical markers showed certain degree of relationship with nutrient intake levels. The results were compared among 3 groups with different nutrient intake level classified by the percentage of Recommended Daily Allowances(RDA) for Koreans as follows low < 75% RDA, 75% RDA < or = adequate< 125% RDA, high > or = 125% RDA. The low energy and low riboflavin groups showed significantly higher serum osteocalcin levels than those of the high intake groups(p<0.05). On the other hand, there was a trend for serum Ca level to be higher with high nutrient intake. In this case, protein and thiamin were the only nutrients that reached a statistical significance(p<0.05). And the groups with low intake for protein and Ca showed significantly lower serum free testosterone levels than that of other intake groups(p<0.05). This study suggests an important role of nutrient intake levels on blood biochemical markers of bone metabolism.
Absorptiometry, Photon ; Biomarkers* ; Calcium ; Diet ; Estradiol ; Fasting ; Female ; Hand ; Humans ; Metabolism* ; Osteocalcin ; Phosphorus ; Postmenopause ; Riboflavin ; Sample Size ; Testosterone

Amino Acid Metabolism, Inborn Errors ; diagnosis ; metabolism ; therapy ; Diagnosis, Differential ; Diet ; Glutarates ; metabolism ; urine ; Humans ; Infant ; Male ; Riboflavin ; therapeutic use ; Treatment Outcome

In this study, nutrient intake status and energy expenditure were examined to investigate the nutritional status of the elderly in a rural community. The results obtained by questionaries, the 24 hour recall method, and time-diary were as follows: The elderly men surveyed were 73.8 years old, on the average. The elderly women surveyed were 73.5 years old, on the average. The proportion of the elderly with diseases was 51.9%. Most of the subjects (86.1%) had a regular meal pattern of consuming three meals a day. The average daily energy intake of the rural elderly was much lower than the Korean RDA. The dietary assessment data showed that each energy intake of the males and the females was 79.5% and 84.3% of the RDA, respectively. The dietary intake of Ca, Fe, niacin, thiamin, and riboflavin was lower than the Korean RDA, and that of P and Vitamin C was adequate. The Fe intake was significantly different with respect to age and sex (p < 0.05). Although, in both elderly men and elderly women it decreased with age, the elderly men's intake was lower than the elderly women's. The heights of the elderly men and the elderly women was 159.7 cm and 147.5 cm, respectively, and the weights were 60.0 kg and 52.2 kg, respectively, and the BMI was in the moderate range. Heights significantly decreased with age (p < 0.05). According to daily living schedules, leisure time (11.0 hour) was the longest, physiological time (9.6 hours) was next, and work time (3.4 hours) was the shortest. Energy expenditure significantly decreased with age (p < 0.01). Energy intake also decreased with aging. Energy balance (energy expenditure/ energy intake) was 93.4% in elderly men and 104.0% in elderly women. Especially, in elderly men in the 65 to 74 age range, the energy balance was the lowest, and the nutrient intake was also much lower than that of elderly women.
Aged* ; Aging ; Appointments and Schedules ; Ascorbic Acid ; Energy Intake ; Energy Metabolism* ; Female ; Humans ; Leisure Activities ; Male ; Meals ; Niacin ; Nutritional Status* ; Riboflavin ; Rural Population* ; Weights and Measures

With the number of persons over 60 years of age increasing at a rapid rate, chronic diseases threaten to cause suffering and disability for an increasing segment of the population while bankrupting health-care systems with the costs of therapeutic and custodial care for the elderly. The dietary intakes of more than 50% of the elderly people did not meet 75% of the estimated average requirements for vitamin A, riboflavin, vitamin C, calcium and iron in Korea. Low dietary intakes of vitamins have been associated with higher risks of diseases in elderly people. Vitamins and minerals are well known essential nutrients for proper metabolism. Causes of lack of data in Korea, we should make some more precise recommendations for vitamins for aging people. Healthy habit such as regular exercise, balanced diet and avoidance of stresses are important way to maintain good health in elderly. But, micronutrients especially vitamins are one of essential nutrients for good health. So, Frail elderly people need to have well balanced diet for those micronutrients.
Aged* ; Aging ; Ascorbic Acid ; Calcium ; Chronic Disease ; Custodial Care ; Diet ; Frail Elderly ; Humans ; Iron ; Korea ; Metabolism ; Micronutrients ; Minerals ; Riboflavin ; Vitamin A ; Vitamins*

This study aims to investigate the mechanism of Linderae Radix water extract(LRWE) in the prevention and treatment of diarrhea-predominant irritable bowel syndrome(IBS-D) based on serum metabolomics. Eighteen 2-week-old male SD rats were randomized into control, IBS-D model, and LRWE groups. The rats in other groups except the control group received gavage of senna concentrate combined with restraint stress for the modeling of IBS-D. The rats in the LRWE group were administrated with LRWE(5.4 g·kg~(-1)) by gavage, and those in the control and IBS-D model groups with an equal volume of distilled water for a total of 14 days. The visceral sensitivity was evaluated by the abdominal withdrawal reflex(AWR) score, and the degree of diarrhea was assessed by the fecal water content(FWC). The morphological changes of the colon and the morphology and number of goblet cells were observed by hematoxylin-eosin(HE) and periodic acid-schiff(PAS) staining, respectively. Ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was used for the screening of the potential biomarkers in the rat serum and their related metabolic pathways. The results showed that LRWE reduced the AWR score, decreased FWC, and alleviated visceral sensitivity and diarrhea symptoms in IBS-D rats. HE and PAS staining showed that LRWE mitigated low-grade intestinal inflammation and increased the number of mature secretory goblet cells in the colonic epithelium of IBS-D rats. A total of 25 potential biomarkers of LRWE in treating IBS-D were screened out in this study, which were mainly involved in riboflavin, tryptophan, glycine, serine and threonine metabolism, glyoxylate and dicarboxylate metabolism, and cysteine and methionine metabolism. The regulatory effects were the most significant on the riboflavin and tryptophan metabolism pathways. LRWE may alleviate the visceral hypersensitivity by promoting energy metabolism and amino acid metabolism, enhancing intestinal barrier function, and improving intestinal immune function in IBS-D rats.
Rats ; Male ; Animals ; Irritable Bowel Syndrome/metabolism* ; Water ; Chromatography, Liquid ; Tryptophan ; Rats, Sprague-Dawley ; Tandem Mass Spectrometry ; Diarrhea/drug therapy* ; Biomarkers ; Riboflavin