• Journal of Nutrition and Health
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• v.27 no.2
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• pp.162-171
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• 1994

The purpose of this study was to describe the effects of caffeine ingestion on the metabolic responses during submaximal exercise. Ten male of rowing player aged 18-22yrs. participated in the study. No subjects had any remarkable medical history and none were taking medications. According to the administration of dehydrated caffeine(CA) (6mg/kg) or placebo(PA), they were classified into two groups such as caffeine group and placebo group. A randomized, double-blind, crossover protocol was employed using either CA or PA. Subjects underwent a submaximal bicycle ergometer. Blood was drawn intravenously prior to 60 min., at rest, at 30, and 45 min. of exercise, and recovery period. Plasma concentrations of glucose, free fatty acid and lactate were obtained using enzymatic method. Followings were obtained by the tests and analyses; 1) Blood glucose(BG) of 45 minute of exercise was significantly decreased in CA group of 76.3$\pm$14.8 mg/100ml compared with PA group of 94.9$\pm$11.2 mg/100mg(p<0.5). 2) Free fatty acid(FFA) of 30minute of exercise was significantly increased in CA group of 720$\pm$80 $\mu$Eq/1 compared with PA group of 360$\pm$120 $\mu$Eq/1(p<0.5). After exercise, FFA was significantly higher in CA group than those in PA group(p<0.1). 3) Blood lactate(BL) was not significantly different between the two. After exercise, BL was significantly different in 30 minute(p<05).

• Korean Journal of Animal Reproduction
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• v.9 no.1
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• pp.62-65
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• 1985

This study was conducted to investigate the effect of progesterone on the oxygen consumption of washed goat spermatozoa. The results obtained were summarized as follows: 1. Progesterone significantly depressed the respilation of the spermatozoa. 2. Caffeine and Di-cAMP greatly increased the oxygen consumption of the spermatozoa. 3. Caffeine plus progesterone and Di-cAMP plus progesterone significantly depressed the oxygen uptake of the cells. 4. There is some indication of a relationship between progesterone and its interference with metabolic behavior of sperm.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.212-213
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• 2002

Using the isolated perfused rat heart this study investigated 1) the cardiac uptake of idarubicin (IDA), 2) the role of P-glycoprotein (P-gp) in the uptake process, 3) the formation of IDOL from IDA in the heart, and 4) the effect of P-gp inhibitors (verapamil, amiodarone, PSC 833), doxorubicin, hypothermia, xanthine derivatives (caffeine, theophylline) and metabolism inhibitors (rutin, phenobarbital) on the pharmacokinetics and pharmacodynamics of IDA using a mathematical modeling approach. A minimal model was constructed; the differential equations were numerically solved and fitted to the data using the ADAPT II-software package using maximum likelihood estimation assuming that the measurement error has a standard deviation which is a linear function of the measured quantity［1］. (omitted)

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.111-111
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• 2003

Green tea have been widely reported as functional foods because of their various bioactivities. In the present study, we used 3T3-Ll cells model of white adipocytes to clarify whether green tea and its main pharmaceutically effective compounds (EGCG, caffeine and theanine) prevent obesity. Cellular viability, glycerol-3-phosphate dehydrogenase activity, glycerol release and HSL mRNA levels were checked. Glycerol release into the medium was significantly increased by the cells treated with green tea extract. Glycerol release into the medium was significantly increased by the cells treated with green tea extract. Caffeine and theanine from green tea showed some level of lipolytic activity, and glycerol-3-phosphate dehydrogenase activity was remarkably decreased by EGCG. These results suggest that green tea has anti-obesity effect through inhibition of adipogenesis and stimulation of lipolysis. Catechins and theanine of green tea might be the factors responsible for the modulation of lipid metabolism and adipocyte differentiation.

• Toxicological Research
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• v.17
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• pp.127-133
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• 2001

Together with cytochrome P450 (CYP), flavin-containing monooxygenase (FMO) present in liver microsomes oxidizes various endogenous and exogenous chemicals. In an effort to determine the human FMO activity, we have developed two non-invasive urine analysis methods using caffeine (CA) and ranitidine (RA) as the probe compounds. As the production of theobromine (TB) and ranitidine N-oxide (RANO) from CA and RA is catalyzed primarily by the hepatic FMO, we have assigned the urinary molar ratios of TB/CA and RA/RANO as the in vivo FMO activity. In 200 age-matched Korean volunteers, the obtained TB/CA ratio ranged from 0.4 to 15.2 (38-fold difference) and the RA/RANO ratio from 5.7 to 27.2 (4.8-fold). The FMO activity of 20's, determined by caffeine metabolism, was the highest (2.5$\pm$l.9) and those of 30's, 40's, 50's, 60's and 70's were 40%, 50%, 24%, 39% and 36% of the 20's, respectively. Intake of grapefruit juice, known to contain flavonoids, inhibited the in vivo FMO (TB/CA) activity by 79%. Addition of the flavonoids like naringin, quercitrin and kaempferol, present in grapefruit juice, to the in vitro microso-mal FMO assay, thiobenzamide S-oxidation, produced 75%, 70% and 60% inhibition, respectively. Obtained Ki values of quercitrin, kaempferol and naringin on the in vitro FMO activity were 6.2, 12.0 and 13.9 $\mu\textrm{M}$, respectively. This suggested that the dose of drug should need to be adjusted to suit the individual FMO activities when the drugs metabolized by FMO are given to patients. As the intake of grapefruit juice has been identified to inhibit the FMO as well as CYP3A4 and lA2 activities, patients taking drugs metabolized by these enzymes should not drink grapefruit juice as the carrier.

• Preventive Nutrition and Food Science
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• v.14 no.3
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• pp.173-178
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• 2009

This study was conducted to determine if supplementation with a compound composed of caffeine (50 mg), capsaicin (75 mg), sesamine (30 mg), L-carnitine (300 mg), banaba (50 mg) and lotus (10 mg) enhanced human autonomic nervous activities (ANS) associated with thermogenic sympathetic activity and fat utilization. Ten healthy college males (21.2$\pm$1.0 yr) volunteered for this experiment. Autonomic nervous activities associated with energy metabolism were examined at 30 min intervals for a total of 120-min while at rest and every 5-min during exercise at 50% of the ventilation threshold before and after intake of the compound or placebo with 100 ml of water for 10 days. In addition, heart rate variability power spectral analysis was used to assess human autonomic nervous activities. The results indicated that there were no significant differences in heart rate during rest and exercise among trials. Furthermore, the autonomic nervous activity tended to increase after 10-days of consumption of the test compounds during the experimental period, but the differences did not reach statistical significance. However, before and after the compound test trial there was a significantly higher respiratory gas exchange ratio (rest 0: 0.83$\pm$0.01 vs. rest 3: 0.89$\pm$0.02, p<0.05), carbohydrate oxidation (CHO) rate (rest 0: 44.57$\pm$5.83 vs. rest 2: 63.86$\pm$5.91%, p<0.05) and a lower fat oxidation rate (rest 0: 55.43$\pm$5.83 vs. rest 2: 36.14$\pm$5.91%, p<0.05. In conclusion, the results of the present study suggested that the compound composed of caffeine, capsaicin, sesamine, L-carnitine, banaba and lotus components that was evaluated in this study did not induce a significant increase in human autonomic nervous activities or lipolysis, even though the individual components have been reported to induce increased fat oxidation.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3559-3563
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• 2015

The aim of the present study was to evaluate the relative contribution of CYP1A2 isoforms (-3860 G/A, -2467T/delT and -163C/A) in control subjects and breast cancer patients to the metabolism of caffeine in human liver. Restriction fragment length polymorphism analysis of PCR-amplified Fragments (PCR-RFLP) was used for the genotyping of CYP1A2 SNPs and HPLC allowed the phenotyping through the measurement of CYP1A2 activity using the 17X + 13X + 37X/137X urinary metabolite ratio (CMR) and plasma caffeine half life (T1/2). The CYP1A2 -3860A genotype was associated with a decreased risk of breast cancer. In contrast, distributions of the CYP1A2 -2467T/delT or -2467delT/delT and -163A/C or A/A genotypes among breast cancer patients and controls were similar. When the genotype and phenotype relationship was measured by comparing the mean CMR ratios and caffeine half life within the genotype groups between subjects and breast cancer patients, there were no significant differences except for -3860 A, most of them being homozygous for the -3860 G/G SNP and had a significant higher mean CMR ratio and half life than those with -3860 G/A (P=0.02). The results of this preliminary study show a significant association between CP1A2 -3860 G variant and CYP1A2 phenotype which must be confirmed by further large-size case-control studies.

• Archives of Obesity and Metabolism
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• v.1 no.2
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• pp.59-65
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• 2022

Obesity is a serious health concern, which has been linked to an increased risk for cardiovascular diseases and some cancers. The traditional obesity control program is expensive. Moreover, it is difficult to maintain a healthy body weight as well as reduce body fat. The long-term use of effective and tolerable medication is carefully recommended to control body weight. In addition to obesity control medications, health functional foods, related to body weight control, have become popular in the commercial market. Known mechanisms include lipolysis, appetite control, inflammation reduction, and lean body mass maintenance. Previous clinical trials have documented the efficacy of some health functional foods; however, there are limitations. Studies on the potential roles and efficacy of some health functional foods, including caffeine, green tea, protein supplement, probiotics, and arginine, were reviewed. More large-scale and randomized placebo-controlled trials should be conducted eventually.

• Allergy, Asthma & Immunology Research
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• v.10 no.6
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• pp.628-647
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• 2018

Purpose: Obesity is associated with metabolic dysregulation, but the underlying metabolic signatures involving clinical and inflammatory profiles of obese asthma are largely unexplored. We aimed at identifying the metabolic signatures of obese asthma. Methods: Eligible subjects with obese (n = 11) and lean (n = 22) asthma underwent body composition and clinical assessment, sputum induction, and blood sampling. Sputum supernatant was assessed for interleukin $(IL)-1{\beta}$, -4, -5, -6, -13, and tumor necrosis factor $(TNF)-{\alpha}$, and serum was detected for leptin, adiponectin and C-reactive protein. Untargeted gas chromatography time-of-flight mass spectrometry (GC-TOF-MS)-based metabolic profiles in sputum, serum and peripheral blood monocular cells (PBMCs) were analyzed by orthogonal projections to latent structures-discriminate analysis (OPLS-DA) and pathway topology enrichment analysis. The differential metabolites were further validated by correlation analysis with body composition, and clinical and inflammatory profiles. Results: Body composition, asthma control, and the levels of $IL-1{\beta}$, -4, -13, leptin and adiponectin in obese asthmatics were significantly different from those in lean asthmatics. OPLS-DA analysis revealed 28 differential metabolites that distinguished obese from lean asthmatic subjects. The validation analysis identified 18 potential metabolic signatures (11 in sputum, 4 in serum and 2 in PBMCs) of obese asthmatics. Pathway topology enrichment analysis revealed that cyanoamino acid metabolism, caffeine metabolism, alanine, aspartate and glutamate metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, pentose phosphate pathway in sputum, and glyoxylate and dicarboxylate metabolism, glycerolipid metabolism and pentose phosphate pathway in serum are suggested to be significant pathways related to obese asthma. Conclusions: GC-TOF-MS-based metabolomics indicates obese asthma is characterized by a metabolic profile different from lean asthma. The potential metabolic signatures indicated novel immune-metabolic mechanisms in obese asthma with providing more phenotypic and therapeutic implications, which needs further replication and validation.

• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.314-319
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• 2007

The effects of common variants of CYP1A2 gene (CYP1A2$^*$1C and CYP1A2$^*$1F) on the CYP1A2 activity and inducibility were controversial. The aim of the present study is to investigate the effects of CYP1A2$^*$1C and CYP1A2$^*$1F on the activity of CYP1A2 determined by urinary caffeine metabolite ratio in Koreans. As might be expected, there was large inter-individual variation (16-folds) of CYP1A2 activity ranged from 2.41 to 39.58. The mean CYP1A2 activity of smokers was significantly higher than that of non-smokers. The frequencies of CYP1A2$^*$1C (-3858A) and $^*$1F (-164A) alleles were 0.219 and 0.646, respectively. The effect of CYP1A2$^*$1C on the CYP1A2 activity was not significant. However, the CYP1A2 activity of subjects with AA genotype for CYP1A2$^*$1F allele was significantly lower than that of non-AA genotypes (CC, or CA). Interestingly, the significant effect of CYP1A2$^*$1F allele on CYP1A2 activity was not observed in nonsmokers. Our results suggest that CYP1A2$^*$1F allele rather than CYP1A2$^*$1C allele significantly influences on the inducibility of CYP1A2 in Koreans. Owing to small sample size of our study, further studies should be conducted to reveal the inter-ethnic difference or the gene-environmental interaction.