second order advantage of excitation-emission fluorescence matrix was applied for the simultaneous determination of ibuprofen and caffeine. the proposed method is based on the measurement of the native fluorescence and recording emission spectra of ibuprofen and caffeine in different excitation wavelengths. the mixture of these compounds was resolved by multivariate curve resolution coupled wit...

BACKGROUND AND OBJECTIVE: Physicians and policy makers are increasingly interested in caffeine intake among children and adolescents in the advent of increasing energy drink sales. However, there have been no recent descriptions of caffeine or energy drink intake in the United States. We aimed to describe trends in caffeine intake over the past decade among US children and adolescents. METHODS:...

OBJECTIVE Investigation of the effect of a green tea-caffeine mixture on weight maintenance after body weight loss in moderately obese subjects in relation to habitual caffeine intake. RESEARCH METHODS AND PROCEDURES A randomized placebo-controlled double blind parallel trial in 76 overweight and moderately obese subjects, (BMI, 27.5 +/- 2.7 kg/m2) matched for sex, age, BMI, height, body mass...

Caffeine is the most widely consumed stimulant to counter sleep-loss effects. While the pharmacokinetics of caffeine in the body is well-understood, its alertness-restoring effects are still not well characterized. In fact, mathematical models capable of predicting the effects of varying doses of caffeine on objective measures of vigilance are not available. In this paper, we describe a phenome...

Johnson, James D., Calvin J. H. Wong, Warren K. Yunker, and John P. Chang. Caffeine-stimulated GTH-II release involves Ca2 stores with novel properties. Am J Physiol Cell Physiol 282: C635–C645, 2002. First published November 7, 2001; 10.1152/ajpcell.00044.2001.—Modulation of Ca2 stores with 10 mM caffeine stimulates robust secretion of gonadotropin (GTH-II) from goldfish gonadotropes. Although...

In a previous study, we isolated Leifsonia sp. strain SIU, a new bacterium from agricultured soil. The bacterium was tested for its ability to degrade caffeine. The isolate was encapsulated in gellan gum and its ability to degrade caffeine was compared with the free cells. The optimal caffeine degradation was attained at a gellan gum concentration of 0.75% (w/v), a bead size of 4 mm diameter, a...

To elucidate the inhibiting mechanisms of fat accumulation by catechins, caffeine, and epigallocatechin gallate (EGCG), ICR mice were fed diets containing either 0.3% catechins or 0.1% EGCG and/or 0.05% caffeine for 4 weeks. After the feeding, intraperitoneal adipose tissues weights were significantly lower in the caffeine, catechins + caffeine, and EGCG + caffeine groups compared to controls. ...

Caffeine has various well-characterized pharmacological effects, but in mammals there are no known plasma membrane receptors or ion channels activated by caffeine. We observed that caffeine activates mouse transient receptor potential A1 (TRPA1) in heterologous expression systems by Ca(2+)(i) imaging and electrophysiological analyses. These responses to caffeine were confirmed in acutely dissoc...

At concentrations between 1 to 10 mM, caffeine reduced the Ca-accumulating capacity of fragmented reticulum obtained from frog and rabbit muscle. With 8 mM caffeine enough Ca was released from frog reticulum to account for the force of the contracture. Caffeine did not affect all reticulum membranes equally. The fraction which was spun down at 2000 g was more sensitive than the lighter fraction...

Caffeine occurs naturally in the leaves and seeds of many plants and is artificially added to some beverages. Consumption of caffeine has been linked to both positive and adverse health outcomes. We incorporated estimates of caffeine content (mg/100g or ml) of foods and drinks, taken from the published literature, to provide a preliminary estimate of caffeine intake for the UK population, based...