Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:APRD00080 (Leaf)
 21,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tannins are increasingly recognized as dietary carcinogens and as antinutrients interfering with the system's full use of protein. Nevertheless, certain tannin-rich beverages, masticatories, and folk remedies, long utilized in African, Asiatic, Pacific, and Latin American countries, are now appearing in North American sundry shops and grocery stores. These include guarana (Paullinia cupana HBK.) from Brazil, kola nut (Cola nitida Schott & Endl. and C. acuminata Schott & Endl.) from West Africa, and betel nut (Areca catechu L.) from Malaya. The betel nut, or arecanut, has long been associated with oral and esophageal cancer because of its tannin content and the tannin contributed by the highly astringent cutch from Acacia catechu L. and Uncaria gambir Roxb. and the aromatic, astringent 'pan' (leaves of Piper betel L.) chewed with it. In addition to the constant recreational/social ingestion of these plant materials, they are much consumed as aphrodisiacs and medications. Guarana and kola nut enjoy great popularity in their native lands because they are also rich in caffeine, which serves as a stimulant. Research and popular education on the deleterious effects of excessive tannin intake could do much to reduce the heavy burden of early mortality and health care, especially in developing countries.
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PMID:Widespread tannin intake via stimulants and masticatories, especially guarana, kola nut, betel vine, and accessories. 141 98

This study tested the hypothesis that differences in the processing of raw coffee beans can account for some of the variability in gastric effects of coffee drinking. Coffees were selected to represent several ways that green coffee beans are treated, ie, processing variables. These included instant and ground coffee processing, decaffeination method (ethyl acetate or methylene chloride extraction), instant coffee processing temperature (112 degrees F or 300 degrees F), and steam treatment. Lower esophageal sphincter pressure, acid secretion, and blood gastrin was measured in eight human subjects after they consumed each of the different coffees. Consumption of coffee was followed by a sustained decrease in lower esophageal sphincter pressure (P less than 0.05) except for three of the four coffees treated with ethyl acetate regardless of whether or not they contained caffeine. Caffeinated ground coffee stimulated more acid secretion that did decaf ground coffees (P less than 0.05), but not more than a steam-treated caffeinated coffee. Instant coffees did not differ in acid-stimulating ability. Ground caffeinated coffee resulted in higher blood gastrin levels than other ground coffees (P less than 0.05). Freeze-dried instant coffee also tended toward higher gastrin stimulation. It is concluded that some of the observed variability in gastric response to coffee consumption can be traced to differences in how green coffee beans are processed.
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PMID:Lower esophageal sphincter pressure, acid secretion, and blood gastrin after coffee consumption. 155 46

Harry Hollingworth's 1911 investigation of the behavioral effects of caffeine is one of the earliest examples of psychological research contracted by a large corporation. The research was necessitated by a federal government suit against the Coca-Cola Company for marketing a beverage with a deleterious ingredient, namely, caffeine. Although Hollingworth's research played little role in the outcome of the Coca-Cola trials, it was important as a model of sophistication in experimental design. As such, it set a standard for psychopharmacological research. It also was particularly important in directing Hollingworth toward a life-long career in applied psychology.
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PMID:Coca-Cola, caffeine, and mental deficiency: Harry Hollingworth and the Chattanooga trial of 1911. 201 Jun 14

The caffeine content of a number of non-alcoholic beverages was determined using HPLC. It was found that Diet Coke had a greater caffeine content than Coke (4.15 compared with 3.13 mg/fl oz), Tab is virtually caffeine free, and Lucozade, sold as a tonic, contains more caffeine than any of the other carbonated beverages tested (5.17 mg/fl oz). The pure instant coffee tested contained much more caffeine than the coffee/chicory mixtures (12.61 compared with 3.18 mg/fl oz). The caffeine content of Ceylon tea blends increases with the time the tea is allowed to draw (from about 8 mg/fl oz after 1 min to about 12 mg/fl oz after 20 min). Tea that has been allowed to draw for 20 min has a caffeine content similar to that of pure coffee.
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PMID:The caffeine contents of non-alcoholic beverages. 270 94

The feasibility and reliability of simultaneously determining debrisoquin oxidation and N-acetylation phenotypes was assessed in children with use of two innocuous substrate probes given by mouth, 30 mg dextromethorphan (Pertussin ES) and 25 to 46 mg caffeine (Coca-Cola beverage). Twenty-six children and adolescents (aged 3 to 21 years) were studied three times, once with each substrate given alone and once with the two substrates given together. Urine was collected for 4 hours, and the molar urinary metabolic ratios for dextromethorphan:dextrorphan and for two caffeine metabolites (AFMU:1X) were determined by HPLC ultraviolet assays. The urinary metabolic ratios for both substrates were not significantly different when the substrates were given alone compared with when they were given together. There also was no difference in either the oxidation or acetylation phenotype assignments when the two substrates were given alone and when they were given together. No adverse effects were observed. We conclude that dextromethorphan and caffeine can be given together to simultaneously determine oxidation and acetylation phenotypes and can thereby provide an innocuous, noninvasive method for the assessment of polymorphic drug metabolism in various pediatric populations.
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PMID:Dextromethorphan and caffeine as probes for simultaneous determination of debrisoquin-oxidation and N-acetylation phenotypes in children. 272 Nov 11

Freeze-dried skinned cardiac and skeletal muscle preparations of the rabbit were immersed in Ca2+-containing solutions with different concentrations of caffeine. The relation between the negative logarithm of the Ca2+ concentration (pCa) and normalized developed force was studied. The exact position of these Ca2+-sensitivity functions proved to be dependent on both the sarcomere length (monitored by means of laser diffraction) and caffeine concentration. High concentrations of caffeine induce a reversible fall in tension, particularly at low binding site saturation (low pCa) and long sarcomere lengths. At a concentration of 10 mM caffeine, the sarcomere length dependency of the Ca2+-sensitivity curves is markedly reduced for the rising part of the curve. Only the depressive effect of caffeine at high pCa remains. A possible mechanism of caffeine action is discussed.
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PMID:Caffeine suppresses length dependency of Ca2+ sensitivity of skinned striated muscle. 335 48

The presence of a concentration of caffeine greater than or equal to 15 micrograms/ml in urine of athletes participating in competitive sport is a disqualifying factor. A study was conducted to establish how much caffeine needs to be ingested--in the form of coffee, tea or Coca-Cola--to approach or exceed this limit. Nine healthy volunteers participated in a randomised cross-over study and received caffeine in the form of these beverages, ingested within 15 minutes, in doses ranging from 1.52 mg/kg to 17.53 mg/kg. The latter dose is equivalent to nearly 8 cups of ordinary percolated coffee. The maximum caffeine concentration in urine recorded was 14 micrograms/ml, 3 hours after ingestion. A significant correlation was found between the caffeine dose and the maximum urinary concentration. The mean recovery of caffeine in urine was between 0.74% and 0.91% of the administered dose. The nature of the beverage did not appear to influence the degree of caffeine excretion. It is concluded that if a concentration of 15 micrograms caffeine/ml urine is recorded, it can safely be accepted that the athlete purposely ingested large amounts of the substance, in whatever form.
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PMID:Caffeine in sport. Urinary excretion of caffeine in healthy volunteers after intake of common caffeine-containing beverages. 340 72

Xenobiotic acetylation by N-acetyltransferase is genetically controlled. This polymorphism governs the intestinal and liver metabolism of numerous amines. The use of caffeine, a ubiquitous and nontoxic amine, has been proposed as a probe for phenotyping. The aim of the present study is to evaluate this test and to identify the metabolite of caffeine used as substrate by the polymorphic enzyme. - A cup of coffee, tea or Coca-Cola is administered to fasting subjects. The molar ratio of two metabolites of caffeine (AFMU and 1X) is determined on a spot urine sample 4-6 hours later by means of a UV liquid chromatographic assay. In a reference population (n = 63), the distribution of molar ratios is trimodal with frequencies of 0.14, 0.35 and 0.51. These results correlate with those obtained by the classic isoniazid test. However, in vitro experiments in human liver subcellular fractions did not lead to the identification of a xanthine as the precursor of the acetylated metabolite.
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PMID:[Evaluation of a caffeine test for determining the phenotype of N-acetyltransferase]. 342 81

Cola nuts are obtained from cola trees growing both wild and cultivated in the equatorial rain forest belf of Nigeria and the rest of West Coast of Africa. There are two common species namely cola accuminata which is multicotyledonous and cola nitida which is dicotyledonous. The cola nitida has two subspecies, alba and rubra (white and red respectively). The cola accuminata is more popular in the Ibo and Igedde tribes of the Eastern and Middle Belt regions respectively in Nigeria, while cola nitida is preferred by the Hausa-Fulani tribes of the Northern part of Nigeria. Both cola species contain xanthines--the same type of alkaloids found in tea and coffee. Common among these xanthine derivatives are caffeine, theophylline and theobromine. These xanthines are known to stimulate gastric acid secretion. We therefore decided to find out the effect of both species of the cola on gastric acid secretion, since this has not been reported previously. We found that both cola species significantly induced gastric acid secretion. This corroborates our clinical advice to peptic ulcer patients not to eat cola nuts.
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PMID:The effect of cola acuminata and cola nitida on gastric acid secretion. 350 43

Testing of various cola formulas on sperm motility using a trans-membrane procedure did not decrease motility to less than 70% control in a 1-hour period. Diet Coca-Cola had the strongest spermicidal effect followed by Classic Coca-Cola, Caffeine-free Coca-Cola and New Coca-Cola. Since there are no known substances in cola that effect cellular membranes, the results of these tests were not unusual. Other tests have been done using higher dilution of cola which could effect sperm motility and give different results for spermicidal potencies. The results show that cola has little if any spermicidal effect. Its use in postcoital douching is ineffective and could cause complications such as infection.
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PMID:The spermicidal potency of Coca-Cola and Pepsi-Cola. 367 47


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