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Amelioration of sodium arsenite-induced clastogenicity by tea extracts in Chinese hamster v79 cells.

Since the early 1980s, an alarming problem of groundwater arsenic (As) contamination has devastated many districts of West Bengal in India. People drinking As-contaminated water have been suffering severe health problems such as hyperkeratosis, blackfoot disease, neuropathy, and cancer of various sites. DNA damage and genetic instability induced by the inorganic arsenicals present in water are thought to be prerequisites for the initiation of carcinogenesis. Many natural polyphenols, which are consumed through our daily diet, possess excellent cancer chemopreventive properties. Tea, a popular beverage worldwide and rich in polyphenols, has exhibited many health benefits. The present study was conducted to examine the anticlastogenic action of tea extracts (both green and black) against the As-induced chromosomal aberrations. We also evaluated the role of tea in inducing antioxidant enzymes such as superoxide dismutase and catalase to provide protection against the oxidative stress induced by As. Our results demonstrated that tea extracts, particularly Darjeeling tea extract, are effective in counteracting the clastogenicity (chromatid breaks, in particular) of the most potent form of As, sodium arsenite. The antioxidant function of tea in reducing clastogenicity may be partly due to the induction of phase II detoxification enymes, such as superoxide dismutase and catalase. Our results suggest that the use of tea may be an effective approach in combating the health crisis generated by As.

Animals↗

Differences in drinking behavior between normal and laryngectomized man.

The properties of drinking in normal and laryngectomized groups were examined. Drinking associated with meals was more frequent in the 76 young and 37 older normal subjects than the 25 laryngectomized persons. The laryngectomized group preferred tea and coffee to water to alleviate thirst sensation, while such a preference was hardly seen in either normal group. Results suggest that the larynx may contribute not only to thirst sensation but may be associated with preference in drinking.

Adult↗

Coffee and cancer of the pancreas.

We questioned 369 patients with histologically proved cancer of the pancreas and 644 control patients about their use of tobacco, alcohol, tea, and coffee. There was a weak positive association between pancreatic cancer and cigarette smoking, but we found no association with use of cigars, pipe tobacco, alcoholic beverages, or tea. A strong association between coffee consumption and pancreatic cancer was evident in both sexes. The association was not affected by controlling for cigarette use. For the sexes combined, there was a significant dose-response relation (P approximately 0.001); after adjustment for cigarette smoking, the relative risk associated with drinking up to two cups of coffee per day was 1.8 (95% confidence limits, 1.0 to 3.0), and that with three or more cups per day was 2.7 (1.6 to 4.7). This association should be evaluated with other data; if it reflects a causal relation between coffee drinking and pancreatic cancer, coffee use might account for a substantial proportion of the cases of this disease in the United States.

Aged↗

Reliability of information on cigarette smoking and beverage consumption provided by hospital controls.

We compared data from interviews of patients admitted to hospital and interviews repeated at home for 400 hospital controls. Of these, 294 (73.5%) could be re-interviewed (responders). Never smoking was reported by 44% of subjects in the in-hospital interviews and by 40% in the repeat at-home interviews. Among those interviewed in hospital, 38% claimed to be nondrinkers, as did 38% of responders, but only 28% characterized themselves as nondrinkers in the repeat interview. For consumption of regular coffee, 15% reported none in the selected sample, 14% among responders, but only 6% in the repeat at-home interview. Agreement was good for decaffeinated coffee and tea consumption.

Alcohol Drinking↗

Chemoprevention of heterocyclic amine-induced mammary carcinogenesis in rats.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is one of the most prevalent carcinogenic heterocyclic amines in the environment, targeting the colon, prostate, pancreas, and mammary gland in rodents. Chemopreventive effects of synthetic and naturally occurring compounds on PhIP-induced rat mammary carcinogenesis were investigated in a series of experiments. In a PhIP feeding model, groups of 20-21 female F344 rats each, were treated with 0.02% PhIP alone or PhIP plus 0.5% 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), 1% green tea catechins, 1% alpha-tocopherol, 0.1% ellagic acid, or 1% chlorophyllin, each in the diet, or 0.1% caffeine in drinking water for 52 weeks. To assess the mechanism of HTHQ and caffeine inhibition of PhIP-induced carcinogenesis, effects of these compound on the in vitro metabolic activation of PhIP were examined in the presence of S9 mix. In the next series of experiments, the PhIP intragastric dose model was applied to allow separate investigation of the effects of chemicals during the initiation and postinitiation periods. In these experiments, female Sprague-Dawley rats were given eight intragastric doses of 100 mg/kg body weight during the first 4-8 weeks for initiation. Either during initiation or after initiation, or only after initiation, animals were treated with either corn or perilla oil at doses of 5 and 20%, conjugated fatty acid derived from safflower oil (CFA-S) or perilla oil (CFA-P) at a dose of 1%, arctiin at doses of 0.02 and 0.2% in the diet, or sodium nitrite (NaNO(2)) at a dose of 0.2% in drinking water. In the PhIP feeding model, administration of PhIP alone for 52 weeks induced adenocarcinomas in 40% of rats, but the incidence was remarkably reduced to 5% by the simultaneous treatment with 0.5% HTHQ, a strong lipophilic phenolic antioxidant, or to 10% by 0.1% caffeine. Administration of 1% chlorophyllin exerted similar, albeit weaker, effects. alpha-Tocopherol at a dose of 0.5% only reduced the multiplicity of carcinomas, and 1% green tea catechins only the mean size of mammary tumors. In a metabolic activation study of PhIP, HTHQ and caffeine clearly inhibited the formation of metabolites. In the PhIP gastric dose model, among the naturally occurring compounds examined, a plant lignan arctiin, perilla oil, which contains a large amount of n-6 alpha-linolenic acid, and CFA-S or CFA-P inhibited mammary tumor development, particularly in the postinitiation period, although a clear dose response was not observed. Treatment with 0.2% NaNO(2) in the initiation period was found to lower the volume of mammary tumors. The present results indicate that a number of compounds may be candidate chemopreventive agents against PhIP-induced mammary carcinogenesis, acting through different mechanisms and depending on the stage of carcinogenesis.

Animals↗

[Tea and coffee consumption among Russian population].

Aim of present study was the getting data on black and green tea and coffee consumption among Russian population in 1995-2003. The consumption of beverages tea and coffee was estimated by 24-hour recall of dietary intake in course of Russian Longitudinal monitoring surveys of economics and health. About 82% of population have consumed the black tea and only 2.2%--the green tea. Mean daily black and green tea intake among all population were 446 ml and 10 ml, correspondingly. The prevalence of black tea consumption was decreased and green tea and coffee consumption were increased from 1995 to 2003.

Adolescent↗

Effect of different drinks on the absorption of non-heme iron from composite meals.

A study was made on the effect of various drinks on the absorption on non-heme iron. The drinks were taken with standard meals composed of a hamburger, string beans and mashed potatoes. In each series identical meals were served to the same subject either with water or with the drink under study, labelling the meals with two different radio-iron isotopes. A reduction in iron absorption was seen when serving tea (62 per cent) or coffee (35 per cent) with the meals. Orange juice increased the iron absorption (85 per cent). Pure alcohol and wine increased only slightly the percentage absorbed. Wine often has a high iron content, which increased significantly the amount of iron absorbed (three times). Milk and beer have no significant effect. Coca-Cola increased only slightly the absorption. The present studies clearly shows that the choice of drink drunk with a meal can markedly affect the absorption of non-heme iron.

Absorption↗

Caries experience and fluorosis prevalence in Chilean children from different socio-economic status.

Caries experience and enamel fluorosis prevalence in 8-year-old children belonging to different socio-economic classes were determined in two Chilean twin cities that are served by optimally fluoridated community water from the same waterworks facility. Low socio-economic status (LSES) children had a higher mean dmft and DMFT indices (P < 0.001) than high socioeconomic status (HSES) children. Prevalence of enamel fluorosis in the permanent teeth of LSES children was 0.79, significantly higher (chi 2 = 9.0; P < 0.003) than the value 0.59 found in HSES children. The proportion of Dean's scores 2, 3, 4 and 5 in first molars, mandibular and maxillary incisors in LSES children was higher than in HSES children (P < 0.001). Differences in prevalence and severity of enamel fluorosis between both groups are tentatively attributed to a different pattern of tap water and tea consumption at pre-school ages. Suggestions are advanced to minimize the undesirable prevalence and severity of enamel fluorosis.

Child↗

Cancer mortality among Mormons.

Preliminary results show that the 1970-72 cancer mortality rate among California Mormon adults is about one-half to three-fourths that of the general California population for most cancer sites, including many sites with an unclear etiology. Furthermore, the cancer death rate in the predominately Mormon state of Utah is about two-thirds to three-fourths of the United States rate, and the lowest in the entire country. Mormons are a large, health-conscious religious group whose Church doctrine forbids the use of tobacco, alcohol, coffee, and tea, and recommends a nutritious diet. Initial indications are that Mormons as a whole smoke and drink about half as much as the general population, and that active Mormons abstain almost completely from tobacco and alcohol. However, they appear to be fairly similar to the general white population in other respects, such as socioeconomic status and urbanization. The significance of these findings is discussed.

Adolescent↗

Variations in tooth surface temperature in the oral cavity during fluid intake.

Measurements were made of the extremes in temperature which occur at different sites in the oral cavity during fluid intake. The results indicate that temperatures noted at the tooth surface, within the mouth, during fluid intake were less than the temperatures of the fluid imbibed. Variations in temperature were noted in different areas of the mouth. This may be associated with the position of the tongue during swallowing and the effect of the tissues of the oral cavity as heat absorbers. The range of temperatures noted at the tooth surface and the duration of the temperature changes were at variance with those utilized in many thermocycling studies. It is suggested that closer alignment with the clinical situation is desirable.

Adult↗

Investigation of biochemical and histopathological effects of Mentha piperita Labiatae and Mentha spicata Labiatae on liver tissue in rats.

The plant Mentha piperita, or peppermint, is commonly used in the treatment of loss of appetite, common cold, bronchitis, sinusitis, fever, nausea and vomiting, and indigestion as a herbal agent. In this study, we aimed to investigate biochemical and histological effects of M. piperita Labiatae, growing in the Yenisar Bademli town of Isparta city, and Mentha spicata Labiatae, growing in the Anamas high plateau of the Yenisar Bademli town, on the rat liver tissue. Forty-eight male Wistar albino rats weighing 200-250 g were used for this study. Rats were divided into four groups of 12 animals: Group I received no herbal tea (control group); Group II received 20 g/L M. piperita tea; Group III received 20 g/L M. spicata tea; and Group IV received 40 g/L M. spicata tea. Herbal teas were prepared daily and provided at all times to the rats during 30 days as drinking water. Liver function tests, including aspartate aminotransferase (AST/GOT) and alanine aminotransferase (ALT/GPT) activities were measured. To evaluate liver antioxidant defences, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and thiobarbituric acid reactive substance (TBARS) activities were determined in the homogenates of liver tissue. In addition, liver tissues were submitted for histopathologic examination. AST and ALT activities were increased in Group II, Group III and Group IV gradually when compared with the control group. The difference between Group II and the control group was not statistically significant (P > 0.016). Increases in AST and ALT activities of Group III and Group IV were statistically significant when compared with the control group. SOD, GSH-Px and CAT activities were increased in Group II when compared with the control group but the difference was not statistically significant (P > 0.016). However, SOD, GSH-Px activities and the TBARS level were significantly increased, and CAT activity was significantly decreased in Group III when compared with the control group. In Group IV, while SOD, GSH-Px and CAT activities were decreased, the TBARS level was increased as compared with the control group (P < 0.0016). Histopathological evaluation of experimental groups revealed a mild to severe degree of hepatic damage when compared to the control group. In Group II, there was only minimal hepatocytes degeneration. In Groups III and IV, there were granular or ballooning hepatocyte degeneration and necrosis, sinusoidal and central vein dilatation. It was concluded that lipid peroxidation and hepatic damage occurs after M. piperita and M. spicata administration in rat liver and the damage seems to be dose dependent.

Alanine Transaminase↗

Determination of St. John's wort components in dietary supplements and functional foods by liquid chromatography.

St. John's wort (Hypericum perforatum L.) preparations, a top-selling botanical dietary supplement used primarily as an antidepressant, has recently been used as an ingredient in some food products sold as functional foods. A rapid extraction technique followed by a liquid chromatographic (LC) method was developed to determine 4 characteristic bioactive compounds (pseudohypericin, hypericin, hyperforin, and adhyperforin) from St. John's wort in dietary supplements and functional foods to which it was added. Solid samples, including dried leaf/flower mixture, dietary supplement capsules, tea bags, puff and snack bar, were extracted with methanol by sonication. Noncarbonated, fruit-flavored drinks were centrifuged and mixed with methanol. Compounds were then determined by isocratic, reversed-phase LC with UV detection at 2 wavelengths and further identified or confirmed by photodiode array spectra and LC/mass spectrometry. Within-laboratory method variations (% RSD) were satisfactory. Very low amounts, if any, of the 4 components were found in drink and puff samples, and none was found in the snack bar. The methods developed provide a useful means for the determination of St. John's wort components in dietary supplements and functional foods.

Algorithms↗

Comparison of the cariostatic effects between regimens to administer oolong tea polyphenols in SPF rats.

The cariostatic effect of oolong tea polyphenols administered according to several regimens was examined in specific pathogen-free (SPF) Sprague-Dawley rats given both a diet containing 20% sucrose and infected with S. sobrinus 6715. The crude preparation (OTE) of oolong tea polyphenols showed the most prominent effect on caries reduction in SPF rats when OTE was administered in the drinking water beginning 1 day prior to the inoculation of S. sobrinus 6715, when compared with chromatographically isolated polyphenol fractions (OTF1 and OTF6) of OTE. Reduction in caries development was found even when OTE was given 1 day after inoculation of the organism. OTE was shown to significantly inhibit dental caries in rats at the concentrations of either more than 5 microg/ml in drinking water or more than 10 microg/g in diet. OTF1 and OTF6 also showed significant inhibition of caries induction, with the minimum inhibitory concentration of OTF6 being 50 microg/ml in drinking water and the minimum inhibitory concentration of OTF1 being 100 microg/g in diet. These results indicate that cariostatic activity of OTE was effective even after the establishment of S. sobrinus in the oral cavity and was more effective in drinking water than in diet. Furthermore, OTE may contain some anticaries substances that affect the virulence of S. sobrinus other than glucosyltransferases.

Analysis of Variance↗

The effect of Chinese tea on occurrence of esophageal tumor induced by N-nitrosomethylbenzylamine in rats.

Five groups of rats (40 rats per group) were given five different varieties of Chinese tea (1 g/50 ml) and another two groups of rats (a positive control and a negative control) were given tap water as drinking water. Except for the negative control group, all the animals were intubated with N-nitrosomethylbenzylamine (NMBzA, 5 mg/kg body wt/week). Half of the animals in each group were sacrificed after 6 weeks and the remaining animals at the end of 12 weeks. The incidences of esophageal mucosa lesions (16-59%) at the end of 6 weeks were significantly lower in the tea-treated rats than in the positive control group (100%). The incidences of esophageal tumor at the end of 12 weeks (42-67%) were also significantly lower in the tea-treated groups than in the positive control group (90%). The same phenomenon was found with respect to the size and number of tumors in each tumor-bearing animal. The relative anticarcinogenic effects of the five varieties of Chinese tea were different. The Fujian oolong tea and jasmine tea exhibited the strongest effects. The results suggest that Chinese tea can effectively inhibit the carcinogenesis caused by an N-nitroso compound.

Animals↗

Effects of black tea extract on transplantable and solid tumors in Swiss albino mice.

The chemopreventive effects of green tea and its polyphenols are well documented in the literature. Epidemiological studies have suggested that green tea consumption might be effective in the prevention of certain human cancers. About 80% of the tea is consumed as black tea. Limited studies have been carried out to assess the usefulness of black tea as anti-carcinogen. The present set of investigations were initiated to study the anti-tumorigenic potential of aqueous black tea extract (ATE) in Swiss albino mice in in vivo animal bioassay, using 7, 12 dimethyl-benzanthracene (DMBA) as carcinogen. In the experimental group, 2% ATE was given orally as sole source of drinking water, while the control were allowed to drink normal water, ad lib. The results revealed that drinking of 2% ATE could effectively inhibit the onset of tumorigenesis, cumulative number of tumors and average number of tumors per mouse. In ATE drinking group 44% animals remained tumor free till the termination of experiment, i.e. 26 weeks. In the second set of experiment the preventive efficacy of 2% ATE of different cultivars of black tea, viz orthodox, CTC and dust were tested in Ehrlich Ascites (EA) tumor bearing mice. The preventive effects of ATE were observed in terms of increased life span (ILS). All the cultivars of tea showed more than 25% increase in life span of the animals. Cytotoxic effect of various doses of all three cultivars of black tea was also observed in vitro on EA cells.

Animals↗