PURPOSE Thirty-five commercially available Camellia sinensis (black and green) and herbal leisure teas and an assortment of Traditional Chinese medicinal teas were randomly selected and examined for their potential to inhibit the drug metabolizing enzyme cytochrome P450 3A4 (CYP3A4). The study was then extended to examine CYP2D6*1 and CYP2D6*10. METHODS Microtiter fluorometric assays were uti...

Tea infusions are consumed frequently and in large amounts, so they may play a role in modelling intestinal microflora or in preventing bacterial diseases. The present study examined the effect of different kinds of tea (black, green and pu-erh) on Lactobacillus rhamnosus, Lactobacillus plantarum, Leuconostoc mesenteroides subsp. mesenteroides, Escherichia coli, Staphylococcus aureus and Salmon...

Total polyphenol content, catechins content, and antioxidant capacities of green, dark, oolong, and black teas made from Camellia sinensis in China were evaluated. The total polyphenol content of 20 samples of tea was in the range of 7.82-32.36%. Total catechins content was in the range of 4.34-24.27%. The antioxidant capacity of tea extract was determined by the oxygen radical absorbance capac...

Treatment of SKH-1 hairless mice with ultraviolet B light (UVB; 30 mJ/cm(2)) twice a week for 22 weeks resulted in tumor-free animals with a high risk of developing malignant and nonmalignant skin tumors during the next several months in the absence of additional UVB treatment (high-risk mice). Oral administration of green tea or black tea (6 mg tea solids/ml) to UVB-pretreated high-risk SKH-1 ...

CONTEXT If tea can be shown to have an inhibitory effect on the growth of Streptococcus mutans there can be a basis for using it as an agent for reducing caries. AIMS The aim of the study was to determine the effect of aqueous and organic extracts of three types of tea (green, oolong, and black tea) on the growth of S. mutans. SETTINGS AND DESIGN In vitro study. MATERIAL AND METHODS Quali...

Over the past 10 years many studies from several laboratories defined anticarcinogenic and anti-inflammatory effects of tea, a widely consumed beverage by the human population. Much of such work has been conducted with green tea or its polyphenolic constituents. Regarding black tea, studies have shown that its water extract affords protection against tumor promotion caused by chemical carcinoge...

duction, and therefore represents one of the most important beverages in the world. Additionally, black tea is rich in polyphenols compared to other beverages, and the various health benefits associated with its consumption, including antioxidative, anticancer and anti-inflammatory activity, have recently been investigated. Black tea is produced by crushing the fresh leaves of Camellia sinensis...

Experimental studies showed that tea polyphenols may inhibit growth of Mycobacterium tuberculosis. However, no prospective epidemiologic study has investigated tea drinking and the risk of active tuberculosis. We investigated this association in the Singapore Chinese Health Study, a prospective population-based cohort of 63,257 Chinese aged 45-74 years recruited between 1993 and 1998 in Singapo...

To determine aluminum and zinc levels in black tea cultivated in north of Iran, 105 black tea samples were collected from the tea growing regions of Guilan and Mazandaran provinces and were analyzed for Al and Zn concentration of tea infusion. Contents of all elements were analyzed three times separately by using an Inductively Coupled Plasma Atomic Emission Spectrometry (ICP - AES). The solubi...