tannins and Esophageal-Neoplasms

Topics: Animals; Breast Neoplasms; Carcinogens, Environmental; Colonic Neoplasms; Diet; Dietary Fats; Esophageal Neoplasms; Humans; Liver Neoplasms; Lung Neoplasms; Mammary Neoplasms, Experimental; Neoplasms; Pancreatic Neoplasms; Stomach Neoplasms; Tannins; Urinary Bladder Neoplasms

Polyphenols in cereals and legumes have been receiving considerable attention largely because of their adverse influence on color, flavor, and nutritional quality. These compounds belong to the flavonoid and tannin groups and are mostly located in the seed coat or pericarp of the grains. The pearl millet flavonoids have been identified as C-glycosylflavones by the combined use of paper chromatography and UV spectroscopy. Although nontoxic, physiological and nutritional significance of these compounds occurring in high amounts in the pearl millet grain are still not clearly understood. In view of aesthetic quality, bleaching of the millet grains in acidic solution is recommended. A large proportion of current assays involves spectrophotometry of tannin or its chromogen and tannin-protein interaction. Sorghum and legume tannins have been characterized as condensed tannins. Several factors such as plant type, age of the plant or plant parts, stage of development, and environmental conditions govern the polyphenol contents in plants. Polyphenols are known to interact with proteins and form tannin-protein complexes leading to either inactivation of enzymes or making proteins insoluble. These are implicated in decreasing the activities of digestive enzymes, protein and amino acid availabilities, mineral uptake, vitamin metabolism, and depression of growth. Polyphenols are known to cause certain ultrastructural changes in the different parts of experimental animals. A correlation between dietary tannins and occurrence of esophageal cancer has been established. Bird resistance and seed germination in food crops have been correlated to high contents of polyphenols. The antinutritional activity of polyphenols can be reduced by removing polyphenols from the grains by chemical treatments or removing pericarp and testa by pearling. Treatment of alkaline reagents and ammonia can remove 90% of the polyphenols. Supplementation of polyphenols-rich diet with protein can alleviate the growth-depressing effect of polyphenols.

Topics: Chemical Phenomena; Chemistry; Edible Grain; Esophageal Neoplasms; Fabaceae; Flavonoids; Food Handling; Glycosides; Nutritive Value; Panicum; Phenols; Plant Proteins; Plants, Edible; Plants, Medicinal; Polymers; Tannins

No single dietary factor or ingested substance has been implicated in the aetiology of oesophageal carcinoma especially in high-risk areas of the world. Although not well defined, there is heavy consumption of tannin-rich foods, particularly sorghum, by populations at high risk for carcinoma. The carcinogenic properties of tannins and extracts of tannin-rich plants have been demonstrated experimentally. It is proposed herein that salivary proline-rich proteins (PRPs) by binding ingested tannins protect the oesophagus from the carcinogenic effects of the latter. It is also possible that genetic variants of PRPs may influence the incidence of oesophageal cancer in different populations.

Topics: Esophageal Neoplasms; Feeding Behavior; Humans; Peptides; Plants, Edible; Proline-Rich Protein Domains; Salivary Proteins and Peptides; Tannins

Topics: Animals; Edible Grain; Esophageal Neoplasms; Humans; Rats; Tannins; Wine

Topics: Diet; Esophageal Neoplasms; Humans; South Africa; Tannins

Topics: Beer; Esophageal Neoplasms; Female; Humans; Male; Oils; Rwanda; Tannins

Topics: Esophageal Neoplasms; Female; Humans; Male; Middle Aged; Tannins; Tea

Topics: Africa, Eastern; Esophageal Neoplasms; Female; Humans; Male; Tannins

Topics: Animals; Diet; Edible Grain; Esophageal Neoplasms; Humans; Rats; Tannins

Topics: Animals; Esophageal Neoplasms; Humans; Tannins; Tea

Twelve medicinal herbs were bioassayed to correlate a high incidence of esophageal carcinoma in natives of different places with their habitual consumption of these products. Outbred NIH Black rats were given 72 weekly sc injections of the total aqueous extracts of the plant materials. The tanninrich plant extracts from Areca catechu and Rhus copallina produced local tumors in 100 and 33%, respectively, of the experimental animals. Other materials included Diospyros virginiana and extracts from plants not rich in tannins. Diospyros and extracts of Sassafras albidum and Chenopodium ambrosiodes were tumorigenic in over 50% of the treated animals.

Topics: Animals; Carcinogens; Esophageal Neoplasms; Humans; Injections, Subcutaneous; Magnoliopsida; Medicine, Traditional; Neoplasms, Experimental; Phytotherapy; Rats; South Carolina; Species Specificity; Tannins

Nutritional factors are suspected to cause oesophageal cancer as well as other cancers of the digestive tract. Sideropenia, lack of molybdenum, tannins have been reported to be associated with the disease. Polycyclic hydrocarbons and nitrosamines have been found in alcoholic beverages from high incidence regions; the significance of the small amounts detected remains to be assessed. A recent survey in Iran points out the role of poor and monotonous diet. In Brittany, no major deficiencies were found, neither in quantity or quality, in the diet of 200 male cases of oesophageal cancer when compared with a population control group. Differences in consumption were detected for a few items; the most obvious discrepancies concerned the various alcoholic beverages for which the proportion of heavy consumers was systematically greater among cases. Alcohol and tobacco are both independently associated with the disease; there is a dose-response relationship for both and their effects are multiplicative. The mechanism of the action of alcohol in oesophageal cancer is briefly discussed.

Topics: Alcoholic Beverages; Deficiency Diseases; Diet; Esophageal Neoplasms; France; Humans; Iran; Iron Deficiencies; Nicotiana; Nitrosamines; Nutrition Surveys; Plants, Toxic; Polycyclic Compounds; Tannins