Carcinogenicity tannins

N.A. Daphnetoxin, mezerein, mucilage, tannins." This herb is toxic. An abortifacient, alterative, carcinogenic, diuretic, purgative, stimulant, sudorific. 

SAFETY PROFILE Poison by subcutaneous, intramuscular, intravenous, and intraperitoneal routes. Questionable carcinogen with experimental tumorigenic data. See also TANNIN. When heated to decomposition it emits acrid and irritating fumes. 

Decomposes when heated above melting point, 536°F/280°C, producing toxic fumes of arsenic, lead. Lead arsenates may be subject to redox reactions. Both arsenic and lead are known human carcinogens. PLUMBOUS ACETATE (6080-56-4) Pb(CjH302)2 3H,0 Contact with acids forms acetic acid. Incompatible with oxidizers, bases, acetic acid alkalis, alkylene oxides, ammonia, amines, bromates, carbonates, citrates, chlorides, chloral hydrate cresols, epichlorohydrin, hydrozoic acid, isocyanates, methyl isocyanoacetate, phenols, phosphates, salicylic acid sodium salicylate, sodium peroxyborate, potassium bromate resorcinol, salicylic acid, strong oxidizers, sulfates, sulfites, tannin, tartrates, tinctures trinitrobenzoic acid, urea nitrate. On small fires, use dry chemical, Halon, or CO2 extinguishers. 

Precautions Polyphenol substances in tea are believed to inhibit the action of carcinogens in food and tobacco, and may protect against heart disease. Other elements of tea may prevent tooth decay. Tannins in tea help fight bacteria and viruses. 

Formulations usually contain a combination of different anodic and cathodic inhibitors. Commonly used are ortho- and polyphosphates, phosphonates, tannins, lignins, benzoates, silicates, chromates, molybdates, nitrites, nitrates, zinc salts, aromatic azoles, carboxylic acids, amides, amines, soluble oils, and oxygen scavengers, such as hydrazine and sulfites [3, 46]. Some of these substances (e.g. silicates) are employed predominantly in synergy with other inhibitors, whereas in other cases the combination of inhibitors may have adverse effects (e.g. nitrites and organic amines or amides may form carcinogenic nitrosamines at elevated temperatures). 

Two major developments have occurred in sheet manufacture. The first relates to concern about the carcinogenic properties of certain types of asbestos. In Britain, although most wines and spirits are now filtered through sheets free of asbestos, such replacement has been slower in the case of beers. Alternatives to charged asbestos fibres include aluminium oxide fibres and zirconium oxide fibres. A second development has been the incorporation of insoluble polyvinyl pyrrolidone (PVPP) into the sheet material which adsorbs phenolic materials from the beer, especially the tannin materials associated with beer haze. The PVPP can be regenerated by washing the sheet in a 0-5 % solution of sodium hydroxide at ambient temperatures. 

Kapadia, G.J., Paul, B.D., Chung, E.B., Ghosh, B., and Pradhan, S.N., 1976, Carcinogenicity of CametVia sinensis (tea) and some tannin-containing folk medicinal herbs administered subcutaneously in rats, J. Natl. Cancer Inst., 57 207. 

Pamukcu, A.M., Wang, C.Y., Hatcher, J. and Bryan, Carcinogenicity of tannin-free extracts of bracken J. Nat. Cancer Inst, 65, 131. 

Obviously, in the past, the difficulty has been that the tannins studied have been difficult to purify and to characterize chemically. This was not the case with the most recent work (59), and precise characterization of structure will be possible in the future. In addition, these studies must include tests in animal models that are recognized as being useful models in place of humans. The differention of a true toxic effect from an irritant one will not be easy. Also, the tumors produced must be examined by an expert pathologist to prove carcinogenicity. 

Kapadia G J, Paul B D, Chung E B Ghosh B, Pradhan S N 1976 Carcinogenicity of Camellia sinesis (tea) and some tannin-containing folk medicinal herbs administered sub-cutaneously in rats. J Nat Cane Inst 57 207-209... 

Pradhan S N, Chung E B, Ghosh B, Paul B D, Kapadia G J 1974 Potential carcinogens. I. Carcinogenicity of some plant extracts and their tannin containing fractions in rats. J Nat Cancer Inst 52 1579-1582... 

Both hydrolyzable and condensed tannins, often with novel structures, have been found to be associated with plant extracts used by traditional Chinese medications. This has led to much work, especially by the Japanese, to explore the pharmacological properties of tannins in such extracts. Such studies have established that various tannins have hypotensive (101, 106, 249), anti-allergic (107), anti-bacterial, against carcinogenic bacteria (108), anti-coagulant (115), antiinflammatory (107, 150, 167), anti-peptic (62), and anti-viral (109, 236) activity. These studies support the view that specific tannin molecules or preparations have potential for new pharmaceutical products in the future. 

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