Tannin activity flavonoids

The leaves of Catha edulis also have a high content of polyphenolic compounds, tannins and flavonoids. The isolated flavonic fraction showed a significant antiulcer activity against the lesions induced by phenylbutazone and pyloric ligature in rats [91]. It is proven that the compounds responsible for this activity are the major constituents of the... 

Main actives Mucilages (about 10%), flavonoids, tannins, chlorogenic acid and volatile oils. 

Hagerman, A.E. and Klucher, K.M., Tannin-protein interactions, in Plant Flavonoids in Biology and Medicine Biochemical, Pharmacological, and Structure Activity Relationships, Middleton, E. and Harbome, J., Eds., Alan R. Liss, Inc., New York, 1996. 

Compounds with different structures but with the same therapeutic activity isolated from different plant species act as active moieties for the treatment of particular diseases. Some of these compounds have been abandoned due to toxicity but these compounds apparently do not cause serious adverse effects. Some of these active principles originate from edible plants and their inclusion in the diet would undoubtedly be of some value because of their hypocholesterolemic potential. Several phytoconstituents including inulin, pectin, gugglu lipids, flavonoids, ginkoloids, saponins, tannins, and others obtained from various plant sources have proven hypolipidemic potentials as has been further explained in Tables I and II. The chemical structures of a few potential phytoconstituents with hypolipidemic activity are shown in Figure 2. It is hoped that as new additions are made to the list of these active compounds causing only minimum untoward side effects, these naturally... 

Tannins are the complex flavonoid compounds. Some of these showed good results when evaluated for the antiosteoporosis. Camelliatanin D (30) was isolated from leaves and fruits of Camellia Japonica (Theaceae). It inhibited elevation of calcium concentration induced by PTH rp (1-34), with the IC50 of 2.4 x 10 M. Activity was done on cultured mouse calvaria [33]. Epigallocatechin (31) and epicatechin (32) are the constituents of Rosa sp. (Rosaceae) distributed widespread in other plants also. They behave as a bone sorption inhibitor [26]. 

However, not all related species or conspecific populations respond similarly under the same UV influence. For example, Betula pendula and B. resinifera, two closely related birch species collected from populations in Europe and Alaska, generally produce a number of flavonoids, hydroxycinnamic acids, and condensed tannins in larger quantity in exposed leaves to artificial UV-B photon fluxes (4.9 kJ m d for 3 hr/day of biologically active radiation) than in non radiated plants (Lavola, 1997). In B. pendula populations the major increase was in flavonoid synthesis but in B. resinifera the bias was towards the hydroxycinnamic acids and condensed tannins. Besides, allopatric (geographically distant) populations of birch reacted differently in the synthesis of specific compounds. For example, chlorogenic acid increased by 22 and 92% in plants from Germany and Alaska, respectively, but in Finnish plants there was no increment at all. 

Both marketers of manufactured superfruit products and the public media have exaggerated the potential antioxidant importance of fruit compounds such as polyphenol pigments (anthocyanins, flavonoids, tannins, catechins, xanthones, and many others). These compounds have antioxidant activity in controlled laboratory conditions, but there is no scientifically confirmed evidence that they have antioxidant roles in the human body. 

Sclerocarya birrea (A. Rich.) Hochst. subsp. cafffra [umganu, marula tree] (Sond.) Kokwaro (Anacardiaceae) stem bark decoction is used for diarrhoea. The stem bark contains alkaloids, flavonoids, glycosides, polyphenols, steroids and tannins 15). Its antidiarrhoeic activity is due to the tannin content 37). The plant is also used for childhood convulsion and epilepsy, and its anticonvulsant activity has been demonstrated in experimental animal model (58). 

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