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PubMed1997

Effects of dietary sorghum of different tannin concentrations and tallow supplementation on the performance of broiler chicks.

1. The chemical compositions and tannin contents of 17 varieties of grain sorghum were determined. 2. Commercial broiler chicks were fed from 7 to 49 d of age on 15 experimental diets which varied in their concentrations of tannins and animal fat (tallow), by the inclusion of different amounts of high and a low protein varieties of sorghum. 3. Substitution of a low tannin sorghum completely for maize did not have any significantly adverse effect on performance. Broiler chicks could tolerate up to 2.6 g tannin/kg above which their performance was reduced. Addition of tallow did not significantly affect broiler performance except at the highest tannin content and added fat intake, where weight gain and efficiency appeared to improve significantly.

Adipose Tissue↗
PubMed2001

Spectrophotometric determination of the tannin contents of various Turkish black tea, beer and wine samples.

This study reports tannin contents of various tea (19), beer (6) and wine (6) samples, produced or sold in Turkey under different brand names. Determinations were carried out by employing a previously reported UV-vis spectrophotometric method. The standard addition procedure was also compared to the direct determination procedure and found to be more reliable. The tannin contents of hot water extracts of tea, tea bag and herbal tea samples ranged between 6.20-8.33, 8.03-6.59 and 2.76-6.54 percent (w/w) respectively. Tannin contents of beer and wine samples determined without extraction were found ranging between 66.36-77.26 and 67.18-107.62 micrograms/mL respectively. Iron contents of analysed wine samples were also found ranging between 0.36 and 10.33 ppm by AAS and no relation is found between tannin and iron contents.

Beer↗
PubMed1985

[Food value of field beans for chickens and evaluation of various portions with special reference to the tannin-poor sort in broiler fattening food].

The investigations were carried out with varieties rich in tannin (Erfordia, Fribo) and one poor in tannin (White Flowering). The protein of the variety poorer in tannin is slightly richer in methionine and is slightly better digested. The studies on the varieties Erfordia, Fribo and White Flowering in quotas of 7.5...45% as component in the fattening feed for broilers resulted in the same fattening performance as in the control group (maize-soybean-fishmeal ration) and had no influence on the chemical composition of the body and the weight of the pancreas. All rations were isonitrogenous and isocaloric. The soybean oilmeal in the ration was replaced gradually resp. completely by the field bean coarse meal in connection with methionine supplements. The variety poorer in tannin did not have nutrition-physiologic advantages in the the growth experiment with young broiler chickens.

Amino Acids↗
PubMed1986

Study of the genotoxicity of the total aqueous extract of betel nut and its tannin.

Frequencies of sister-chromatid exchanges (SCEs) were measured to study the genotoxicity of the total aqueous extract of betal nut and its tannin on mouse bone-marrow cells in vivo. Betal nut aqueous extract and tannin were injected i.p. into mice at doses of 12.5, 25 or 50 micrograms/g body weight and 50, 100 or 200 micrograms/g body weight respectively for 5, 10 or 15 days. Betal nut extract induced a dose-related increase in the frequency of SCEs after five daily doses of 12.5, 25 or 50 micrograms. Significant increases in SCEs were also observed in animals dosed for 10 days with 50 micrograms/g and for 15 days with 25 or 50 micrograms/g extract. After five daily doses of 50, 100 or 200 micrograms/g of betel nut tannin there was no significant induction of SCE. Mice dosed with 200 micrograms/g tannin for 10 days, or 100 or 200 micrograms/g for 15 days, showed significant increases in the frequency of SCEs.

Animals↗
PubMed1976

Identification of carcinogenic tannin isolated from Bracken fern (Pteridium aquilinum).

We attempted to isolate a carcinogenic substance from bracken fern (Pteridium aquilinum), a naturally occurring toxicant responsible for the production of chronic enzootic hematuria and urinary bladder cancer of cattle and carcinogenic for various target organs of several species. Hot methanol extracts of bracken fern were solubilized in water and extracted with chloroform followed by a mixture of n-butanol-butanone (1:1). That fraction was dried and triturated with ether-methanol (4:1), n-butanol, and finally absolute ethanol. The insoluble residue was dissolved in 10% aqueous methanol and passed through Dowex 1 OH-, Dowex 50 H+, or Dowex 1 OH- and then Dowex 50 H+ ion exchange resins. A condensed tannin, isolated from one ot the fractions, was identical to that isolated from bracken fern by the caffeine procedure used for the separation of tannins from other plant constituents. Three systems were used for bioassay; induction of bladder carcinoma by implantation of cholesterol pellets containing bracken fern fractions into the bladder lumens of mice; acute toxicity by ip injection of brachen fern fraction into mice; and growth inhibition of Escherichia coli. The following fractions induced significantly greater incidences of bladder carcinoma than did cholesterol pellets only: tannin, Dowex 50 H+, residue, n-butanol, and methanol. Tiliroside, a component of bracken fern fractions into the bladder lumens of mice; acute genic acid, and quercetin were not carcinogenic. Tannin was the most toxic (mean lethal dose: 0.16 mg/g) and carcinogenic. None of the carcinogenic fractions inhibited growth of E. coli.

Escherichia coli↗
PubMed1995

Effects of (-)-epigallocatechin-3-O-gallate (green tea tannin) on the life span of stroke-prone spontaneously hypertensive rats.

1. Effect of (-)-epigallocatechin-3-O-gallate (EGCG), a condensed tannin isolated from green tea leaves, on the life span and hypertensive lesions in the stroke-prone spontaneously hypertensive rat (SHRSP) was compared with that of persimmon tannin. 2. Long-term administration of either 0.5% EGCG or 0.5% persimmon tannin to SHRSP inhibited the incidence of stroke and prolonged the life span, but did not affect the blood pressure. 3. These results indicate that EGCG may prevent incidence of stroke due to the radical scavenging action and inhibition of lipid peroxidation, and may result in prolonging the life span of SHRSP, as in the case of persimmon tannin.

Animals↗
PubMed1996

Isolation of a tannin-protein complex-degrading fungus from faeces of hill cattle.

Faecal samples of 52 hill cattle fed largely on oak leaves were screened for tannin-protein complex-degrading micro-organisms under different culture conditions using tannin-treated brain heart infusion agar medium. None of the animals were found to harbour tannin-protein complex-degrading enterobacteria. However, a fungus identified as Aspergillus niger van Tieghem having tannin-protein complex-degrading activity, was consistently isolated from the faeces of such animals. Optimum growth and sporulation was noticed under aerobic conditions at 30 degrees C on Czapek Yeast Agar medium.

Aerobiosis↗
PubMed1995

The inhibitory effect of tannins on lipid peroxidation of rat heart mitochondria.

We induced lipid peroxidation in rat heart mitochondria with ferrous sulphate (FeSO4) and compared the inhibitory effect of various tannins on the peroxidation. Oxygen consumption and malondialdehyde (MDA) formation were used to quantitate the amount of lipid peroxidation, and the free radical scavenger activity of tannins was measured with a diphenyl-p-picryl hydrazyl (DPPH) method. Of 25 tannins and related compounds tested, catechin benzylthioether and procyanidin B-2 benzylthioether were the most potent in inhibiting lipid peroxidation, with inhibitory effects stronger than that of trolox, a water soluble analogue of vitamin E. The concentrations (IC50) required for catechin benzylthioether and procyanidin B-2 benzylthioether to inhibit oxygen consumption to 50% of control values were 0.85 and 2.0 microM, respectively, while their IC50 values from the inhibition of MDA formation were 0.9 and 1.70 microM, respectively. The IC50 values for catechin, and procyanidin B-2 to inhibit oxygen consumption were 34.0 and 11.0 microM. Both compounds were less potent than their benzylthioether derivatives. However, the ability of catechin and procyanidin B-2 to scavenge DPPH were similar to that of their benzylthioether derivatives. We conclude that conjugation with a benzylthioether group enhances the inhibitor effect of tannins on lipid peroxidation, and that the mechanism is not an increase in its scavenger activity.

Animals↗
PubMed2002

Effect of condensed tannins on egg hatching and larval development of Trichostrongylus colubriformis in vitro.

The effects of condensed tannins extracted from seven forages on the viability of the eggs and first stage (L1) larvae of the sheep nematode Trichostrongylus colubriformis were evaluated in in vitro assays. The extracts of condensed tannins were obtained from Lotus pedunculatus (LP), Lotus corniculatus (LC), sulla (Hedysarum coronarium), sainfoin (Onobrychus viciifolia), Dorycnium pentaphylum (DP), Dorycnium rectum (DR) and dock (Rumex obtusifolius). Extracts containing 200 to 500 microg/ml reduced the proportion of eggs that hatched. The larval development assay was used to evaluate the effect of the extracts on the development of either eggs or L1 larvae to L3 infective larvae. Development was allowed to proceed for seven days by which time the larvae in control incubations had reached the infective L3 stage. Extracts containing 200 microg/ml from LP, DP, DR or dock prevented egg development, and only 11, 8 and 2 per cent of the eggs developed to L3 larvae with extracts from LC, sulla and sainfoin, respectively. When the concentration was 400 microg/ml no eggs developed to L3 larvae. The addition of the extracts after hatching also inhibited the development of L1 to L3 larvae; 200 microg/ml extracted from LP, LC, sulla, sainfoin, DP, DR and dock resulted in only 14, 18, 17, 15, 14, 16 and 4 per cent of L1 larvae developing to the L3 stage compared with 85 per cent for controls, and 400 microg/ml further reduced the development of L1 larvae. Statistical analyses showed that when the extracts were added before hatching they were significantly (P<0.001) more effective at inhibiting the larval development than when they were added after hatching. The condensed tannins from dock had the greatest inhibitory effect on egg development followed by the tannins from DR, sainfoin, DP, LP, sulla and LC.

Animals↗
PubMed2001

The in vitro inhibitory effect of tannin derivatives on 3-hydroxy-3-methylglutaryl-coenzyme a reductase on vero cells.

Coronary heart disease is still the major cause of death in industrialized countries. Multiple primary or secondary interventional trials to lower serum cholesterol in humans have resulted in significant reduction of coronary events and death, one of the major reasons attributed to developing a 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor such as pravastatin. Developing new inhibitors of cholesterol synthesis is still common in the pharmaceutical industry. Tannin comprises a large group of natural polyphenolic compounds possessing antioxidant effects. The methods for analysis of specific inhibitors of mevalonate biosynthesis have already been well established by using Vero cells, a cell line obtained from kidneys of African green monkeys. Tannin derivatives isolated from different traditional Chinese herbs were dissolved in DMSO and incubated with Vero cells with or without the addition of 1 mmol/l mevalonate or 5 mmol/l sodium acetate for 24 h in order to observe cell growth. Pravastatin, a specific HMG-CoA reductase inhibitor, was used as positive control which could inhibit Vero cells growth effectively and cell growth inhibition was reversible after adding 1 mmol/l mevalonate. More than 50 tannin derivatives were used for the study, but only two compounds - proanthrocyanidin A-2 (belonging to the flavan-3-ol group) and 1,2,3,6-tetra-O-galloyl-beta-D-glucose (belonging to the gallotannin group) - showed significant growth inhibition of Vero cells. This study showed that some isolated tannin derivatives from traditional herbs were effective HMG-CoA reductase inhibitors which might be developed into new hypocholesterolemic agents.

Acyl Coenzyme A↗
PubMed1999

Inhibitory effects of hydrolyzable tannins from Melastoma dodecandrum Lour. on nitric oxide production by a murine macrophage-like cell line, RAW264.7, activated with lipopolysaccharide and interferon-gamma.

An extract of Melastoma dodecandrum LOUR. with 80% aqueous acetone (MDL) inhibited nitric oxide (NO) production by a murine macrophage-like cell line, RAW264.7, activated with lipopolysaccharide (LPS) and recombinant mouse interferon-gamma (IFN-gamma). On further fractionation of the extract, the majority of the inhibitory activity was recovered in the 50% methanol extracts, which contained hydrolyzable tannins. Among the latter, casuarinin, casuarictin, pedunclagin and nobotannin B exhibited strong inhibitory activities toward NO production, with ID50 values between 2.0 and 5.1 microM. Both MDL and the purified tannins significantly reduced the induction of the inducible nitric oxide synthase (iNOS) protein in the course of macrophage activation with LPS and IFN-gamma. In addition, the NO production by macrophages preactivated with LPS and IFN-gamma for 16 h was also inhibited by these tannins, with IC50 values around 30-130 microM, but not by MDL. These results suggest that MDL has the pharmacological ability to suppress NO production by activated macrophages and that the hydrolyzable tannins have major inhibitory activities.

Animals↗
PubMed1987

Inhibitory effects of condensed tannins on angiotensin converting enzyme.

Effects of condensed tannins isolated from Rhei Rhizoma on the activities of angiotensin converting enzyme (ACE) and various proteases were examined in vitro. Among the various condensed tannins tested, procyanidin B-5 3,3'-di-O-gallate and procyanidin C-1 3,3',3"-tri-O-gallate strongly inhibited the activity of ACE. The concentration of procyanidin B-5 3,3'-di-O-gallate required for 50% inhibition of ACE was 1.3 X 10(-6) M. The inhibition of ACE by condensed tannins was reversible and non-competitive, according to dialysis and to Dixon plots. However, over one hundred times the concentration was required to inhibit activities of other proteases such as trypsin, chymotrypsin, leucine aminopeptidase, carboxypeptidase A and urinary kallikrein. These results suggest that the inhibitory effects of condensed tannins on the activities of ACE are specific.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1996

Effectiveness of green tea tannin on rats with chronic renal failure.

The effects of green tea tannin on nephrectomized rats were examined. There were increases in blood urea nitrogen, serum creatinine, and urinary protein, and a decrease in creatinine clearance in the nephrectomized control rats, whereas better results for these parameters were obtained in rats given green tea tannin after nephrectomy, demonstrating a suppressed progression of the renal failure. When the renal parenchyma was partially resected, the remnant kidney showed a decrease in the activity of radical scavenger enzymes. Green tea tannin, however, was found to lighten the kidney under such oxidative stress. Mesangial proliferation and glomerular sclerotic lesions, which were conspicuous in the rats that were not given green tea tannin after nephrectomy, were also relieved.

Animals↗
PubMed1975

[Comparative study of different extraction methods and assays of tannins in some pteridophytes].

Various processes of extraction and quantitative analysis of a condensed tannin in a plant extract, which also includes some chlorogenic acids, have been examined. 60% methanol, at 50 degrees C, proved the most efficient extraction solvent. Several methods of analysis have been tried. The measure of the colour intensity obtained by the action of sulphuric vanilline on flavanols cannot be used because it depends on the tannin condensation stage. It is impossible to separate tannin from chlorogenic acids using the methods of adsorption by skin or nylon powders, or precipitation by polyvinylpyrrolidone. Only paper chromatography, followed by the distinct elution of the various phenolic compounds, allows the tannin evaluation by subtraction; but owing to the variability of the results, many more experiments are necessary. Some other processes are being studied.

Chlorogenic Acid↗
PubMed1976

[Effect of prolonged glucidic starvation on the contents of starch and tannins of Blechnum brasiliense L. gametophytes].

Some Blechnum brasiliense gametophytes have been maintained in darkness, in a purely mineral medium, for the purpose of investigating the effect of prolonged glucidic starving on the amount of tannins and starch that they contain. During the first two months the tannin contents undergoes a fast decrease. The starch variations are different : a transitory increase simultaneous with the fall in tannin; a decrease after the disappearance of 3/4 of the tannin contents; and lastly, a new amylogenese which precedes the prothallus necrosis. It seems that the gametophytes, in order to survive, degrade first their tannoidic reserves, and they utilize the starch that they contain only with difficulty. This behaviour can be explained by the distribution of the two metabolites; by the acid pH of the medium, which is not very propitious to the phosphorylases activity and lastly by the presence of chlorogenic acids, which are inhibitors of those enzymes.

Cells, Cultured↗
PubMed1983

Effects of sorghum grain tannins and dietary protein on the activity of liver UDP-glucuronyltransferase.

The activity of liver microsomal UDP-glucuronyltransferase (EC 2.4.1.17), an enzyme known to detoxify phenolic compounds, was measured in chicks and rats fed high- (HTS) and low-tannin sorghums (LTS). In an initial investigation, activity was significantly elevated in chicks fed HTS-soybean meal diets over those fed the LTS control diet. Other studies were designed to differentiate between the effects due to tannin and those resulting from a protein deficiency which had previously been reported to increase the activity of this enzyme. In general, only a relatively small part of the increased activity observed by feeding HTS to chicks could be attributed to a tannin-induced protein deficiency. The same phenomenon of elevated activity produced by feeding HTS to chicks was not observed in the rat. These results would suggest that sorghum tannins, or their breakdown products, are absorbed and activating UDP-glucuronyltransferase in the chick, but not the rat.

Animals↗
PubMed1983

The effects of sorghum tannin and protein level on the performance of laying hens maintained in two temperature environments.

A study was conducted to investigate the effect of sorghum grain tannins on the performance of laying hens. A total of 144 White Leghorn hens were arrayed according to egg production during a 10-day preexperimental period into eight groups consisting of four nutritional treatments in each of two constant temperature environments (22 and 28 C). The nutritional treatments consisted of low (RS610) and high (Savanna) tannin sorghum grains compared isonitrogenously within a protein level at two protein levels (11.5 and 14.5%) in sorghum-soybean meal diets. These diets were fed for an experimental period of 6 weeks. Egg production and feed efficiency were reduced and weight loss was increased by 11.5% protein as compared with 14.5% protein. Tannin significantly reduced egg production and feed efficiency at both protein levels while egg specific gravity and shell thickness were adversely affected only at the lower level of protein. Egg weight and weight loss of hens were not affected by tannin. Except for weight loss, all parameters were slightly reduced by the higher temperature. At the end of the experiment, all hens were placed on a commercial laying ration for a 31-day period. Recovery from the treatment effects was evidenced by the similar egg production, body weight, egg weight, and shell characteristics among the previous treatments at the end of this period.

Animals↗
PubMed2001

[The domestic processing of the common bean resulted in a reduction in the phytates and tannins antinutritional factors, in the starch content and in the raffinose, stachiose and verbascose flatulence factors].

The objective of this study was to evaluate the effect of the soaking step and the domestic processing of the common bean, on the chemical composition, the levels of phytate, tannin, starch and flatulence factors by utilizing the follows treatments: raw bean (FC), freeze-dried cooked unsoaked bean (FCSM), freeze-dried cooked bean without the non-absorbed soaking water (FCSAM), freeze-dried cooked bean with the non-absorbed soaking water (FCCAM) and the soaking water (AM). The beans were soaking for a period for 16 hours in the proportion 3:1 (water:beans) at room temperature. The effect of the phytates and tannins on the net protein efficiency ratio (NPR) and protein digestibility using male Wistar rats were studied. A decrease in the phytate content of the beans (85%) with use of soaking was observed. In the case of the tannin content, only the cooking of the beans promoted high decomposition (84%). In the (FCSAM) treatment a decrease in the raffinose (25.0%), stachiose (24.8%), verbascose (41.7%) and starch (26.8%) contents was observed. Diets containing casein (control), casein plus the soluble solids obtain from the soaking water showed no significant difference (p > 0.05) for the NPR, as well as for the different bean treatments, although these showing lower values. The treatment (FCSM) showed the higher digestibility (74.3 +/- 5.8%) of the bean treatments, the casein diets showing 94.6 +/- 0.9%. The reduction of the phytates, tannin, starch contents and flatulence factors in the common bean was most effective when the soaking water not absorbed was discarded (FCSAM).

Animals↗