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PubMed2004

Use of community genome arrays (CGAs) to assess the effects of Acacia angustissima on rumen ecology.

This research developed a community genome array (CGA) to assess the effects of Acacia angustissima on rumen microbiology. A. angustissima produces non-protein amino acids as well as tannins, which may be toxic to animals, and CGA was used to assess the effects of this plant on the ecology of the rumen. CGAs were developed using a 7.5 cmx2.5 cm nylon membrane format that included up to 96 bacterial genomes. It was possible to separately hybridize large numbers of membranes at once using this mini-membrane format. Pair-wise cross-hybridization experiments were conducted to determine the degree of cross-hybridization between strains; cross-hybridization occurred between strains of the same species, but little cross-reactivity was observed among different species. CGAs were successfully used to survey the microbial communities of animals consuming an A. angustissima containing diet but quantification was not precise. To properly quantify and validate the CGA, Fibrobacter and Ruminococcus populations were independently assessed using 16S rDNA probes to extracted rRNA. The CGA detected an increase in these populations as acacia increased in the diet, which was confirmed by rRNA analysis. There was a great deal of variation among strains of the same species in how they responded to A. angustissima. However, in general Selenomonas strains tended to be resistant to the tannins in the acacia while Butyrivibrio fibrisolvens was sensitive. On the other hand some species, like streptococci, varied. Streptococcus bovis-like strains were sensitive to an increase in acacia in the diet while Streptococcus gallolyticus-like strains were resistant. Strep. gallolyticus has independently been shown to be resistant to tannins. It is concluded that there is significant variation in tannin resistance between strains of the same species. This implies that there are specific molecular mechanisms at play that are independent of the phylogenetic position of the organism.

Acacia↗
PubMed2005

[Influence of manufacturing procedure on stability of Unguentum contra perniones preparations].

BACKGROUND: Application of various technological procedures for the manufacture of officinal preparation ointment against chilblains (Unguentum contra perniones) produce essential variations in the quality and stability of the final product. Changing the sequence of admixing active substances into the ointment base indicated the presence of incompatibility between the active substances, as well as between the active substances and the ointment base components. The aim was to examine the influence of various technological manufacturing procedures on quality and stability of the preparation. METHODS: Changes in the samples of ointments and aqueous solutions of active substances were analysed microscopically. RESULTS: Microscopic analysis of hydrosoluble active substance solutions demonstrated destruction of ichthammol, induced by an acidic medium due to the dissolution of tannin and resorcinol, which is well known from the literature. It also demonstrated the destruction of tannin and resorcinol in aqueous solution, which had not been described in the literature. Application of the prescribed procedure for the manufacturing of ointment against chilblains, conceals the incompatibility reactions due to a slow dissolution of the tannin suspended in the officinal ointment base Unguentum cera lanae. Admixture of an ready-made aqueous solution of tannin caused an instant contact between ichthammol and the acidic medium, which caused the destruction or the complete absence of the formation of emulsion droplets. The problem of incompatibility reactions between lanolin alcohols in the ointment base and ichthammol and resorcinol, as well as the reaction between Peruvian balsam and sulfur from the ichthammol sulfate ion was observed. Numerous incompatibility reactions of ointment against chilblains, components indicated that it was necessary to introduce alterations in both the qualitative and quantitative composition of the preparation. CONCLUSION: Excipient preparation procedure, as well as the technological procedure for incorporation of active ingredients can cause the incompatibilities and therefore the formulation stability problems.

Chemistry, Pharmaceutical↗
PubMed1991

[Effect of reheating on iron availability and the protein nutritive value of cooked black bean (Phaseolus vulgaris)].

In Guatemala, at the rural level, beans are prepared for family consumption every two days. Beans are cooked again every 12 hours for 15 minutes prior to their consumption. Due to the adverse effect that the process causes on nutritive value, the present study evaluated the method and preparation practice of beans on protein value; tannin and soluble and ionizable iron content. As to the effect of re-cooking on protein level, findings revealed that there were no significant statistical effects on net protein ratio (NPR) or in protein efficiency ratio (PER) and number of bean cooking. Nevertheless, a constant effect in quality in the first and second cooking procedure was detected. The second cooking gave a similar value as the first. Also, the first and second heating reduced protein digestibility, but the third gave a value similar to the initial one. No changes were observed in the digestibility of dry matter. Relatively high amounts of protein were found in the cooking broth, which was not affected by the number of heating. It was also found that the bean broth contained high levels of tannins in the initial heating, decreasing later significantly. The same was observed in the cooked beans alone and in beans with their broth. With respect to iron, findings showed a relatively high transference of beans to broth, in total iron as well as in soluble, ionizable and insoluble iron. No changes were observed in whole beans without broth caused by number of heatings, on total, soluble or ionizable iron. In beans with their broth, a similar effect was observed, although a slight increase in insoluble iron was detected at the end of heating. A decrease in soluble and insoluble iron was observed in broth with number of heatings. Correlations were calculated among the parameters studied, which suggested an effect of tannins on the bioavailability of iron caused by tannins.

Fabaceae↗
PubMed2001

In vitro antiprotozoal activity of extract and compounds from the stem bark of Combretum molle.

The antiprotozoal activity of the Ethiopian medicinal plant Combretum molle (R. Br. ex G. Don.) Engl & Diels (Combretaceae) was evaluated by in vitro testing against Plasmodium falciparum, Trypanosoma brucei rhodesiense, Trypanosoma cruzi and Leishmania donovani. The acetone fraction of the stem bark of this plant prepared by soxhlet extraction was inactive against the intracellular amastigotes of L. donovani and T. cruzi in murine peritoneal macrophages but showed significant activity against extracellular T. b. rhodesiense blood stream form trypomastigotes and trophozoites of P. falciparum with IC(50) values of 2.19 and 8.17 microg/mL, respectively. Phytochemical examination of the bioactive fraction resulted in the isolation of two tannins and two oleanane-type pentacyclic triterpene glycosides. One of the tannins was identified as the ellagitannin, punicalagin, whilst the structure of the other (CM-A) has not yet been fully elucidated. The saponins that were characterized as arjunglucoside (also called 4-epi-sericoside) and sericoside displayed no activity against any of the four species of protozoa tested. On the other hand, punicalagin and CM-A had IC(50) values of 1.75 and 1.50 microM, respectively, against T. b. rhodesiense and were relatively less toxic to KB cells (cytotoxic/antiprotozoal ratios of 70 and 48, respectively). The tannins also showed intermediate activity against P. falciparum, although their selectivity against these parasites was less favourable than the above. It appears that our findings are the first report of hydrolysable tannins exhibiting antitrypanosomal and antiplasmodial activities.

Animals↗
PubMed2001

Inhibition of UDP-glucuronosyltransferases in rat liver microsomes by natural mutagens and carcinogens.

Eight toxic compounds of natural origin present in the human diet or used as drugs were tested as inhibitors of UDP-glucuronosyltransferase (UGT) activity in rat liver microsomes with 1-naphthol (1-NA), phenolphthalein (PPh) and 4-nitrophenol (4-NP) as substrates. Strong inhibitory effects were observed with tannic acid (tannin) and the antifungal drug griseofulvin (GF): at a concentration of 1 mM, the two compounds completely suppressed the glucuronidation of 1-NA and PPh, respectively. A concentration of 0.1 mM still proved to be highly inhibitory, and even at a concentration as low as 50 microM, tannin produced nearly 50% inhibition of 1-NA conjugation. The UGT isoforms converting 4-NP were less sensitive to the tested compounds (with the exception of GF). Kinetic studies with tannin revealed an uncompetitive type of inhibition toward 1-NA, with an apparent Ki value of 20 microM. The inhibition by GF was non-competitive with respect to PPh and was of a mixed type toward UDP-glucuronic acid, with apparent Ki values of 40 microM and 30 microM, respectively. Tannin and GF did not act as substrates for rat microsomal UGT.

Animals↗
PubMed2004

Organic and inorganic nitrogen nutrition of western red cedar, western hemlock and salal in mineral N-limited cedar-hemlock forests.

Western red cedar (Thuja plicata Donn.), western hemlock (Tsuga heterophylla Raf. Sarge) and salal (Gaultheria shallon Pursh) are the main species growing in cedar-hemlock forests on Vancouver Island, Canada. Based on the dominance of organic N in these systems, we tested the hypotheses that: (1) organic N can be utilized by the three plant species; and (2) salal, which is ericoid mycorrhizal and has high tannin concentration in its tissues, would absorb more N from the complex organic N compounds than the other two species. The abilities of cedar, hemlock and salal to take up 15N,13C-labelled glutamic acid were measured and the capacities of the three species to use nitrate (NO3-), ammonium (NH4+), glutamic acid, protein and protein-tannin N were compared over a 20-day period. Based on 13C enrichment, all three species absorbed at least a portion of glutamic acid intact. Cedar, hemlock and salal also showed similar patterns of N uptake from the NO3-, NH4+, glutamic acid, protein and protein-tannin treatments. The largest proportions of applied N were taken up from the NO3- and NH4+ treatments while smaller amounts of N were absorbed from the organic N compounds. Thus organic N was accessed to a modest degree by all three species, and salal did not have a greater capacity to utilize protein and protein-tannin-N.

Carbon Isotopes↗
PubMed2006

Age-related shifts in leaf chemistry of clonal aspen (Populus tremuloides).

Developmental changes in plant structure and function can influence both mammalian and arthropod feeding preferences for many woody plant species. This study documents age-related changes that occur in the leaf chemistry of trembling aspen (Populus tremuloides Michx., Salicaceae) and discusses implications for the herbivore community and ecosystem processes. We collected leaves from replicate ramets from six age classes (1-25+ yr) in each of seven aspen clones growing in south central Wisconsin, USA. Chemical analyses were conducted to determine concentrations of condensed tannins, phenolic glycosides (salicortin and tremulacin), nitrogen, starch, and soluble sugars. Each variable differed significantly among clones and among age classes. On average, condensed tannin concentrations doubled in the first five years and then remained fairly constant among older age classes. Combined phenolic glycoside (salicortin + tremulacin) concentrations were high in the youngest ramets (ca. 19%) and decreased sharply with age. Developmental changes in tannin, salicortin, and tremulacin concentrations exceeded those of nitrogen and carbohydrates. Developmental shifts of this magnitude, and the age-related tradeoff that occurs between condensed tannins and phenolic glycosides, are likely to have significant influence on the herbivore community of aspen and may influence leaf litter decomposition and nutrient cycling.

Carbohydrates↗
PubMed2005

Inhibition of Naja kaouthia venom activities by plant polyphenols.

Plant polyphenols from the aqueous extracts of Pentace burmanica, Pithecellobium dulce, Areca catechu and Quercus infectoria were tested for their inhibitory activities against Naja kaouthia (NK) venom by in vitro neutralization method. The first three extracts could completely inhibit the lethality of the venom at 4 LD50 concentration and the venom necrotizing activity at the minimum necrotizing dose while also inhibited up to 90% of the acetylcholinesterase activity of NK venom at much lower tannin concentrations than that of Quercus infectoria. The ED50 of plant tannins in inhibiting NK venom activities varied according to condensed tannins and their content in the extracts. Molecular docking of the complexes between alpha-cobratoxin and either hydrolysable or condensed tannins at their lowest energetic conformations were proposed. The anti-venom activities of these plant polyphenols by selectively blocking the nicotinic acetylcholine receptor and non-selectively by precipitation of the venom proteins were suggested.

Animals↗
PubMed2000

Genetic selection for enhanced bioavailable levels of iron in bean (Phaseolus vulgaris L.) seeds.

The bioavailability of Fe from 24 select genotypes of bean (Phaseolus vulgaris L.) seeds containing a range of concentrations of Fe, myo-inositol pentaphosphate plus phytic acid (IP5+IP6), and tannins was studied using a rat model. Bean accessions, selected from field trials for their variations in Fe, phytate, and tannin seed concentrations, were grown in a greenhouse in nutrient solutions radiolabeled with (59)Fe. Mature seeds were autoclaved and lyophilized. Test meals (containing 1 g of dried bean, 0.5 g of sucrose, and 1 g of basal Fe-deficient diet) were fed to marginally Fe-depleted weanling rats over a 3-h period; rats were radioassayed in a gamma-spectrometer immediately after feeding and daily thereafter for the next 10 d. Radioiron retention data were used to calculate percent Fe absorption (i.e., Fe bioavailability) from the meals. Seed Fe concentrations ranged from 52 to 157 microg g(-)(1) dry weight. There was a tendency to also select for higher Zn concentrations in the beans when selecting for high Fe concentrations. The Fe bioavailability to rats from test meals depended on the genotype and varied from 53% to 76% of the total Fe. Bean genotypes with higher seed Fe concentrations resulted in increased amounts of bioavailable Fe to rats. There was no significant correlation between the Fe concentration in different bean genotypes and Fe bioavailability to rats attributable to variations in IP5+IP6 or tannins, even though these antinutrients varied widely (i.e., from 19.6 to 29.2 micromol of IP5+IP6 g(-)(1) and from 0.35 to 2.65 mg of tannins g(-)(1)) in the test meals. Other unknown seed factors (i.e., antinutrients or promoter substances) may be contributing factors affecting Fe bioavailability from bean seeds.

Animals↗
PubMed2005

Interactions between yeast lees and wine polyphenols during simulation of wine aging: I. Analysis of remnant polyphenolic compounds in the resulting wines.

Wine aging on yeast lees is a traditional enological practice used during the manufacture of wines. This technique has increased in popularity in recent years for the aging of red wines. Although wine polyphenols interact with yeast lees to a limited extent, such interactions have a large effect on the reactivity toward oxygen of wine polyphenolic compounds and yeast lees. Various domains of the yeast cell wall are protected by wine polyphenols from the action of extracellular hydrolytic enzymatic activities. Polysaccharides released during autolysis are thought to exert a significant effect on the sensory qualities of wine. We studied the chemical composition of polyphenolic compounds remaining in solution or adsorbed on yeast lees after various contact times during the simulation of wine aging. The analysis of the remnant polyphenols in the wine indicated that wine polyphenols adsorption on yeast lees follows biphasic kinetics. An initial and rapid fixation is followed by a slow, constant, and saturating fixation that reaches its maximum after about 1 week. Only very few monomeric phenolic compounds remained adsorbed on yeast lees, and no preferential adsorption of low or high polymeric size tannins occurred. The remnant condensed tannins in the wine contained fewer epigallocatechin units than the initial tannins, indicating that polar condensed tannins were preferentially adsorbed on yeast lees. Conversely, the efficiency of anthocyanin adsorption on yeast lees was unrelated to its polarity.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Digestibility, nitrogen excretion, and mean retention time by North American porcupines (Erethizon dorsatum) consuming natural forages.

North American porcupines (Erethizon dorsatum) subsist predominantly on low-protein, high-fiber, high-tannin diets. Therefore, we measured the porcupine's ability to digest dry matter, fiber, and protein by conducting digestion trials on eight natural forages and one pelleted ration varying in concentration of fiber, nitrogen, and tannins. On these diets, dry matter intake ranged from 5 to 234 g/kg(0.75)/d and dry matter digestibility ranged from 62% to 96%. Porcupines digested highly lignified fiber better than many large hindgut fermenters and ruminants. The porcupine's ability to digest fiber may be explained, in part, by their lengthy mean retention time of particles (38.43+/-0.56 h). True nitrogen digestibility was 92% for nontannin forages and pellets. Endogenous urinary nitrogen was 205 mg N/kg(0.75)/d, and metabolic fecal nitrogen was 2.8 g N/kg dry matter intake. Porcupines achieved nitrogen balance at relatively low levels of nitrogen intake (346 mg N/kg(0.75)/d). Tannins reduced the porcupines' ability to digest protein. However, the reduction in protein digestion was not predictable from the amount of bovine serum albumin precipitated. Like many herbivores, porcupines may ameliorate the effects of certain tannins in natural forages on protein digestibility through physiological and behavioral adaptations.

Animals↗
PubMed2002

Effect of dietary sorghum cultivars on the storage stability of broiler breast and thigh meat.

A total of 450 1-d-old male broiler chicks were fed a corn-soy-flax meal-based diet (control), two cultivars of sorghum--Ruby Red (low tannin content) and Valpo Red (high tannin content)--were used at 10% level. Birds were slaughtered at the end of 42-d feeding trial. Boneless, skinless breast and thigh muscles were separated and ground to make patties. Half of the breast and thigh meat patties were individually packaged in zipper bags, and 2-TBA-reactive substances (TBARS) and colors of the patties were determined after 0 and 7 d of storage at 4 C. The other half was cooked and vacuum-packaged. The vacuum-packaged patties were used to determine time-dependent volatile production and oxidative change during 12-h holding time before analyses. Thigh meat from broilers fed the Valpo Red cultivar produced lower TBARS than that from control at Day 0. The amounts of aldehydes and sulfur compounds of cooked breast meats were lower from chickens fed the Valpo Red cultivar than those fed the control or Ruby Red cultivar. Dietary Valpo Red cultivar improved the oxidative stability of breast meat 8 and 12 h after cooking. Dietary sorghum slightly improved the color a* stability of raw thigh meat patties. This result indicated that feeding sorghum to broilers could improve some measures of the storage stability of broiler meat, but sorghum with high tannin content was more effective than that with low tannin content.

Aldehydes↗
PubMed1986

Digestibility and utilization of ammonia-treated and urea-supplemented peanut skin diets fed to cattle.

A metabolism study and two feedlot trials were conducted to evaluate urea supplementation of peanut skin (PS) diets and ammoniation of PS as methods of reducing detrimental effects of tannins in PS on nutrient digestibility and performance of beef cattle. Tannin content of PS was reduced by 42% after ammoniation. Digestibility coefficients for dry matter, crude protein, nitrogen free extract, energy and total digestible nutrients were higher (P less than .05) for the control diet without PS compared with urea-supplemented PS (UPS) and ammoniated PS (APS) diets. Ether extract digestibility was higher (P less than .05) for UPS and APS diets compared with the control diet. Fecal N was higher (P less than .05) and N retention was lower (P less than .05) in steers fed UPS and APS diets compared with controls, which suggested that in UPS and APS diets dietary protein was being complexed with tannins and excreted. Steers fed the APS diet had lower (P less than .05) plasma urea nitrogen compared with control and UPS diets at 2, 4 and 6 h post-feeding. Eighteen heifers were fed control, UPS and APS diets individually for 84 d, resulting in similar (P less than .05) feedlot performance and carcass traits for heifers on all dietary treatments. Rumen fluid propionic acid levels were similar for control and APS heifers and somewhat lower (P greater than .05) for UPS heifers at 3 and 6 h post-feeding on d 62 of the trial. The experimental diets were fed to 54 steers (360 kg initial wt) ad libitum. After 98 d on dietary treatments average daily gains (ADG), final weights, carcass weights and carcass quality grades were not different (P greater than .05) for control and APS steers. Live weight and ADG were lower (P less than .05) for UPS steers on d 98 compared with control and APS steers, and UPS steers continued in the feedlot through d 147. After 98 d on control or APS diets 72.2% of the beef carcasses produced on each diet graded USDA Choice, and 100% of the carcasses of steers fed UPS graded USDA Choice after 147 d. A urea-supplemented PS diet or a diet containing ammoniated PS was ineffective in improving digestibility and N retention of PS diets when limit-fed to steers. However, ad libitum feeding of an ammoniated PS diet was effective in overcoming detrimental effects of tannins on feedlot performance of heifers and steers.

Ammonia↗
PubMed1998

[Effect of cooking on protein digestibility of sorghum (Sorghum bicolor (L.) Moench)].

The changes in protein digestibility that occur during cooking have interested many scientists. In this study the effect of cooking sorghum in water on the in vitro protein digestibility (IVPD) was evaluated using sorghum grains not containing tannin (SST), and grains containing detoxified tannin (SPD). The results were compared with rice and maize. The effect of sulfites present in the water used for cooking was also determined. The IVPD of sorghum excent of tannins before cooking was 71.1% smaller (p < 0.05) than that obtained for com (80.8%), polished rice (90.6%) or sorgum with detoxified tannins (80.4%). After cooking in water the IVPD decreased to 23.1%, 66.3%, 3.1% and 3.2% for SST, SPD, polished rice and corn endosperms, respectively. The IVPD of SST and SPD treated with 0.1M sodium bisulfite was 65.2 and 50.1%, which corresponds to a decrease in IVPD of 8.0 and 37.7%, respectively. Similar results were obtained when 0.1M sodium metabisulfite is added to the cooking media. These findings demonstrate that sulfites inhibit the sudden decrease of the IVPD of cooked sorghum grains, and suggest that these compounds may block the formation of disulfide bridges (-S-S-) among the gamma-kafirins molecules located on the surface of the sorghum protein bodies or possibly other factors involved which will be later studied.

Dietary Proteins↗
PubMed1993

Novel inhibitors of poly(ADP-ribose) glycohydrolase.

The inhibitory effects on poly(ADP-ribose) glycohydrolase purified from human placenta of three classes of chemically defined tannins; gallotannins, ellagitannins and condensed tannins, were examined in vitro. Oligomeric ellagitannins were found to be most potent inhibitors of poly(ADP-ribose) glycohydrolase, their potencies increasing with increasing number of monomeric residues (dimer < trimer < tetramer). Monomeric ellagitannins and gallotannins were less inhibitory. Condensed tannins, which consist of an epicatechin gallate oligomer without a glucose core, were not appreciably inhibitory. A structure-activity study showed that higher-order conformations of the conjugates with glucose of hexahydroxydiphenoyl and valoneoyl groups, which are unique components of ellagitannins, cooperatively potentiated the inhibitory activity.

Enzyme Inhibitors↗
PubMed1993

Antitumor activity of oenothein B, a unique macrocyclic ellagitannin.

The antitumor effect of oenothein B, a macrocyclic ellagitannin from Oenothera erythrosepala Bordas, on rodent tumors was studied. Oenothein B exhibited a strong antitumor activity against MM2 ascites tumors upon intraperitoneal administration to the mice before or after the tumor inoculation. The tannin also inhibited the growth of Meth-A solid type tumor in mice. This antitumor effect of the tannin could not be attributed to its direct cytotoxic action on tumor cells, because the cytotoxicity was very weak in the presence of serum protein. When oenothein B was injected into the peritoneal cavity of mice, peritoneal exudate cells, including cytostatic macrophages, were induced. Furthermore, in the in vitro treatment of macrophages from mice and humans, the tannin stimulated release of an interleukin 1 (IL-1)-like activity and IL-1 beta from the cells. These results suggest that oenothein B exerts its antitumor effect through potentiation of the host-immune defense via activation of macrophages.

Animals↗
PubMed2001

Effect of processing on the nutrients and anti-nutrients of lima bean (Phaseolus lunatus L.) flour.

The effect of soaking, autoclaving and toasting methods on the proximate and mineral composition and anti-nutrients of lima (butter) bean (Phaseolus lunatus L.) was investigated. The raw seed showed high content of proteins, lipids and ash with good values of K, Ca, Mg, P, Na and Fe in comparison with other legumes. Potassium was the most abundant macro mineral while sodium was the least. Iron content was the highest among the micro minerals. Manganese was not detected in any of the samples. Raw lima bean contained cyanide, trypsin inhibitor, lectin, phytin and tannin. Phytate phosphorus was calculated to be 28.2% of total phosphorus. There was no significantly different (P > 0.05) in the crude protein content of raw and processed flour. There was significant difference (P < 0.05) in the values of the macro and micro mineral. Soaking, autoclaving and toasting completely eliminated trypsin inhibitor and lectin while it significantly (P < 0.05) reduced the levels of phytin, tannin and cyanide. Except for tannin autoclaving for 20 min was found to eliminate all the other anti-nutrients in lima bean.

Cyanides↗