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Green acorns are known to contain high concentrations of pyrogallol. Here, we describe an extended case report of two pigeons found dead with a filled muscular stomach of acorns. The following pathologic findings were observed: irritation of mucosal membranes in the gastrointestinal tract, blackish discolored chyme, hyperemic organs, and general edemas. The muscular stomach (ventriculus) was filled with pieces of acorns, and the abdominal cavity contained bloody aqueous fluid. In order to uncover the cause of death, we determined pyrogallol in liver and kidney of one dead pigeon and in ventriculus contents of both pigeons by gas chromatography/mass spectrometry. A further aim of our study was to compare pathologic findings and pyrogallol concentrations in kidney, liver, and ventriculus of poisoned pigeons with those of healthy pigeons. The pyrogallol concentrations in samples of dead pigeons were 16-1200-fold higher than in control animals fed grass and maize-corn. Altogether, the acorn-filled ventriculus, the pathologic findings, the well nourished state, and the high pyrogallol concentrations in the dead pigeons suggest an acute pyrogallol poisoning by acorn. With respect to controls, we conclude that pyrogallol concentrations of 6 ng/g of kidney, 8 ng/g of liver, and 2 ng/g of gastric content do not affect the health of pigeons.
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... Tannins, a diverse group of water-soluble phenolics, are thought to be provide a defense against herbivory by reducing protein digestibility (Zucker 1983;Hagerman and Klucher 1986;Mehansho et al. 1987). They are also potential toxins that cause direct detrimental effects to gastrointestinal mucosa and epithelia, kidney and liver failure, intrinsic nitrogen loss, and disturbance of sodium balance (Fowler and Richards 1965;Glick and Joslyn 1970;Freeland et al. 1985;Robbins et al. 1987; Thomas et al. 1988;Dietz et al. 1994;Dearing 1997a;Meiser et al. 2000). In fact, 3% quebracho (a type of condensed tannins) added to the control diet causes a significant de-crease of survival rate of the prairie vole Microtus ochrogaster (Lindroth and Batzli 1984), and similar results are reported in other rodents (rat, Joslyn and Glick 1968;hamster, Mehansho et al. 1984;mouse, Freeland et al. 1985; the meadow vole Microtus pennsylvanicus, Dietz et al. 1994). ...
... Negative nitrogen balances have been reported only by Short (1976) in fox squirrels to which acorns were fed. Contrary to this finding, lethal damage, such as gastrointestinal lesions, kidney failure, and steep reduction in body weight, has been reported in livestock (Fowler and Richards 1965;Basden and Dalvi 1987) and avian species (Dixon et al. 1997;Johnson et al. 1993;Meiser et al. 2000). These interspecific differences in response of mammals to acorn feeding may be related to proline-rich proteins (PRPs), which are produced in saliva by some mammalian species. ...
... Mammalian herbivores producing PRPs are expected not to suffer heavy damage from natural diets containing tannins, unlike animals without PRPs (Robbins et al. 1991;Juntheikki 1996). Cattle, sheep, and avian species, which suffer acorn poisoning (Fowler and Richards 1965;Johnson et al. 1993;Dixon et al. 1997; Meiser et al. 2000), do not produce PRPs. The gray squirrel and fox squirrel have not been investigated for the production of PRPs. A. speciosus does possess PRPs (Shimada et al., unpublished manuscript). ...
Antinutritional effects of acorns and tannic acid on the Japanese wood mouse Apodemus speciosus were examined in the laboratory. The first feeding experiment was conducted for 15 days using three types of diet: control
diet (laboratory chow for mice), acorns of Quercus serrata (QS), and acorns of Q. mongolica var. grosseserrata (QM), which differ in tannin content (control, tannin free; QS, 2.7% tannic acid equivalent; QM, 8.5%). Six and one of eight
mice died in the QM and QS groups, respectively, whereas all mice survived in good health in the control group. Body weight
in the QM and QS groups decreased as much as 23.6% and 16.8% in the first 5 days, respectively, whereas that in the control
group did not change significantly. Dry matter intake in the QM group was 50.0% and 38.7% less than that in the control and
QS, respectively. Apparent dry matter digestibility was not different among the diets, but apparent nitrogen digestibility
did differ between the two acorn groups (QM, −17.5%; QS, 12.0%). The logistic regression analyses revealed that the survival
of mice was synergistically influenced by both dry matter intake and apparent nitrogen digestibility. In the second experiment,
wood mice fed the tannin-free formula diet, which is nutritionally matched to QS and QM acorns except for the tannin, did
not suffer antinutritional effects, whereas mice fed the tannin-supplemented formula diets suffered body weight loss and negative
nitrogen digestibility. These results indicate that the tannins in acorns could cause serious damage to the wood mouse, which
may rely on acorns as a usual diet. Plausible hypotheses explaining how the wood mice could overcome the deleterious effects
of the acorns are discussed.
... Secondary chemical compounds (e.g., tannins and other polyphenols) may also affect seed removal (e.g. Robbins et al., 1991;Dearing, 1997;Meiser et al., 2000;Burritt and Provenza, 2000;Dearing et al., 2000;Shimada and Saitoh, 2003). Tannins, a diverse group of soluble phenolic compounds, are thought to be defenses against herbivory (Robbins et al., 1991;Dearing, 1997;Meiser et al., 2000;Shimada and Saitoh, 2003). ...
... Robbins et al., 1991;Dearing, 1997;Meiser et al., 2000;Burritt and Provenza, 2000;Dearing et al., 2000;Shimada and Saitoh, 2003). Tannins, a diverse group of soluble phenolic compounds, are thought to be defenses against herbivory (Robbins et al., 1991;Dearing, 1997;Meiser et al., 2000;Shimada and Saitoh, 2003). Rodents often avoid acorns with high tannin concentration (Shimada, 2001;Shimada and Saitoh, 2003). ...
Seed traits are important factors affecting seed predation by rodents and thereby the success of recruitment. Seeds of many tree species have hard hulls. These are thought to confer mechanical protection, but the effect of endocarp thickness on seed predation by rodents has not been well investigated. Wild apricot (Prunus armeniaca), wild peach (Amygdalus davidiana), cultivated walnut (Juglans regia), wild walnut (Juglans mandshurica Maxim) and Liaodong oak (Quercus liaotungensis) are very common tree species in northwestern Beijing city, China. Their seeds vary greatly in size, endocarp thickness, caloric value and tannin content. This paper aims to study the effects of seed traits on seed removal speed of these five tree species by small rodents in a temperate deciduous forest, with emphasis on the effect of endocarp thickness. The results indicated that speed of removal of seeds released at stations in the field decreased significantly with increasing endocarp thickness. We found no significant correlations between seed removal speed and other seed traits such as seed size, caloric value and tannin content. In seed selection experiments in small cages, Père David's rock squirrel (Sciurotamias davidianus), a large-bodied, strong-jawed rodent, selected all of the five seed species, and the selection order among the five seed species was determined by endocarp thickness and the ratio of endocarp mass/seed mass. In contrast, the Korean field mouse (Apodemus peninsulae) and Chinese white-bellied rat (Niviventer confucianus), with relatively small bodies and weak jaws, preferred to select small seeds like acorns of Q. liaotungensis and seeds of P. armeniaca, indicating that rodent body size is also an important factor affecting food selection based on seed size. These results suggest endocarp thickness significantly reduces seed removal speed by rodents and then negatively affects dispersal fitness of seeds before seed removal of tree species in the study region. However, effect of endocarp thickness on final dispersal fitness needs further investigation because it may increase seed caching and survival after seed removal.
... There are two main subgroups of tannins: condensed (not readily susceptible to degradation) and hydrolyzable tannins (susceptible to acid, base, or enzyme-catalyzed hydrolysis) (Hagerman 2011). Hydrolysis of tannins in the mammalian digestive tract releases phenolic acids that may be locally toxic to the gut microbiota and may damage the gastrointestinal mucosa and epithelium (McLean and Duncan 2006;Meiser et al. 2000). These products of hydrolysis may also be absorbed from the intestine and cause systemic harm (Niho et al. 2001). ...
Dietary tannins are ubiquitous in woody plants and may have serious negative effects on herbivores by inducing a loss of dietary protein and producing toxins if they are hydrolyzed in the gut. Many herbivorous mammals counter the negative effects of tannins through tannin-binding salivary proteins (TBSPs) that inactivate tannins by forming insoluble complexes and prevent them from interacting with other more valuable proteins. Howlers are the most folivorous New World primates and ingest foods with varying tannin content. We studied the presence of TBSPs in six wild mantled howlers (Alouatta palliata mexicana) immediately after capture and in captivity when fed on two diets composed of natural ingredients: a mixture of fruit and leaves or only leaves. Protein concentration was determined in whole saliva samples, followed by gel electrophoresis. We identified two protein bands of 17 and 25 kDa that have tannin-binding capacity. Although the monkeys ate almost twice as much condensed tannins in the leaf diet than in the fruits and leaves diet (7 vs. 4 g/d dry matter) the salivary protein concentration did not differ between the two diets (leaf diet: 3.29 ± SE 0.82 vs. fruit and leaves diet: 3.42 ± SE 0.62 mg/ml) and we found no additional protein bands in response to either diet. We suggest that the continuous expression of TBSPs is part of a dietary strategy that enables howlers to consume diets with variable tannin contents, thus partly explaining their dietary flexibility. Although the importance of salivary proteins to arboreal primates is broadly accepted, to our knowledge this is the first report of TBSPs in any Neotropical primate.
... Skin irritation is defined as a locally arising and non-immunogenic inflammatory reaction, which appears shortly after stimulation and usually disappears in a few days (Harvell et al., 1995). As an acid, PYR has been shown to cause irritation of mucosal membranes in the gastrointestinal tract (Meiser et al., 2000;Gosselin et al., 1981). Therefore, the acidic nature of PYR may be responsible for its irritant effects. ...
Hair dye components such as pyrogallol and cresol have been shown previously to promote allergic reactions such as rashes, dermal inflammation, irritation and dermatitis. The objective of this study was to determine the contact sensitization potential of pyrogallol (PYR) and 5-amino-o-cresol (AOC) when applied dermally to female BALB/c mice. Measurement of the contact hypersensitivity response was initially accomplished using the local lymph node assay. For PYR, significant increases in the proliferation of lymph node cells were observed at concentrations of 0.5% (w/v) and higher. For AOC, borderline increases, albeit significant, in auricular lymph node cell proliferation were observed at 5% and 10%. Results from the irritancy assay suggested that PYR, but not AOC, was an irritant. To further delineate whether PYR was primarily an irritant or a contact sensitizer, the mouse ear swelling test (MEST) was conducted. A significant increase in mouse ear thickness was observed at 72 hr following challenge with 0.5% PYR in mice that had been sensitized with 5% PYR. In contrast, no effects were observed in the MEST in mice sensitized and challenged with the highest achievable concentration of AOC (10%). Additional studies examining lymph node subpopulations and CD86 (B7.2) expression by B cells further support the indication that PYR was a sensitizer in BALB/c mice. The results demonstrate that PYR is both a sensitizer and an irritant in female BALB/c mice. However, the contact sensitization potential of AOC is minimal in this strain of mouse.
... Tannins are a widespread group of PSMs that are broadly distributed in various plant parts (Waterman and Mole 1994). Ingesting tannins, a diverse group of watersoluble phenolics with high affinity for proteins, may have negative effects on herbivores, such as reduction in protein digestibility (Robbins et al. 1987;Chung-MacCoubrey et al. 1997;Shimada and Saitoh 2003), damage to the gastrointestinal mucosa and epithelium (Meiser et al. 2000), or endogenous nitrogen loss (Shimada and Saitoh 2003). ...
Mammalian herbivores adopt various countermeasures against dietary tannins, which are among the most widespread plant secondary metabolites. The large Japanese wood mouse Apodemus speciosus produces proline-rich salivary tannin-binding proteins in response to tannins. Proline-rich proteins (PRPs) react with tannins to form stable complexes that are excreted in the feces. Here, we developed a new method for estimating the tannin intake of free-living small rodents, by measuring fecal proline content, and applied the method to a field investigation. A feeding experiment with artificial diets containing various levels of tannic acid revealed that fecal proline content was clearly related to dietary tannin content in three species (A. speciosus, Apodemus argenteus, and Myodes rufocanus). We then used fecal proline content to estimate the tannin intakes of these three forest-dwelling species in a forest in Hokkaido. In the autumn, estimated tannin intakes increased significantly in the Apodemus species, but not in M. rufocanus. We speculated that an increase in tannin intake during autumn may result from consumption of tannin-rich acorns. This hypothesis was consistent with population fluctuation patterns of the three species, which were well-synchronized with acorn abundance for the Apodemus species but not for M. rufocanus.
... 9 Pigeons poisoned with green acorns, which contain high concentrations of pyrogallol, developed gastroenteritis. 10 The characteristic lesion in mice 5 and chickens 11 fed toxic quantities of tannic acid experimentally is periacinar hepatic necrosis. Australian king parrots affected by wasting and diarrhoea in the ACT in 1990 and 1991 had been feeding on acorns, most had diarrhoea and some exhibited dysentery, but none had nephrosis or periacinar hepatic necrosis. ...
To describe a syndrome of wasting, diarrhoea and mortality in Australian king parrots (Alisterus scapularis).
Field observations and laboratory examinations. Procedure Pathological examinations were performed on 50 Australian king parrots with wasting and diarrhoea. Wet preparations of intestinal contents were examined by light microscopy. Tannins were extracted from acorns (Quercus sp) and tested for toxicity in mice. CLINICAL SIGNS AND EPIDEMIOLOGY: A syndrome of wasting, diarrhoea and mortality was observed in wild juvenile Australian king parrots in eastern Australia from 1984 to 2000. Sporadic cases and outbreaks of disease occurred from May to September in New South Wales, the Australian Capital Territory and Victoria. Outbreaks in the Australian Capital Territory in 1990 and 1991 were associated with parrots congregating to feed on acorns. Most affected birds failed to respond to treatment with dimetridazole and died 1 to 14 days after hospitalisation. Selected cases recovered following treatment with metronidazole. PATHOLOGY: Affected birds were emaciated, with faecal matting of feathers around the cloaca and yellow-green fluid, foamy intestinal contents. Abundant motile Spironucleus trophozoites were observed in wet preparations of faeces of clinically affected birds and intestinal contents of birds examined within 1 h of death. Protozoa were detected histologically in crypts of Lieberkühn in the intestine in association with exudation of mucus (catarrhal enteritis) or lymphoplasmacytic enteritis. Toxicology Tannin extracts from acorns induced periacinar hepatic necrosis in mice.
Wasting, diarrhoea and mortality in wild juvenile Australian king parrots were associated with Spironucleus-like protozoa in the intestine. Acorns were not considered to be the cause of the syndrome.
A selective and sensitive analytical method for the determination of selected catechins (catechin, epicatechin, gallocatechin, epigallocatechin) and pyrogallol in biological matrices by HPLC-MS/MS was developed. The utilized sample preparation technique was a two-stage liquid-liquid extraction using ethyl acetate. The HPLC-system was equipped with a Phenomenex Luna Pentafluorophenyl Column (150 x 2 mm, 5 µm) and operated with an acetonitrile-water gradient as a mobile phase system. Detection was performed with a 3200 Q Trap mass spectrometer. For analysis the mass spectrometer was used in the MRM-mode with negative ionization.
The method validation was performed with serum as matrix. The selectivity of the method as well as the linearity of calibration was successfully proven for all analytes. The limits of quantification were between 5.3 and 11.2 ng/mL and the recovery rates were above 50 % for all analytes.
Results from the samples of three deer poisoning cases demonstrated that the developed HPLC-MS/MS method is applicable to real biological samples.
In the present study, we investigated the protective effect of Quercus aliena acorn extracts against CCl4-induced hepatotoxicity in rats, and the mechanism underlying the protective effects. Aqueous extracts of Quercus aliena acorn had higher superoxide radical scavenging activity than other types of extracts. The Quercus aliena acorn extracts displayed dose-dependent superoxide radical scavenging activity (IC50 = 4.92 microg/ml), as assayed by the electron spin resonance (ESR) spin-trapping technique. Pretreatment with Quercus aliena acorn extracts reduced the increase in serum aspartate aminotransferase (AST) and serum alanine aminotransferase (ALT) levels. The hepatoprotective action was confirmed by histological observation. The aqueous extracts reversed CCl4-induced liver injury and had an antioxidant action in assays of FeCl2- ascorbic acid induced lipid peroxidation in rats. Expression of cytochrome P450 2E1 (CYP2E1) mRNA, as measured by RT-PCR, was significantly decreased in the livers of Quercus aliena acorn-pretreated rats compared with the livers of the control group. These results suggest that the hepatoprotective effects of Quercus aliena acorn extract are related to its antioxidative activity and effect on the expression of CYP2E1.
A selective and sensitive method was developed for the quantitative determination of pyrogallol and detection of gallic acid in biological samples. Pyrogallol was measured as a metabolite of gallotannin in bovine urine and serum samples. Gallic acid was formed by hydrolysis of the gallotannins in blue oak (Quercus douglasii) leaves, tannic acid standards, and rumen contents. Acid hydrolyzed or acidified samples were extracted with 5% ethanol in ethyl acetate (v/v), followed by evaporation and derivatization with Deriva-sil. The trimethylsilyl derivatives were analyzed by gas chromatography/mass spectrometry using selected ion monitoring. Method detection limits for gallic acid and pyrogallol were 0.5 ppm in urine and serum samples and 5 ppm in rumen contents. The diagnostic utility of the method was tested by analyzing samples from heifers dosed with blue oak leaves and commercial tannic acid. Keywords: Pyrogallol; gallic acid; gallotannins; GC/MS determination
1. In the isolated mesenteric vein of the dog, dipyridamole inhibited both the excitatory junction potential (e.j.p.) and the slow depolarization evoked by perivascular nerve stimulation, to 60-70% of control, with no change in the postjunctional membrane potential. These inhibitory actions of dipyridamole were not modified by 8-phenyltheophylline or phentolamine, suggesting that the inhibition did not involve either the actions of endogenous adenosine or the prejunctional alpha-autoregulation mechanism. 2. Dipyridamole did not produce any detectable effects on either the facilitation process of the e.j.ps or the postjunctional membrane depolarization produced by exogenously applied noradrenaline (NA). 3. Dipyridamole reduced the outflow of both the NA and the 3,4-dihydroxyphenylglycol (DOPEG) evoked by perivascular nerve stimulation to below 10% of control, the effect being much greater than that of exogenously applied adenosine (to about 90% of the control). 4. Exogenously-added NA was degraded by incubation with a segment of the vein. Dipyridamole itself produced degradation of NA and accelerated the NA-induced degradation. By contrast, pyrogallol, but not pargyline or imipramine, prevented the NA-induced degradation. 5. It is suggested that dipyridamole degrades NA directly, and also indirectly through activation of catechol-O-methyl transferase, with no alteration of the activity of monoamine oxidase or of the uptake mechanisms of NA into nerve terminals.
A number of plants are capable of producing intoxication of sufficient severity as to cause death within 12 hours of the onset of clinical signs. Those most rapid in their lethal effects are the cyanogenic plants and yew. Nitrate-accumulating plants likewise are capable of causing sudden death with only a brief appearance of signs. Most toxic plants, however, typically either require a longer time for the intoxication to develop and become lethal or sudden death is the exception rather than the rule following ingestion. In these cases, diagnosis of the problem may be facilitated by recognition of arrays of clinical signs that appear. Seven major groups of presenting signs can be distinguished: dyspnea and polypnea, hemorrhage, prominent excessive muscular activity, depression and/or weakness, diarrhea and weakness, excessive salivation and/or regurgitation and/or colic, and weakness and incoordination and/or tremors. Based on these and accompanying signs in surviving animals, many of the causes of sudden death can be differentiated. In addition, pathological changes visible on necropsy and identification of plant fragments in the rumen and stomach may be of diagnostic value.
A double-wattled cassowary died following a clinical course of severe diarrhea, anorexia, and polydypsia. At necropsy, prolapse of the penis, severe enteritis, and swelling of the kidneys with subcapsular heavy deposits of urates were noted. Histologic lesions comprised nephrosis, interstitial edemia of the muscle, and sloughing of the intestinal villi. Leaves collected from the gizzard were identified as coast live oak (Quercus agrifolia). Diagnosis of oak poisoning was made based on the renal lesions and the finding of a high content of tannins in the liver and gastrointestinal tract. Oak poisoning has not been reported previously in avian species.
Although acorn poisoning is more commonly seen in cattle as a susceptible animal species, several other factors such as species of acorns also have a distinct bearing on the degree of acorn toxicity. In this study, 3 species of acorns (Quercus alba, Q velutina and Q rubera) were analyzed for their total phenolic contents. Q velutina was found to have the highest level of total phenolics and Q alba the lowest among the 3 species. The total phenolic content in Q rubera was slightly lower than that of Q velutina but markedly higher than that of Q alba. The data suggest that when evaluating a pasture on the likelihood of acorn toxicity, one containing mainly Q alba may be safer than Q velutina and Q rubera.
Two outbreaks of oak poisoning in cattle in the Republic of South Africa are described. In the first outbreak 22 out of 80 head of cattle were severely affected while 40 out of a herd of 135 cattle were affected in the second outbreak. Of these 40, only one survived after 9 months despite vigorous treatment. Only young cattle under 2 years were affected during both outbreaks in spite of an average herd age of approximately 6 years in the second group of cattle. Clinical signs included severe weakness with a swaying gait, diarrhoea and dehydration. Some were pot bellied while others were emaciated and remained stunted. The most prominent macroscopic and microscopic lesion present in 3 animals autopsied, was a non-suppurative interstitial nephritis which was accompanied by oedema and ulceration of the caecum and colon. Histochemical studies were carried out on pigment granules observed in kidney sections.
The detection of 4-hydroxycoumarin rodenticides in poisoned domestic animals requires a highly sensitive method as tissue and serum levels of anticoagulants may be very low owing to rapid elimination, metabolism or post-mortem degradation. Thin-layer chromatography (TLC) and reversed-phase high-performance liquid chromatography (RP-HPLC) with fluorescence detection were used to identify the anticoagulants in spiked tissues and in suspicious samples. The analysis of ten suspicious samples highlighted the limitations of both methods. Only the three samples of baits were found positive by TLC whereas one of the five anticoagulants was detected in eight samples by RP-HPLC with fluorescence detection. Therefore, RP-HPLC with fluorescence detection proved to be the more sensitive method for detecting low levels of 4-hydroxycoumarins in blood serum, liver and ingesta, whereas TLC is usually sufficient for analysing baits.