Metabolism of pyrrolizidine alkaloids in the ovine rumen. IV. Effects of chloral hydrate and halogenated methanes on rumen methanogenesis and alkaloid metabolism in fistulated sheep

1972 ◽  
Vol 23 (6) ◽  
pp. 1085 ◽  
Author(s):  
GW Lanigan

Five halogenated methane analogues (bromoform, chloroform, iodoform, carbon tetrabromide, and carbon tetrachloride) have been shown to inhibit methane formation in the sheep's rumen as well as in rumen fluid in vitvo. On a molar basis the methane analogues were 100-200 times as effective as chloral hydrate in vitro, but in the rumen this difference was reduced by a factor of 10 with four of the compounds and to parity with chloral hydrate in the case of carbon tetrachloride. When rumen methanogenesis was inhibited by administration of chloral hydrate, bromoform, or iodoform, the time taken for metabolism of 2 g of Heliotropium europaeum alkaloids was reduced to 25-40% of that taken in animals not so treated. These results support the conclusion that inhibition of methanogenesis may be a useful protective measure for sheep ingesting plants which contain hepatotoxic pyrrolizidine alkaloids.

1970 ◽  
Vol 21 (3) ◽  
pp. 493 ◽  
Author(s):  
GW Lanigan ◽  
LW Smith

In vitro studies have demonstrated that the rate of metabolism of pyrrolizidine alkaloids in sheep's rumen fluid varies greatly. Fluids from sheep at pasture display much higher activity than do those from chaff-fed animals. Addition of dried Heliotropium europaeum to a chaff ration leads to a marked increase in the in vitro rate of alkaloid degradation by the rumen fluid but activity rapidly declines again when the H. europaeum is withdrawn. Thus a major factor limiting multiplication in the rumen of bacteria responsible for alkaloid breakdown appears to be lack of their specific substrates. N-oxides of pyrrolizidine alkaloids are rapidly reduced to tertiary bases in rumen fluid, even in samples from sheep not previously exposed to these substrates. The stimulation of the alkaloid-metabolizing system by vitamin B12 also varies greatly, both in whole rumen fluid and in fluids with activity reduced by removal of coarsely particulate matter. It is concluded that the B12 effect is not related to a specific requirement of the alkaloid-utilizing bacteria but to stimulation of other species which produce a metabolite essential for pyrrolizidine alkaloid metabolism.


1970 ◽  
Vol 21 (4) ◽  
pp. 633 ◽  
Author(s):  
GW Lanigan

When the pyrrolizidine alkaloids heliotrine and lasiocarpine were incubated in vitro with sheep's rumen contents, a common metabolic product was formed. This compound was also found as an end-product of metabolism in the rumen contents of sheep fed on a ration containing the plant Heliotropium europaeum. Previously described rumen metabolites of the Heliotropium alkaloids were 1-methylenepyrrolizidine derivatives, e.g. l-goreensine. The newly found product represents a further stage of reduction of l-goreensine in which the 1-methylene group has been replaced by a 1-methyl group. This compound has been identified as 7�-hydroxyla- methyl-8�-pyrrolizidine, a previously unknown pyrrolizidine derivative.


1971 ◽  
Vol 22 (1) ◽  
pp. 123 ◽  
Author(s):  
GW Lanigan

Inclusion of up to 80% hydrogen in the gas phase markedly stimulated the in vitro metabolism of heliotrine in sheep rumen fluid. The maximal rate of heliotrine breakdown under these conditions was twice that obtained when cyanocobalamin was added and 10 times the rate in unsupplemented rumen fluid. A maximal rate of heliotrine metabolism equal to that in the presence of 80% hydrogen gas could be obtained with a pure carbon dioxide atmosphere if certain inhibitors of methanogenic bacteria were added to the rumen fluid. It is concluded that the heliotrine-metabolizing bacteria are normally at a disadvantage in competition with the methanogenic bacteria for metabolic hydrogen, and that inhibition of the latter organisms in vivo could provide a basis for development of effective prophylaxis in sheep at risk with Heliotropium europaeum in the field.


1978 ◽  
Vol 29 (6) ◽  
pp. 1281 ◽  
Author(s):  
GW Lanigan ◽  
AL Payne ◽  
JE Peterson

Most sheep fed for prolonged periods on a ration containing 50% dried Heliotropium europaeum developed some of the clinical manifestations seen in field cases of pyrrolizidine alkaloidosis. Histologically demonstrated liver damage in the laboratory animals was comparatively mild, but the marked decline in their bromosulphophthalein (BSP) clearance rates indicated severe depletion of liver functional capacity. In sheep fed on H. europaeum for 13-week periods separated by 18-week rests, simultaneous oral administration of iodoform (16 mg twice daily) led to an increase from 33 to 55 weeks in the time required for death of half the susceptible sheep. Iodoform at levels of 32 mg and above twice daily proved hepatotoxic when given orally for several months. All susceptible sheep not given iodoform died following two periods of H. europaeum feeding, whereas three such periods were needed for iodoform-treated animals. It is concluded that iodoform prophylaxis may be a useful protective measure in the field for sheep exposed to H. europaeum grazing during a single season. Up to 20% of the sheep used survived ingestion of H. europaeum for the full experimental term; some of them sustained little or no decline in BSP clearance rate. This finding indicates that there are prospects for development of a pyrrolizidine-tolerant strain of sheep by selective breeding. Chloral hydrate proved unsatisfactory as a replacement for iodoform.


Author(s):  
Nurgozhin T. ◽  
Sergazy S. H. ◽  
Adilgozhina G. ◽  
Gulyayev A. ◽  
Shulgau Z. ◽  
...  

Objective:This study investigates the hepatoprotective effect and the antioxidant role of polyphenol concentrate in the experimental model of carbon tetrachloride (CCl4) induced toxicity. Methods: Antioxidant activity of Cabernet Sauvignon grape polyphenol were evaluated by radical scavenging of 1,1-diphenyl-2-picryl hydrazyl radical (DPPH), 2,2’-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS.+). In addition, the effects of polyphenol concentrate on the survival of Wistar rats in the toxicity model, was also investigated. The polyphenol concentrate was administered for 5 five days prior to injection of carbon tetrachloride in a sub-lethal dose of 300 mg/kg of animal body weight in order to perform histological examinations of the liver and kidney, and detect the levels of AST, ALT and bilirubin. Results: Administration of polyphenol concentrate increased animal survival in the experimental model. Moreover, the intragastric administration of polyphenol concentrate prior to the initiation of the experimental model of toxicity, which was caused by a sub-lethal CCl4 dose, reduced morphological injuries in the liver and kidney, decreased the AST and ALT levels of the blood serum. Discussion and conclusion: Our data demonstrate that polyphenol concentrate possesses an antioxidant potential both in vitro and in vivo by reducing antioxidant stress that was caused by CCl4 administration into rats.


Author(s):  
B N Harsh ◽  
B J Klatt ◽  
M J Volk ◽  
A R Green-Miller ◽  
J C McCann

Abstract The objective was to quantify the effects of the beta-adrenergic agonist (β-AA) ractopamine hydrochloride (Actogain, Zoetis, Parsippany, NJ) on nitrogen excretion and nutrient digestibility in feedlot cattle. In experiment 1, twelve Simmental × Angus steers were blocked by bodyweight (531 ± 16 kg) and used in a randomized complete block design. Dietary treatments included: 1) a control without β-AA (CON) or 2) 400 mg/steer/d ractopamine hydrochloride (RAC) for 35 d before slaughter. Diets contained (DM basis) 55% dry rolled corn, 20% corn silage, 15% modified wet distillers grains with solubles, and 10% supplement. For each block, total collection of feed, orts, feces and urine were conducted for two 5 d sampling periods during week 2 and 4 of RAC supplementation. No interaction (P > 0.21) between treatment and collection period was observed for any parameter evaluated. Dietary treatment had no effect (P = 0.51) on DMI, but RAC had decreased fecal DM output (P = 0.04) compared with CON. Thus, RAC had greater apparent total tract DM digestibility (77.2 vs. 73.5%; P < 0.01), N digestibility (72.4 vs. 69.4%; P = 0.01), and NDF digestibility (65.6 vs. 60.2%; P < 0.01) than CON. Although treatment did not affect nitrogen intake (P = 0.52), RAC tended to reduce total nitrogen excretion (113.3 vs. 126.7 g/d; P = 0.10) compared with CON due to a tendency for decreased fecal nitrogen output (53.9 vs. 61.3 g/d; P = 0.10). However, dietary treatment had no effect (P = 0.53) on urinary nitrogen output or percentage of urinary nitrogen excreted as urea (P = 0.28). Experiment 2 was an in vitro experiment conducted to validate the effects of RAC on nutrient digestibility using Simmental × Angus heifers (451 ± 50 kg). Rumen fluid was collected individually by stomach tube from CON- (n = 9) and RAC-fed (n = 10) heifers to inoculate bottles containing a CON or RAC-containing substrate in a split-plot design. No interaction between rumen fluid source and in vitro substrate was observed. Greater IVDMD (P = 0.01) was observed in rumen fluid from RAC-fed heifers compared with rumen fluid from CON-fed heifers. Inclusion of RAC in the in vitro substrate increased IVDMD (P < 0.01). Overall, feeding RAC increased microbial digestion of the dry-rolled corn-based finishing diet to increase total tract dry mater digestion by 5% and reduce nitrogen excretion by 10.6% in the 35 d period prior to slaughter.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 307
Author(s):  
Yuhui Zheng ◽  
Yanyan Zhao ◽  
Shenglin Xue ◽  
Wei Wang ◽  
Yajing Wang ◽  
...  

The feeding value of replacing concentrate with cassava (Manihot esculenta) residue in the feed of Holstein cows was confirmed using an in vitro gas test. The treatments consisted of 0% (control, CON), 5%, 10%, 15%, 20%, 25%, and 30% inclusion of cassava residue in fermentation culture medium composed of buffer solution (50 mL) and filtrated rumen fluid (25 mL). The parameters analyzed included the kinetics of gas production and fermentation indexes. Forty-eight hours later, there were no significant differences on in vitro dry matter disappearance (IVDMD), pH, and microbial crude protein (MCP) content among treatments (p > 0.05). However, the “cumulative gas production at 48 h” (GP48), the “asymptotic gas production” (A), and the “maximum gas production rate” (RmaxG) all increased linearly or quadratically (p < 0.01). The GP48 was significantly higher in the 25% treatment compared to the other treatments, except for the 30% (p < 0.01). The A was significantly larger in the 25% treatment compared to the other treatments, except for the 20% and 30% (p < 0.01). The RmaxG was distinctly larger in the 25% treatment compared to other treatments (p < 0.01); moreover, the “time at which RmaxG is reached” (TRmaxG) and the “time at which the maximum rate of substrate degradation is reached” (TRmaxS) were significantly higher in the 25% treatment than the CON, 20%, and 30% treatments (p < 0.01). Additionally, the content of ammonia-N (NH3-N) in all treatments showed linearly and quadratically decreases (p < 0.01), whereas total volatile fatty acid (VFA), iso-butyrate, butyrate, and iso-valerate contents changed quadratically (p = 0.02, p = 0.05, p = 0.01, and p = 0.02, respectively); all of these values peaked in the 25% treatment. In summary, the 25% treatment was associated with more in vitro gas and VFA production, indicating that this cassava residue inclusion level may be used to replace concentrate in the feed of Holstein cows. However, these results need to be verified in vivo.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Avijit Dey ◽  
Shyam Sundar Paul ◽  
Puran Chand Lailer ◽  
Satbir Singh Dahiya

AbstractEnteric methane production contributes significantly to the greenhouse gas emission globally. Although, buffaloes are integral part of livestock production in Asian countries, contributing milk, meat and draft power, the contribution of enteric methane to environmental pollution attracts attention. The present study investigated the efficacy of garlic (Allium sativum) oil in reducing enteric methane production from buffaloes (Bubalus bubalis) by in vitro rumen fermentation. Garlic oil (GOL) was tested at four concentrations [0 (Control), 33.33 µl (GOL-1), 83.33 µl (GOL-2) and 166.66 µl (GOL-3) per litre of buffered rumen fluid] in 100-ml graduated glass syringes and incubated at 39℃ for 24 h for in vitro rumen fermentation study. Supplementation of GOL-1 increased (p < 0.05) total gas production in comparison with GOL-3; however, it remained comparable (p > 0.05) with control and GOL-2. Graded doses of garlic oil inclusions reduced (p < 0.001) methane concentration (%) in total gas and total methane production (ml/g DM), irrespective of concentrations. The feed degradability, volatile fatty acids and microbial biomass production (MBP) were not affected (p > 0.05) by GOL-1, but these tended to decrease in GOL-2 with marked reduction (p < 0.01) in GOL-3. The decrease (p < 0.01) in NH3–N concentration in fermentation fluid in the presence of garlic oil, irrespective of concentration, suggests reduced deamination by inhibiting rumen proteolytic bacterial population. The activities of ruminal fibrolytic enzymes (CMCase, xylanase, β-glucosidase, acetyl esterase) were not affected by lower dose (GOL-1) of garlic oil; however, reduction (p < 0.05) of these enzymes activity in rumen liquor was evident at higher doses (GOL-2 and GOL-3) of supplementation. This study shows positive impact of garlic oil supplementation at low dose (33.33 µl/l of rumen fluid) in reducing enteric methane production, thereby, abatement of environmental pollution without affecting feed digestibility.


2020 ◽  
Vol 22 (1) ◽  
pp. 202
Author(s):  
Josephin Glück ◽  
Julia Waizenegger ◽  
Albert Braeuning ◽  
Stefanie Hessel-Pras

Pyrrolizidine alkaloids (PAs) are a group of secondary metabolites produced in various plant species as a defense mechanism against herbivores. PAs consist of a necine base, which is esterified with one or two necine acids. Humans are exposed to PAs by consumption of contaminated food. PA intoxication in humans causes acute and chronic hepatotoxicity. It is considered that enzymatic PA toxification in hepatocytes is structure-dependent. In this study, we aimed to elucidate the induction of PA-induced cell death associated with apoptosis activation. Therefore, 22 structurally different PAs were analyzed concerning the disturbance of cell viability in the metabolically competent human hepatoma cell line HepaRG. The chosen PAs represent the main necine base structures and the different esterification types. Open-chained and cyclic heliotridine- and retronecine-type diesters induced strong cytotoxic effects, while treatment of HepaRG with monoesters did not affect cell viability. For more detailed investigation of apoptosis induction, comprising caspase activation and gene expression analysis, 14 PA representatives were selected. The proapoptotic effects were in line with the potency observed in cell viability studies. In vitro data point towards a strong structure–activity relationship whose effectiveness needs to be investigated in vivo and can then be the basis for a structure-associated risk assessment.


Sign in / Sign up

Export Citation Format

Share Document