• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.898-907
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• 2005

Chromium has emerged as an essential trace mineral in nutrition. However, it readily causes toxicity because of slightly excessive dose and/or form of chromium supplement. Therefore, developing a noble form of chromium supplement which is capable of not only an increased availability but also a reduced toxicity has been a critical issue in chromium nutrition. Chromium-methionine chelate has been, so far, one of the latest developments in its kind. Although not much information is available for the chromium-methionine chelate, especially in view of animal performances upon dietary supplementation, several studies indicated chromium methionine chelate could be effective to improve meat quality by increasing muscle mass but decreasing body fat. Highly-graded beef was produced by dietary chromium methionine supplementation during fattening stage of Korean native steers. Body muscle was increased in replace of decreasing body fat in both pig and rat that were dietary supplemented with chromium methionine chelate. However, a pig farm study did not show any significant improvement of body gain upon supplementation of chromium methionine. Immune responses of pig and rat were not always dependent upon chromium form but were varied by species. These results suggest there could be a different mode of responses due to species as well as onset time of dietary supplementation of chromium methionine. It is still early to conclude the bio-efficacy of chromium methionine chelate presumably due to its recent appearance into the field. But the chelate is certainly worth more application to animal since it certainly reduced the application level of dietary chromium.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.5
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• pp.477-480
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• 1995

The effects of formic acid and formaldehyde treatment and methionine supplementation to ladino clover fibrous residue silage on eating and rumination behaviour were studied in sheep. From the ladino clover fibrous residue, two silage were prepared, either untreated or treated with formic acid and formaldehyde. Four experimental diets: untreated silage, treated silage, untreated silage with supplementation of methionine and treated silage with supplementation of methionine, were offered to four sheep at a restricted level of DM intake (2% of BW/d) twice daily in a two-way layout design. Methionine supplementation with the treated silage significantly (p < 0.05) reduced daily time spent eating, and consequently, markedly increased rate of eating. However, there was little effect of methionine supplementation on the daily time spent eating and eating rate for sheep offered untreated silage. Methionine supplementation with the treated silage reduced daily time spent ruminating, although the same effect was not observed for untreated silage. The rumination index (time spent ruminating/100 g DM eaten) was remarkably smaller (p < 0.05) with methionine supplement in feeding treated silage, although it did not differ for sheep offered untreated silage. There were no clear effect of methionine supplementation on the rumination efficiency (i.e. number of chews/bolus, bolus time and rumination chewing rate) both feeding untreated silage and treated silage.

• The Korean Journal of Food And Nutrition
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• v.12 no.1
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• pp.33-38
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• 1999

This study was conducted to investigate the synergic effect of dietary selenium and methionine levels on hepatic lipid metabolism in ethanol treated rats. Sprague-Dawley male rats were fed diets containing three levels of methionine(0,3 and 9g/kg diet) with or without selenium(0.45mg/kg diet). Ethanol was administered with 25%(v/v) ethanol orally at the same time once a day in ethanol group and isocalori sucrose was administered to the control group. The rate were sacrificed after 5 and 10 weeks of feeding period. Glutathione content was decreased by ethanol treatment and significantly increased in proportion to level of dietary methionine and was higher in selenium deficiency group than that of selenium admin-istration group. Lipid peroxide content was significantly increased in deficiency of both methionine and selenium(LMet-Se+EtOH) group. Total lipid triglyceride and cholesteol contents in liver were increas-ed and phospholipid content was decreased in ethanol treated group and ethanol treatment accelerated those increment and decrement in methionine deficiency(LMt) group and excessive methionine admin-istration(HMet)group.

• Nutritional Sciences
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• v.9 no.2
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• pp.106-111
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• 2006

Chronic alcohol consumption is associated with perturbation of hepatic metabolism of sulphur-containing amino acid. The goal of present study was to evaluate the influence of dietary supplementation of methionine or folate to chronically ethanol-fed mts on the metabolism of sulfur-containing amino acids and one-carbon metabolism. Sprague-Dawley male mts were fed Lieber-Decarli liquid diet with 0% ethanol (control), 36% ethanol (E), 36% ethanol combined with methionine supplement (EM) or folate supplement (EF) for 8 weeks. Hepatic S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), plasma folate and homocysteine (Hcy), urinary excretion of folate and formiminoglutamate were investigated after feeding experimental diets. Growth was retarded by 36% ethanol consupmtion (E, EM and EF) (p<0.01). Liver total fat (p<0.05) and plasma ALT (P<0.01) were increased by methionine supplementation (EM), implicating fatty liver and liver injury. Liver folate was increased slightly by folate supplementation (EF) (p=0.077). Urinary folate loss was increased 2.3 fold by ethanol consumption (E) and 17.2 fold by folate supplementation (EF), while decreased by methionine supplementation (EM) (p<0.000l). Plasma Hcy was increased 1.9 fold by methionine supplementation (EM) in ethanol-fed mts (p<0.05), which was related with decreased methionine synthase activity (p<0.05). Hepatic SAM/SAH ratio was depressed by methionine supplementation in ethanol-fed mts (EM) (p<0.05). Urinary formininoglutamate (Figlu) excretion after histidine loading was increased by ethanol ingestion and reduced by methionine supplementation (p<0.00l). Based on these data, methionine supplementation appears to accelerate histidine oxidation. In conclusion, dietary supplementation of methionine to ethanol-fed mts exacerbates alcoholic liver injury possibly by complicating sulphur-containing amino acid metabolism, as while it may have beneficial effects on folate and histidine metabolism.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.7
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• pp.974-981
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• 2011

This study was designed to re-evaluate the dietary methionine requirement by means of the plasma methionine and ammonia concentrations in surgically modified rainbow trout, Oncorhynchus mykiss. A total of 35 rainbow trout averaging $505{\pm}6.5$ g (initial body weight, mean${\pm}$SD) were randomly distributed into seven groups with five fish in each group. After 48 h of feed deprivation, each group of fish was fed one of seven L-amino acid based diets containing 0.5% cystine and graded levels of methionine (0.25, 0.40, 0.50, 0.60, 0.70, 0.80 or 0.95% of diet, dry matter bases) by intubation at 1% body weight on dry matter basis. Blood samples were taken at 0, 5 and 24 h after intubation. Post-prandial plasma free methionine concentrations (PPmet, 5 h after intubation) and post-absorptive plasma free methionine concentrations (PAmet, 24 h after intubation) of fish fed diets containing 0.60% or higher methionine were significantly (p<0.05) higher than those of fish fed diets containing 0.50% or lower methionine. PPmet and PAmet in fish fed diets containing 0.60% or higher methionine were not significantly different except PPmet of fish fed diet containing 0.95% methionine. Post-prandial plasma ammonia concentrations (PPA, 5 h after intubation) of fish fed diets containing 0.70% or higher methionine were significantly higher than those of fish fed diets containing 0.60% or lower methionine, and PPA of fish fed diets containing 0.25 and up to 0.60% methionine were not significantly different from each other. Broken-line model analyses on PPmet, PAmet, and PPA indicated that the dietary methionine requirement of rainbow trout was between 0.59 (1.69) and 0.67 (1.91) % of diets (% dietary protein bases) when the diets contained 0.5% cystine.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.4
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• pp.376-383
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• 1988

The effect of dietary methionine level on lipid peroxidation of rats was studied. Rats were fed vitamin E- selenium- deficient diet or diet supplemented with various levels (0.3, 0.6, 0.9%) of methionine. In rat fed MF diet, body weight gain and feed efficiency ratio were decreased compared with those of control rats, but reversed by supplementation with 0.3 and 0.6% methionine. Lipid peroxide levels in plasma and hepatic mitochondrial fraction of MF group rats were significantly higher than those of control rats. However, supplementation with 0.6% methionine modified this increment. GSH-Px activity was decrased to varying degrees in erythrocyte and hepatic mitochondrial fraction from rats fed MF diet. Methionine supplementation did not affect induction of this enzyme activity. Examination of hepatocytes by electronmicroscopy showed that Influence of vitamin E, selenium, and methionine deficiency was mainly characterized by lipid droplets, swollen mitochondria and microvilli destruction. Supplementation with various levels of dietary methionine modified these changes to some extent. The results of this experiment indicated that MF diet causes significant change in lipid peroxide level, GSH-Px activity and morphology of rats which these changes may lessen by supplementation with 0.6% methionine.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.377-382
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• 2003

Purification of methioninase resulted in a yield of 69%, and SDS-PAGE analysis of the purified product revealed a single band of approximately 43 kDa in molecular weight. in vitro experiments with cancer cells incubated in methionine-free media demonstrated an increase in $^{11}$ C-methionine uptake to 25.8$\pm$1.1% at 6 hr, 31.8$\pm$0.8% at 24 hr, and 62.2$\pm$0.6% at 48hr, compared to controls. Treatment of the cancer cells with purified methioninase showed no decrease in survival after a 2 hr incubation with 0.01 U/ml, but survival of RR1022 cells decreased 30% after 24 to 48 hr incubation. SKOV-3 cells showed a 5% and 14% decrease in survival with 0.1 and 1 U/ml methioninase after 24 hr. After 48hr survival decreased 15% and 24% with 0.1 and 1 U/ml methioninase. Measurements of $^{11}$ C-methionine uptake in RR1022 cells demonstrated no change at 2 hr, but a 13.7$\pm$4.7% and 40.7$\pm$2.6% increase in uptake at 24 and 48 hr, respectively. SKOV-3 cells also showed no change at 2 hr, but had a 17.7$\pm$7.2% and 38.9$\pm$4.9% increase in $^{11}$ C-methionine uptake after 24 hr and 48 hr treatment with methioninase, respectively. $^{11}$ C-methionine PET imaging revealed clear visualization of both the tumors and contralateral infectious lesions. Administration of rMET appeared to result in a slight increase in tumor:nontumor contrast on $^{11}$ C-methionine PET images. Injection of purified methioninase also produced PET images where tumor uptake was higher than that of infectious lesions.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.373-378
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• 2004

The regulatory mechanism of methionine biosynthesis in Corynebacterium glutamicum was analyzed at the protein arid gene expression level. O-Acetylhomoserine sulfhydraylase (encoded by metY) was inhibited by 10 mM methionine to a residual activity of 10% level, whereas no such inhibition was found with cystathionine $\gamma$-synthase (encoded by metB) and cystathionine $\beta$-lyase (encoded by metC). The enzymatic activity of homoserine acetyltransferase (encoded by metX) was repressed to a residual activity of 25% level by 10 mM methionine which was added to the growth medium. Cystathionine $\gamma$-synthase and cystathionine $\beta$-lyase were also repressed by 10 mM methionine, but only to a residual activity of 50-70% level. O-Acetylhomoserine sulfhydrylase was very sensitive to repression by 10 mM methionine, showing residual activity of 13%. In addition, homoserine acetyltransferase was also repressed by 10 mM cysteine to 50% of its original activity. No repression of the enzymes by S-adenosyl methionine was observed. The pattern of repression by methionine indicated that the metB and aecD genes might be regulated by a common mechanism, while the metA and metY genes are differently regulated.

• Nutrition Research and Practice
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• v.16 no.6
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• pp.729-744
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• 2022

BACKGROUND/OBJECTIVES: 4-Hydroxy-2-nonenal (HNE) is a biomarker for oxidative stress to induce inflammation. Methionine is an essential sulfur-containing amino acid with antioxidative activity. On the other hand, the evidence on whether and how methionine can depress HNE-derived inflammation is lacking. In particular, the link between the regulation of the nuclear factor-κB (NF-κB) signaling pathway and methionine intake is unclear. This study examined the link between depression from HNE accumulation and the anti-inflammatory function of ⳑ-methionine in rats. MATERIALS/METHODS: Male Wistar rats (3-week-old, weighing 70-80 g) were administered different levels of ⳑ-methionine orally at 215.0, 268.8, 322.5, and 430.0 mg/kg body weight for two weeks. The control group was fed commercial pellets. The hepatic HNE contents and the protein expression and mRNA levels of the inflammatory mediators were measured. The interleukin-10 (IL-10) and glutathione S-transferase (GST) levels were also estimated. RESULTS: Compared to the control group, hepatic HNE levels were reduced significantly in all groups fed ⳑ-methionine, which were attributed to the stimulation of GST by ⳑ-methionine. With decreasing HNE levels, ⳑ-methionine inhibited the activation of NF-κB by up-regulating inhibitory κBα and depressing phosphoinositide 3 kinase/protein kinase B. The mRNA levels of the inflammatory mediators (cyclooxygenase-2, interleukin-1β, interleukin-6, inducible nitric oxide synthase, tumor necrotic factor alpha) were decreased significantly by ⳑ-methionine. In contrast, the protein expression of these inflammatory mediators was effectively down regulated by ⳑ-methionine. The anti-inflammatory action of ⳑ-methionine was also reflected by the up-regulation of IL-10. CONCLUSIONS: This study revealed a link between the inhibition of HNE accumulation and the depression of inflammation in growing rats, which was attributed to ⳑ-methionine availability. The anti-inflammatory mechanism exerted by ⳑ-methionine was to inhibit NF-κB activation and to up-regulate GST.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1090-1095
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• 1999

In order to minimize the occurrence of fatty liver, this study investigated how adding a high level of dietary choline or methionine affected the lipid metabolism of Tsaiya ducks. Feeding trials were conducted with sixty Tsaiya ducks during their growing period, when they were 8-12 weeks old, and during their laying period, 10-14 weeks after the onset of laying when they were 26-30 weeks old. The ducks were randomly assigned to one of three groups: a control group (basal diet), a group in which methionine was added to the basal diet, and a group in which choline was added to the basal diet. The levels of methionine and choline added were twice as high as the levels recommended by the NRC for layer-type chickens. Experimental results indicated that adding choline to the basal diet of growing ducks significantly (p<0.05) increased their body weight, while adding methionine significantly (p<0.05)reduced their body weight. Adding either choline or methionine reduced the ducks' liver fat content in both the growing and the laying periods (p<0.05). Ducks receiving added methionine or choline in their diets displayed enhanced egg production (p<0.05). Adding choline increased serum triacylglycerol (TG) in the laying period (p<0.05). Adding either choline or methionine did not significantly (p>0.05) affect the t-globulin level. Adding methionine increased the activity of liver malic dehydrogenase in both the growing and the laying periods, and increased fatty acid synthetase in the laying period (p<0.05). While adding choline markedly (p>0.05) increased VLDL and apo B in both the growing and the laying periods, it decreased HDL and apo A in the laying period (p<0.05). This study found that adding a high level of choline to the basal diets of Tsaiya ducks in both the growing and the laying periods had beneficial effects. Furthermore, adding methionine affected the lipid metabolism of Tsaiya ducks to a lesser extent than adding choline.