Sulfur is an essential element for the entire biological kingdom because of its incorporation into amino acids, proteins and other biomolecules. Sulfur atoms are also important in the iron-containing flavoenzymes. Unlike humans, plants can use inorganic sulfur to synthesize sulfur-containing amino acids. Therefore, plants are an important source of sulfur for humans. Sulfur-containing compounds are found in all body cells and are indispensable for life. Some of sulfur-containing antioxidant compounds are, cysteine, methionine, taurine, glutathione, lipoic acid, mercaptopropionylglycine, N-acetylcysteine, and the three major organosulfur compounds of garlic oil, diallylsulfide, diallyldisulfide and diallyltrisulfide. In a comparison of the structure-function relationship among these sulfur-containing antioxidant compounds, dihydrolipoic acid (the reduced form of LA) is the most effective antioxidant. Dihydrolipoic acid contains two sulfhydryl groups and can undergo further oxidation reaction to form lipoic acid. The antioxidative activities of sulfur-containing compounds follow a general trend, the more highly reduced forms are stronger antioxidants and the number of sulfur atoms determine, at least in part, their modulatory activites on the glutathione related antioxidant enzymes. In this article, the antioxidant effects and the antioxidative activities, of sulfur-containing amino acids, are reviewed. In addition, the general antioxidant effects and the structure-function relationship of some sulfur-containing compounds are also reviewed.
Acetylcysteine/pharmacology ; Amino Acids, Sulfur/*pharmacology ; Antioxidants/*pharmacology ; Cysteine/pharmacology ; Glutathione/pharmacology ; Methionine/pharmacology ; Structure-Activity Relationship ; Taurine/pharmacology ; Thioctic Acid/pharmacology ; Thiopronine/pharmacology

OBJECTIVETo establish an in vitro model of mouse cochlear basilar membrane impairment using cisplatin, and observe the protective effect of methionine on the hair cells.

METHODSThe cochlear basilar membrane samples of thirty two Kunming mice were harvested on the 2nd day after birth and randomly divided into four groups. Each group had 16 samples. Overnight preincubation the cochlear organ followed by appropriate treatment respectively as follows: the serum-free culture medium, the serum-free culture medium with methionine and cisplatin, the cisplatinum-containing serum-free culture medium, and the methionine-containing serum-free culture medium. The protective effect of methionine for injury of cochlea hair cells induced by cisplatin was observed by myosin-VI immunofluorescence, light microscopy, laser confocal scanning microscope and hair cells counting.

RESULTSThe outer hair cells (OHC) and inner hair cells (IHC) of control group and methionine group were not damaged. The outer and inner hair cells of cisplatin group were damaged in various degree, and had remarkable difference compared with control group and methionine group (P < 0.05). The outer hair cells and inner hair cells of cisplatin + methionine group were damaged less than the cisplatin group with remarkable difference (t(IHC) = 3.929, t(OHC) = 8.582, P < 0.05).

CONCLUSIONSCisplatinum could damage the cochlear hair cells of the basal membrane in Kunming mice. Methionine might protect against cisplatin's damage on the cochlear hair cells.

Animals ; Cisplatin ; adverse effects ; pharmacology ; Hair Cells, Auditory ; drug effects ; In Vitro Techniques ; Methionine ; pharmacology ; Mice ; Mice, Inbred Strains

Animals ; Cadmium/toxicity* ; Dysbiosis/metabolism* ; Gastrointestinal Microbiome ; Glutamine/pharmacology* ; Methionine ; Mice ; Mice, Inbred C57BL ; Ostreidae ; Protein Hydrolysates ; Tyrosine

An efficient protocol for plant regeneration from protoplasts of the methionine resistant variant of Astragalus melilotoides was established. The friable calli induced from internode segments of variant plants were used for protoplast preparation. The protoplasts were isolated through enzyme digestion. Calli were formed after sustained divisions of protoplasts. High frequency of shoot differentiation was obtained from the protocalli on differentiated medium. The effects of different media, culturing methods and plating densities on protoplast divisions and plant regeneration were studied. The results show that agarose-beads culture method, KM8p medium supplemented with 1.0 mg/L 2,4-D, 0.5mg/L 6BA, 0.3 mol/L mannitol, 2% (W/V) sucrose and 500 mg/L casein hydrolysate at a plating density of 3 x 10(5)/mL are the appropriate conditions for protoplast division of the methionine resistant cell line. The division frequency is over 38%. The protoplast-regenerated plants still preserve resistance to methionine and ethionine.This research builds up the foundation for the resistant cell line as a parent of somatic hybridization.
Astragalus Plant ; growth & development ; physiology ; Culture Media ; Culture Techniques ; methods ; Drug Resistance ; Methionine ; pharmacology ; Protoplasts ; cytology ; Regeneration

OBJECTIVETo investigate the effect of L-methionine (L-Met) on the content of Zn, Cu, Mn, Fe in liver, brain, spleen and kidney of lead intoxicated mice.

METHODSDistilled water was given to 10 mice (normal control group) and lead acetate solution of 400 micro g/ml Pb(2+) to 20 mice to serve as drinking water for 10 days. The lead administration was then withdrawn and lead exposed mice were randomly divided into two groups: the lead control group took distilled water as drinking water for 4 weeks to serve as positive control, the other one took L-Met solution (0.5 mg/ml) as drinking water for 4 weeks (Pb + L-Met group) to serve as the treatment group. All the animals were sacrificed on the 1st day after 4 weeks, and the contents of Zn, Cu, Fe, Mn, Pb in liver, brain, spleen and kidney were measured by Inductively Coupled Plasma (ICP) Emission Spectrometry.

RESULTSLead contents in liver, brain, spleen and kidney of Pb control group [(1.490 +/- 1.654) micro g/g, (3.470 +/- 2.757) micro g/g, (4.975 +/- 2.993) micro g/g, (0.066 +/- 0.001) micro g/g respectively], were higher than those in normal control group [(0.015 +/- 0.001) micro g/g, (0.009 +/- 0.007) micro g/g, (0.027 +/- 0.002) micro g/g, (0.006 +/- 0.015) micro g/g, P < 0.05] while Zn contents in liver, brain, spleen and Fe and Mn content in liver, brain, spleen and kidney in Pb control group were lower than those in normal control group (P < 0.05). Pb contents of brain, spleen and Cu content of kidney in Pb + L-Met group were higher than those in normal control group (P < 0.05). Zn contents of liver, brain, spleen, Fe contents of liver, brain, spleen, kidney, and Mn contents of brain, spleen in Pb + L-Met group were lower than those in normal control group (P < 0.05). Fe contents of liver, brain, Zn content of spleen, Cu content of kidney and Mn contents of liver, brain, spleen in the Pb + L-Met group were higher than those in the Pb control group (P < 0.05). The lead levels of four organs in the Pb + L-Met group were lower than those in the Pb control group (P < 0.05).

CONCLUSIONLead could be eliminated by L-Met, which may affect the distribution and metabolism of trace elements in mice.

Animals ; Brain ; metabolism ; Female ; Kidney ; metabolism ; Lead Poisoning ; metabolism ; Liver ; metabolism ; Male ; Methionine ; pharmacology ; Mice ; Spleen ; metabolism ; Trace Elements ; metabolism

OBJECTIVETo explore the role of glial cell metabolism in the generation and regulation of central respiratory rhythm.

METHODSThe medulla oblongata slices (600-700 microm) containing the medial region of the nucleus retrofacialis (mNRF) with the hypoglossal nerve rootlets retained from 12 neonatal (0-3 days) Sprague-Dawley rats were prepared and perfused with modified Kreb's solution (MKS). Upon recording of respiratory rhythmical discharge activity (RRDA) of the rootlets of the hypoglossal nerve, the brain slices were treated with glial cell metabolism antagonist L-methionine sulfoximine (L-MSO, 50 micromol/L) for 20 min followed by application of glial cell metabolism agonist L-glutamine (L-GLN, 30 micromol/L) for 20 min, or with L-MSO for 20 min with additional L-GLN for 20 min. The changes in the RRDA of the rootlets of the hypoglossal nerve in response to the treatments were recorded.

RESULTSL-MSO prolonged the respiratory cycle (RC) and expiratory time (TE), and reduced the integral amplitude (IA) and the inspiratory time (TI) in the brain slices. L-GLN induced a significant decrease in RC and TE, but IA and TI showed no obvious variations. The effect of L-MSO on the respiratory rhythm was reversed by the application of L-GLN.

CONCLUSIONGlial cell metabolism may play an important role in the modulation of RRDA in neonatal rat brainstem.

Animals ; Animals, Newborn ; Glutamine ; pharmacology ; In Vitro Techniques ; Medulla Oblongata ; metabolism ; physiology ; Methionine Sulfoximine ; pharmacology ; Neuroglia ; metabolism ; Periodicity ; Rats ; Rats, Sprague-Dawley ; Respiration

The aim of this study was to investigate the effects of D-methionine (D-met) on the hematopoietic system injury in irradiated mice. C57BL/6 mice were divided into control group, irradiated group, 300 mg/kg D-met plus irradiation group and 1000 mg/kg D-met plus irradiation group. The control mice received sham irradiation, and the mice in remainder groups were exposed to 7.5 Gy; 1,4,8 Gy and 1 Gy of (137)Cs γ-ray respectively, were used to detect the survival rate, survival rate of bone marrow cells, WBC and its differential counts as well the colony formation ability in irradiated mice, respectively. The D-met was intraperitoneally injected to mice at 30 min before irradiation. The results showed that 300 and 1000 mg/kd D-met did not obviously enhance the survival rate of mice exposed to 7.5 Gy; the 10(-2),10(-3),10(-4) mol/L D-met significantly increased the survival rate of bone marrow cells in mice exposed to 1,4,8 Gy; 300 and 1000 mg/kg D-met even so increased the WBC count of peripheral blood in mice exposed to 1 Gy, but there was no statistical difference as compared with irradiated alone mice, moreover 300 and 1000 mg/kg D-met could obviously promote the colony formation ability of bone marrow cells in irradiated mice, the CFU-GM count was higher than that in 1 Gy irradiated mice (P < 0.05). It is concluded that the D-met can effectively mitigate the marrow cell injury resulted from irradiation, enhance the survival rate of bone marrow cells in irradiated mice, promote the recovery of hematopoietic function from radiation injury in mice.
Animals ; Bone Marrow Cells ; drug effects ; radiation effects ; Hematopoietic System ; drug effects ; radiation effects ; Leukocyte Count ; Methionine ; pharmacology ; Mice ; Mice, Inbred C57BL ; Radiation Injuries ; prevention & control

OBJECTIVETo study the protective impact of tea polyphenols (TP) on the injury of fibrinolytic functions induced by high-methionine dietary in rats.

METHODS50 male Wistar rats were divided by stratified based on body weight into 5 groups with 10 in each group: namely control group, model group, low-dose TP group, medium-dose TP group and high-dose TP group. The rats in model group and TP groups were fed with 3% methionine dietary, control group rats with routine diet. In addition, rats in low-dose, medium-dose and high-dose TP groups were treated with TP at 50, 100 and 200 mg/kg dosage respectively by gavages every day, control group and model group rats were given with same amount distilled water. The animals were sacrificed after 8 weeks. The levels of tissue-type plasminogen activator (t-PA) and type-1 plasminogen activator inhibitor (PAI-1) in plasma were determined by ELISA assays, mRNA levels of t-PA and PAI-1 in aortic arch were detected by RT-PCR, t-PA and PAI-1 expression in aortic arch were detected by immunohistochemistry strept-avidin-biotin complex (SABC).

RESULTSAfter experiment, the t-PA expression of aortic arch in control group, model group, low-dose TP group, medium-dose TP group and high-dose TP group were 133.03 ± 10.14, 95.46 ± 11.08, 111.97 ± 11.91, 130.23 ± 10.80, 139.39 ± 9.41 (F = 14.15, P < 0.01), respectively, and the PAI-1 expression were 90.91 ± 8.67, 166.76 ± 12.18, 139.63 ± 12.71, 134.66 ± 13.19, 109.49 ± 10.82 (F = 31.44, P < 0.01). The t-PA concentration of plasma were (10.69 ± 1.26), (6.13 ± 0.92), (8.56 ± 1.19), (9.69 ± 0.92), (11.97 ± 1.08) ng/ml, respectively (F = 41.98, P < 0.01), and the PAI-1 concentration of plasma were (6.31 ± 0.81), (16.98 ± 1.27), (11.39 ± 0.82), (8.46 ± 0.67), (8.08 ± 0.91) ng/ml, respectively (F = 207.74, P < 0.01). The mRNA levels of t-PA in aortic arch were 1.12 ± 0.02, 0.75 ± 0.14, 1.01 ± 0.09, 0.95 ± 0.08, 1.05 ± 0.13 (F = 5.77, P < 0.05), and the mRNA levels of PAI-1 in aortic arch were 1.25 ± 0.11, 1.74 ± 0.06, 1.23 ± 0.05, 1.09 ± 0.14, 1.23 ± 0.04 (F = 23.56, P < 0.01).

CONCLUSIONThe results indicate that TP seems to have regulatory function on transcription and protein levels of t-PA and PAI-1, in addition to maintaining the balance between PAI-1 and t-PA and healing the injury of fibrinolytic functions in rats induced by high-methionine dietary.

Animals ; Diet ; Fibrinolysis ; drug effects ; Male ; Methionine ; adverse effects ; Plasminogen Activator Inhibitor 1 ; blood ; Polyphenols ; pharmacology ; Rats ; Rats, Wistar ; Tea ; chemistry ; Tissue Plasminogen Activator ; blood

In this study, an ultra-performance liquid chromatography-quadrupole time-of-flight high resolution mass spectrometer(UPLC-Q-TOF-HRMS) was used to investigate the effects of the active ingredients in Periploca forrestii compound on spleen metabolism in rats with collagen-induced arthritis(CIA), and its potential anti-inflammatory mechanism was analyzed by network pharmacology. After the model of CIA was successfully established, the spleen tissues of rats were taken 28 days after administration. UPLC-Q-TOF-HRMS chromatograms were collected and analyzed by principal component analysis(PCA), orthogonal partial least squares discriminant analysis(OPLS-DA), and MetPA. The results showed that as compared with the blank control group, 22 biomarkers in the spleen tissues such as inosine, citicoline, hypoxanthine, and taurine in the model group increased, while 9 biomarkers such as CDP-ethanolamine and phosphorylcholine decreased. As compared with the model group, 21 biomarkers such as inosine, citicoline, CDP-ethanolamine, and phosphorylcholine were reregulated by the active ingredients in P. forrestii. Seventeen metabolic pathways were significantly enriched, including purine metabolism, taurine and hypotaurine metabolism, glycerophospholipid metabolism, and cysteine and methionine metabolism. Network pharmacology analysis found that purine metabolism, glycerophospholipid metabolism, and cysteine and methionine metabolism played important roles in the pathological process of rheumatoid arthritis. This study suggests that active ingredients in P. forrestii compound can delay the occurrence and development of inflammatory reaction by improving the spleen metabolic disorder of rats with CIA. The P. forrestii compound has multi-target and multi-pathway anti-inflammatory mechanism. This study is expected to provide a new explanation for the mechanism of active ingredients in P. forrestii compound against rheumatoid arthritis.
Rats ; Animals ; Periploca ; Cysteine ; Cytidine Diphosphate Choline ; Network Pharmacology ; Phosphorylcholine ; Metabolomics ; Arthritis, Rheumatoid/drug therapy* ; Biomarkers ; Glycerophospholipids ; Methionine ; Purines ; Chromatography, High Pressure Liquid

Effective drug to manage constipation has been unsatisfactory. We sought to determine whether methionine has effect on the human colon. Human colon tissues were obtained from the specimens of colon resection. Microelectrode recording was performed and contractile activity of muscle strips and the propagation of the contractions in the colon segment were measured. At 10 microM, methionine depolarized the resting membrane potential (RMP) of circular muscle (CM) cells. In the CM strip, methionine increased the amplitude and area under the curve (AUC) of contractions. In the whole segment of colon, methionine increased the amplitude and AUC of the high amplitude contractions in the CM. These effects on contraction were maximal at 10 microM and were not observed in longitudinal muscles in both the strip and the colon segment. Methionine reversed the effects of pretreatment with sodium nitroprusside, tetrodotoxin and Nw-oxide-L-arginine, resulting in depolarization of the RMP, and increased amplitude and AUC of contractions in the muscle strip. Methionine treatment affected the wave pattern of the colon segment by evoking small sized amplitude contractions superimposed on preexisting wave patterns. Our results indicate that a compound mimicking methionine may provide prokinetic functions in the human colon.
Area Under Curve ; Arginine/pharmacology ; Colon/drug effects/physiology ; Humans ; Membrane Potentials/drug effects ; Methionine/*pharmacology ; Microelectrodes ; Muscle Contraction/*drug effects ; Muscle, Smooth/drug effects/*physiology ; Nitroprusside/pharmacology ; Tetrodotoxin/pharmacology