Dietary supplementation of Eucommia leaf extract to growing-finishing pigs alters muscle metabolism and improves meat quality

Shen Zhenglei,Liu Chuxin,Deng Chuangye,Guo Qiuping,Li Fengna,Shen Qingwu W. 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.4

Objective: The objective of this study was to investigate the influence of dietary supplementation of Eucommia ulmoides leaf extract (ELE) on muscle metabolism and meat quality of pigs with and without pre-slaughter transportation. Methods: In a 43-day feeding experiment, a total of 160 pigs with an initial body weight 60.00±2.00 kg were randomly assigned into four groups in a completely randomized design with 10 replicates. Pigs in groups A and C were fed a basal diet and pigs in groups B and D were fed a basal diet supplemented with 0.5% ELE. Pigs were slaughtered with (group B and D) or without (group A and C) pre-slaughter transport. Muscle chemical composition, postmortem glycolysis, meat quality and muscle metabolome were analyzed. Results: Dietary ELE supplementation had no effect on the proximate composition of porcine muscle, but increased free phenylalanine, proline, citruline, norvaline, and the total free amino acids in muscle. In addition, dietary ELE increased decanoic acid and eicosapentaenoic acid, but decreased heptadecanoic acid, oleic acid, trans-oleic acid, and monounsaturated fatty acids in muscle. Meat quality measurement demonstrated that ELE improved meat water holding capacity and eliminated the negative effects of pre-slaughter transport on meat cooking yield and tenderness. Dietary ELE reduced muscle glycolytic potential, inhibited glycolysis and muscle pH decline in the postmortem conversion of muscle to meat and increased the activity of citrate synthase in muscle. Metabolomics analysis by liquid chromatographic tandem mass spectrometric showed that ELE enhanced muscle energy level, regulated AMP-activated protein kinase (AMPK) signaling, modulated glycogenolysis/glycolysis, and altered the metabolism of carbohydrate, fatty acids, ketone bodies, amino acids, purine, and pyrimidine. Conclusion: Dietary ELE improved meat quality and alleviated the negative effect of preslaughter transport on meat quality by enhancing muscle oxidative metabolism capacity and inhibiting glycolysis in postmortem muscle, which is probably involved its regulation of AMPK.

Phosphoproteomic profiling of myofibrillar and sarcoplasmic proteins of muscle in response to salting

Caixia Zhang,Zhenyu Wang,Zheng Li,Qingwu Shen,Lijuan Chen,Lingling Gao,Dequan Zhang 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.4

A phosphoproteomic profile of myofibrillar and sarcoplasmic proteins of muscle inresponse to salting was investigated. Myofibrillar and sarcoplasmic proteins extracted from saltedmeat with 0, 1, 2, 3, 4, and 5% salt for 0, 2, 4, 6, 8, and 16 h were analyzed by SDS-PAGE electrophoresisand fluorescence staining. The global phosphorylation of myofibrillar proteins in salted meat was lowerthan that in control muscle at 16 h of salting (p<0.05), and the global phosphorylation of myofibrillarproteins in 3% salt-treated group at 16 h was the lowest. However, salting showed no significant effecton phosphorylation of sarcoplasmic proteins. Four categories of phosphorylated protein wereidentified by LC-MS/MS, involved in stress response (heat shock protein), glycometabolism (glycogenphosphorylase, glyceraldehyde-3-phosphate dehydrogenase), oxidation or reduction (superoxidedismutase), and others (myoglobin), the phosphorylation of which was affected by salting. Thus,salting may influence meat quality through protein phosphorylation, which regulates proteindegradation and glycolysis.

Phosphoproteomic profiling of myofibrillar and sarcoplasmic proteins of muscle in response to salting

Zhang, Caixia,Wang, Zhenyu,Li, Zheng,Shen, Qingwu,Chen, Lijuan,Gao, Lingling,Zhang, Dequan 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.4

A phosphoproteomic profile of myofibrillar and sarcoplasmic proteins of muscle in response to salting was investigated. Myofibrillar and sarcoplasmic proteins extracted from salted meat with 0, 1, 2, 3, 4, and 5% salt for 0, 2, 4, 6, 8, and 16 h were analyzed by SDS-PAGE electrophoresis and fluorescence staining. The global phosphorylation of myofibrillar proteins in salted meat was lower than that in control muscle at 16 h of salting (p<0.05), and the global phosphorylation of myofibrillar proteins in 3% salt-treated group at 16 h was the lowest. However, salting showed no significant effect on phosphorylation of sarcoplasmic proteins. Four categories of phosphorylated protein were identified by LC-MS/MS, involved in stress response (heat shock protein), glycometabolism (glycogen phosphorylase, glyceraldehyde-3-phosphate dehydrogenase), oxidation or reduction (superoxide dismutase), and others (myoglobin), the phosphorylation of which was affected by salting. Thus, salting may influence meat quality through protein phosphorylation, which regulates protein degradation and glycolysis.

Histone acetyltransferase inhibitors antagonize AMP-activated protein kinase in postmortem glycolysis

Qiong Li,Zhongwen Li,Aihua Lou,Zhenyu Wang,Dequan Zhang,Qingwu W. Shen 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.6

Objective: The purpose of this study was to investigate the influence of AMP-activated protein kinase (AMPK) activation on protein acetylation and glycolysis in postmortem muscle to better understand the mechanism by which AMPK regulates postmortem glycolysis and meat quality. Methods: A total of 32 mice were randomly assigned to four groups and intraperitoneally injected with 5-Aminoimidazole-4-carboxamide1-β-D-ribofuranoside (AICAR, a specific activator of AMPK), AICAR and histone acetyltransferase inhibitor II, or AICAR, Trichostatin A (TSA, an inhibitor of histone deacetylase I and II) and Nicotinamide (NAM, an inhibitor of the Sirt family deacetylases). After mice were euthanized, the Longissimus dorsi muscle was collected at 0 h, 45 min, and 24 h postmortem. AMPK activity, protein acetylation and glycolysis in postmortem muscle were measured. Results: Activation of AMPK by AICAR significantly increased glycolysis in postmortem muscle. At the same time, it increased the total acetylated proteins in muscle 45 min postmortem. Inhibition of protein acetylation by histone acetyltransferase inhibitors reduced AMPK activation induced increase in the total acetylated proteins and glycolytic rate in muscle early postmortem, while histone deacetylase inhibitors further promoted protein acetylation and glycolysis. Several bands of proteins were detected to be differentially acetylated in muscle with different glycolytic rates. Conclusion: Protein acetylation plays an important regulatory role in postmortem glycolysis. As AMPK mediates the effects of pre-slaughter stress on postmortem glycolysis, protein acetylation is likely a mechanism by which antemortem stress influenced postmortem metabolism and meat quality though the exact mechanism is to be elucidated.

Proteomic Analysis of Goat Longissimus dorsi Muscles with Different Drip Loss Values Related to Meat Quality Traits

Zhenyu Wang,Fan He,Weili Rao,Na Ni,Qingwu Shen,Dequan Zhang 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.2

Longissimus dorsi muscles from 3 goat species were assigned to high and low drip loss groups. Physio-chemical properties, sarcomere length, and proteome profiles were investigated. The high drip loss group had lower pH, higher brightness, and higher shear force values, and shorter sarcomere lengths than the low drip loss group. 22 differential proteins were identified between high and low loss groups. α-Enolase, NADH dehydrogenase, pyruvate dehydrogenase E1, HSP27, superoxide dismutase, peroxiredoxin-2, myosin, and the myosin light chain were among these proteins, which were metabolic enzymes, stress response factors, and structural proteins that affected glycolysis, oxidation, and muscle contraction. Drip loss was probably produced via proteins involved in glycolysis, oxidation, and muscle contraction.