Dietary coated cysteamine improves antioxidant status of muscle in pig model
Authors: Liu Hongnan , Bai Miaomiao , Yin Yulong 
Published: June 2021

BackgroundMuscle fatigue and injury is common in daily life. Contracting skeletal muscles generate free radicals, which can result in oxidative damage to cellular constituents. The development of targeted antioxidants remains an important area of research in redox biology. Cysteamine is used as a novel feed additive in animal production in the form of coated cysteamine because of its antioxidant activities. However, oral formulations of cysteamine may cause adverse effects, including reduction of motor activity and generalized hemorrhage in gastrointestinal tract and kidneys. An enteric coating is a polymer barrier applied on oral medication that prevents its dissolution or disintegration in the gastric environment. The effects of coated cysteamine on oxidation in muscle and lesions in gastrointestinal (GI) mucosal were investigated in this experiment using a pig model.MethodsA total of 288 crossbred finishing pigs (Duroc × Landrace × Yorkshire) with an initial BW of 88.3 ± 0.3 kg were randomly assigned into 4 dietary groups, with 8 pens/group and 9 pigs/pen. Castrated pigs had free access to feed and drinking water, and they were fed a corn‐soybean meal diet containing 0 (control), 0.035, 0.070, or 0.140 g kg‐1 of CC for 29 days. Coated cysteamine hydrochloride contained 270 g kg‐1 cysteamine hydrochloride. At the end of experiment, one pig was randomly selected from each pen and was slaughtered by exsanguination after electrical stunning to collect samples of the longissimus dorsi muscle and GI tissue.ResultsDietary CC increased (P < 0.05) the a*(redness) and H* values, reduced (P < 0.05) the L* (lightness) value in the muscles at 48 h postmortem (P < 0.05). The contents of deoxymyoglobin (deoxyMb) was enhanced (P < 0.05) and the contents of metmyoglobin (MetMb) and malondialdehyde (MDA) were reduced (P < 0.05) in pig fed the dietary CC. Pigs fed a dietary CC of 0.035 g kg−1 had a higher a* (24 h) value in the longissimus dorsi muscles than control treatment. Pig fed the dietary CC of 0.140 g kg−1 had a higher GSH (P < 0.05) in muscle. And the mRNA expression of SOD1 was up‐regulated (P < 0.05) in the muscle of pigs fed the dietary CC of 0.140 g kg−1. Supplementation with CC in the 0.035 g kg−1 increased villus height:crypt depth ratio in ileum (P<0.01). Ileal lesion score was decreased in pigs fed a dietary CC of 0.035 g kg−1 (P<0.01).ConclusionDietary supplementation with CC could improve antioxidant status by improving GSH levels and antioxidase activity during a long recovery (48 h). Dietary supplementation with coated cysteamine hydrochloride in the 0.035 g kg−1 may improve the muscle antioxidant status without mucosal injury of GI.Support or Funding InformationWe would like to express our sincere gratitude to the National Natural Science Foundation of China (31501964; 31402088) and China Agriculture Research System (CARS‐35). The research was also funded by a research program of the State Key Laboratory of Food Science and Technology and Key Research and Development program of Shandong province (2015STS007).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.