The accumulation of reactive oxygen species (ROS) triggers oxidative stress in cells by oxidizing and modifying various cellular components, preventing them from performing their inherent functions, ultimately leading to apoptosis and autophagy. Glutathione (GSH) is a ubiquitous intracellular peptide with multiple functions. In this study, a hydrogen peroxide (H${}_2$O${}_2$)-induced oxidative damage model in IPEC-J2 cells was used to investigate the cellular protection mechanism of exogenous GSH against oxidative stress. The results showed that GSH supplement improved the cell viability reduced by H${}_2$O${}_2$-induced oxidative damage model in IPEC-J2 cells in a dose-dependent manner. Moreover, supplement with GSH also attenuated the H${}_2$O${}_2$-induced MMP loss, and effectively decreased the H${}_2$O${}_2$-induced mitochondrial dysfunction by increasing the content of mtDNA and upregulating the expression TFAM. Exogenous GSH treatment significantly decreased the ROS and MDA levels, improved SOD activity in H${}_2$O${}_2$-treated cells and reduced H${}_2$O${}_2$-induced early apoptosis in IPEC-J2 cells. This study showed that exogenous GSH can protect IPEC-J2 cells against apoptosis induced by oxidative stress through mitochondrial mechanisms.

This study aims to investigate the effects of guanidine acetic acid (GAA) on carcass traits, plasma biochemical parameters, tissue antioxidant capacity, and tissue-bound amino acid contents in finishing pigs. Seventy-two 140-day-old (body weight 86.59 ± 1.16 kg) crossbred pigs (Duroc × Landrace × Large White) were randomly assigned into four treatments with six replicate pens and three pigs per pen, which were fed the basal diets supplemented with 0, 0.05%, 0.10%, or 0.15% GAA, respectively. The plasma glucose concentration decreased, and creatine kinase activity and levels of GAA and creatine increased with the dietary GAA concentration. GAA linearly improved creatine content in the longissimus thoracis muscle (LM) and heart. The activities of superoxide dismutase, total antioxidant capacity, and glutathione peroxidase increased linearly in tissue or/and plasma, while the contents of malondialdehyde and protein carbonyl decreased linearly. GAA improved the contents of multiple-bound amino acids (such as proline or isoleucine) in the myocardium and LM. In conclusion, GAA enhanced the plasma biochemical parameters, oxidative status, and bound amino acid profiles of the heart and LM in finishing pigs.

Diets containing higher-amylose-content starches were proved to have some beneficial effects on monogastric animals, such as promoting the proliferation of intestinal probiotics. However, current research on the effects of diets with different starch sources on animals at the extraintestinal level is still very limited. We hypothesized that diets with different starch sources may affect lipid-related gene expression and metabolism in the liver of pigs. This study aimed to use adult pig models to evaluate the effects of diets with different starch sources (tapioca starch, TS; pea starch, PS) on the liver gene expressions and metabolism. In total, 48 growing pigs were randomly assigned to the TS and PS diets with 8 replicate pens/group and 3 pigs per pen. On day 44 of the experiment, liver samples were collected for metabolome and transcriptome analysis. Metabolome data suggested that different starch sources affected (p < 0.05) the metabolic patterns of liver. Compared with the TS diet, the PS diet increased (p < 0.05) some unsaturated fatty acids and several amino acids or peptide levels in the liver of pigs. Moreover, transcriptome data indicated the PS diets elevated (p < 0.05) fatty acid β-oxidation-related gene expression in the liver of pigs, and reduced (p < 0.05) unsaturated fatty acid metabolism-related gene expression. The results of quantitative real-time PCR confirmed that the PS diet upregulated (p < 0.05) the expression of acyl-CoA dehydrogenase very long chain (ACADVL), carnitine palmitoyl transferase (CPT) 1A, and malonyl-CoA decarboxylase (MLYCD), and downregulated (p < 0.05) the expression level of cytochrome P450 2U1 (CYP2U1) and aldehyde dehydrogenase 1B1 (ALDH1B1) in the liver. In addition, the results of a Mantel test indicated the muscle fatty acids were significantly closely correlated (p < 0.05) with liver gene expressions and metabolites. In summary, these findings suggest that diets containing higher amylose starches improved the lipid degradation and the unsaturated fatty acid levels in pig livers, and thus can generate some potential beneficial effects (such as anti-inflammatory and antioxidant) on pig health.

Reduced glutathione (GSH) is a main nonenzymatic antioxidant, but its effects and underlying mechanisms on growth and intestinal health in weaned piglets still require further assessment. A total of 180 weaned piglets were randomly allotted to 5 groups: a basal diet (CON), and a basal diet supplemented with antibiotic chlortetracycline (ABX), 50 (GSH1), 65 (GSH2), or 100 mg/kg GSH (GSH3). Results revealed that dietary GSH1, GSH2, and ABX improved body weight and the average daily gain of weaned piglets, and ABX decreased albumin content but increased aspartate aminotransferase (AST) activity and the ratio of AST to alanine transaminase levels in plasma. GSH2 significantly decreased glucose content but increased the content of triglyceride and cholesterol in the plasma. Both GSH1 and GSH2 improved the jejunal mucosa architecture (villus height, crypt depth, and the ratio of villus height to crypt depth), tight junction protein (ZO-1 and Occludin), and antioxidant capacity (CAT and MDA), and the effects were superior to ABX. Dietary GSH improved the jejunal barrier by probably inhibiting the myosin light chain kinas pathway to up-regulate the transcript expression of tight junction protein (ZO-1 and Occludin) and Mucins. Through the proteomics analysis of the jejunal mucosa using 4D-DIA, the KEGG pathway enrichment analysis showed that differentiated proteins were significantly enriched in redox homeostasis-related pathways such as glutathione metabolism, cytochrome P450, the reactive oxygen species metabolic pathway, the oxidative phosphorylation pathway, and the phosphatidylinositol 3-kinase-serine/threonine kinase pathway in GSH2 vs. CON and in GSH2 vs. ABX. The results of proteomics and qRT-PCR showed that GSH supplementation might dose-dependently promote growth performance and that it alleviated the weaning stress-induced oxidative injury of the jejunal mucosa in piglets by activating SIRTI and Akt pathways to regulate GPX4, HSP70, FoxO1. Therefore, diets supplemented with 50–65 mg/kg GSH can promote the growth of and relieve intestinal oxidative injury in weaned piglets.

This study investigated the effects of microenapsulated hydrolyzed tannins (MHTs) on the growth performance and meat quality of Zhongshan shelducks. A total of 288 healthy Zhongshan shelducks with an average initial weight of 1790.27 ± 0.14 kg were randomly divided into four groups through a 56 d experiment period and were fed a basal diet supplemented with 0 (CON), 400, 800, and 1600 mg/kg MHTs, respectively. Results showed that 400 and 800 mg/kg MHTs improved the final body weight, average daily gain, glutathione peroxidase activity, and total antioxidant capacity compared to CON (p ≤ 0.05). The diet supplemented with 400 mg/kg MHTs decreased shear force and 800 mg/kg MHTs increased the yield of pectoralis major muscle compared to CON (p ≤ 0.05). Dietary MHTs increased inosine monophosphate content and decreased percentage C14:0 content in meat; however, the b*45 min value, 48 h drip loss, and shear force were increased but the percentage intramuscular fat (IMF) content was decreased in pectoralis major muscle with the increase in MHTs (p ≤ 0.05). Compared to CON, 400 and 800 mg/kg MHTs increased the percentage content of IMF, C18:1n-9, C18:2n-6, monounsaturated fatty acids, polyunsaturated fatty acids, and unsaturated fatty acids in pectoralis major muscle (p ≤ 0.05). Furthermore, 400 and 800 mg/kg MHTs improved the lipid metabolism of IMF deposition, fatty acid uptake, and adipogenesis by activating the peroxisome proliferator-activated receptor gamma pathway to regulate fatty acid synthetase and lipoprotein lipase genes. In conclusion, diets supplemented with 400 and 800 mg/kg MHTs could improve growth, meat quality, antioxidant capacity, and lipid metabolism in Zhongshan shelducks.