Vitamin C injection improves antioxidant stress capacity through regulating blood metabolism in post-transit yak

www.nature.com/scientificreports OPEN Vitamin C injection improves antioxidant stress capacity through regulating blood metabolism in post‑transit yak Li Zhang 1,6, Yi Chen 2,6, Ziyao Zhou 1,3,6, Zhiyu Wang 3, Lin Fu 1, Lijun Zhang 4, Changhui Xu 4, Juan J. Loor 5, Gaofu Wang 1, Tao Zhang 2* & Xianwen Dong 1* Transportation stress is one of the most serious issues in the management of yak. Previous studies have demonstrated that transport stress is caused by a pro-oxidant state in the animal resulting from an imbalance between pro-oxidant and antioxidant status. In this context, vitamin C has the ability to regulate reactive oxygen species (ROS) synthesis and alleviate oxidative stress. Although this effect of vitamin C is useful in pigs, goats and cattle, the effect of vitamin C on the mitigation of transport stress in yaks is still unclear. The purpose of this study was to better assess the metabolic changes induced by the action of vitamin C in yaks under transportation stress, and whether these changes can influence antioxidant status. After the yaks arrived at the farm, control or baseline blood samples were collected immediately through the jugular vein (VC_CON). Then, 100 mg/kg VC was injected intramuscularly, and blood samples were collected on the 10th day before feeding in the morning (VC). Relative to the control group, the VC injection group had higher levels of VC. Compared with VC_CON, VC injection significantly (P < 0.05) decreased the blood concentrations of ALT, AST, T-Bil, D-Bil, IDBIL, UREA, CRP and LDH. However, VC injection led to greater (P < 0.05) AST/ALT and CREA-S relative to VC_CON. There was no difference (P > 0.05) in GGT, ALP, TBA, TP, ALBII, GLO, A/G, TC, TG, HDL-C, LDL-C, GLU and l-lactate between VC_CON and VC. The injection of VC led to greater (P < 0.05) concentration of MDA, but did not alter (P > 0.05) the serum concentrations of LPO and ROS. The injection of VC led to greater (P < 0.05) serum concentrations of POD, CAT and GSH-PX. In contrast, lower (P < 0.05) serum concentrations of SOD, POD and TPX were observed in VC relative to VC_CON. No difference (P > 0.05) in GSH, GSH-ST and GR was observed between VC_CON and VC. Compared with the control group, metabolomics using liquid chromatography tandem–mass spectrometry identified 156 differential metabolites with P < 0.05 and a variable importance in projection (VIP) score > 1.5 in the VC injection group. The injection of VC resulted in significant changes to the intracellular amino acid metabolism of glutathione, glutamate, cysteine, methionine, glycine, phenylalanine, tyrosine, tryptophan, alanine and aspartate. Overall, our study indicated that VC injections were able to modulate antioxidant levels by affecting metabolism to resist oxidative stress generated during transport. Yak (Bos grunnien) is a unique breed of bovine that can adapt to the Qinghai-Tibet Plateau’s (QTP) distinctive and severe natural environment1. About 90% of the world’s yaks live in China at an altitude of 3500–5000 m all year round. Yak are important to herdsmen in the QTP for providing daily necessities such as meat, milk, wool, skin, draught and f uel2–4. However, the severe natural environment often results in feed shortage5, often resulting in marked live-weight loss especially during the winter-spring period6. Thus, transporting yak to low altitude districts with abundant feed resources for fattening is a suitable strategy to promote sustainability of the 1 Chongqing Academy of Animal Sciences, Rongchang 402460, China. 2Chongqing Engineering Laboratory of Nano/Micro Biomedical Detection; Chongqing Key Laboratory of Nano/Micro Composite Material and Device, College of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing 401331, China. 3The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China. 4Tibet Leowuqi Animal Husbandry Station, Changdu Tibet 855600, China. 5Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801, USA. 6These authors contributed equally: Li Zhang, Yi Chen and Ziyao Zhou. *email: ; Scientific Reports | (2023) 13:10233 | https://doi.org/10.1038/s41598-023-36779-w 1 Vol.:(0123456789) www.nature.com/scientificreports/ yak industry. Oxidative stress might be induced during transit and may damage the health of yak and reduce production performance. Transportation stress is induced by fasting, capture, vibration, collision, scraping, environmental changes, turbulence and psychological pressure during t ransport7. It has been demonstrated that transportation stress in yak could lead to poor health, immune dysfunction, morbidity, mortality, reduced production performance and product quality, all of which result in huge economic losses8–10. Thus, way to reduce transport stress in the yak are urgently needed. Previous studies confirmed that transportation stress damage is derived from oxidative stress, which is defined as the unbalance between pro-oxidants and antioxidants in the body11–13. Vitamin C (VC), as a potent antioxidant, regulates the synthesis of reactive oxygen species (ROS) and alleviates oxidative stress damage8,9. This vitamin has been widely used to relieve transportation stress damage in pigs, goats and cattle14–17. Furthermore, VC can elicit effects on metabolism at the cellular level18. Previous studies reported that VC could alter the synthesis of glutathione (GSH) through regulation of glucose metabolism, amino acid metabolism and energy metabolism19,20. GSH is the most potent cellular a ntioxidant21, but to our knowledge, whether VC can elicit antioxidant effects in yak after transportation is unknown. Metabolomics uses gas chromatography–mass spectrometry (GC–MS), liquid chromatography-tandem–mass spectrometry (LC–MS), and nuclear magnetic resonance (NMR) to elucidate the changes in metabolites and compounds produced by low molecular weight cells and tissues22. Recently, metabolomics has been used to study the changes in metabolites in bovine gastric juice, serum, and urine, aiming to identify unknown biomarkers and particular metabolic pathways related to bovine diseases to ensure the health of cattle and reduce economic damage23. Our previous research has confirmed that injecting vitamin E into yaks can enhance their ability to resist oxidative stress by inducing changes in metabolites, such as changes in α-Oxo-glutarate, phenylalanine, choline, and m alate24. To our knowledge, metabolomics has been widely used to study various animal diseases, but the effect of VC on yaks still needs to be determined. Given the severe natural environment and bad rudimentary facilities of farms in the QTP, from a management standpoint, it is more effective to implement anti-transportation stress treatments in yak after arrival at the destination feedlo (...truncated)