Effects of lipoic acid on muscle quality in finishing pigs under diquat-induced oxidative stress challenge

and significantly affected shear force, with a pronounced interaction under oxidative stress. DQ markedly upregulated Nrf2 protein expression, while LA partially attenuated this increase without affecting Keap1. DQ and LA significantly modulated myofiber type-related genes, with stress-dependent interactions observed for MyHC I and MyHC IIb. Moreover, DQ enhanced SOD mRNA, protein expression and enzyme activity, whereas LA increased SOD mRNA expression independently of oxidative stress, with no significant interaction effects. In conclusion, dietary LA modulated antioxidant capacity and muscle fibre gene expression in finishing pigs challenged with DQ; However, its effects on meat quality were stress-dependent rather than uniformly beneficial, indicating that further studies are needed to clarify its role in maintaining overall pork quality under diquat-induced oxidative stress challenge.