Dietary conjugated linoleic acid supplementation alters skeletal muscle mitochondria and antioxidant status in young horses

Abstract

Conjugated linoleic acid (CLA) improves oxidative stress and mitochondrial biogenesis in various species but has not been thoroughly investigated in horses. We collected blood and muscle samples from lightly exercising horses before and 6 and 12 wk after receiving either soybean oil (CON; n = 5) or CLA (CLA; n = 5) supplementation. Samples were analyzed for markers of mitochondrial characteristics, antioxidant status, oxidative stress, and muscle damage. Data were analyzed using a linear model with repeated measures. In the triceps brachii (TB), citrate synthase (CS) activity was higher in CON than CLA horses (P = 0.003) but was unaffected by diet in the gluteus medius (GM). Integrative (relative to mg protein) cytochrome c oxidase (CCO) activity was higher in TB than the GM (P < 0.0001), while intrinsic (relative to CS) CCO was lower in the TB than the GM (P = 0.02) and tended to be lower in CON than CLA horses (P = 0.06). Neither CS nor integrative CCO activities were affected by time. In the GM, superoxide dismutase activity tended to increase in CON through wk 12 (P = 0.10). Over both muscle groups, glutathione peroxidase activity tended to be higher in CON compared to CLA at wk 12 (P = 0.06). Malondialdehyde was higher in the TB than the GM (P = 0.0004) but was unaffected by diet, while serum creatine kinase activity tended to be lower in CLA than CON horses (P = 0.07). These results suggest that CLA supplementation may lead to mitochondrial adaptations and prevent myofiber perturbation in skeletal muscle of young, lighlty exercised horses.

Fueling equine performance: importance of mitochondrial phenotype in equine athletes

“…Similarly, supplementation of a more bioavailable complexed trace mineral mix containing zinc, manganese, and copper resulted in higher GPx activity when compared with inorganic forms of the minerals in young horses in a light exercise training program ( Latham et al, 2021 ). Conjugated linoleic acid ( Mrugala et al, 2021 ), N -acetyl cysteine and coenzyme Q10 ( Henry et al, 2021 ), and other supplements with antioxidant properties have also been shown to impact mitochondrial and antioxidant adaptations. These adaptations to nutritional supplementation provide promising management interventions to optimize mitochondrial function in exercising horses.…”