Effects of oral and intravenous dimethylglycine treatment on hematobiochemical profiles and total oxidant/antioxidant status in low-intensity exercised horses.

Overview

• This study examined the impact of oral and intravenous dimethylglycine (DMG) on blood health, biochemical markers, and oxidative stress in horses undergoing low-intensity aerobic exercise.
• The research aimed to determine whether DMG could help reduce exercise-induced muscle fatigue, oxidative damage, and maintain physiological balance in athletic horses.

Study Design and Methodology

• Subjects: 30 Turkish Arab saddle horses were randomly assigned to three groups (10 horses each).
• Treatment groups:
  • Group A: Received 1500 mg of 10% DMG intravenously twice daily for three days.
  • Group B: Received 1500 mg of DMG powder orally twice daily for three days.
  • Group C (Control): Received intravenous injections of 15 mL saline (0.9% NaCl) twice daily for three days.
• Exercise protocol: Following the last dose, all horses performed 30 minutes of cantering with 15 minutes of warm-up and 15 minutes of walk cool-down.

Parameters Measured

• Physiological parameters: Heart rate (HR), respiratory rate (RR), and rectal temperature (RT) — measured pre-exercise (-2 h), immediately post-exercise (0 h), and at 2, 4, and 6 hours post-exercise.
• Hematological and biochemical markers: White blood cell count (WBC), aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), creatinine, and urea — to check for inflammation, muscle damage, or subclinical disease.
• Blood gas analysis: To ensure physiological stability and detect any acid-base imbalances due to exercise or treatment.
• Oxidative stress markers:
  • Total oxidative status (TOS): Measures total oxidants present in the blood.
  • Total antioxidant status (TAS): Measures the overall antioxidant capacity.
  • Oxidative stress index (OSI): Ratio of TOS to TAS to reflect oxidative stress balance.
• Lactate levels: Assessed post-exercise as an indicator of muscle fatigue.

Key Findings

• Physiological responses:
  • Exercise caused mild increases in HR, RR, and RT, typical of exertion, but no indication of heat stress.
  • Blood gases remained within normal physiological ranges, showing treatments did not disrupt homeostasis.
• Muscle fatigue and damage indicators:
  • DMG-treated groups, especially intravenous, showed stabilized lactate levels post-exercise, suggesting reduced muscle fatigue.
  • CK, AST, and LDH levels did not suggest harmful muscle damage or subclinical infection in any group.
• Oxidative stress parameters:
  • TOS values were significantly lower in both DMG treatment groups compared to controls, indicating reduced oxidative damage.
  • This effect was most pronounced immediately after exercise in the intravenous DMG group.
  • TAS levels were also reduced in treated horses, likely due to increased utilization of antioxidants during exercise to counteract oxidative stress.
  • OSI did not differ significantly, suggesting that although oxidants and antioxidants were altered, the overall oxidative stress balance remained similar.

Conclusions and Implications

• DMG administration, particularly intravenous, may help mitigate oxidative stress and support muscle recovery following aerobic exercise in horses.
• It appears to reduce oxidative damage without causing physiological imbalance or negative side effects.
• The findings support DMG’s potential as a supplement in equine sports medicine to reduce muscle fatigue and oxidative injury during low-intensity exercise.
• However, the study calls for further research to clarify the long-term effects, optimal dosages, and mechanisms of DMG in athletic performance and recovery.