Dihydromyricetin improves physical performance under simulated high altitude.

Area of Science:

• Biochemistry
• Exercise Physiology
• Altitude Medicine

Background:

• Hypobaric hypoxia (HH) at high altitudes impairs physical performance and induces cellular stress.
• Dihydromyricetin (DHM), a key component of rattan tea, is known for its potential health benefits.
• Investigating DHM's effects on HH-induced exercise intolerance is crucial for understanding its therapeutic potential.

Purpose of the Study:

• To elucidate the mechanism by which DHM counteracts hypobaric hypoxia (HH)-induced exercise intolerance.
• To evaluate the efficacy of DHM in improving physical performance under simulated high-altitude conditions.

Main Methods:

• Male Sprague-Dawley rats were pretreated with varying doses of DHM (50, 75, 100 mg·kg⁻¹) for 7 days.
• Rats were exposed to simulated high-altitude conditions (5000 m, 10.9% oxygen) and assessed for exercise performance using a run-to-fatigue model.
• Mitochondrial morphology, protein expression (including biogenesis markers), and electron transport chain activity in gastrocnemius muscle were analyzed.

Main Results:

• DHM administration significantly improved run-to-fatigue time in a dose-dependent manner.
• DHM treatment reduced markers of muscle damage (serum BUN, LDH, CK) and attenuated HH-induced mitochondrial injuries.
• DHM restored mitochondrial biogenesis markers and modulated mitochondrial dynamics (fusion/fission) in skeletal muscle.

Conclusions:

• Dihydromyricetin (DHM) effectively improves physical performance under simulated high-altitude conditions.
• DHM exerts its protective effects by preserving mitochondrial biogenesis and regulating mitochondrial dynamics in skeletal muscle cells.
• These findings highlight DHM as a potential therapeutic agent for mitigating exercise intolerance associated with high-altitude exposure.