Protective effects of myricetin on acute hypoxia-induced exercise intolerance and mitochondrial impairments in rats.

Abstract

PURPOSE:

Exercise tolerance is impaired in hypoxia. The aim of this study was to evaluate the effects of myricetin, a dietary flavonoid compound widely found in fruits and vegetables, on acute hypoxia-induced exercise intolerance in vivo and in vitro.

METHODS:

Male rats were administered myricetin or vehicle for 7 days and subsequently spent 24 hours at a barometric pressure equivalent to 5000 m. Exercise capacity was then assessed through the run-to-fatigue procedure, and mitochondrial morphology in skeletal muscle cells was observed by transmission electron microscopy (TEM). The enzymatic activities of electron transfer complexes were analyzed using an enzyme-linked immuno-sorbent assay (ELISA). mtDNA was quantified by real-time-PCR. Mitochondrial membrane potential was measured by JC-1 staining. Protein expression was detected through western blotting, immunohistochemistry, and immunofluorescence.

RESULTS:

Myricetin supplementation significantly prevented the decline of run-to-fatigue time of rats in hypoxia, and attenuated acute hypoxia-induced mitochondrial impairment in skeletal muscle cells in vivo and in vitro by maintaining mitochondrial structure, mtDNA content, mitochondrial membrane potential, and activities of the respiratory chain complexes. Further studies showed that myricetin maintained mitochondrial biogenesis in skeletal muscle cells under hypoxic conditions by up-regulating the expressions of mitochondrial biogenesis-related regulators, in addition, AMP-activated protein kinase(AMPK) plays a crucial role in this process.

CONCLUSIONS:

Myricetin may have important applications for improving physical performance under hypoxic environment, which may be attributed to the protective effect against mitochondrial impairment by maintaining mitochondrial biogenesis.

• Authors: Dan Zou, Peng Liu, Ka Chen, Qi Xie, Xinyu Liang, Qian Bai, Qicheng Zhou, Kai Liu, Ting Zhang, Jundong Zhu, Mantian Mi
• Journal: PloS one (PLoS One) Vol. 10 Issue 4 Pg. e0124727 ( 2015) ISSN: 1932-6203 [Electronic] United States
• PMID: 25919288 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Mitochondrial
• Flavonoids
• Protective Agents
• myricetin
• AMP-Activated Protein Kinases

Topics

• AMP-Activated Protein Kinases (metabolism)
• Acute Disease
• Animals
• DNA, Mitochondrial (metabolism)
• Electron Transport (drug effects)
• Exercise Tolerance (drug effects)
• Flavonoids (pharmacology)
• Hypoxia (complications)
• Male
• Membrane Potential, Mitochondrial (drug effects)
• Mitochondria, Muscle (drug effects, metabolism, ultrastructure)
• Muscle Cells (drug effects, metabolism)
• Organelle Biogenesis
• Physical Conditioning, Animal
• Protective Agents (pharmacology)
• Rats, Sprague-Dawley