[Note: quercetin is a plant-based pigment chemical that protects plants (berries, tea leaves, cherries, apples, for example) against environmental stresses. Mitochondrial biogenesis is the proliferation & development of the many tiny bodies within our cells needed to transform fuel to energy.]
Quercetin is one of a broad group of natural polyphenolic flavonoid substances that are being investigated for their widespread health benefits.
• These benefits have generally been ascribed to its combination of antioxidant and anti-inflammatory activity,
• But recent in vitro evidence suggests that improved mitochondrial biogenesis could play an important role.
• In addition, the in vivo effects [in a living body] of quercetin on mitochondrial biogenesis exercise tolerance are unknown.
We examined the effects of 7 days of quercetin feedings in mice on markers of mitochondrial biogenesis in skeletal muscle and brain, and on endurance exercise tolerance. Mice were randomly assigned to one of the following three treatment groups: placebo, 12.5 mg/kg quercetin, or 25 mg/kg quercetin. Following 7 days of treatment, mice were killed, and soleus muscle and brain were analyzed for messenger RNA (mRNA) expression of peroxisome proliferator-activated receptor-gamma coactivator (PGC-1alpha) and sirtuin 1 (SIRT1), and mitochondrial DNA (mtDNA) and cytochrome c.
Additional mice underwent a treadmill performance run to fatigue or were placed in voluntary activity wheel cages, and their voluntary activity (distance, time, and peak speed) was recorded.
Quercetin increased mRNA expression of PGC-1alpha and SIRT1 (P < 0.05), mtDNA (P < 0.05) and cytochrome c concentration (P < 0.05).
These changes in markers of mitochondrial biogenesis were associated with an increase in both:
• Maximal endurance capacity (P < 0.05)
• And voluntary wheel-running activity (P < 0.05).
These benefits of quercetin on fitness without exercise training may have important implications for enhancement of athletic and military performance and may also extend to prevention and/or treatment of chronic diseases.
Source: American Journal of Physiology, Apr 2009;296(4):R1071-7. PMID: 19211721, by Davis JM, Murphy EA, Carmichael MD, Davis B. Department of Exercise Science, University of South Carolina, Columbia, South Carolina. [E-mail: email@example.com]