Effects of tadalafil administration on plasma markers of exercise-induced muscle damage, IL6 and antioxidant status capacity.
BACKGROUND
Physical exercise is associated with enhanced production of reactive oxygen species, which if uncontrolled can result in tissue injury. Phosphodiesterase type 5 inhibitors (PDE5i) exhibit protective effect against oxidative stress, both in animals and healthy/unhealthy humans. However, the effect of a chronic administration of PDE5i, particularly combined with physical exercise, has never been investigated.


OBJECTIVE
The present study was designed to evaluate the effect of the long-acting PDE5i tadalafil on oxidative status and muscle damage after exhaustive exercise in healthy males included in a double-blind crossover trial.


OBJECTIVE
Tadalafil, having a putative antioxidant activity, may reduce oxidative damage after strenuous exercise.


METHODS
Each volunteer randomly received two tablets of placebo or tadalafil (20 mg/day) with 36 h of interval before performing exhaustive exercise. After 2 weeks of washout, the volunteers were crossed over. Blood samples were collected immediately before exercise, immediately after, and during recovery (15, 30, 60 min). Plasma total antioxidant status, glutathione homeostasis (GSH/GSSG), malondialdehyde (MDA), protein carbonyls, creatine kinase (CK), lactate dehydrogenase (LDH) and the inflammatory cytokine interleukin 6 were assessed.


RESULTS
Tadalafil administration per se affected redox homeostasis (GSH/GSSG -36%; p < 0.05), cellular (CK +75% and LDH +36%; p < 0.05) and oxidative damage (MDA +41% and protein carbonyls +50%; p < 0.05) markers. The exhaustive exercise increased all the above-reported biochemical parameters, with subjects from the tadalafil group showing significantly higher values with respect to the placebo group.


CONCLUSIONS
A prolonged exposure to tadalafil decreases antioxidant capacity at resting condition, therefore making subjects more susceptible to the oxidative stress induced by an exhaustive bout of exercise.
Unit of Biology, Genetics and Biochemistry, University of Rome "Foro Italico", Piazza Lauro De Bosis 15, 00135, Rome, Italy, roberta.ceci@uniroma4.it.
Roberta
R
Ceci
Guglielmo
G
Duranti
Paolo
P
Sgrò
Massimiliano
M
Sansone
Laura
L
Guidetti
Carlo
C
Baldari
Stefania
S
Sabatini
Luigi
L
Di Luigi
D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D002243:Carbolines / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D003402:Creatine Kinase / Q000097:blood; D015444:Exercise; D005260:Female; D005978:Glutathione / Q000097:blood; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D063806:Myalgia / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D018384:Oxidative Stress; D058986:Phosphodiesterase 5 Inhibitors / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D050050:Protein Carbonylation; D000068581:Tadalafil
D000975:Antioxidants; D015415:Biomarkers; D002243:Carbolines; D015850:Interleukin-6; D058986:Phosphodiesterase 5 Inhibitors; D008315:Malondialdehyde; D000068581:Tadalafil; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase; D005978:Glutathione