The action of pre-exercise low-level laser therapy (LLLT) on the expression of IL-6 and TNF-α proteins and on the functional fitness of elderly rats subjected to aerobic training

Lasers Med Sci. 2015 Apr;30(3):1127-34. doi: 10.1007/s10103-015-1713-x. Epub 2015 Feb 3.


The aim of the present study was to determine whether low-level laser therapy (LLLT), when used in conjunction with aerobic training, interferes with the expression of inflammatory markers IL-6 and TNF-α, thereby influencing the performance of old rats participating in swimming. A total of 30 Wistar rats (Rattus norvegicus albinus) were used for this study: 24 aged rats, and 6 young rats. The older animals were randomly divided into four groups designated as follows: aged-control, aged-exercise, aged-LLLT, aged-LLLT/exercise group, and young-control animals. Aerobic capacity (VO2max) was analyzed before and after training period. The aged-exercise and aged-LLLT/exercise groups were trained for 6 weeks. LLLT laser was applied before each training session with 808 nm and 4 J of energy to the indicated groups throughout training. The rats were euthanized, and muscle tissue and serum were collected for muscle cross-sectional area and IL-6 and TNF-α protein analysis. In VO2 showed statistical difference between young- and aged-control groups (used as baseline) (p < 0.05). The same difference can be observed in the young control group compared with all intervention groups (exercise, LLLT and LLLT + exercise). In comparison with the aged-control group, a difference was observed only for comparison with the exercise group (p < 0.05), and exercise associated with LLLT group (p < 0.001). Levels of IL-6 and TNF-α for the aged-exercise and the aged-LLLT/exercise groups were significantly decreased compared to the aged-control group (p < 0.05). Analysis of the transverse section of the gastrocnemius muscle showed a significant difference between the aged-exercise and aged-LLLT/exercise groups (p < 0.001). These results suggest that laser therapy in conjunction with aerobic training may provide a therapeutic approach for reducing the inflammatory markers (IL-6 and TNF-α), however, LLLT without exercise was not able to improve physical performance of aged rats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Gene Expression / radiation effects
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism*
  • Low-Level Light Therapy*
  • Male
  • Muscle, Skeletal / anatomy & histology
  • Muscle, Skeletal / metabolism
  • Organ Size
  • Physical Conditioning, Animal
  • Rats
  • Rats, Wistar
  • Swimming
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism*


  • Interleukin-6
  • Tumor Necrosis Factor-alpha