Effects of different doses of silk peptide on energy metabolism during exercise in mice.

PURPOSE

This study was carried out to determine the optimal dose of silk peptide for enhancing fat metabolism during exercise.

METHODS

Fifty male ICR mice were randomly divided into five groups: Sed, SP0, SP200, SP400, and SP800. All SP mice underwent training by running on a treadmill 5 times a week for 2 weeks (20 m/min, 8° slope, 50 min/day for the first week and 25 m/min, 8° slope, 50 min/day at about 70-75% of maximum oxygen uptake for the second week).

RESULTS

After the 2 weeks, fat oxidation was measured during a 1-h exercise at the training conditions of the second week and was found to be 1.02 ± 0.15, 1.04 ± 0.17, 0.98 ± 0.10, 1.14 ± 0.19, and 1.15 ± 0.07 g/kg/h for Sed, SP0, SP200, SP400, and SP800 groups, respectively. The SP800 group had significantly higher fat oxidation levels than the SP0 group did at 36, 40, and 56 min and the Sed group did at 2, 4, 6, 8, 12, 14, 16, 20, 40, 46, 50, 52, 56, and 60 min. However, there was no significant difference among the groups in carbohydrate oxidation during the 1-h exercise. SP doses of 200 mg/kg and 400 mg/kg did not show any effect on fat and carbohydrate oxidation.

CONCLUSION

In conclusion, 800 mg/kg of silk peptide is the optimal dose for enhancing fat metabolism during exercise. In addition, silk peptide treatment could reduce body weight by enhancing fat metabolism.