The Effect of Hydroxyproline on the Improvement of Facial Wrinkles

Suh, Kee Suck; Choi, Soo Young; Kim, Sang Tae

Abstract

BACKGROUND: Many treatment modalities for wrinkle reduction have been developed in the field of dermatology. Hydroxyproline plays a critical role in stabilizing the triple helix of collagen. The triple-helical conformation gives collagen most of its unique properties and is essential for normal fibrillogenesis.
OBJECTIVE
This study was performed to investigate the effect of hydroxyproline on the improvement of wrinkles in vitro and in vivo.
METHODS
Cultured fibroblasts and 25 human volunteers were used for in vitro and in vivo studies respectively. Hydroxyproline was administered to a fibroblast culture system and was also applied to periorbital wrinkle lesions twice daily for 12 weeks. The effect of hydroxyproline was examined by using an image analysis system with skin replica, and subjective and objective assessment of wrinkles were evaluated.
RESULTS
With the in vitro study, the number of cultured fibroblasts did not increase in the 10(-4), 10(-6) and 10(-8)microgram/ ml hydroxyproline groups compared to the control groups. Procollagen Type 1 C-peptide of cultured fibroblasts did increase in the 10(-8)microgram/ml hydroxyproline group compared to the control group (p<0.05). With the in vivo study, there was a significant decrease in wrinkles at 8 and 12 weeks after application in the 0.5% hydroxyproline applied group compared to the control group (p<0.001). In the subjective visual assessment by the investigator and the subjects at 8 and 12 weeks after application, the 0.5% hydroxyproline treated group showed a significant improvement of wrinkles and more personal satisfaction than the control group (p<0.05).
CONCLUSION
0.5% hydroxyproline had an effect in vivo and in vitro on wrinkle improvement. It is suggested that hydroxyproline might be a candidate compound for treatment or reduction of wrinkles.