Effect of orally ingested diosgenin into diet on skin collagen content in a low collagen skin mouse model and its mechanism of action.

AIMS: Influence on collagen content with oral ingestion of diosgenin (Dios) was investigated in established low collagen skin mouse model. And its mechanism of action was investigated using primary cultured fibroblasts.

MAIN METHODS: Hairless mice were fed a low protein diet with Dios for 8weeks and the contents of collagen in skin were determined by measuring the content of hydroxyproline (Hyp). In primary cultured fibroblasts, the numbers of fibroblast were determined by incubating with Dios for 120h; the contents of Hyp were determined by incubating with Dios for 24 or 72h using fibroblasts of confluent state; the expressions of messenger ribonucleic acid (mRNA) were determined by incubating with Dios for 24h.

KEY FINDINGS: Oral ingestion of Dios in the diet for 8weeks led to a dose-dependent increase in the Hyp content as collagen content of skin. In proliferating of primary cultured fibroblasts, Dios treatment led to a decrease of adenosine 5'-triphosphate content indicating decrease of the cell number. In the cells reached to confluent, although increase of Hyp content in the control indicating progress of fibroblasts differentiation were observed, the content of Hyp remained unchanged with Dios treatment. Finally, addition of Dios led to a decrease the α-tubulin and c-fos mRNA expressions relating to the cell cycle.

SIGNIFICANCE: It is concluded that Dios can improve skin collagen content by shifting the dynamics of the fibroblasts from proliferation to differentiation via cell cycle arrest.