RESUMO
A promoting effect of Na2SiO3 on hair regrowth was investigated using an animal model of C57BL/6 mice. There were four experimental groups including distilled water (DW, a negative control), 5% minoxidil (MXD, a positive control), 50% Na2SiO3, and 100% Na2SiO3 solution. The animals were shaved with an electric clipper and then test solutions applied daily with a volume of 0.2 ml per to the dorsal skin of mice for 3 weeks. Body weight and food and water consumption were measured weekly. Photographs of hair regrowth were taken at experimental day 0, 4, 7, 10, 14, 17, and 21. Activities of alkaline phosphatase and gamma-glutamyl transpeptidase as well as expressions of growth factors were also determined in the dorsal skin of mice. The animal body weight were not significantly changed among the experimental groups. The MXD and Na2SiO3 accelerated hair regrowth compared with DW. The elongation of hair follicles were evidently observed in MXD and 50 or 100% Na2SiO3 groups. MXD significantly increased gamma-glutamyl transpeptidase at day 14, compared with DW (P<0.05). But the activities of alkaline phosphatase and gamma-glutamyl transpeptidase were not significantly increased in Na2SiO3 groups, compared with DW. The expression of epidermal growth factor was significantly increased in MXD and Na2SiO3 groups, compared with DW (P<0.05). The expression of vascular endothelial growth factor was not significantly changed by MXD or Na2SiO3 treatments. The expression of transforming growth factor (TGF)-beta1 was clearly decreased in MXD and Na2SiO3 groups, compared with DW. These results indicate that Na2SiO3 may have a hair growth-promoting activity and it can be used for treatment of alopecia or boldness in humans.
