Aqueous extracts of Centella asiatica L. Urban were encapsulated by an edible biopolymer, gelatin, which
has no effect on their cosmetic activities. The nanoparticles were w/o-type spherical liposomes that had
an average diameter of 115.0 nm. The encapsulation efficiency was estimated to be approximately 67%,
which was relatively high for these aqueous extracts. The nanoparticles showed lower cytotoxicity (10%)
in human skin fibroblast cells than the unencapsulated crude extract(15%) at 1.0 mg/ml,this was possibly
because a smaller amount of the extract was present in the nanoparticles. The nanoparticles efficiently
reduced the expression of matrix metalloproteinase (MMP)-1 in UV-irradiated cells from 136.1% to 77.6%
(UV-irradiated control) and inhibited hyaluronidase expression (>60%) at a concentration of 0.5 mg/ml,
which was higher than the levels produced by the unencapsulated crude extracts. The nanoparticles had a
very high flux through mouse skin and also remained at relatively large concentrations in the derma when
compared to the unencapsulated crude extracts. These results clearly indicate that the skin-protective
activities of C. asiatica were significantly improved through the nano-encapsulation process. These findings
also imply that a crude extract can be used and have the same efficacy as purified compounds, which
should reduce the purification process and production costs.