RESUMO
Objective: To study the enhancing effect of essential oil from asarum (EOA) on percutaneous delivery of sinapine and its mechanism. Methods: Transepidermal water loss (TEWL) was determined with Vapo Meter to evaluate the decrease of skin barrier by asarum essential oil. In vitro permeation of sinapine through rat skin was performed in the presence or absence of EOA, and the permeated cumulative amount and retention of sinapine were compared. In vivo percutaneous test was further performed to estimate the improvement of EOA on percutaneous delivery of sinapine. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and differential scanning calorimeter (DSC) were used to evaluate the changes of lipid and protein in stratum corneum. Results: TEWL value increased after the treatment of EOA, which indicated the decrease of skin barrier. The permeated cumulative amount and retention of sinapine in the presence of EOA were higher than those in the absence of EOA, and in vivo percutaneous test further confirmed this issue. After EOA treatment, the lipid and protein disorder could be observed from ATR-FTIR and DSC map, which indicated the increasing of skin permeability. Conclusion: EOA can enhance the percutaneous delivery of sinapine through improving the disorder of lipid and protein of stratum corneum.
